Reproductive Factors and Thyroid Cancer Risk: The Multiethnic Cohort Study

Women are three times more likely to be diagnosed with thyroid cancer than men, with incidence rates per 100,000 in the United States of 20.2 for women and 7.4 for men. Several reproductive and hormonal factors have been proposed as possible contributors to thyroid cancer risk, including age at menarche, parity, age at menopause, oral contraceptive use, surgical menopause, and menopausal hormone therapy. Our study aimed to investigate potential reproductive/hormonal factors in a multiethnic population.