Occupational Sun Exposure and Melanoma Development: A Review of the Evidence.

Cutaneous melanomas arise through a number of causal pathways, all of which involve exposure to sunshine or artificial ultraviolet (UV) radiation to some extent. Their initiation also depends on host factors that determine susceptibility to melanoma, and whether the UV exposure is intermittent or chronic. The question of whether occupational sun exposure causes melanoma has important implications for employees, employers and litigants. This review assessed the evidence linking melanoma development to occupational exposure to sunlight. Electronic literature searches of Medline, Embase and Cochrane CENTRAL to 6 May 2025 were conducted using terms for occupational solar exposure and melanoma. The reviewed observational studies of occupational sun exposure and melanoma development reported both increased and reduced risk. Many of these studies had limited sample sizes and few considered important details such as anatomical site and age, preventing exploration of features that might explain the differing results. The most robust pooled analysis suggested a 45% increase in the risk of melanoma with occupational exposure when studies included the lentigo maligna melanoma (LMM) subtype (relative risk (RR) 1.45, 95% CI 1.08-1.94). When studies excluded LMM the risk of melanoma was reduced (RR 0.69, 95% CI 0.55-0.86). Very few studies have considered occupational sun exposure in the context of the acknowledged causal heterogeneity for melanoma, with the role of chronic sun exposure now understood to differ by anatomical site of tumour, age at diagnosis, and other features. Large-scale cohort studies reporting risks for the various melanoma subtypes and stratifying for other important risk factors are required. Until the results of such studies are available the contribution of occupational sun exposure to melanoma development in any given patient will continue to require considered, personalised assessment.