Risk factors for non-melanoma skin cancer in Taubaté, São Paulo, Brazil: a case-control study

Abstract

To identify factors associated with non-melanoma skin cancer in the city of Taubaté, São Paulo, Brazil. Hospital-based case-control study with individuals residing in Taubaté, treated between January 2005 and December 2006. The subjects were matched 1:1 according to gender and age. Age, gender, phototype, European descent, time of residence, sun exposure, time (in years), number of hours and time of occupational and non-occupational sun exposure, photoprotection, family history and photodamage were independent variables. A hierarchical logistic regression was used at three levels. The model adjustment was performed using the Hosmer-Lemeshow test and its accuracy was verified by ROC curve. The significance level was p < 0.05. There were 132 cases and 132 controls. Phototype with OR = 3.14 (95% CI 1.79-5.49), hours of occupational 1.76 (1.04-2.99) and non-occupational sun exposure 1.80 (0.98-3.29) and family history 2.10 (1.13-3.93) were the variables in the final model. Hosmer-Lemeshow test, p = 0.97. Accuracy 70% (95% CI 63-76). We concluded that fair skin, family history and occupational and non-occupational sun exposure were associated with non-melanoma skin cancer in Taubaté-São Paulo.