History of infertility and risk of colorectal cancer

Background: There has been limited prior research on the association between infertility and risk of colorectal cancer. Methods: Data from postmenopausal women in the Women’s 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.