Risk associations of melanoma in a Southern European population: results of a case/control study.

Objectives: Limited data exist about the risk factors of melanoma in the Greek population. We investigated the association of melanoma with phenotypic and solar indices in this darker skin population residing in an environment of high ambient ultraviolet radiation.

Methods: Our study included 200 sporadic melanoma cases and 200 age-, sex-matched control subjects. Information on history of sun exposure patterns and cutaneous reaction to sunlight was obtained and a clinical evaluation of pigmentary traits, pigmented lesions, and actinic keratoses was performed.

Results: In the multivariate analysis, fair skin (OR: 4.63, for fair skin versus light brown, 95% CI: 1.54-13.92), intermittent sun exposure during childhood (OR: 3.33, >2 weeks/year of sun exposure versus < or =2 weeks/year 95% CI: 1.37-8.09), and outdoor leisure activities (OR: 2.74, 95% CI: 1.28-5.89), but not skin phototype or sunburns, were positively related to the risk of melanoma. In addition to an elevated count of common melanocytic nevi (OR: 6.27, > or =10 nevi versus no nevi, 95% CI: 1.65-23.76) and the presence of clinically atypical nevi (OR: 2.84, 95% CI: 1.16-6.98), solar lentigenes were an independent risk factor of melanoma (OR: 4.33, 95% CI: 1.67-11.22).

Conclusions: Intermittent sun exposure of moderate intensity during childhood/adolescence and outdoor leisural activities, in conjunction with a more resistant skin phenotype to acute sunburns and a strong association with nevi and solar lentigenes was a prominent determinant of melanoma risk in our population.