The impact of hormones and reproductive factors on the risk of bladder cancer in women: results from the Nurses’ Health Study and Nurses’ Health Study II

Background With three out of four new bladder cancer (BCa) cases occurring in men, an apparent gender disparity exists. We aimed to investigate the role of hormonal and reproductive factors in BCa risk using two large female US prospective cohorts. Methods Our study population comprised 118 256 and 115 383 female registered nurses who were recruited in the Nurses' Health Study (NHS) and NHS II, respectively. Reproductive and hormonal factors and...