Solar UV exposure and mortality from skin tumors.

Solar ultraviolet radiation (UVR) exposure is clearly associated with increased mortality from nonmelanoma skin cancer--usually squamous cell carcinoma. However, the association with cutaneous melanoma is unclear from the evidence in ecologic studies and the few analytic studies show that high levels of intermittent UV exposure prior to diagnosis are somehow associated with improved survival from melanoma. Understanding this conundrum is critical to present coherent public health messages and to improve the mortality rates from melanoma.