07/22/2026
A recent study assessed the associations between reproductive factors and ovarian cancer risk across menopausal status and birth cohorts. Women aged >40 years who underwent health screening in 2009 were included and followed up until ovarian cancer diagnosis, death, or December 31, 2022. The primary outcome was the incidence of ovarian cancer. In total, 2,285,774 women (932,637 [40.8%] premenopausal, 1, 353,137 [59.2%] postmenopausal were included in the study.
Over a follow-up duration of 10.7 years, 10,729 ovarian cancer cases were identified. For both premenopausal women and postmenopausal women, early menarche (aged โค12 vs >16 years) was associated with higher ovarian cancer risk, while parity of >2 births was associated with lower ovarian cancer risk. Breastfeeding for >12 months and oral contraceptive use for >1 year were associated with lower ovarian cancer risk in premenopausal women but not postmenopausal women. Among postmenopausal women, later menopause (โฅ55 years), longer reproductive span (โฅ40 years), and hormone replacement therapy use for 2 to 5 years were associated with higher risk of ovarian cancer.
Overall, this study found associations between reproductive factors and cancer risk that differed across menopausal status and birth cohorts, highlighting the need for tailored prevention strategies for these populations.
1. Across the premenopausal and postmenopausal groups, early menarche, later menopause, and longer reproductive span were associated with higher ovarian cancer risk, while parity was associated with lower risk of ovarian cancer. Evidence Rating Level: 2 (Good) Although reproductive factors have been...