SYSTEMATIC REVIEW article

Front. Oncol.

Sec. Gynecological Oncology

Volume 15 - 2025 | doi: 10.3389/fonc.2025.1544786

Intratumoral microbiota composition in women's cancers: a systematic review and meta-analysis

Provisionally accepted
Qin  WenQin Wen1,2Shubin  WangShubin Wang1,2Shunlian  FuShunlian Fu3Xinxiang  ZhouXinxiang Zhou1,2Yalan  MinYalan Min1,2Jinyi  LangJinyi Lang1,2*Meihua  ChenMeihua Chen2*
  • 1School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
  • 2Department of Radiation Oncology, Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Center, Sichuan Cancer Hospital & Institute, Affiliated cancer hospital of University of Electronic Science and Technology of China, Chengdu, China
  • 3School of Clinical Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China

The final, formatted version of the article will be published soon.

The intratumoral microbiota has attracted considerable interest in carcinogenesis, progression, and treatment owing to advancements in sequencing technology. This systematic review provides a comprehensive overview of the current literature regarding the diversity and compositional characteristics of the intratumoral microbiota in women's cancers. Additionally, it also explores potential associations among intratumoral microbiota, estrogen, and anti-tumor therapies.A comprehensive literature search was conducted using PubMed, Embase, Web of Science, and the Cochrane Library from their inception to May 1, 2024. The review protocol was pre-registered in PROSPERO (CRD 42024601213). Articles were assessed utilizing the Newcastle-Ottawa Scale (NOS). To estimate the effect size and variability in microbial diversity changes, the standardized mean difference (SMD) and 95% confidence intervals (CIs) were employed. This systematic review included 29 of 8,291 studies after a thorough screening process. Of the 22 studies investigating α-diversity in women's cancers, disease-free controls, and those with benign conditions, notable changes in diversity indices were observed. Compared to adjacent normal tissues, the Simpson index significantly decreased in breast cancer (SMD = -0.75, 95% CI: [-0.94, -0.55]) and endometrial cancer (SMD = -0.83, 95% CI: [-1.37, -0.28]). The Chao1 index was reduced in endometrial cancer tumor tissues relative to normal tissues (SMD = -2.25, 95% CI: [-3.13, -1.36]), while the Shannon index decreased in ovarian cancer tumor tissues (SMD = -0.61, 95% CI: [-1.18, -0.04]). In comparisons between tumor and benign tissues, the Chao1 index was decreased (SMD = -0.64, 95% CI: [-1.20, -0.08], I² = 0%), while the Simpson index was increased (SMD = 0.36, 95% CI: [0.01, 0.71], I² = 0%) in patients with ovarian cancer.Other microbial diversity indices showed no significant differences between tumor and non-tumor tissues. This study highlights significant differences in microbiota composition between tumor and nontumor tissues in women's cancers, emphasizing changes in intratumoral microbiota influenced by estrogen and antineoplastic treatments. Further research is needed to explore the potential for developing targeted therapies based on estrogen-driven microbiota alterations. Investigations may yield insights into the enhancement of female reproductive health and the improvement of treatment efficacy for female cancers.

Keywords: intratumoral microbiota, 16S rRNA gene sequencing, breast cancer, gynecologic cancer, estrogen, Meta-analysis

Received: 17 Dec 2024; Accepted: 30 May 2025.

Copyright: © 2025 Wen, Wang, Fu, Zhou, Min, Lang and Chen. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Jinyi Lang, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
Meihua Chen, Department of Radiation Oncology, Radiation Oncology Key Laboratory of Sichuan Province, Sichuan Clinical Research Center for Cancer, Sichuan Cancer Center, Sichuan Cancer Hospital & Institute, Affiliated cancer hospital of University of Electronic Science and Technology of China, Chengdu, China

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