Postmenopausal hormone use and cutaneous melanoma risk: A French prospective cohort study

Cutaneous melanoma has been suspected to be influenced by female hormones. Several studies reported a positive association between menopausal hormone therapy (MHT) use and melanoma risk; however, previous findings were conflicting. We sought to explore the associations between MHT use and melanoma risk in a prospective cohort of women in France, where a particularly wide variety of MHT formulations are available. E3N is a prospective cohort of 98,995 French women aged 40-65 years in 1990. MHT use was assessed through biennial self-administered questionnaires. We used Cox proportional hazards regression models adjusted for age and skin cancer risk factors. Over 1990-2008, 444 melanoma cases were ascertained among 75,523 postmenopausal women. Ever use of MHT was associated with a higher melanoma risk (hazard ratio (HR) = 1.35, 95% confidence intervals (CI) = 1.07-1.71). The association was strongest among past users (HR = 1.55, CI = 1.17-2.07, homogeneity for past vs. recent use: p = 0.11), and users of MHT containing norpregnane derivatives (HR = 1.59, CI = 1.11-2.27), although with no heterogeneity across types of MHT (p = 0.13). Among MHT users, the association was similar across durations of use. However, a higher risk was observed when treatment onset occurred shortly after menopause (