Reproductive Factors and Endometrial Cancer Risk Among Women

Ryoko Katagiri, Motoki Iwasaki, Sarah Krull Abe, Md Rashedul Islam, Md Shafiur Rahman, Eiko Saito, Melissa A. Merritt, Ji Yeob Choi, Aesun Shin, Norie Sawada, Akiko Tamakoshi, Woon Puay Koh, Ritsu Sakata, Ichiro Tsuji, Jeongseon Kim, Chisato Nagata, Sue K. Park, Sun Seog Kweon, Xiao Ou Shu, Yu Tang GaoShoichiro Tsugane, Takashi Kimura, Jian Min Yuan, Seiki Kanemura, Yukai Lu, Yumi Sugawara, Keiko Wada, Min Ho Shin, Habibul Ahsan, Paolo Boffetta, Kee Seng Chia, Keitaro Matsuo, You Lin Qiao, Nathaniel Rothman, Wei Zheng, Manami Inoue, Daehee Kang

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

Importance: Despite evidence of an association between reproductive factors and endometrial cancer risk, prospective studies have been conducted mainly in non-Asian countries. Objective: To assess the association between reproductive factors, such as number of deliveries, age at menarche, or menopause, and endometrial cancer risk. Design, Setting, and Participants: This cohort study used pooled individual data from 13 prospective cohort studies conducted between 1963 and 2014 in the Asia Cohort Consortium. Participants were Asian women. Data analysis was conducted from September 2019 to April 2023. Exposures: Reproductive factors were assessed using a questionnaire in each cohort. Main Outcomes and Measures: The main outcome was time to incidence of endometrial cancer. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% CIs. Results: A total of 1005 endometrial cancer cases were detected among 332 625 women (mean [SD] age, 54.3 [10.4] years) during a mean (SD) of 16.5 (6.4) years of follow-up. Increasing number of deliveries was associated with a decreased endometrial cancer risk in a dose-response manner (≥5 deliveries vs nulliparous [reference]: HR, 0.37; 95% CI, 0.26-0.53; P for trend < .001). Compared with menarche at younger than 13 years, menarche at 17 years or older had an HR of 0.64 (95% CI, 0.48-0.86; P for trend < .001). Late menopause (age ≥55 years) showed an HR of 2.84 (95% CI, 1.78-4.55; P for trend < .001) compared with the youngest age category for menopause (<45 years). Age at first delivery, hormone therapy, and breastfeeding were not associated with endometrial cancer risk. Conclusions and Relevance: This large pooled study of individual participant data found that late menarche, early menopause, and a higher number of deliveries were significantly associated with a lower risk of endometrial cancer. These convincing results from Asian prospective studies add to the growing body of evidence for the association between reproductive factors and endometrial cancer.

Original languageEnglish
Pages (from-to)e2332296
JournalJAMA network open
Volume6
Issue number9
DOIs
StatePublished - 5 Sep 2023
Externally publishedYes

Fingerprint

Dive into the research topics of 'Reproductive Factors and Endometrial Cancer Risk Among Women'. Together they form a unique fingerprint.

Cite this