Female Estrogen-Related Factors and Incidence of Basal Cell Carcinoma in a Nationwide US Cohort

Purpose UV radiation exposure is the primary risk factor for basal cell carcinoma (BCC), the most common human malignancy. Although the photosensitizing properties of estrogens have been recognized for decades, few studies have examined the relationship between reproductive factors or exogenous estrogen use and BCC. Methods Using data from the US Radiologic Technologists Study, a large, nationwide, prospective cohort, we assessed the relationship between reproductive factors, exogenous estrogen use, and first primary BCC while accounting for sun exposure, personal sun sensitivity, and lifestyle factors for geographically dispersed women exposed to a wide range of ambient UV radiation. Results Elevated risk of BCC was associated with late age at natural menopause (hazard ratio [HR] for ≥ 55 years v 50 to 54 years, 1.50; 95% CI, 1.04 to 2.17) and any use of menopausal hormone therapy (MHT; HR, 1.16; 95% CI, 1.03 to 1.30; P for trend for duration = .001). BCC risk was most increased among women reporting nat...