Women’s Health
Female cancer risks and infertility diagnosis: an analysis based on Taiwanese national data Tingju Hsu* Tingju Hsu Hsu National Cheng Kung University
Introduction: Infertility affects approximately 17.5% of women globally and 15% in Taiwan. Associations between infertility and hormone-sensitive cancers remain inconclusive from prior studies. Using national data, we examined the association between the infertility diagnosis and subsequent risk of breast, endometrial, and ovarian cancers among Taiwanese women. Methods: From Taiwan’s National Health Insurance Research Database (1990–2021), we identified 65,860 women aged 18 to 60 years with incident infertility diagnosis and matched them individually by birth year to three controls. Incident breast, endometrial, and ovarian cancers were identified through registry linkage. Cox proportional hazards models adjusted for income levels and urbanicity for the cancer outcomes were evaluated. The models were further stratified by age at the first infertility diagnosis to five groups, less than 30, 30 to 34, 35 to 39, 40 to 44, and 45 years or older, for strata-specific HR. Results: Infertility diagnosis was not associated with overall breast cancer risk (HR=1.07 with 95% CI [0.99–1.15]). However, women first diagnosed at age 40 to 44 showed a significantly higher risk (HR=1.29 with 95%CI [1.05–1.60]). Infertility diagnosis was associated with increased endometrial cancer risk overall (HR=1.63 with 95%CI [1.38-1.92]) and also in less than 30 (HR=1.99 with 95%CI [1.45–2.73]), 30–34 (HR=1.49 with 95%CI [1.12–1.99]) and 35–39 (HR=1.70 with 95%CI [1.19–2.42]) age groups. No significant association for infertility diagnosis and ovarian cancer risk overall (HR=1.06 with 95%CI [0.86–1.31]) or in any age groups. Conclusion: Infertility diagnosis was associated with increased endometrial cancer risk, especially when diagnosed before age 40, and with increased breast cancer risk when first diagnosed at ages 40 to 44. The findings suggest that age at infertility diagnosis may identify subgroups with distinct hormone-related cancer risks and inform risk stratification in future studies.