Negative Associations between Macronutrient Quality Index and Lung Cancer Incidence and Mortality: Results from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

Dazhan Feng¹Qi Wei¹Dengliang Liu^2*Yi Xiao¹Haitao Gu¹Linglong Peng¹Yuxiang Luo³Ling Xiang¹Yunhao Tang^1*

• ¹The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
• ²Jiulongpo District People's Hospital, Chongqing, China
• ³Erasmus MC, Rotterdam, Netherlands

Background: Prior research has not examined the connection between the quality of macronutrients and the occurrence as well as fatality rates of lung cancer (LC). Consequently, to delve deeper into the correlations between macronutrient quality and the likelihood of developing LC, we carried out an extensive, long-term prospective cohort study of 101,755 American adults from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. Methods: Our research cohort comprised 154,887 adults, aged between 55 and 74, who were enrolled from 10 screening facilities across the United States. The macronutrient quality index (MQI) was derived from participants' responses to a dietary history questionnaire (DHQ). To quantify the strength and precision of the relationships between MQI and the incidence as well as mortality of LC, we employed Cox proportional hazards regression modeling to estimate hazard ratios (HRs) alongside their corresponding 95% confidence intervals (CIs). Additionally, we conducted subgroup analyses to scrutinize whether the observed link between MQI and LC risk was subject to modification by potential confounding variables. To reinforce the reliability of our results, sensitivity analyses were also carried out. Results: Over an average follow-up period spanning 8.82 ± 1.95 years (accumulating to 897,809 person-years of observation), we recorded 1,706 LC diagnoses, encompassing 1,464 cases of non-small cell lung cancer (NSCLC) and 242 cases of small cell lung cancer (SCLC). Additionally, there were 1,217 deaths attributed to LC, with 1,005 NSCLC-related and 212 SCLC-related fatalities. Our results demonstrate a distinct, statistically significant inverse association between a higher MQI and both a reduced incidence (HR Q4 vs. Q1: 0.65; 95% CI: 0.56–0.76; P < 0.001 for trend) and decreased mortality (HR Q4 vs. Q1: 0.71; 95% CI: 0.60–0.84; P < 0.001 for trend) of LC. This inverse relationship held true for both NSCLC and SCLC subtypes. The robustness of the associations between MQI and the incidence as well as mortality of LC was solidly affirmed through sensitivity analyses. Conclusions: Our research outcomes imply that prioritizing the intake of higher - quality macronutrients could serve as a viable strategy to mitigate LC risk within the American population.