RESUMO
OBJECTIVE: The present study was aimed at examining the local distribution of GSTM1, GSTT1, MDR1, and VEGF gene polymorphisms as possible risk factors contributing to the development of bladder cancer among the population from Canary Islands, Spain. MATERIALS AND METHODS: The genotypes were determined by PCR-based methods in a hospital-based case-control study consisting of 119 cases and 110 controls. The socio-demographic and clinicopathologic data were collected, including the smoking habits of the population covered in the study. RESULTS: The observed allelic frequencies were (%): GSTM1-GSTT1, (positive) 54 and (null) 46 in cases, and 65 and 35, respectively, in controls (P = 0.144); MDR1 C3435T, (C) 57 and (T) 43 in cases, and 54 and 46, respectively, in controls (P = 0.633); VEGF A2578C, (A) 40 and (C) 60 in cases, and 51 and 49, respectively, in controls (P = 0.221). Among Canary Islands subjects, GSTT1-null genotype appeared as a significant risk factor for bladder cancer (odds ratio (OR) 2.0; 95% confidence interval (CI), 1.0-3.7; P = 0.041), in multivariate analysis adjusted by age and smoking habits. No statistical changes in genotype distribution of GSTM1, MDR1 C3435T, and VEGF A2578C gene polymorphisms were observed between cases and controls. The distribution of the initial clinical stage, clinical grade, or recurrence status was not significantly different among the polymorphic variants in the case group (P = NS). CONCLUSIONS: Subjects with the GSTT1-null genotype might be at an increased risk of bladder cancer in Canary Islands, Spain. However, extensive studies are required for accurate confirmation of these results.
