P2-442 European ancestry, phenotypic characteristics and risk of cutaneous melanoma: a case-control study in Sao Paulo, Brazil

Cutaneous melanoma shows high rates of mortality and its incidence has increased worldwide over the last century. This also is the trend for Brazil. Identified risk factors for melanoma include the pattern of sun exposure, family history of melanoma, number of nevi and phenotypic characteristics. Ethnicity could also influence the outcome of melanomas like European ancestry in different populations. We carried out a hospital-based case-control study in Brazil to evaluate the contribution of phenotypic factors and European ancestry to melanoma risk. A total of 412 subjects (202 cases and 210 controls) were analysed regarding phenotypic characteristics for risk of melanoma as well as number of grandparents born in Europe. European ancestry (Spanish, Italian, Germanic or Slavic, and 2 or more European country), eye colour (light brown and green or blue), presence of nevi, use of sunscreen, referred episodes of sunburn in adolescence or not, were independently associated with melanoma. Portuguese ancestry was not associated in multivariate logistic regression analysis. Our data confirmed the importance of European ancestry as a susceptibility factor. The higher tendency to develop melanoma in persons with those ancestries could be related not only to the phenotypic but probably also to other genetic characteristics.