UC Davis

BACKGROUND: There has been limited prior research on the association between infertility and risk of colorectal cancer. METHODS: Data from postmenopausal women in the Womens Health Initiative were used to estimate the association between self-reported infertility (12 months of trying to get pregnant without achieving a pregnancy) and the risk of colorectal cancer using Cox proportional hazard models. RESULTS: No association was observed between infertility and risk of postmenopausal colorectal cancer [RR, 0.97; 95% confidence interval (CI), 0.87-1.08], invasive colorectal cancer (RR, 0.99; 95% CI, 0.88-1.10), or colorectal cancer mortality (RR, 0.89; 95% CI, 0.71-1.12). CONCLUSIONS: Infertility was not found to be associated with colorectal cancer risk among postmenopausal women. Risk did not vary by specific infertility diagnoses. IMPACT: Infertility may not be associated with colorectal cancer risk.