Gender differences, UV exposure and risk of lentigo maligna in a nationwide healthcare population cohort study.

ABSTRACT

BACKGROUND: Our understanding of the relationship between ultraviolet (UV) radiation exposure and lentigo maligna (LM) has been largely derived from epidemiologic/clinical studies based on invasive melanoma. Recent studies have shown gender differences in melanocytic tumours incidence. OBJECTIVE: To examine the association of UV light with LM by gender remains unclear. METHODS: Two prospective cohort study [Nurses' Health Study (1980-2012)] and [Health Professionals Follow-up Study (1986-2010)] were analysed. All participants with LM or MIS, non-LM type were included in analysis. UV index at birth, age 15, and age 30 were calculated by gender. Lifetime UV flux was calculated. Hazard ratios (HRs) were calculated. RESULTS: A total of 110 485 women from NHS and 41 015 men from HPFS were examined. A total of 281 LM and 776 melanoma in situ (MIS), non-LM cases were reported. Risk of LM increased with increasing UV flux exposure in multivariate-adjusted models for men (P for trend = 0.04), but not for women (P for trend = 0.91). CONCLUSIONS: UV flux may be associated with LM in men but not in women.