Association of female reproductive and hormonal factors with gallbladder cancer risk in Asia: A pooled analysis of the Asia Cohort Consortium
Aesun Shin, Sooyoung Cho, Sarah Krull Abe, Md Rashedul Islam, Md Shafiur Rahman, Eiko Saito, Sayada Zartasha Kazmi, Ryoko Katagiri, Melissa Merritt, Ji‐Yeob Choi, Xiao‐Ou Shu, Norie Sawada, Akiko Tamakoshi, Woon‐Puay Koh, Ritsu Sakata, Atsushi Hozawa, Jeongseon Kim, Sue K. Park, Sun‐Seog Kweon, Wanqing Wen, Shoichiro Tsugane, Takashi Kimura, Jian‐Min Yuan, Seiki Kanemura, Yumi Sugawara, Min‐Ho Shin, Habibul Ahsan, Paolo Boffetta, Kee Seng Chia, Keitaro Matsuo, You‐Lin Qiao, Nathaniel Rothman, Wei Zheng, Manami Inoue, Daehee Kang- Cancer Research
- Oncology
Abstract
The female predominance of gallbladder cancer (GBC) has led to a hypothesis regarding the hormone‐related aetiology of GBC. We aimed to investigate the association between female reproductive factors and GBC risk, considering birth cohorts of Asian women. We conducted a pooled analysis of 331,323 women from 12 cohorts across 4 countries (China, Japan, Korea, and Singapore) in the Asia Cohort Consortium. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) to assess the association between reproductive factors (age at menarche, parity, age at first delivery, breastfeeding, and age at menopause) and GBC risk. We observed that a later age at menarche was associated with an increased risk of GBC (HR 1.4, 95% CI 1.16–1.70 for 17 years and older vs. 13–14 years), especially among the cohort born in 1940 and later (HR 2.5, 95% CI 1.50–4.35). Among the cohort born before 1940, women with a later age at first delivery showed an increased risk of GBC (HR 1.56, 95% CI 1.08–2.24 for 31 years of age and older vs. 20 years of age and younger). Other reproductive factors did not show a clear association with GBC risk. Later ages at menarche and at first delivery were associated with a higher risk of GBC, and these associations varied by birth cohort.