Ultraviolet carcinogenesis in nonmelanoma skin cancer part II: review and update on epidemiologic correlations.

The relationship between ultraviolet radiation and nonmelanoma skin cancer (NMSC) is further elucidated by a review of case-control studies relating type of exposure to the development of NMSC. Intermittent sun exposure is important in the pathogenesis of basal cell carcinoma, whereas cumulative exposure is important for both basal cell carcinoma and squamous cell carcinoma. The regional distribution of NMSC is also in areas of sun exposure. Furthermore, there are inherent risk factors for the development of NMSC that include hair and eye colors. Once an individual develops NMSC, he/she has increased risk of developing basal cell carcinoma, squamous cell carcinoma, or melanoma.