SYSTEMATIC REVIEW article

Front. Oncol., 02 May 2025

Sec. Breast Cancer

Volume 15 - 2025 | https://doi.org/10.3389/fonc.2025.1541233

Risk factors for breast cancer: an umbrella review of observational cohort studies and causal relationship analysis

  • Department of Oncology, Shengjing Hospital of China Medical University,Shenyang, China

Abstract

Objective:

To conduct an umbrella review of prospective meta-analyses and perform a causal relationship analysis to evaluate causal effects.

Methods:

PubMed, Web of Science, Embase, and manual reference list searches were used from database inception to July 27, 2023. Meta-analyses of prospective studies on non-genetic risk factors for breast cancer incidence were included. Overlapping articles were assessed using corrected coverage area. We utilized the AMSTAR-2 criteria to evaluate methodological quality and graded each meta-analysis to assess the strength of evidence. This study is registered with PROSPERO (CRD42023470151). We further explored the causal impacts.

Results:

Risk factors were classified into 11 categories. Among the 281 meta-analyses of cohort studies, five (1.8%) provided strong evidence, eight (2.8%) indicated highly suggestive evidence, and 23 (8.2%) and 55 (19.6%) showed suggestive and weak evidence, respectively. Breast density (2.89; 2.57-3.25), cardiac glycoside (1.39; 1.33-1.45), atrial fibrillation (1.18; 1.14-1.22), vegetable-fruit-soybean dietary pattern (0.87; 0.83-0.92), and postmenopausal women with BMI ≥25 (0.86; 0.81-0.91) were strongly associated with breast cancer incidence. For all associations graded as weak evidence or higher, further confirmed the causal relationship between BMI, fruit intake, calcium channel blockers, cheese intake, insulin like growth factor-1 levels, serum triglyceride levels causally

Discussion:

Identifying primary risk factors is crucial for delineating high-risk populations among women, facilitating tailored prevention strategies and advancing investigations into underlying mechanisms.

Systematic review registration:

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023470151.

1 Introduction

By 2023, breast cancer (BC) accounted for 11.6% of all cancer diagnoses worldwide, with 2.3 million new cases representing 31% of diagnoses in women. It is the second most common cancer globally, following lung cancer, and the most common cancer among women (, ). Despite medical advances, BC incidence continues to rise (). Identifying and mitigating risk factors is crucial to addressing the growing BC burden. Genetic factors such as BRCA gene mutations contribute to BC occurrence () but offer limited preventive value. Recent research has highlighted modifiable factors, such as environmental and lifestyle influences, that impact BC risk (). Mitigating these non-genetic risk factors is crucial for lowering BC incidence. However, owing to the impracticality of studying these exposures through randomized controlled trials, these studies may introduce inherent biases, including selection bias (i.e., inappropriate participant selection) and information bias (i.e., inaccurate data collection), which could lead to either an overestimation or underestimation of the results. Furthermore, wide effect size ranges, and even conflicts often exhibited. For example, Kast et al. () reported that a higher BMI in young adults is associated with a reduced risk of BC. In contrast, Fakhri et al. () found that obese women have a higher risk of BC compared to those with a BMI below 30. In this context, meta-analysis is a useful tool to address studies with varying effect sizes and directions.

Nevertheless, recently, as original research continuously updates and more meta-analyses emerge, there are obvious discrepancies in findings, even within the same topic. For instance, two recent meta-analyses investigating the relationship between atrial fibrillation (AF) and breast cancer (BC) incidence reached entirely contradictory conclusions (, ). The umbrella review effectively evaluate these diverse results, combining systematic reviews and meta-analyses on a given topic, assessing sample size, association strength, heterogeneity, and bias.

However, establishing causality is challenging with observational research. Mendelian randomization (MR) uses genetic variation as a proxy for exposure, reducing confounding factors and enhancing causal inference (, ). Pearson-Stuttard et al. () explored the risk of developing multiple-site cancers with type 2 diabetes using an umbrella review and MR, exemplifying effective methodology.

Therefore, we aimed to conduct an umbrella review to explore BC risk factors and perform a MR analysis to evaluate the causal effects.

2 Materials and methods

2.1 Literature search and selection criteria

We conducted a comprehensive search using keywords across PubMed, Web of Science, and Embase databases. Our search encompassed meta-analyses that examined the association between non-genetic risk factors for BC from database inception to July 27, 2023. Supplementary Table 1 outlines the complete search strategy. We also manually reviewed reference lists of eligible studies.

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline () and was registered at PROSPERO (https://www.crd.york.ac.uk/PROSPERO/) with CRD42023470151.

Two authors independently searched the databases, screened titles and abstracts, and identified meta-analyses meeting the inclusion criteria through full-text reading. A third author resolved any discrepancies. Inclusion criteria involved meta-analyses with: 1. observational cohort study designs; 2. non-genetic risk factors as the exposure of interest; 3. BC as the reported outcome; 4. available risk estimates between risk factors and BC (risk ratio, odds ratio, hazard ratio) with 95% confidence intervals (CIs), number of cases/controls, or total population size; 5. publication in English; and 6. study population comprising women. We excluded meta-analyses of genetic markers, systematic reviews without quantitative analyses, animal or laboratory studies, and reviews lacking study-specific data (risk ratio, odds ratio, hazard ratio) that could not be retrieved from the original studies. We also excluded studies with baseline populations already diagnosed with cancer.

2.2 Overlapping and outdated reviews

When two or more reviews examine the same exposure and outcome, overlapping associations may result in multiple primary studies being included in the reviews. Additionally, research indicates that half of published reviews become outdated within 5.5 years. We first identified meta-analyses with identical risk factors and outcomes to mitigate bias in interpreting such outcomes. Subsequently, we:

  • Selected the most recent literature for reviews with the same author.

  • Excluded outdated overlapping reviews published before 2018 with different authors.

  • Assessed the extent of overlap using a generated graphical cross-table (citation matrix) for reviews published before or after 2018 with different authors and used an index termed corrected coverage area (CCA) to quantify the degree of overlap, calculated as CCA = (N - r)/(r * c - r) * 100%, where N: the total number of primary studies across all reviews, r: rows, and c: columns, expressed as a percentage.

Overlap was categorized as follows: 1. very high: CCA >15%, 2. high: CCA=11-15%, 3. moderate: CCA=6-10%, and 4. slight: CCA=0-5% (). Both reviews were retained for slight or moderate overlap. For high or very high overlap, the review with the highest quality based on the AMSTAR 2 tool was prioritized. The most recent review was included when quality ratings were identical (, ).

2.3 Data extraction

Two reviewers independently extracted data, including the first author’s name, journal name, publication year, study design, exposure factors, health outcomes, included studies, cases, total participants, and the estimated summary effects with 95% CIs, from eligible studies. Additionally, if available, information relevant to dose-response relationships was retrieved from meta-analyses. To ensure transparency, a third author reviewed the discrepancies between the two reviewers and resolved them by considering all relevant data and methodologies.

2.4 Evaluation of the quality of included meta-analyses

Two reviewers (WZ and XYQ) evaluated the methodological quality of the included studies using the AMSTAR-2 tool (), assigning an overall score. In case of disagreement, a third author (GS) was consulted. AMSTAR-2 assesses 16 items, with 7 considered critical. Deficiencies in any critical item may affect the overall review quality. The key areas deemed crucial included: protocol registered before the commencement of the review; adequacy of the literature search; justification for excluding individual studies; risk of bias in the included studies; appropriateness of meta-analytical methods; considering bias risk when interpreting results; and assessment of the presence and likely impact of publication bias. The final ratings were classified into four levels ranging from “high” to “very low”: 1. high: no defects or one non-critical area with defects; 2. moderate: more than one non-critical area with defects; 3. low: one critical area with or without non-critical areas with defects and 4. very low: more than one critical area with or without non-critical areas with defects. AMSTAR-2 scoring results assess the quality of the included studies and account for potential biases and methodological limitations, providing a more reliable interpretation of results.

2.5 Evaluating the strength of evidence using grading criteria

BC risk factors were categorized into four evidence-based classes: class I (strong evidence), class II (highly suggestive evidence), class III (suggestive evidence), and class IV (weak evidence) (, ) (Table 1). This classification system offers an objective, standardized approach, consistent with other grading schemes in cancer epidemiology. This classification method enables the study to rank the strength of evidence for each risk factor. class I and II evidence correspond to factors with a high level of confidence, whereas class III and IV represent factors with lower confidence. Specifically, class IV (weak evidence) factors are associated with reduced confidence, which may be influenced by factors such as data heterogeneity, insufficient sample size, or methodological limitations.

Table 1

EvidenceCriteria usedDecreased RiskIncreased Risk
Strongp < 10–6; >1000 cases;
I2 < 50%; no small
study effects;
prediction interval
excludes the null
value; no excess
significance bias
Dietary intake
Vegetable-fruit-soybean dietary pattern: highest vs. lowest;
Anthropometric indices
BMI>=25: high vs. low, postmenopausal;
Imageological diagnosis
Breast density: highest vs. lowest category;
Use of medical/hormonal therapy
Cardiac glycosides use: ever vs. never;
Pre-existing medical conditions and interventions
Atrial fibrillation: ever vs. never;
Highly
Suggestive
p < 10–6; >1000 cases;
p < 0.05 of the largest
study in a
meta-analysis
Life behaviour
Physical activity: highest vs. lowest category;
Anthropometric indices
BMI iya:per 5 kg/m2;
Life behaviour
Education level: highest vs. lowest category;
Smoking:ever vs. never;
light exposure at night: highest vs. lowest category;
Use of medical/hormonal therapy
Antipsychotic use: ever vs. never;
Calcium channel blockers: ever vs. never;
antibiotic use: ever vs. never;
Suggestivep < 10–3; >1000 casesDietary intake
Fruit intake: per 100 g/day;
Fiber intake: highest vs. lowest category;
Selenium: ever vs. never;
Tofu intake: highest vs. lowest category;
Adherence score: highest vs. lowest category;
Life behaviour
Lifestyle Quality Indices: highest vs. lowest category;
Anthropometric indices
BMI: per 5 kg/m2;
BMI<25:high vs. low, postmenopausal;
Use of medical/hormonal therapy
Aspirin intake: ever vs. never;
Pre-existing medical conditions and interventions
Bariatric Surgery: ever vs. never;
Dietary intake
Alcohol: highest vs. lowest category;
Total meat intake: per 100 g/day;
Red meat intake: per 100 g/day;
Imageological diagnosis
Bone mineral density: highest vs. lowest category;
Life behaviour
Famine exposure: ever vs. never;
Anthropometric indices
BMI: highest vs. lowest category;
Fat mass: highest vs. lowest category;
Weight gain: highest vs. lowest category;
Biomarkers
IGF1: highest vs. lowest category;
Pre-existing medical conditions and interventions
Antibody: ever vs. never;
Periodontal disease: ever vs. never;
Metabolic Syndrome: ever vs. never;
Hyperthyroidism: ever vs. never;
Weakp < 0.05Dietary intake
Vegetable intake: per 100 g/day;
Soy intake: per 30 g/day;
Soy isoflavone: per 10mg/day;
Coffee intake: highest vs. lowest category;
Vitamin D intake: highest vs. lowest category;
Cheese intake:per 30 g/day;
B-carotene:per 5000ug/day;
Flavonols: highest vs. lowest category;
Dietary calcium intake: per 350mg/day;
Dietary folate intake: highest vs. lowest category;
Prudent/healthy dietary pattern: highest vs. lowest category;
Fruit intake: highest vs. lowest category;
Adherence score: per 1-point;
A-carotene: highest vs. lowest category;
Vitamin B2: highest vs. lowest category;
Fruits and vegetables intake: highest vs. lowest category;
Total dairy food intake: highest vs. lowest category;
Dietary calcium intake: highest vs. lowest category;
Marine n-3 PUFA: highest vs. lowest category;
Vegetarians: yes vs. no;
Higher Mushroom Consumption: highest vs. lowest category;
Life behaviour
Physical activity at a young age: highest vs. lowest category;
Time in the Sun: highest vs. lowest category;
Past gynaecological history
Parity: parous vs. nulliparous;
Anthropometric indices
Weight loss: highest vs. lowest category;
Use of medical/hormonal therapy
Bisphosphonates: ever vs. never;
Thiazolidinediones use: ever vs. never;
Insulins: ever vs. never;
Biomarkers
Serum TG levels: highest vs. lowest category;
Pre-existing medical conditions and
interventions
CAD: ever vs. never;
congenital factor
Twin membership: highest vs. lowest category;
Dietary intake
DII: per 1-point;
Wine Drinking: highest vs. lowest category;
Processed meat intake: per 50 g/day;
SSBs: per 250mg/day;
Processed meat intake: per 50 g/day;
Glycemic index/Glycemic load: highest vs. lowest category;
Glycemic index: highest vs. lowest category;
Glycemic index: per 10 units/day;
Total fat intake: highest vs. lowest category;
Life behaviour
Negative Emotions: ever vs. never;
Flight attendants: yes vs. no;
Sedentary work: highest vs. lowest category;
Occupational exposure-organic solvents: ever vs. never;
Environment:
NO2: per 10 ug/m3;
Anthropometric indices
Birth length: highest vs. lowest category;
BMI>= 30: ever vs. never;
Birth Weight: highest vs. lowest category;
Biomarkers
Serum/plasma iron: highest vs. lowest category;
Plasma prolactin levels: highest vs. lowest category;
Use of medical/hormonal therapy
Antidepressant use: ever vs. never;
Pre-existing medical conditions and
interventions
Obstructive sleep apnea: ever vs. never;
Autoimmune thyroiditis: ever vs. never;
Goitre: ever vs. never;
Sleep-disordered breathing: ever vs. never;
Diabetes: ever vs. never;
congenital factor
Paternal age: per 15 years;

Evidence grading for meta-analyses of risk factors associated with breast cancer incidence (cohort studies only).

BMI, body mass index; BMI iya, Body mass index in young adulthood; CAD, coronary artery disease; outdoor LAN, outdoor light at night.

The bold text represents the main categories of the risk factors.

2.6 Data analysis

We focused on cohort studies, recalculating summary effects and 95% CIs using random- or fixed-effects models (). Heterogeneity was evaluated using the I² statistic and 95% predicted intervals (PIs) () to account for variability across studies and reduce its impact on the results. We evaluated the presence of publication bias by assessing small-study effects and excess significance bias. Egger’s regression asymmetry test (P<.10) and whether the summary estimate of random effects exceeded the point estimate of the largest study in the meta-analysis were used to assess small-study effects (). Additionally, sensitivity analyses were conducted on all eligible cohort and case-control studies using the same criteria as those used in the primary analysis. R software version 4.3.0 was used for all statistical analyses (http://cran.r-project.org/).

2.7 MR

We performed a two-sample MR analysis using genetic variants as proxies for exposure to explore the causal impacts of non-genetic risk factors on BC () Genome-wide association study (GWAS) catalogs were queried for exposures rated as weak evidence or higher in the umbrella review to find relevant GWAS offering summary-level genetic information (). We used data from previous GWAS to ascertain the association between single nucleotide polymorphisms (SNPs) and BC risk ().

Given the necessity of MR analysis to validate the three core assumptions (), we established stringent criteria for selecting the instrumental variables (IVs) to ensure the robustness and reliability of the results (). First, we set a significance threshold of P<5e−08 to choose SNPs as IVs for each exposure. Second, we addressed linkage disequilibrium (LD) between SNPs by excluding those with strong LD (r2 = 0.001, κb=10,000 kb). The PhenoScanner database was used to mitigate the effects of confounding factors. Finally, we computed the F-statistic for all selected SNPs to evaluate weak instrument bias, excluding SNPs with an F-statistic <10, to ensure that all remaining SNPs were strongly associated with exposure ().

Causal impacts were estimated using the inverse variation-weighted (IVW) MR as the primary analysis. In instances where exposure exhibited significant effects in the main IVW MR analysis, we applied various robust MR methods (such as the weighted median and MR-Egger) in the sensitivity analyses to address potential violations of the IV assumption (). We systematically employed leave-one-out modeling to evaluate the potential influence of outliers and pleiotropic SNPs (). We excluded one SNP at a time to determine whether individual SNPs affected the primary causal relationship. Considering the potential for genetic pleiotropy, interactions, and confounding effects among the different exposure factors, we conducted multivariable MR (MVMR) analyses () to assess the direct effects of various exposure factors on BC. To further investigate reverse causation, we performed a reverse MR analysis using BC-related SNPs as IVs (treating BC as the exposure and various risk factors as outcomes).

3 Results

3.1 Literature retrieval and selection

Figure 1 depicts the literature retrieval and selection process. Up to July 2023, we retrieved 58,242 articles. After screening and following the exclusion of duplicate meta-analyses based on assessed exposure and outcome () (Supplementary Table 7), 218 articles, including 427 meta-analyses remained (269).

Figure 1

3.2 Characteristics of meta-analyses

Among the 427 included meta-analyses, the estimated values from studies ranged from 2 to 69 (median, 10). The median number of cases and individuals for each meta-analysis were 14,055 and 3,328,403, respectively. The minimum and maximum numbers of cases in meta-analyses were 138 and 591,297, respectively. The smallest total population was 1,083, whereas the largest was 18,281,388. Furthermore, 403 of the 427 meta-analyses included >1,000 patients with BC.

From the pool of 427 meta-analyses, 281 consisted exclusively of cohort studies, including at least two that evaluated 202 risk factors and categorized into 10 major groups. (Figure 2 and Supplementary Table 2).

Figure 2

3.3 Quality assessment

We evaluated the methodological quality of 218 studies, which included meta-analyses of 427 observational studies, using the AMSTAR-2 tool (Supplementary Table 4). Overall, most meta-analyses exhibited low to very low quality owing to various factors such as study design limitations and reduced methodological rigor (such as potential publication bias, indirectness, and inconsistency). Specifically, only a small proportion was rated as having “high” or “moderate” quality.

3.4 Main analysis

3.4.1 Summary effect size

When using P<.05 as the threshold for statistical significance, among the 281 studies solely comprising cohort studies, 150 (53%) and 115 (41%) meta-analyses presented significant summary fixed- and random-effects estimates, respectively (Supplementary Table 2). Applying a threshold of P<.001, 78 (28%) and 40 (14%) studies produced significant findings using summary fixed- and random-effects models, respectively. In case of P<10-6, 49 (17%) and 21 (7%) studies provided significant summary fixed- and random-effects estimates, respectively. In meta-analyses where the random-effects estimate had P<10-6, 13 reported different risk factors associated with an increased BC incidence. These thresholds were selected in alignment with the evidence grading system used in this study, which allow for a clearer distinction of the strength and reliability of the findings at each level of evidence.

3.4.2 Heterogeneity between studies

We reanalyzed 281 meta-analyses using random or fixed-effects models and found that 91 (32%) exhibited significant heterogeneity (I² = 50–75%). Notably, 33 (12%) of the meta-analyses showed substantial heterogeneity (I² > 75%) (Supplementary Table 3). The heterogeneity observed in most outcomes can be attributed to several factors, including study design, sample size, study quality, environmental influences, and population characteristics. When calculating the 95% PIs, the null hypothesis was excluded in 22 studies, including alcohol, smoking, glycemic index, glycemic index/glycemic load, coffee intake, breast density, IGF-1 concentrations, serum triglyceride (TG) levels and the like.

3.4.3 Grading the evidence

Evidence from 46 meta-analyses suggested the presence of small-study effects. Moreover, evidence of excessive significant bias (P<.10) was observed in 65 meta-analyses with different exposures, including BMI, total meat intake, vegetable intake, metabolic syndrome, dietary calcium intake, and PA. For further details, please refer to Supplementary Table 3.

3.4.4 Grading the evidence

We classified the strength of evidence for each risk factor associated with BC (Table 1). Moreover, Supplementary Table 5 presents information on elaborate explanations of the assessment criteria (specifically for cohort studies), whereas Supplementary Table 6 details the outcomes for all studies.

Among the 281 meta-analyses included in the primary analysis, only five (1.8%) met the criteria for strong evidence. Including breast density (2.89; 95% CI: 2.57-3.25), cardiac glycosides use (1.39; 95% CI: 1.33-1.45), AF history (1.18; 95% CI: 1.14-1.22), adherence to a vegetable-fruit-soybean dietary pattern (0.87; 95% CI: 0.83-0.92) and Postmenopausal women with a BMI ≥25 (0.86high vs. low; 95% CI: 0.81-0.91) (Table 1, Supplementary Table 5). Eight analyses (2.8%) provided highly suggestive evidence (Table 1, Figure 3). Twenty-three analyses (8.2%) provided suggestive evidence, 55 (19.6%) provided weak evidence, and the remaining showed no significant association.

Figure 3

3.5 Sensitivity analyses

When cohort and case-control studies were included (Supplementary Table 6), additional four exposure factors associated with increased BC incidence provided strong evidence: autoimmune thyroiditis (2.71; 95% CI: 2.13-3.43), weight gain (1.55; 95% CI: 1.40-1.71), oral progestogen (1.28; 95% CI: 1.19-1.39), and light exposure at night (1.13; 95% CI: 1.09-1.16). Strong evidence for two exposures reducing BC incidence was also found: number of births (0.79; 95% CI: 0.75-0.83) and sex hormone-binding globulin (0.65; 95% CI: 0.58-0.73); both associations were only included in case-control studies and were not evaluated in the main analysis. Conversely, when case-control studies were included, the strong correlations between breast density, BMI ≥25 (high vs. low, postmenopausal), and BC risk were downgraded to highly suggestive evidence (2.89; 95% CI: 2.57-3.25) and not significant (0.86; 95% CI: 0.81-0.91), whereas the remaining three strong associations remained strong.

3.6 MR

In the MR analysis, 22 risk factors had available genetic instruments (Supplementary Table 8). The genetically predicted IGF-1 concentrations demonstrated a correlation with BC (1.08; 95% CI: 1.02-1.14) (Figure 4, Supplementary Table 9). Additionally, higher fruit intake (0.64; 95% CI: 0.46-0.90), cheese intake (0.82; 95% CI: 0.69-0.98), higher serum TG levels (0.91; 95% CI: 0.86-0.97) and higher BMI category (0.82; 95% CI: 0.71-0.95) were found to have protective effects against BC. The sensitivity analysis yielded directions consistent with the main analysis, supporting potential causal effects (Supplementary Figures 1, 2, Supplementary Table 10). Reverse MR-IVW analysis (Supplementary Figure 3) indicated a potential bidirectional relationship between calcium channel blockers (CCBs) and BC. No other exposures demonstrated a similar reverse causal association with BC incidence.

Figure 4

In the MVMR analysis, genetic predictions of CCBs and IGF-1 concentrations showed independent associations with BC after adjusting for BMI and serum TG levels. Similarly, the genetic predictions of fruit and cheese intake were independently linked to a decreased risk of BC (Supplementary Table 11).

4 Discussion

This umbrella review analyzed data from 427 meta-analyses, with 281 including at least two cohort studies. In the primary analysis, only five meta-analyses provided strong evidence regarding BC, showing significant strength and no bias. Increased breast density, AF history, and cardiac glycoside use were linked to an elevated BC risk. Conversely, adherence to a vegetable-fruit-soybean dietary pattern was associated with a decreased BC incidence. Furthermore, BMI inversely correlated with BC risk among postmenopausal women with a BMI ≥25. Using MR analysis, we identified causal effects between six risk factors and BC: BMI, CCBs, fruit intake, cheese intake, IGF-1 levels, and serum TG levels. CCBs exhibited bidirectional effects on BC.

A meta-analysis examining the relationship between AF history and cardiac glycoside use in BC incidence has garnered substantial evidence. Prior investigations into whether AF increases BC incidence have produced conflicting findings, with this link absent in the WCRF CUP report (270). Hence, our evidence grading system offers valuable supplementary insights. Some studies have proposed that the increased BC risk might stem from shared risk factors such as obesity, diabetes, and unhealthy lifestyles. Nonetheless, these assertions require further validation using clinical data. Another suggested mechanism linking AF to BC involves a systemic inflammatory response (271, 272); however, large-scale epidemiological studies have not confirmed this link. Additionally, cardiac glycosides, particularly digoxin, emerged as potent BC risk factors in our study, possibly because of their estrogenic properties and binding to estrogen receptors (273). In a sizable prospective study involving postmenopausal women (274), adjustment for multiple variables revealed a heightened risk of incident BC associated with AF in women; however, further adjustment for cardiac glycosides mitigated this risk, indicating their potential intermediary role.

Our meta-analysis revealed strong evidence supporting an inverse relationship between BMI and BC incidence, irrespective of menopausal status. Our results are consistent with those of the 2018 WCRF CUP report. Several mechanisms may explain the inverse correlation between BMI and BC risk. First, studies have indicated a negative correlation between breast density and BMI (275, 276), with women who are obese or overweight exhibiting lower breast density and, thus, a reduced BC risk. Second, Among obesity-related protein biomarkers, lower adiponectin levels and higher leptin and IGF-1 levels were associated with an increased BC risk. Adiponectin levels were negatively correlated with BMI and leptin concentration in women (277). Reduced adiponectin levels may enhance insulin signaling (278), which is associated with tumor growth. Another adipokine, leptin, is a key molecular mediator of the relationship between obesity and BC and is overexpressed in individuals who are obese or overweight. Finally, IGF-1, which is mediated by the IGF-1 receptor, is implicated in BC development and progression by regulating proliferation and survival genes via multiple signaling pathways (279). Our comprehensive review, supported by the MR analysis, confirmed the causal relationship between increased IGF-1 concentrations and elevated BC risk, further strengthening our findings.

Substantial suggestive evidence indicates an association between CCB use and an increased BC risk, as confirmed through the MR analysis. Prior studies, such as that by Thakur et al. (174), have suggested an elevated risk of BC with CCB use, whereas Wright et al. (280) indicated no significant association. These differing conclusions likely stem from the high heterogeneity in study design, population, and follow-up duration (281). However, the mechanisms underlying the effect of CCBs on BC risk remain unclear (282). In vitro CCB treatment has been shown to upregulate pathways related to breast cell proliferation and migration (283), whereas calcium-dependent processes exhibit tumor-suppressive effects in BC (284). Moreover, the MR reverse causation analysis suggested that BC influences the use of CCBs. This finding reveals a complex bidirectional relationship, highlighting the need for additional research on its mechanisms and clinical implications. Given the uncertainty surrounding the underlying mechanisms, this area presents a novel and important avenue for future studies, particularly in investigating causality pathways and their potential roles in BC risk.

Our study has several strengths. First, we prioritized prospective cohort studies as the main analysis to avoid the influence of epidemiological bias as much as possible. At the same time, in order to make the results comprehensive, all observational studies including case-control studies were further included in the sensitivity analysis, and the differences were discussed. Overlapping articles were assessed using CCA, and the highest quality or most recent reviews of overlapping articles were included to avoid duplicate inclusion. We employed comprehensive and robust methodologies, ensuring the rigor and reliability of our findings. Moreover, the large sample size further enhanced the credibility and precision of our results. Finally, given the inherent limitations of inferring causation from observational studies, this pioneering effort amalgamated umbrella reviews with bidirectional two-sample MR studies in the BC risk domain, providing novel insights into the potential and reverse causal relationships among risk exposures.

However, this study has some limitations. First, it relies on literature retrieval by the original authors and findings from past meta-analyses, potentially leading to some studies being overlooked. Second, we found significant heterogeneity across studies, likely attributable to differences in study design, sample characteristics, and measurement methods. Although random effects models and sensitivity analyses were employed to account for heterogeneity, its impact could not be completely eliminated. Furthermore, the AMSTAR-2 assessment indicated that most of the included studies were of low quality, suggesting a potential risk of bias. Despite conducting bias tests, the exact sources of bias could not be definitively identified. Future research should implement more consistent study designs and enhance methodological quality to minimize both heterogeneity and bias. Third, studies that separately reported the results for pre- and postmenopausal women were limited. Consequently, stratified analyses based on menopausal status were not conducted in this study, potentially overlooking the differential effects of certain exposures owing to differences in menopausal status. Fourth, the umbrella review identified numerous significant exposures. However, the MR analysis has limitations owing to genetic instrument constraints and sample size issues, resulting in fewer established causal effects. This limitation does not imply that the exposures not identified in this analysis lack causal effects, nor does it confirm the absolute accuracy of the conclusions drawn from the MR analysis.

This umbrella review synthesized meta-analyses focusing on the risk factors associated with BC. The MR analysis elucidated the causal relationships between specific risk factors and BC incidence. Identifying these factors facilitates the development of targeted preventive strategies for high-risk populations and investigations into their underlying mechanisms.

Statements

Data availability statement

The original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding authors.

Author contributions

ZW: Conceptualization, Data curation, Formal Analysis, Methodology, Software, Writing – original draft, Writing – review & editing. LF: Investigation, Methodology, Validation, Visualization, Writing – original draft. YX: Data curation, Software, Validation, Visualization, Writing – original draft. ZZ: Data curation, Writing – original draft. LW: Investigation, Project administration, Resources, Supervision, Writing – review & editing. SG: Conceptualization, Funding acquisition, Project administration, Supervision, Writing – review & editing.

Funding

The author(s) declare that financial support was received for the research and/or publication of this article. This study was supported in part by Natural Science Foundation of Liaoning Province. (No. 2023JH2/101700135).

Acknowledgments

The authors would like to thank all the participants in this study, and those all who provide help to this study.

Conflict of interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Generative AI statement

The author(s) declare that no Generative AI was used in the creation of this manuscript.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fonc.2025.1541233/full#supplementary-material

References

  • 1

    SiegelRLMillerKDWagleNSJemalA. Cancer statistics, 2023. CA Cancer J Clin. (2023) 73:1748. doi: 10.3322/caac.21763

  • 2

    BrayFLaversanneMSungHFerlayJSiegelRLSoerjomataramIet al. Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. (2024) 74:229–63. doi: 10.3322/caac.21834

  • 3

    ClusanLFerriereFFlouriotGPakdelF. A basic review on estrogen receptor signaling pathways in breast cancer. Int J Mol Sci. (2023) 24(7):6834. doi: 10.3390/ijms24076834

  • 4

    SlepickaPFCyrillSLDos SantosCO. Pregnancy and breast cancer: pathways to understand risk and prevention. Trends Mol Med. (2019) 25:866–81. doi: 10.1016/j.molmed.2019.06.003

  • 5

    WintersSMartinCMurphyDShokarNK. Breast cancer epidemiology, prevention, and screening. Prog Mol Biol Transl Sci. (2017) 151:132. doi: 10.1016/bs.pmbts.2017.07.002

  • 6

    SunYSZhaoZYangZNXuFLuHJZhu.ZYet al. Risk factors and preventions of breast cancer. Int J Biol Sci. (2017) 13:1387–97. doi: 10.7150/ijbs.21635

  • 7

    LoiblSPoortmansPMorrowMDenkertCCuriglianoG. Breast cancer. Lancet. (2021) 397:1750–69. doi: 10.1016/S0140-6736(20)32381-3

  • 8

    HongRXuB. Breast cancer: an up-to-date review and future perspectives. Cancer Commun (Lond). (2022) 42:913–36. doi: 10.1002/cac2.12358

  • 9

    KastKJohnEMHopperJHAndrieuNNoguèsCMouret-FourmeEet al. Associations of height, body mass index, and weight gain with breast cancer risk in carriers of a pathogenic variant in BRCA1 or BRCA2: the BRCA1 and BRCA2 Cohort Consortium. Breast Cancer Res. (2023) 25:72. doi: 10.1186/s13058-023-01673-w

  • 10

    FakhriNChadMALahkimMHouariADehbiHBelmoudenAet al. Risk factors for breast cancer in women: an update review. Med Oncol. (2022) 39:197. doi: 10.1007/s12032-022-01804-x

  • 11

    ZhangMLiLLZhaoQQPengXDWuKLiXet al. The association of new-onset atrial fibrillation and risk of cancer: A systematic review and meta-analysis. Cardiol Res Pract. (2020) 2020:2372067. doi: 10.1155/2020/2372067

  • 12

    BaoYLeeJThakurURamkumarSMarwickTH. Atrial fibrillation in cancer survivors - a systematic review and meta-analysis. Cardiooncology. (2023) 9:29. doi: 10.1186/s40959-023-00180-3

  • 13

    SekulaPDel GrecoMFPattaroCKottgenA. Mendelian randomization as an approach to assess causality using observational data. J Am Soc Nephrol. (2016) 27:3253–65. doi: 10.1681/ASN.2016010098

  • 14

    BowdenSJBodinierBKallialaIZuberVVuckovicDDoulgerakiTet al. Genetic variation in cervical preinvasive and invasive disease: a genome-wide association study. Lancet Oncol. (2021) 22:548–57. doi: 10.1016/s1470-2045(21)00028-0

  • 15

    Pearson-StuttardJPapadimitriouNMarkozannesGCividiniSKakourouAGillDet al. Type 2 diabetes and cancer: an umbrella review of observational and mendelian randomization studies. Cancer Epidemiol Biomarkers Prev. (2021) 30:1218–28. doi: 10.1158/1055-9965.EPI-20-1245

  • 16

    GatesMGatesAPieperDFernandesRMTriccoACMoherDet al. Reporting guideline for overviews of reviews of healthcare interventions: development of the PRIOR statement. BMJ. (2022) 9:e070849. doi: 10.1136/bmj-2022-070849

  • 17

    PieperDAntoineSLMathesTNeugebauerEAEikermannM. Systematic review finds overlapping reviews were not mentioned in every other overview. J Clin Epidemiol. (2014) 67:368–75. doi: 10.1016/j.jclinepi.2013.11.007

  • 18

    OkothKChandanJSMarshallTThangaratinamSThomasGNNirantharakumarKet al. Association between the reproductive health of young women and cardiovascular disease in later life: umbrella review. BMJ. (2020) 371:m3502. doi: 10.1136/bmj.m3502

  • 19

    PollockMFernandesRMNewtonASScottSDHartlingL. A decision tool to help researchers make decisions about including systematic reviews in overviews of reviews of healthcare interventions. Syst Rev. (2019) 8:29. doi: 10.1186/s13643-018-0768-8

  • 20

    SheaBJReevesBCWellsGThukuMHamelCMoranJet al. AMSTAR 2: a critical appraisal tool for systematic reviews that include randomised or non-randomised studies of healthcare interventions, or both. BMJ. (2017) 358:j4008. doi: 10.1136/bmj.j4008

  • 21

    KallialaIMarkozannesGGunterMJParaskevaidisEGabraHMitraAet al. Obesity and gynaecological and obstetric conditions: umbrella review of the literature. BMJ. (2017) 359:j4511. doi: 10.1136/bmj.j4511

  • 22

    KyrgiouMKallialaIMarkozannesGGunterMJParaskevaidisEGabraHet al. Adiposity and cancer at major anatomical sites: umbrella review of the literature. BMJ. (2017) 356:j477. doi: 10.1136/bmj.j477

  • 23

    DerSimonianRLairdN. Meta-analysis in clinical trials. Control Clin Trials. (1986) 7:3. doi: 10.1016/0197-2456(86)90046-2

  • 24

    Higgins.JPTThompson.SGDeeks.JJAltmanDG. Measuring inconsistency in meta-analyses. BMJ Open. (2003) 327:557–60. doi: 10.1136/bmj.327.7414.557

  • 25

    IntHoutJIoannidisJPRoversMMGoemanJJ. Plea for routinely presenting prediction intervals in meta-analysis. BMJ Open. (2016) 6:e010247. doi: 10.1136/bmjopen-2015-010247

  • 26

    RileyRDHigginsJPTDeeksJJ. Interpretation of random effects meta-analyses. BMJ. (2011) 10:d549. doi: 10.1136/bmj.d549

  • 27

    EggerMSmithGDSchneiderMMinderC. Bias in meta-analysis detected by a simple, graphical test. BMJ. (1997) 13:629–34. doi: 10.1136/bmj.315.7109.629

  • 28

    BurgessSFoleyCNZuberV. Inferring causal relationships between risk factors and outcomes from genome-wide association study data. Annu Rev Genomics Hum Genet. (2018) 19:303–27. doi: 10.1146/annurev-genom-083117-021731

  • 29

    SollisEMosakuAAbidABunielloACerezoMGilLet al. The NHGRI-EBI GWAS Catalog: knowledgebase and deposition resource. Nucleic Acids Res. (2023) 51:D977–85. doi: 10.1093/nar/gkac1010

  • 30

    Escala-GarciaMMorraACanisiusSChang-ClaudeJKarSZhengWet al. Breast cancer risk factors and their effects on survival: a Mendelian randomisation study. BMC Med. (2020) 18:327. doi: 10.1186/s12916-020-01797-2

  • 31

    HartwigFPBorgesMCHortaBLBowdenJDavey SmithG. Inflammatory biomarkers and risk of schizophrenia: A 2-sample mendelian randomization study. JAMA Psychiatry. (2017) 74:1226–33. doi: 10.1001/jamapsychiatry.2017.3191

  • 32

    TangPGuoXChongLLiR. Mendelian randomization study shows a causal effect of asthma on epilepsy risk. Front Immunol. (2023) 14:1071580. doi: 10.3389/fimmu.2023.1071580

  • 33

    BurgessSButterworthAThompsonSG. Mendelian randomization analysis with multiple genetic variants using summarized data. Genet Epidemiol. (2013) 37:658–65. doi: 10.1002/gepi.21758

  • 34

    WuFHuangYHuJShaoZ. Mendelian randomization study of inflammatory bowel disease and bone mineral density. BMC Med. (2020) 18:312. doi: 10.1186/s12916-020-01778-5

  • 35

    CarterARSandersonEHammertonGRichmondRCDavey SmithGHeronJet al. Mendelian randomisation for mediation analysis: current methods and challenges for implementation. Eur J Epidemiol. (2021) 36:465–78. doi: 10.1007/s10654-021-00757-1

  • 36

    WuDZhaoZChenCLuGWangCGaoSet al. Impact of obstructive sleep apnea on cancer risk: a systematic review and meta-analysis. Sleep Breath. (2023) 27:843–52. doi: 10.1007/s11325-022-02695-y

  • 37

    WeiFChenWLinX. Night-shift work, breast cancer incidence, and all-cause mortality: an updated meta-analysis of prospective cohort studies. Sleep Breath. (2021) 26:1509–26. doi: 10.1007/s11325-021-02523-9

  • 38

    SantucciCGallusSMartinettiMLa VecchiaCBosettiC. Aspirin and the risk of nondigestive tract cancers: An updated meta-analysis to 2019. Int J Cancer. (2021) 148:1372–82. doi: 10.1002/ijc.33311

  • 39

    LiYMaL. The association between coffee intake and breast cancer risk: a meta-analysis and dose-response analysis using recent evidence. Ann Palliat Med. (2021) 10:3804–16. doi: 10.21037/apm-20-1962

  • 40

    ChenSWuFHaiRYouQXieLShuLet al. Thyroid disease is associated with an increased risk of breast cancer: a systematic review and meta-analysis. Gland Surg. (2021) 10:336–46. doi: 10.21037/gs-20-878

  • 41

    WeiJShiZNaRWangCHResurreccionWKZhengSLet al. Germline HOXB13 G84E mutation carriers and risk to twenty common types of cancer: results from the UK Biobank. Br J Cancer. (2020) 123:1356–9. doi: 10.1038/s41416-020-01036-8

  • 42

    IshiharaBPFarahDFonsecaMCMNazarioA. The risk of developing breast, ovarian, and endometrial cancer in obese women submitted to bariatric surgery: a meta-analysis. Surg Obes Relat Dis. (2020) 16:1596–602. doi: 10.1016/j.soard.2020.06.008

  • 43

    FarvidMSSpenceNDHolmesMDBarnettJB. Fiber consumption and breast cancer incidence: A systematic review and meta-analysis of prospective studies. Cancer. (2020) 126:3061–75. doi: 10.1002/cncr.32816

  • 44

    FarahmandMMonavariSHShojaZGhaffariHTavakoliMTavakoliA. Epstein-Barr virus and risk of breast cancer: a systematic review and meta-analysis. Future Oncol. (2019) 15:2873–85. doi: 10.2217/fon-2019-0232

  • 45

    XiaoYKeYWuSHuangSLiSLvZet al. Association between whole grain intake and breast cancer risk: a systematic review and meta-analysis of observational studies. Nutr J. (2018) 17:87. doi: 10.1186/s12937-018-0394-2

  • 46

    AndersonJJDarwisNDMMackayDFCelis-MoralesCALyallDMSattarNet al. Red and processed meat consumption and breast cancer: UK Biobank cohort study and meta-analysis. Eur J Cancer. (2018) 90:7382. doi: 10.1016/j.ejca.2017.11.022

  • 47

    ChenYTanFWeiLLiXLyuZFengXet al. Sleep duration and the risk of cancer: a systematic review and meta-analysis including dose-response relationship. BMC Cancer. (2018) 18(1):1149. doi: 10.1186/s12885-018-5025-y

  • 48

    TuratiFGaleoneCGandiniSAugustinLSJenkinsDJPelucchiCet al. High glycemic index and glycemic load are associated with moderately increased cancer risk. Mol Nutr Food Res. (2015) 59:1384–94. doi: 10.1002/mnfr.201400594

  • 49

    ChenQLangLWuWXuGZhangXLiTet al. A meta-analysis on the relationship between exposure to ELF-EMFs and the risk of female breast cancer. PloS One. (2013) 8:e69272. doi: 10.1371/journal.pone.0069272

  • 50

    TurnerLB. A meta-analysis of fat intake, reproduction, and breast cancer risk: an evolutionary perspective. Am J Hum Biol. (2011) 23:601–8. doi: 10.1002/ajhb.21176

  • 51

    González-PérezAGarcía RodríguezLALópez-RidauraR. Effects of non-steroidal anti-inflammatory drugs on cancer sites other than the colon and rectum: a meta-analysis. BMC Cancer. (2003) 3:28. doi: 10.1186/1471-2407-3-28

  • 52

    ZhouJDaiYZuoZLiuTLiS. Famine exposure during early life and risk of cancer in adulthood: A systematic review and meta-analysis. J Nutr Health Aging. (2023) 27(7):550–8. doi: 10.1007/s12603-023-1947-4

  • 53

    YeXZhangYHeYShengMHuangJLouW. Association between consumption of artificial sweeteners and breast cancer risk: A systematic review and meta-analysis of observational studies. Nutr Cancer. (2023) 75:795804. doi: 10.1080/01635581.2023.2178957

  • 54

    YaoXHuQLiuXLingQLengYZhaoHet al. Atrial fibrillation and breast cancer-Vicious twins? A systematic review and meta-analysis. Front Cardiovasc Med. (2023) 10:1113231. doi: 10.3389/fcvm.2023.1113231

  • 55

    YangJZhangSJiangW. Impact of beta blockers on breast cancer incidence and prognosis. Clin Breast Cancer. (2023) 23(6):664–71.e21. doi: 10.1016/j.clbc.2023.05.014

  • 56

    YangJShenHMiMQinY. Isoflavone consumption and risk of breast cancer: an updated systematic review with meta-analysis of observational studies. Nutrients. (2023) 15(10):2402. doi: 10.3390/nu15102402

  • 57

    XiongFDaiQZhangSBentSTahirPVan BlariganELet al. Diabetes and incidence of breast cancer and its molecular subtypes: A systematic review and meta-analysis. (2023) 40(1):e3709. doi: 10.1101/2023.05.13.23289893

  • 58

    WilsonRBLathigaraDKaushalD. Systematic review and meta-analysis of the impact of bariatric surgery on future cancer risk. Int J Mol Sci. (2023) 24(7):6192. doi: 10.3390/ijms24076192

  • 59

    WangYTHuKRZhaoJAiFLShiYLWangXWet al. The association between exposure to second-hand smoke and disease in the chinese population: A systematic review and meta-analysis. BioMed Environ Sci. (2023) 36:2437. doi: 10.3967/bes2023.003

  • 60

    Van PuyveldeHDimouNKatsikariAIndave RuizBIGodderisLHuybrechtsIet al. The association between dietary intakes of methionine, choline and betaine and breast cancer risk: A systematic review and meta-analysis. Cancer Epidemiol. (2023) 83:102322. doi: 10.1016/j.canep.2023.102322

  • 61

    ShinSFuJShinWKHuangDMinSKangD. Association of food groups and dietary pattern with breast cancer risk: A systematic review and meta-analysis. Clin Nutr. (2023) 42:282–97. doi: 10.1016/j.clnu.2023.01.003

  • 62

    Armenta-GuiradoBIGonzález-RochaAMérida-OrtegaÁLópez-CarrilloLDenova-GutiérrezE. Lifestyle quality indices and female breast cancer risk: A systematic review and meta-analysis. Adv Nutr. (2023) 14:685709. doi: 10.1016/j.advnut.2023.04.007

  • 63

    PraudDDeygasFAmadouABouillyMTuratiFBraviFet al. Traffic-related air pollution and breast cancer risk: A systematic review and meta-analysis of observational studies. Cancers (Basel). (2023) 15(3):927. doi: 10.3390/cancers15030927

  • 64

    PengCWuKChenXLangHLiCHeLet al. Migraine and risk of breast cancer: A systematic review and meta-analysis. Clin Breast Cancer. (2023) 23:e122–30. doi: 10.1016/j.clbc.2022.12.011

  • 65

    PanBLaiHMaNLiDDengXWangXet al. Association of soft drinks and 100% fruit juice consumption with risk of cancer: a systematic review and dose-response meta-analysis of prospective cohort studies. Int J Behav Nutr Phys Act. (2023) 20:58. doi: 10.1186/s12966-023-01459-5

  • 66

    TranTVKitaharaCMLeenhardtLde VathaireFBoutron-RuaultMCJournyN. The effect of thyroid dysfunction on breast cancer risk: an updated meta-analysis. Endocr Relat Cancer. (2023) 30(1):e220155. doi: 10.1530/erc-22-0155

  • 67

    MalcomsonFCWigginsCParra-SotoSHoFKCelis-MoralesCSharpLet al. Adherence to the 2018 World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) Cancer Prevention Recommendations and cancer risk: A systematic review and meta-analysis. Cancer. (2023) 21(1):407. doi: 10.1002/cncr.34842

  • 68

    LouMWCDrummondAESwainCTVMilneRLEnglishDRBrownKAet al. Linking physical activity to breast cancer via inflammation, part 2: the effect of inflammation on breast cancer risk. Cancer Epidemiol Biomarkers Prev. (2023) 32:597605. doi: 10.1158/1055-9965.Epi-22-0929

  • 69

    LianYWangGPChenGQChenHNZhangGY. Association between ultra-processed foods and risk of cancer: a systematic review and meta-analysis. Front Nutr. (2023) 10:1175994. doi: 10.3389/fnut.2023.1175994

  • 70

    HetingMWenpingLYananWDongniZXiaoqingWZhliZ. Levonorgestrel intrauterine system and breast cancer risk: An updated systematic review and meta-analysis of observational studies. Heliyon. (2023) 9:e14733. doi: 10.1016/j.heliyon.2023.e14733

  • 71

    HassanHAllenISofianopoulouEWalburgaYTurnbullCEcclesDMet al. Long- term outcomes of hysterectomy with bilateral salpingo-oophorectomy: a systematic review and meta-analysis. Am J Obstet Gynecol. (2023) 230(1):44–57. doi: 10.1016/j.ajog.2023.06.043

  • 72

    GhoreishySMBagheriANejadMMLarijaniBEsmaillzadehA. Association between calcium intake and risk of breast cancer: An updated systematic review and dose–response meta-analysis of cohort studies. Clin Nutr ESPEN. (2023) 55:251–9. doi: 10.1016/j.clnesp.2023.03.026

  • 73

    Florez-GarciaVAGuevara-RomeroECHawkinsMMBautistaLEJensonTEYuJet al. Cadmium exposure and risk of breast cancer: A meta-analysis. Environ Res. (2023) 219:115109. doi: 10.1016/j.envres.2022.115109

  • 74

    FitzpatrickDPirieKReevesGGreenJBeralV. Combined and progestagen-only hormonal contraceptives and breast cancer risk: A UK nested case–control study and meta-analysis. PloS Med. (2023) 20(3):e1004188. doi: 10.1371/journal.pmed.1004188

  • 75

    DeheshTFadaghiSSeyediMAbolhadiEIlaghiMShamsPet al. The relation between obesity and breast cancer risk in women by considering menstruation status and geographical variations: a systematic review and meta-analysis. BMC Womens Health. (2023) 23:392. doi: 10.1186/s12905-023-02543-5

  • 76

    de OliveiraVAOliveiraIKFPereiraICMendesLKFCarneiro da SilvaFCTorres-LealFLet al. Consumption and supplementation of vitamin E in breast cancer risk, treatment, and outcomes: A systematic review with meta-analysis. Clin Nutr ESPEN. (2023) 54:215–26. doi: 10.1016/j.clnesp.2023.01.032

  • 77

    CongXLiuQLiWWangLFengYLiuCet al. Systematic review and meta-analysis of breast cancer risks in relation to 2,3,7,8-tetrachlorodibenzo-p-dioxin and per- and polyfluoroalkyl substances. Environ Sci Pollut Res Int. (2023) 30(37):86540–55. doi: 10.1007/s11356-023-28592-9

  • 78

    ChenYMushashiFSonSBhattiPDummerTMurphyRA. Diabetes medications and cancer risk associations: a systematic review and meta-analysis of evidence over the past 10 years. Sci Rep. (2023) 13:11844. doi: 10.1038/s41598-023-38431-z

  • 79

    ZhouWVelizPTSmithEMLChenWReddyRMLarsonJL. Comparison of pre-diagnosis physical activity and its correlates between lung and other cancer patients: accelerometer data from the UK biobank prospective cohort. Int J Environ Res Public Health. (2023) 20(2):1001. doi: 10.3390/ijerph20021001

  • 80

    BakierzynskaMCullinaneMCRedmondHPCorriganM. Prophylactic aspirin intake and breast cancer risk; A systematic review and meta-analysis of observational cohort studies. Eur J Surg Oncol. (2023) 49(10):106940. doi: 10.1016/j.ejso.2023.05.015

  • 81

    LiZWangYHWangLLHuDTTengYZhangTYet al. Polycystic ovary syndrome and the risk of endometrial, ovarian and breast cancer: An updated meta-analysis. Scott Med J. (2022) 67:109–20. doi: 10.1177/00369330221107099

  • 82

    ZhuangYPangXQiYZhangTCaoGXueHet al. The incidence risk of breast and gynecological cancer by antidepressant use: A systematic review and dose-response meta-analysis of epidemiological studies involving 160,727 patients. Front Oncol. (2022) 12:939636. doi: 10.3389/fonc.2022.939636

  • 83

    ZhengXLiNZhangYZhaoJ. Is heart failure a new risk factor for incident cancer? Front Cardiovasc Med. (2022) 9:828290. doi: 10.3389/fcvm.2022.828290

  • 84

    ZhangJYangJ. Allium vegetables intake and risk of breast cancer: A meta-analysis. Iran J Public Health. (2022) 51:746–57. doi: 10.18502/ijph.v51i4.9235

  • 85

    YeJPengHHuangXQiX. The association between endometriosis and risk of endometrial cancer and breast cancer: a meta-analysis. BMC Womens Health. (2022) 22:455. doi: 10.1186/s12905-022-02028-x

  • 86

    YapDWTTanNKWTanBKJTeoYHTanVKMSeeAet al. The association of obstructive sleep apnea with breast cancer incidence and mortality: A systematic review and meta-analysis. J Breast Cancer. (2022) 25:149–63. doi: 10.4048/jbc.2022.25.e11

  • 87

    XuCGanesanKLiuXYeQCheungYLiuDet al. Prognostic value of negative emotions on the incidence of breast cancer: A systematic review and meta-analysis of 129,621 patients with breast cancer. Cancers (Basel). (2022) 14(3):475. doi: 10.3390/cancers14030475

  • 88

    XiaoWHuangJWangJChenYHuNCaoS. Occupational exposure to organic solvents and breast cancer risk: a systematic review and meta-analysis. Environ Sci Pollut Res Int. (2022) 29:1605–18. doi: 10.1007/s11356-021-17100-6

  • 89

    van WeersSHrzicRElandsRJJ. Oral contraceptive use and breast cancer risk according to molecular subtypes status: A meta-analysis. Eur J Public Health. (2022) 14(3):574. doi: 10.3390/cancers14030574

  • 90

    RengQZhuLLFengLLiYJZhuYXWangTTet al. Dietary meat mutagens intake and cancer risk: A systematic review and meta-analysis. Front Nutr. (2022) 9:962688. doi: 10.3389/fnut.2022.962688

  • 91

    WeinmannSTanakaLFSchaubergerGOsmaniVKlugSJ. Breast cancer among female flight attendants and the role of the occupational exposures: A systematic review and meta-analysis. J Occup Environ Med. (2022) 64:822–30. doi: 10.1097/jom.0000000000002606

  • 92

    Parra-SotoSAhumadaDPetermann-RochaFBoonpoorJGallegosJLAndersonJet al. Association of meat, vegetarian, pescatarian and fish-poultry diets with risk of 19 cancer sites and all cancer: findings from the UK Biobank prospective cohort study and meta-analysis. BMC Med. (2022) 20:79. doi: 10.1186/s12916-022-02257-9

  • 93

    NouriMMohsenpourMAKatsikiNGhobadiSJafariAFaghihSet al. Effect of serum lipid profile on the risk of breast cancer: systematic review and meta-analysis of 1,628,871 women. J Clin Med. (2022) 11(15):4503. doi: 10.3390/jcm11154503

  • 94

    NajdiNEsmailzadehAShokrpourMNikfarSRazaviSZSepidarkishMet al. A systematic review and meta-analysis on tubal ligation and breast cancer risk. Syst Rev. (2022) 11:126. doi: 10.1186/s13643-022-02000-8

  • 95

    ManouchehriETaghipourAGhavamiVShandizFHEbadiARoudsariRL. Menstrual and reproductive factors and risk of breast cancer in Iranian female population: A systematic review and meta-analysis. Int J Prev Med. (2022) 13:26. doi: 10.4103/ijpvm.IJPVM_646_20

  • 96

    MarkellosCOurailidouMEGavriatopoulouMHalvatsiotisPSergentanisTNPsaltopoulouT. Olive oil intake and cancer risk: A systematic review and meta-analysis. PloS One. (2022) 17:e0261649. doi: 10.1371/journal.pone.0261649

  • 97

    LongTLiuKLongJLiJChengL. Dietary glycemic index, glycemic load and cancer risk: a meta-analysis of prospective cohort studies. Eur J Nutr. (2022) 61:2115–27. doi: 10.1007/s00394-022-02797-z

  • 98

    WuSYuanCLiuSZhangQYangZSunFet al. Irritable bowel syndrome and long-term risk of cancer: A prospective cohort study among 0.5 million adults in UK biobank. Am J Gastroenterol. (2022) 117:785–93. doi: 10.14309/ajg.0000000000001674

  • 99

    LiuFPengYQiaoYHuangYSongFZhangMet al. Consumption of flavonoids and risk of hormone-related cancers: a systematic review and meta-analysis of observational studies. Nutr J. (2022) 21:27. doi: 10.1186/s12937-022-00778-w

  • 100

    LiNGuoXSunCLoweSSuWSongQet al. Dietary carbohydrate intake is associated with a lower risk of breast cancer: A meta-analysis of cohort studies. Nutr Res. (2022) 100:7092. doi: 10.1016/j.nutres.2022.01.004

  • 101

    KhoramdadMSolaymani-DodaranMKabirAGhahremanzadehNHashemiE-oFahimfarNet al. Breast cancer risk factors in Iranian women: a systematic review and meta-analysis of matched case-control studies. Eur J Med Res. (2022) 27(1):311. doi: 10.1186/s40001-022-00952-0

  • 102

    KacimiSEOElgenidyACheemaHAOuld SettiMKhoslaAABenmeloukaAYet al. Prior tonsillectomy and the risk of breast cancer in females: A systematic review and meta-analysis. Front Oncol. (2022) 12:925596. doi: 10.3389/fonc.2022.925596

  • 103

    IslamMASathiNJAbdullahHMTabassumT. A meta-analysis of induced abortion, alcohol consumption, and smoking triggering breast cancer risk among women from developed and least developed countries. Int J Clin Pract. (2022) 2022:6700688. doi: 10.1155/2022/6700688

  • 104

    HanXZhaoRWangYMaHYuMChenXet al. Dietary vitamin A intake and circulating vitamin A concentrations and the risk of three common cancers in women: A meta-analysis. Oxid Med Cell Longev. (2022) 2022:7686405. doi: 10.1155/2022/7686405

  • 105

    HanMWangYJinYZhaoXCuiHWangGet al. Benign thyroid disease and the risk of breast cancer: An updated systematic review and meta-analysis. Front Endocrinol (Lausanne). (2022) 13:984593. doi: 10.3389/fendo.2022.984593

  • 106

    GaoZXiYShiHNiJXuWZhangK. Antipsychotic exposure is an independent risk factor for breast cancer: A systematic review of epidemiological evidence. Ca-a Cancer J Clinicians. (2022) 12:993367. doi: 10.3389/fonc.2022.993367

  • 107

    BodewesFTHvan AsseltAADorriusMDGreuterMJWde BockGH. Mammographic breast density and the risk of breast cancer: A systematic review and meta-analysis. Breast. (2022) 66:62–8. doi: 10.1016/j.breast.2022.09.007

  • 108

    Gamboa-LoiraBLopez-CarrilloLMar-SanchezYSternDCebrianME. Epidemiologic evidence of exposure to polycyclic aromatic hydrocarbons and breast cancer: A systematic review and meta-analysis. Chemosphere. (2022) 290:133237. doi: 10.1016/j.chemosphere.2021.133237

  • 109

    ByunDHongSRyuSNamYJangHChoYet al. Early-life body mass index and risks of breast, endometrial, and ovarian cancers: a dose-response meta-analysis of prospective studies. Br J Cancer. (2022) 126:664–72. doi: 10.1038/s41416-021-01625-1

  • 110

    AmerizadehAVaseghiGFarajzadeganZAsgaryS. An updated systematic review and meta-analysis on association of serum lipid profile with risk of breast cancer incidence. Int J Prev Med. (2022) 13:142. doi: 10.4103/ijpvm.IJPVM_285_20

  • 111

    ZhangHGuoLTaoWZhangJZhuYAbdelrahimMEAet al. Possible breast cancer risk related to background parenchymal enhancement at breast MRI: A meta-analysis study. Nutr Cancer. (2021) 73:1371–7. doi: 10.1080/01635581.2020.1795211

  • 112

    WongATYHeathAKTongTYNReevesGKFloudSBeralVet al. Sleep duration and breast cancer incidence: results from the Million Women Study and meta-analysis of published prospective studies. Sleep. (2021) 44(2):zsaa166. doi: 10.1093/sleep/zsaa166

  • 113

    WeiWWuBJWuYTongZTZhongFHuCY. Association between long-term ambient air pollution exposure and the risk of breast cancer: a systematic review and meta-analysis. Environ Sci Pollut Res Int. (2021) 28:63278–96. doi: 10.1007/s11356-021-14903-5

  • 114

    WeiLHanNSunSMaXZhangY. Sleep-disordered breathing and risk of the breast cancer: A meta-analysis of cohort studies. Int J Clin Pract. (2021) 75:e14793. doi: 10.1111/ijcp.14793

  • 115

    UrbanoTVincetiMWiseLAFilippiniT. Light at night and risk of breast cancer: a systematic review and dose-response meta-analysis. Int J Health Geogr. (2021) 20:44. doi: 10.1186/s12942-021-00297-7

  • 116

    WongATYFensomGKKeyTJCharlotte Onland-MoretNTongTYNTravisRC. Urinary melatonin in relation to breast cancer risk: Nested case–Control analysis in the DOM study and meta-analysis of prospective studies. Cancer Epidemiol Biomarkers Prevention. (2021) 30:97103. doi: 10.1158/1055-9965.EPI-20-0822

  • 117

    VanNTHHoangTMyungSK. Night shift work and breast cancer risk: a meta-analysis of observational epidemiological studies. Carcinogenesis. (2021) 42:1260–9. doi: 10.1093/carcin/bgab074

  • 118

    NourmohammadiHShoushtariSYJoybariLGhasemiMGhaysouriAKeshavarzK. Human papillomavirus infection and risk of breast cancer in Iran: A meta-analysis. Iranian Red Crescent Med J. (2021) 23(7):e646. doi: 10.32592/ircmj.2021.23.7.646

  • 119

    MichelsNSpechtIOHeitmannBLChajèsVHuybrechtsI. Dietary trans-fatty acid intake in relation to cancer risk: a systematic review and meta-analysis. Nutr Rev. (2021) 79:758–76. doi: 10.1093/nutrit/nuaa061

  • 120

    NaghshiSSadeghianMNasiriMMobarakSAsadiMSadeghiO. Association of total nut, tree nut, peanut, and peanut butter consumption with cancer incidence and mortality: A comprehensive systematic review and dose-response meta-analysis of observational studies. Adv Nutrition. (2021) 12:793808. doi: 10.1093/advances/nmaa152

  • 121

    LiCFanZLinXCaoMSongFSongF. Parity and risk of developing breast cancer according to tumor subtype: A systematic review and meta-analysis. Cancer Epidemiol. (2021) 75:102050. doi: 10.1016/j.canep.2021.102050

  • 122

    LeeJLeeJLeeDWKimHRKangMY. Sedentary work and breast cancer risk: A systematic review and meta-analysis. J Occup Health. (2021) 63:e12239. doi: 10.1002/1348-9585.12239

  • 123

    KeefeD. Fertility treatment and cancers-the eternal conundrum: A systematic review and meta-analysis. Obstetrical Gynecological Survey. (2021) 76:343–4. doi: 10.1097/01.ogx.0000754400.96078.d7

  • 124

    KazemiABarati-BoldajiRSoltaniSMohammadipoorNEsmaeilinezhadZClarkCCTet al. Intake of various food groups and risk of breast cancer: A systematic review and dose-response meta-analysis of prospective studies. Adv Nutr. (2021) 12:809–49. doi: 10.1093/advances/nmaa147

  • 125

    HaoYJiangMMiaoYLiXHouCZhangXet al. Effect of long-term weight gain on the risk of breast cancer across women's whole adulthood as well as hormone-changed menopause stages: A systematic review and dose–response meta-analysis. Obesity Res Clin Practice. (2021) 15:439–48. doi: 10.1016/j.orcp.2021.08.004

  • 126

    FarvidMSSidahmedESpenceNDMante AnguaKRosnerBABarnettJB. Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies. Eur J Epidemiol. (2021) 36:937–51. doi: 10.1007/s10654-021-00741-9

  • 127

    ChongFWangYSongMSunQXieWSongC. Sedentary behavior and risk of breast cancer: a dose–response meta-analysis from prospective studies. Breast Cancer. (2021) 28:4859. doi: 10.1007/s12282-020-01126-8

  • 128

    ChenHGaoYWeiNDuKJiaQ. Strong association between the dietary inflammatory index(DII) and breast cancer: a systematic review and meta-analysis. Aging (Albany NY). (2021) 13:13039–47. doi: 10.18632/aging.202985

  • 129

    BarańskaABłaszczukAKanadysWMalmMDropKPolz-DacewiczM. Oral contraceptive use and breast cancer risk assessment: A systematic review and meta-analysis of case-control studies, 2009–2020. Cancers. (2021) 13(22):5654. doi: 10.3390/cancers13225654

  • 130

    BaDMSsentongoPBeelmanRBMuscatJGaoXRichieJP. Higher mushroom consumption is associated with lower risk of cancer: A systematic review and meta-analysis of observational studies. Adv Nutr. (2021) 12:1691–704. doi: 10.1093/advances/nmab015

  • 131

    ArafatHMOmarJMuhamadRAl-AstaniTADShafiiNAl LahamNAet al. Breast cancer risk from modifiable and non-modifiable risk factors among palestinian women: A systematic review and meta-analysis. Asian Pac J Cancer Prev. (2021) 22:1987–95. doi: 10.31557/apjcp.2021.22.7.1987

  • 132

    ZhouWChenXHuangHLiuSXieALanL. Birth weight and incidence of breast cancer: dose-response meta-analysis of prospective studies. Clin Breast Cancer. (2020) 20:e555–68. doi: 10.1016/j.clbc.2020.04.011

  • 133

    ZhangDXuPLiYWeiBYangSZhengYet al. Association of vitamin C intake with breast cancer risk and mortality: a meta-analysis of observational studies. Aging (Albany NY). (2020) 12:18415–35. doi: 10.18632/aging.103769

  • 134

    ZengJGuYFuHLiuCZouYChangH. Association between one-carbon metabolism-related vitamins and risk of breast cancer: A systematic review and meta-analysis of prospective studies. Clin Breast Cancer. (2020) 20:e469–80. doi: 10.1016/j.clbc.2020.02.012

  • 135

    WuYWangMSunWLiSWangWZhangD. Age at last birth and risk of developing breast cancer: a meta-analysis. Eur J Cancer Prev. (2020) 29:424–32. doi: 10.1097/cej.0000000000000560

  • 136

    WeiYLvJGuoYBianZGaoMDuHet al. Soy intake and breast cancer risk: a prospective study of 300,000 Chinese women and a dose-response meta-analysis. Eur J Epidemiol. (2020) 35:567–78. doi: 10.1007/s10654-019-00585-4

  • 137

    WangYZhaoYChongFSongMSunQLiTet al. A dose-response meta-analysis of green tea consumption and breast cancer risk. Int J Food Sci Nutr. (2020) 71:656–67. doi: 10.1080/09637486.2020.1715353

  • 138

    WangYYanPFuTYuanJYangGLiuYet al. The association between gestational diabetes mellitus and cancer in women: A systematic review and meta-analysis of observational studies. Diabetes Metab. (2020) 46:461–71. doi: 10.1016/j.diabet.2020.02.003

  • 139

    WangQLiuXRenS. Tofu intake is inversely associated with risk of breast cancer: A meta-analysis of observational studies. PloS One. (2020) 15:e0226745. doi: 10.1371/journal.pone.0226745

  • 140

    SongHJJeonNSquiresP. The association between acid-suppressive agent use and the risk of cancer: a systematic review and meta-analysis. Eur J Clin Pharmacol. (2020) 76:1437–56. doi: 10.1007/s00228-020-02927-8

  • 141

    SiminJTamimiRMEngstrandLCallensSBrusselaersN. Antibiotic use and the risk of breast cancer: A systematic review and dose-response meta-analysis. Pharmacol Res. (2020) 160:105072. doi: 10.1016/j.phrs.2020.105072

  • 142

    RenXXuPZhangDLiuKSongDZhengYet al. Association of folate intake and plasma folate level with the risk of breast cancer: a dose-response meta-analysis of observational studies. Aging (Albany NY). (2020) 12:21355–75. doi: 10.18632/aging.103881

  • 143

    RamalhoNMCarneiroVCG. Education level and breast cancer incidence: a meta-analysis of cohort studies. Menopause-the J North Am Menopause Society. (2020) 27:119–9. doi: 10.1097/GME.0000000000001464

  • 144

    PengRLiangXZhangGYaoYChenZPanXet al. Association use of bisphosphonates with risk of breast cancer: A meta-analysis. BioMed Res Int. (2020) 2020:5606573. doi: 10.1155/2020/5606573

  • 145

    OkekunleAPGaoJWuXFengRSunC. Higher dietary soy intake appears inversely related to breast cancer risk independent of estrogen receptor breast cancer phenotypes. Heliyon. (2020) 6:e04228. doi: 10.1016/j.heliyon.2020.e04228

  • 146

    LiMHanMChenZTangYMaJZhangZet al. Does marital status correlate with the female breast cancer risk? A systematic review and meta-analysis of observational studies. PloS One. (2020) 15:e0229899. doi: 10.1371/journal.pone.0229899

  • 147

    KimYKimJ. N-6 polyunsaturated fatty acids and risk of cancer: accumulating evidence from prospective studies. Nutrients. (2020) 12(9):2523. doi: 10.3390/nu12092523

  • 148

    KhatamiAPormohammadAFarziRSaadatiHMehrabiMKianiSJet al. Bovine Leukemia virus (BLV) and risk of breast cancer: a systematic review and meta-analysis of case-control studies. Infect Agent Cancer. (2020) 15:48. doi: 10.1186/s13027-020-00314-7

  • 149

    JinQSuJYanDWuS. Epstein-barr virus infection and increased sporadic breast carcinoma risk: A meta-analysis. Med Princ Pract. (2020) 29:195200. doi: 10.1159/000502131

  • 150

    HillerTWRO'SullivanDEBrennerDRPetersCEKingWD. Solar ultraviolet radiation and breast cancer risk: A systematic review and meta-analysis. Environ Health Perspect. (2020) 128:16002. doi: 10.1289/ehp4861

  • 151

    HidayatKZhouHJShiBM. Influence of physical activity at a young age and lifetime physical activity on the risks of 3 obesity-related cancers: systematic review and meta-analysis of observational studies. Nutr Rev. (2020) 78:118. doi: 10.1093/nutrit/nuz024

  • 152

    AdaniGFilippiniTWiseLAHalldorssonTIBlahaLVincetiM. Dietary intake of acrylamide and risk of breast, endometrial, and ovarian cancers: A systematic review and dose-response meta-analysis. Cancer Epidemiol Biomarkers Prev. (2020) 29:1095–106. doi: 10.1158/1055-9965.Epi-19-1628

  • 153

    ZhaoTTJinFLiJGXuYYDongHTLiuQet al. Dietary isoflavones or isoflavone-rich food intake and breast cancer risk: A meta-analysis of prospective cohort studies. Clin Nutr. (2019) 38:136–45. doi: 10.1016/j.clnu.2017.12.006

  • 154

    ZhangLHuangSCaoLGeMLiYShaoJ. Vegetable-fruit-soybean dietary pattern and breast cancer: A meta-analysis of observational studies. J Nutr Sci Vitaminol (Tokyo). (2019) 65:375–82. doi: 10.3177/jnsv.65.375

  • 155

    YuSZhuLWangKYanYHeJRenY. Green tea consumption and risk of breast cancer: A systematic review and updated meta-analysis of case-control studies. Med (Baltimore). (2019) 98:e16147. doi: 10.1097/md.0000000000016147

  • 156

    XipingZShuaiZFeijiangYBoCShifengYQihuiC. Meta-analysis of the correlation between schizophrenia and breast cancer. Clin Breast Cancer. (2019) 19:e172–85. doi: 10.1016/j.clbc.2018.10.012

  • 157

    VishwakarmaGNdetanHDasDNGuptaGSuryavanshiMMehtaAet al. Reproductive factors and breast cancer risk: A meta-analysis of case-control studies in Indian women. South Asian J Cancer. (2019) 8:80–4. doi: 10.4103/sajc.sajc_317_18

  • 158

    YoonYSKwonARLeeYKOhSW. Circulating adipokines and risk of obesity related cancers: A systematic review and meta-analysis. Obes Res Clin Pract. (2019) 13:329–39. doi: 10.1016/j.orcp.2019.03.006

  • 159

    SongDDengYLiuKZhouLLiNZhengYet al. Vitamin D intake, blood vitamin D levels, and the risk of breast cancer: a dose-response meta-analysis of observational studies. Aging (Albany NY). (2019) 11:12708–32. doi: 10.18632/aging.102597

  • 160

    SeretisACividiniSMarkozannesGTseretopoulouXLopezDSNtzaniEEet al. Association between blood pressure and risk of cancer development: a systematic review and meta-analysis of observational studies. Sci Rep. (2019) 9:8565. doi: 10.1038/s41598-019-45014-4

  • 161

    RenCZengKWuCMuLHuangJWangM. Human papillomavirus infection increases the risk of breast carcinoma: a large-scale systemic review and meta-analysis of case-control studies. Gland Surg. (2019) 8:486500. doi: 10.21037/gs.2019.09.04

  • 162

    NindreaRDAryandonoTLazuardiLDwiprahastoI. Association of dietary intake ratio of n-3/n-6 polyunsaturated fatty acids with breast cancer risk in western and asian countries: A meta-analysis. Asian Pac J Cancer Prev. (2019) 20:1321–7. doi: 10.31557/apjcp.2019.20.5.1321

  • 163

    NindreaRDAryandonoTLazuardiLDwiprahastoI. Association of overweight and obesity with breast cancer during premenopausal period in asia: A meta-analysis. Int J Prev Med. (2019) 10:192. doi: 10.4103/ijpvm.IJPVM_372_18

  • 164

    NindreaRDAnwarSLHarahapWALazuardiLDwiprahastoIAryandonoT. Oral contraceptive used more than 5 years is associated with increased risk of breast cancer: A meta-analysis of 28,776 South east Asian women. Systematic Rev Pharmacy. (2019) 10:137–48. doi: 10.5530/srp.2019.2.22

  • 165

    MaoJShiJHeSLiNShiJYangF. Reproductive factors and risk of breast cancer: a pooled meta-analysis of 55 case-control studies based on different source populations. Int J Clin Exp Med. (2019) 12:6453–68.

  • 166

    NamaziNIrandoostPHeshmatiJLarijaniBAzadbakhtL. The association between fat mass and the risk of breast cancer: A systematic review and meta-analysis. Clin Nutr. (2019) 38:1496–503. doi: 10.1016/j.clnu.2018.09.013

  • 167

    JiLWJingCXZhuangSLPanWCHuXP. Effect of age at first use of oral contraceptives on breast cancer risk: An updated meta-analysis. Med (Baltimore). (2019) 98:e15719. doi: 10.1097/md.0000000000015719

  • 168

    HossainSBeydounMABeydounHAChenXZondermanABWoodRJ. Vitamin D and breast cancer: A systematic review and meta-analysis of observational studies. Clin Nutr ESPEN. (2019) 30:170–84. doi: 10.1016/j.clnesp.2018.12.085

  • 169

    GuoMLiuTLiPWangTZengCYangMet al. Association between metabolic syndrome and breast cancer risk: an updated meta-analysis of follow-up studies. Front Oncol. (2019) 9:1290. doi: 10.3389/fonc.2019.01290

  • 170

    ChenXWangQZhangYXieQTanX. Physical activity and risk of breast cancer: A meta-analysis of 38 cohort studies in 45 study reports. Value Health. (2019) 22:104–28. doi: 10.1016/j.jval.2018.06.020

  • 171

    ChenJHYuanQMaYNZhenSHWenDL. Relationship between bone mineral density and the risk of breast cancer: A systematic review and dose–response meta-analysis of ten cohort studies. Cancer Manage Res. (2019) 11:1453–64. doi: 10.2147/CMAR.S188251

  • 172

    ChangVCCotterchioMKhooE. Iron intake, body iron status, and risk of breast cancer: a systematic review and meta-analysis. BMC Cancer. (2019) 19:543. doi: 10.1186/s12885-019-5642-0

  • 173

    ChanDSMAbarLCariolouMNanuNGreenwoodDCBanderaEVet al. World Cancer Research Fund International: Continuous Update Project—systematic literature review and meta-analysis of observational cohort studies on physical activity, sedentary behavior, adiposity, and weight change and breast cancer risk. Cancer Causes Control. (2019) 30:1183–200. doi: 10.1007/s10552-019-01223-w

  • 174

    ThakurAAWangXGarcia-BetancourtMMForseRA. Calcium channel blockers and the incidence of breast and prostate cancer: A meta-analysis. J Clin Pharm Ther. (2018) 43:519–29. doi: 10.1111/jcpt.12673

  • 175

    TangGHSatkunamMPondGRSteinbergGRBlandinoGSchünemannHJet al. Association of metformin with breast cancer incidence and mortality in patients with type II diabetes: A GRADE-assessed systematic review and meta-analysis. Cancer Epidemiol Biomarkers Prev. (2018) 27:627–35. doi: 10.1158/1055-9965.Epi-17-0936

  • 176

    SunMFanYHouYFanY. Preeclampsia and maternal risk of breast cancer: a meta-analysis of cohort studies. J Matern Fetal Neonatal Med. (2018) 31:2484–91. doi: 10.1080/14767058.2017.1342806

  • 177

    ShaoJWuLLengWDFangCZhuYJJinYHet al. Periodontal disease and breast cancer: A meta-analysis of 1,73,162 participants. Front Oncol. (2018) 8:601. doi: 10.3389/fonc.2018.00601

  • 178

    RezaianzadehAGhorbaniMRezaeianSKassaniA. Red meat consumption and breast cancer risk in premenopausal women: A systematic review and meta-analysis. Middle East J Cancer. (2018) 9:512.

  • 179

    QiaoYYangTGanYLiWWangCGongYet al. Associations between aspirin use and the risk of cancers: a meta-analysis of observational studies. BMC Cancer. (2018) 18:288. doi: 10.1186/s12885-018-4156-5

  • 180

    LiuKZhangWDaiZWangMTianTLiuXet al. Association between body mass index and breast cancer risk: Evidence based on a dose–response meta-analysis. Cancer Manage Res. (2018) 10:143–51. doi: 10.2147/CMAR.S144619

  • 181

    LiDHaoXLiJWuZChenSLinJet al. Dose-response relation between dietary inflammatory index and human cancer risk: evidence from 44 epidemiologic studies involving 1,082,092 participants. Am J Clin Nutrition. (2018) 107:371–88. doi: 10.1093/ajcn/nqx064

  • 182

    LafranconiAMicekAPaoliPDBimonteSRossiPQuagliarielloVet al. Coffee intake decreases risk of postmenopausal breast cancer: A dose-response meta-analysis on prospective cohort studies. Nutrients. (2018) 10(2):112. doi: 10.3390/nu10020112

  • 183

    KimASKoHJKwonJHLeeJM. Exposure to secondhand smoke and risk of cancer in never smokers: A meta-analysis of epidemiologic studies. Int J Environ Res Public Health. (2018) 15(9):1981. doi: 10.3390/ijerph15091981

  • 184

    HidayatKYangCMShiBM. Body fatness at a young age, body fatness gain and risk of breast cancer: systematic review and meta-analysis of cohort studies. Obes Rev. (2018) 19:254–68. doi: 10.1111/obr.12627

  • 185

    DuRLinLChengDXuYXuMChenYet al. Thiazolidinedione therapy and breast cancer risk in diabetic women: A systematic review and meta-analysis. Diabetes Metab Res Rev. (2018) 34(2). doi: 10.1002/dmrr.2961

  • 186

    DengYXuHZengX. Induced abortion and breast cancer: An updated meta-analysis. Med (Baltimore). (2018) 97:e9613. doi: 10.1097/md.0000000000009613

  • 187

    Cordina-DuvergerEMenegauxFPopaARabsteinSHarthVPeschBet al. Night shift work and breast cancer: a pooled analysis of population-based case-control studies with complete work history. Eur J Epidemiol. (2018) 33:369–79. doi: 10.1007/s10654-018-0368-x

  • 188

    ChenHShaoFZhangFMiaoQ. Association between dietary carrot intake and breast cancer: A meta-analysis. Med (Baltimore). (2018) 97:e12164. doi: 10.1097/md.0000000000012164

  • 189

    XuJHuangLSunGP. Urinary 6-sulfatoxymelatonin level and breast cancer risk: systematic review and meta-analysis. Sci Rep. (2017) 7:5353. doi: 10.1038/s41598-017-05752-9

  • 190

    SchlesingerSChanDSMVingelieneSVieiraARAbarLPolemitiEet al. Carbohydrates, glycemic index, glycemic load, and breast cancer risk: a systematic review and dose-response meta-analysis of prospective studies. Nutr Rev. (2017) 75:420–41. doi: 10.1093/nutrit/nux010

  • 191

    NindreaRDAryandonoTLazuardiL. Breast cancer risk from modifiable and non-modifiable risk factors among women in southeast asia: A meta-analysis. Asian Pac J Cancer Prev. (2017) 18:3201–6. doi: 10.22034/apjcp.2017.18.12.3201

  • 192

    NiHRuiQZhuXYuZGaoRLiuH. Antihypertensive drug use and breast cancer risk: a meta-analysis of observational studies. Oncotarget. (2017) 8:62545–60. doi: 10.18632/oncotarget.19117

  • 193

    NagelGPeterRSKlotzEBrozekWConcinH. Bone mineral density and breast cancer risk: Results from the Vorarlberg Health Monitoring & Prevention Program and meta-analysis. Bone Rep. (2017) 7:83–9. doi: 10.1016/j.bonr.2017.09.004

  • 194

    Kolahdouz MohammadiRBagheriMKolahdouz MohammadiMShidfarF. Ruminant trans-fatty acids and risk of breast cancer: a systematic review and meta-analysis of observational studies. Minerva Endocrinol. (2017) 42:385–96. doi: 10.23736/s0391-1977.16.02514-1

  • 195

    KarasnehRAMurrayLJCardwellCR. Cardiac glycosides and breast cancer risk: A systematic review and meta-analysis of observational studies. Int J Cancer. (2017) 140:1035–41. doi: 10.1002/ijc.30520

  • 196

    JiaYLiFLiuYFZhaoJPLengMMChenL. Depression and cancer risk: a systematic review and meta-analysis. Public Health. (2017) 149:138–48. doi: 10.1016/j.puhe.2017.04.026

  • 197

    ChenYLiuLZhouQImamMUCaiJWangYet al. Body mass index had different effects on premenopausal and postmenopausal breast cancer risks: a dose-response meta-analysis with 3,318,796 subjects from 31 cohort studies. BMC Public Health. (2017) 17:936. doi: 10.1186/s12889-017-4953-9

  • 198

    Neil-SztramkoSEBoyleTMilosevicENugentSFGotayCCCampbellKL. Does obesity modify the relationship between physical activity and breast cancer risk? Breast Cancer Res Treat. (2017) 166:367–81. doi: 10.1007/s10549-017-4449-4

  • 199

    ZhouYWangTZhaiSLiWMengQ. Linoleic acid and breast cancer risk: a meta-analysis. Public Health Nutr. (2016) 19:1457–63. doi: 10.1017/s136898001500289x

  • 200

    WangMWuXChaiFZhangYJiangJ. Plasma prolactin and breast cancer risk: a meta- analysis. Sci Rep. (2016) 6:25998. doi: 10.1038/srep25998

  • 201

    SunSLiXRenADuMDuHShuYet al. Choline and betaine consumption lowers cancer risk: a meta-analysis of epidemiologic studies. Sci Rep. (2016) 6:35547. doi: 10.1038/srep35547

  • 202

    NeilsonHKFarrisMSStoneCRVaskaMMBrennerDRFriedenreichCM. Moderate-vigorous recreational physical activity and breast cancer risk, stratified by menopause status: A systematic review and meta-analysis. Menopause. (2016) 24:322–44. doi: 10.1097/GME.0000000000000745

  • 203

    MulliePKoechlinABoniolMAutierPBoyleP. Relation between breast cancer and high glycemic index or glycemic load: A meta-analysis of prospective cohort studies. Crit Rev Food Sci Nutr. (2016) 56:152–9. doi: 10.1080/10408398.2012.718723

  • 204

    LiCYangLZhangDJiangW. Systematic review and meta-analysis suggest that dietary cholesterol intake increases risk of breast cancer. Nutr Res. (2016) 36:627–35. doi: 10.1016/j.nutres.2016.04.009

  • 205

    LeiLYangYHeHChenEDuLDongJet al. Flavan-3-ols consumption and cancer risk: A meta-analysis of epidemiologic studies. Oncotarget. (2016) 7:73573–92. doi: 10.18632/oncotarget.12017

  • 206

    GongW-JZhengWXiaoLTanL-MSongJLiX-Pet al. Circulating resistin levels and obesity-related cancer risk: a meta-analysis. Oncotarget. (2016) 7:57694–704. doi: 10.18632/oncotarget.11034

  • 207

    FabianiRMinelliLRosignoliP. Apple intake and cancer risk: a systematic review and meta-analysis of observational studies. Public Health Nutr. (2016) 19:2603–17. doi: 10.1017/s136898001600032x

  • 208

    ChenJ-YZhuH-CGuoQShuZBaoX-HSunFet al. Dose-dependent associations between wine drinking and breast cancer risk - meta-analysis findings. Asian Pacific J Cancer prevention: APJCP. (2016) 17:1221–33. doi: 10.7314/APJCP.2016.17.3.1221

  • 209

    CaoYHouLWangW. Dietary total fat and fatty acids intake, serum fatty acids and risk of breast cancer: A meta-analysis of prospective cohort studies. Int J Cancer. (2016) 138:1894–904. doi: 10.1002/ijc.29938

  • 210

    CaiXWangCYuWFanWWangSShenNet al. Selenium exposure and cancer risk: an updated meta-analysis and meta-regression. Sci Rep. (2016) 6:19213. doi: 10.1038/srep19213

  • 211

    BaeJMKimEH. Human papillomavirus infection and risk of breast cancer: a meta-analysis of case-control studies. Infect Agent Cancer. (2016) 11:14. doi: 10.1186/s13027-016-0058-9

  • 212

    ZhangJHuangYWangXLinKWuK. Environmental polychlorinated biphenyl exposure and breast cancer risk: A meta-analysis of observational studies. PloS One. (2015) 10:e0142513. doi: 10.1371/journal.pone.0142513

  • 213

    XinYLiXYSunSRWangLXHuangT. Vegetable oil intake and breast cancer risk: a meta-analysis. Asian Pac J Cancer Prev. (2015) 16:5125–35. doi: 10.7314/apjcp.2015.16.12.5125

  • 214

    WuYCZhengDSunJJZouZKMaZL. Meta-analysis of studies on breast cancer risk and diet in Chinese women. Int J Clin Exp Med. (2015) 8:7385.

  • 215

    WangT. The link between Parkinson's disease and breast and prostate cancers: A meta-analysis. Int J Neurosci. (2015) 125:895903. doi: 10.3109/00207454.2014.986265

  • 216

    TouvierMFassierPHisMNoratTChanDSBlacherJet al. Cholesterol and breast cancer risk: a systematic review and meta-analysis of prospective studies. Br J Nutr. (2015) 114:347–57. doi: 10.1017/s000711451500183x

  • 217

    ShiYLiTWangYZhouLQinQYinJet al. Household physical activity and cancer risk: a systematic review and dose-response meta-analysis of epidemiological studies. Sci Rep. (2015) 5:14901. doi: 10.1038/srep14901

  • 218

    LarssonSCOrsiniNWolkA. Urinary cadmium concentration and risk of breast cancer: a systematic review and dose-response meta-analysis. Am J Epidemiol. (2015) 182:375–80. doi: 10.1093/aje/kwv085

  • 219

    HuFWuZLiGTengCLiuYWangFet al. The plasma level of retinol, vitamins A, C and α-tocopherol could reduce breast cancer risk? A meta-analysis and meta-regression. J Cancer Res Clin Oncol. (2015) 141:601–14. doi: 10.1007/s00432-014-1852-7

  • 220

    HeXYLiaoYDYuSZhangYWangR. Sex hormone binding globulin and risk of breast cancer in postmenopausal women: a meta-analysis of prospective studies. Horm Metab Res. (2015) 47:485–90. doi: 10.1055/s-0034-1395606

  • 221

    GuoJHuangYYangLXieZSongSYinJet al. Association between abortion and breast cancer: an updated systematic review and meta-analysis based on prospective studies. Cancer Causes Control. (2015) 26:811–9. doi: 10.1007/s10552-015-0536-1

  • 222

    de PedroMBaezaSEscuderoMTDierssen-SotosTGómez-AceboIPollánMet al. Effect of COX-2 inhibitors and other non-steroidal inflammatory drugs on breast cancer risk: a meta-analysis. Breast Cancer Res Treat. (2015) 149:525–36. doi: 10.1007/s10549-015-3267-9

  • 223

    ChenZShaoJGaoXLiX. Effect of passive smoking on female breast cancer in China: a meta-analysis. Asia Pac J Public Health. (2015) 27:Np58–64. doi: 10.1177/1010539513481493

  • 224

    BaeJMKimEH. Hormone replacement therapy and risk of breast cancer in korean women: A quantitative systematic review. J Prev Med Public Health. (2015) 48:225–30. doi: 10.3961/jpmph.15.046

  • 225

    ZhaoGLinXZhouMZhaoJ. Relationship between exposure to extremely low-frequency electromagnetic fields and breast cancer risk: a meta-analysis. Eur J Gynaecol Oncol. (2014) 35:264–9.

  • 226

    YuFJinZJiangHXiangCTangJLiTet al. Tea consumption and the risk of five major cancers: a dose-response meta-analysis of prospective studies. BMC Cancer. (2014) 14:197. doi: 10.1186/1471-2407-14-197

  • 227

    YangW-SDengQFanW-YWangW-YWangX. Light exposure at night, sleep duration, melatonin, and breast cancer: a dose-response analysis of observational studies. Eur J Cancer Prevention. (2014) 23:269–76. doi: 10.1097/cej.0000000000000030

  • 228

    SergentanisTNDiamantarasAAPerlepeCKanavidisPSkalkidouAPetridouET. IVF and breast cancer: a systematic review and meta-analysis. Hum Reprod Update. (2014) 20:106–23. doi: 10.1093/humupd/dmt034

  • 229

    ParkJHChaESKoYHwangMSHongJHLeeWJ. Exposure to dichlorodiphenyltrichloroethane and the risk of breast cancer: A systematic review and meta-analysis. Osong Public Health Res Perspect. (2014) 5:7784. doi: 10.1016/j.phrp.2014.02.001

  • 230

    NieXCDongDSBaiYXiaP. Meta-analysis of black tea consumption and breast cancer risk: update 2013. Nutr Cancer. (2014) 66:1009–14. doi: 10.1080/01635581.2014.936947

  • 231

    LvMZhuXZhongSChenWHuQMaTet al. Radial scars and subsequent breast cancer risk: a meta-analysis. PloS One. (2014) 9:e102503. doi: 10.1371/journal.pone.0102503

  • 232

    LiuXOHuangYBGaoYChenCYanYDaiHJet al. Association between dietary factors and breast cancer risk among Chinese females: systematic review and meta-analysis. Asian Pac J Cancer Prev. (2014) 15:1291–8. doi: 10.7314/apjcp.2014.15.3.1291

  • 233

    ChenCHuangYBLiuXOGaoYDaiHJSongFJet al. Active and passive smoking with breast cancer risk for Chinese females: a systematic review and meta-analysis. Chin J Cancer. (2014) 33:306–16. doi: 10.5732/cjc.013.10248

  • 234

    ZhengJSHuXJZhaoYMYangJLiD. Intake of fish and marine n-3 polyunsaturated fatty acids and risk of breast cancer: meta-analysis of data from 21 independent prospective cohort studies. Bmj. (2013) 346:f3706. doi: 10.1136/bmj.f3706

  • 235

    YangYZhangFSkripLWangYLiuS. Lack of an association between passive smoking and incidence of female breast cancer in non-smokers: evidence from 10 prospective cohort studies. PloS One. (2013) 8:e77029. doi: 10.1371/journal.pone.0077029

  • 236

    WarrenGWGritzER. Active smoking and breast cancer risk: Original cohort data and meta-analysis: Gaudet MM, Gapstur SM, Sun J, et al. (American Cancer Society, Atlanta, GA) J Natl Cancer Inst 105:515-525, 2013. Breast Diseases. (2013) 24:319–20. doi: 10.1016/j.breastdis.2013.10.029

  • 237

    WuWKangSZhangD. Association of vitamin B6, vitamin B12 and methionine with risk of breast cancer: a dose-response meta-analysis. Br J Cancer. (2013) 109:1926–44. doi: 10.1038/bjc.2013.438

  • 238

    SongJKBaeJM. Citrus fruit intake and breast cancer risk: a quantitative systematic review. J Breast Cancer. (2013) 16:72–6. doi: 10.4048/jbc.2013.16.1.72

  • 239

    QuXZhangXQinALiuGZhaiZHaoYet al. Bone mineral density and risk of breast cancer in postmenopausal women. Breast Cancer Res Treat. (2013) 138:261–71. doi: 10.1007/s10549-013-2431-3

  • 240

    LiuXLvK. Cruciferous vegetables intake is inversely associated with risk of breast cancer: a meta-analysis. Breast. (2013) 22:309–13. doi: 10.1016/j.breast.2012.07.013

  • 241

    LinYWangCZhongYHuangXPengLShanGet al. Striking life events associated with primary breast cancer susceptibility in women: a meta-analysis study. J Exp Clin Cancer Res. (2013) 32:53. doi: 10.1186/1756-9966-32-53

  • 242

    KimJSKangEJWooOHParkKHWooSUYangDSet al. The relationship between preeclampsia, pregnancy-induced hypertension and maternal risk of breast cancer: a meta-analysis. Acta Oncol. (2013) 52:1643–8. doi: 10.3109/0284186x.2012.750033

  • 243

    KamdarBBTergasAIMateenFJBhayaniNHOhJ. Night-shift work and risk of breast cancer: a systematic review and meta-analysis. Breast Cancer Res Treat. (2013) 138:291301. doi: 10.1007/s10549-013-2433-1

  • 244

    HeikkiläKNybergSTTheorellTFranssonEIAlfredssonLBjornerJBet al. Work stress and risk of cancer: meta-analysis of 5700 incident cancer events in 116,000 European men and women. Bmj. (2013) 346:f165. doi: 10.1136/bmj.f165

  • 245

    HuiCQiXQianyongZXiaoliPJundongZMantianM. Flavonoids, flavonoid subclasses and breast cancer risk: a meta-analysis of epidemiologic studies. PloS One. (2013) 8:e54318. doi: 10.1371/journal.pone.0054318

  • 246

    GaoYHuangYBLiuXOChenCDaiHJSongFJet al. Tea consumption, alcohol drinking and physical activity associations with breast cancer risk among Chinese females: a systematic review and meta-analysis. Asian Pac J Cancer Prev. (2013) 14:7543–50. doi: 10.7314/apjcp.2013.14.12.7543

  • 247

    BonifaziMTramacereIPomponioGGabrielliBAvvedimentoEVLa VecchiaCet al. Systemic sclerosis (scleroderma) and cancer risk: systematic review and meta-analysis of observational studies. Rheumatol (Oxford). (2013) 52:143–54. doi: 10.1093/rheumatology/kes303

  • 248

    AmadouAFerrariPMuwongeRMoskalABiessyCRomieuIet al. Overweight, obesity and risk of premenopausal breast cancer according to ethnicity: a systematic review and dose-response meta-analysis. Obes Rev. (2013) 14:665–78. doi: 10.1111/obr.12028

  • 249

    UndelaKSrikanthVBansalD. Statin use and risk of breast cancer: a meta-analysis of observational studies. Breast Cancer Res Treat. (2012) 135:261–9. doi: 10.1007/s10549-012-2154-x

  • 250

    NiXJXiaTSZhaoYCMaJJZhaoJLiuXAet al. Postmenopausal hormone therapy is associated with in situ breast cancer risk. Asian Pac J Cancer Prev. (2012) 13:3917–25. doi: 10.7314/apjcp.2012.13.8.3917

  • 251

    HuFWang YiBZhangWLiangJLinCLiDet al. Carotenoids and breast cancer risk: a meta-analysis and meta-regression. Breast Cancer Res Treat. (2012) 131:239–53. doi: 10.1007/s10549-011-1723-8

  • 252

    DuXZhangRXueYLiDCaiJZhouSet al. Insulin glargine and risk of cancer: a meta-analysis. Int J Biol Markers. (2012) 27:e241–6. doi: 10.5301/jbm.2012.9349

  • 253

    AuneDChanDSVieiraARRosenblattDAVieiraRGreenwoodDCet al. Fruits, vegetables and breast cancer risk: a systematic review and meta-analysis of prospective studies. Breast Cancer Res Treat. (2012) 134:479–93. doi: 10.1007/s10549-012-2118-1

  • 254

    AuneDChanDSVieiraARNavarro RosenblattDAVieiraRGreenwoodDCet al. Dietary compared with blood concentrations of carotenoids and breast cancer risk: a systematic review and meta-analysis of prospective studies. Am J Clin Nutr. (2012) 96:356–73. doi: 10.3945/ajcn.112.034165

  • 255

    AngelousiAGAnagnostouVKStamatakosMKGeorgiopoulosGAKontzoglouKC. Primary HT and risk for breast cancer: a systematic review and meta-analysis. Eur J Endocrinol. (2012) 166:373–81. doi: 10.1530/eje-11-0838

  • 256

    WalkerKBrattonDJFrostC. Premenopausal endogenous oestrogen levels and breast cancer risk: a meta-analysis. Br J Cancer. (2011) 105:1451–7. doi: 10.1038/bjc.2011.358

  • 257

    DongJYZhangLHeKQinLQ. Dairy consumption and risk of breast cancer: a meta-analysis of prospective cohort studies. Breast Cancer Res Treat. (2011) 127:2331. doi: 10.1007/s10549-011-1467-5

  • 258

    ChanALLeungHWWangSF. Multivitamin supplement use and risk of breast cancer: a meta-analysis. Ann Pharmacother. (2011) 45:476–84. doi: 10.1345/aph.1P445

  • 259

    KeyTJApplebyPNReevesGKRoddamAW. Insulin-like growth factor 1 (IGF1), IGF binding protein 3 (IGFBP3), and breast cancer risk: pooled individual data analysis of 17 prospective studies. Lancet Oncol. (2010) 11:530–42. doi: 10.1016/s1470-2045(10)70095-4

  • 260

    BuckKZaineddinAKVrielingALinseisenJChang-ClaudeJ. Meta-analyses of lignans and enterolignans in relation to breast cancer risk. Am J Clin Nutr. (2010) 92:141–53. doi: 10.3945/ajcn.2009.28573

  • 261

    XuXDaileyABPeoples-ShepsMTalbottEOLiNRothJ. Birth weight as a risk factor for breast cancer: a meta-analysis of 18 epidemiological studies. J Womens Health (Larchmt). (2009) 18:1169–78. doi: 10.1089/jwh.2008.1034

  • 262

    VojtechovaPMartinRM. The association of atopic diseases with breast, prostate, and colorectal cancers: a meta-analysis. Cancer Causes Control. (2009) 20:1091–105. doi: 10.1007/s10552-009-9334-y

  • 263

    SadriGMahjubH. Passive or active smoking, which is more relevant to breast cancer. Saudi Med J. (2007) 28:254–8.

  • 264

    XueFMichelsKB. Intrauterine factors and risk of breast cancer: a systematic review and meta-analysis of current evidence. Lancet Oncol. (2007) 8:1088–100. doi: 10.1016/s1470-2045(07)70377-7

  • 265

    TakkoucheBEtminanMMontes-MartínezA. Personal use of hair dyes and risk of cancer: a meta-analysis. Jama. (2005) 293:2516–25. doi: 10.1001/jama.293.20.2516

  • 266

    RenehanAGZwahlenMMinderCO'DwyerSTShaletSMEggerM. Insulin-like growth factor (IGF)-I, IGF binding protein-3, and cancer risk: systematic review and meta-regression analysis. Lancet. (2004) 363:1346–53. doi: 10.1016/s0140-6736(04)16044-3

  • 267

    BoydNFStoneJVogtKNConnellyBSMartinLJMinkinS. Dietary fat and breast cancer risk revisited: a meta-analysis of the published literature. Br J Cancer. (2003) 89:1672–85. doi: 10.1038/sj.bjc.6601314

  • 268

    KhuderSASimonVJJr.Is there an association between passive smoking and breast cancer? Eur J Epidemiol. (2000) 16:1117–21. doi: 10.1023/a:1010967513957

  • 269

    BrennanSFCantwellMMCardwellCRVelentzisLSWoodsideJV. Dietary patterns and breast cancer risk: a systematic review and meta-analysis. Am J Clin Nutr. (2010) 91:1294–302. doi: 10.3945/ajcn.2009.28796

  • 270

    HarrisHRTamimiRMWillettWCHankinsonSEMichelsKB. Body size across the life course, mammographic density, and risk of breast cancer. Am J Epidemiol. (2011) 174:909–18. doi: 10.1093/aje/kwr225

  • 271

    DanforthDN. The role of chronic inflammation in the development of breast cancer. Cancers (Basel). (2021) 13(15):3918. doi: 10.3390/cancers13153918

  • 272

    TanRCongTXuGHaoZLiaoJXieYet al. Anthracycline-induced atrial structural and electrical remodeling characterizes early cardiotoxicity and contributes to atrial conductive instability and dysfunction. Antioxid Redox Signal. (2022) 37:1939. doi: 10.1089/ars.2021.0002

  • 273

    BiggarRJWohlfahrtJOudinAHjulerTMelbyeM. Digoxin use and the risk of breast cancer in women. J Clin Oncol. (2011) 29:2165–70. doi: 10.1200/JCO.2010.32.8146

  • 274

    Wassertheil-SmollerSMcGinnAPMartinLRodriguezBLStefanickMLPerezM. The associations of atrial fibrillation with the risks of incident invasive breast and colorectal cancer. Am J Epidemiol. (2017) 185:372–84. doi: 10.1093/aje/kww185

  • 275

    VachonCMSasanoHGhoshKBrandtKRWatsonDAReynoldsCet al. Aromatase immunoreactivity is increased in mammographically dense regions of the breast. Breast Cancer Res Treat. (2011) 125:243–52. doi: 10.1007/s10549-010-0944-6

  • 276

    Garcia-EstevezLCortesJPerezSCalvoIGallegosIMoreno-BuenoG. Obesity and breast cancer: A paradoxical and controversial relationship influenced by menopausal status. Front Oncol. (2021) 11:705911. doi: 10.3389/fonc.2021.705911

  • 277

    RyanASBermanDMNicklasBJ. Plasma adiponectin and leptin levels, body composition, and glucose utilization in adult women with wide ranges of age and obesity. Diabetes Care. (2003) 26:2383–8. doi: 10.2337/diacare.26.8.2383

  • 278

    KimKYBaekAHwangJEChoiYAJeongJLeeMSet al. Adiponectin-activated AMPK stimulates dephosphorylation of AKT through protein phosphatase 2A activation. Cancer Res. (2009) 69:4018–26. doi: 10.1158/0008-5472.CAN-08-2641

  • 279

    ZhongWWangXWangYSunGZhangJLiZ. Obesity and endocrine-related cancer: The important role of IGF-1. Front Endocrinol (Lausanne). (2023) 14:1093257. doi: 10.3389/fendo.2023.1093257

  • 280

    Wright.CMMoorin.REChowdhury.EKStricker.BHReid.CMSaunders.CMet al. Calcium channel blockers and breast cancer incidence: An updated systematic review and meta-analysis of the evidence. Cancer Epidemiol. (2017) 50:Pt A. doi: 10.1016/j.canep.2017.08.012

  • 281

    HoCHaNTYouensDAbhayaratnaWPBulsaraMKHughesJDet al. Association between long-term use of calcium channel blockers (CCB) and the risk of breast cancer: a retrospective longitudinal observational study protocol. BMJ Open. (2024) 14:e080982. doi: 10.1136/bmjopen-2023-080982

  • 282

    LinSYHuangHYChiangLTHuangLYWangCC. Use of calcium channel blockers and risk of breast cancer among women aged 55 years and older: a nationwide population-based cohort study. Hypertens Res. (2023) 46:2272–9. doi: 10.1038/s41440-023-01321-y

  • 283

    RaebelMAZengCCheethamTCSmithDHFeigelsonHSCarrollNMet al. Risk of breast cancer with long-term use of calcium channel blockers or angiotensin-converting enzyme inhibitors among older women. Am J Epidemiol. (2017) 185:264–73. doi: 10.1093/aje/kww217

  • 284

    XieYWangMXuPDengYZhengYYangSet al. Association between antihypertensive medication use and breast cancer: A systematic review and meta-analysis. Front Pharmacol. (2021) 12:609901. doi: 10.3389/fphar.2021.609901

Summary

Keywords

breast cancer, etiology, cohort studies, umbrella review, meta-analysis

Citation

Wang Z, Feng L, Xia Y, Zhu Z, Wu L and Gao S (2025) Risk factors for breast cancer: an umbrella review of observational cohort studies and causal relationship analysis. Front. Oncol. 15:1541233. doi: 10.3389/fonc.2025.1541233

Received

07 December 2024

Accepted

11 April 2025

Published

02 May 2025

Volume

15 - 2025

Edited by

Tewodros Eshete, St. Paul’s Hospital Millennium Medical College, Ethiopia

Reviewed by

Maryam Khayamzadeh, Academy of Medical Sciences, Iran

Niyat Essayas Tekie, Addis Ababa University, Ethiopia

Updates

Copyright

*Correspondence: Lina Wu, ; Song Gao,

Disclaimer

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.

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