Association study between GSTM1 and GSTT1 genotypes and other possible risk factors in prostate cancer patients in a population from southwest Bahia, Brazil
Prostate cancer (PCa) is the second most common type of tumor among men over 50 years old and its etiology includes environmental, demographic, and genetic risk factors. We investigated a possible association between GSTM1 and GSTT1 polymorphisms, sociodemographic, and clinical factors with PCa in a population of southwestern Bahia, Brazil. The research used a case-control design and was carried out with 268 men aged 50 years or older (134 cases and 134 controls). The mean age was 74 years old (± 7.9) in the case group and 55 years old (± 4.3) in the control group. Polymorphisms were determined by multiplex PCR, followed by electrophoresis. The genotypic frequencies found were 0.45 for GSTM1 -/- (null), 0.55 for GSTM1 +/- or +/+ (non-null), 0.37 for GSTT1 -/- (null) and 0.62 for GSTT1 +/- or +/+ (non-null). The estimated allele frequencies were: GSTM1 - (null allele) 0.60 for the case group and 0.67 for the control group, and GSTT1 - (null allele) 0.49 for the case group and 0.65 for the control group. These polymorphisms were not significantly associated (P-values 0.68 and 0.21, respectively) with PCa. However, non-white ethnicity (self-reported), sexually transmitted infections, and cigarette consumption were significantly associated with PCa (P-value: 0.03, 0.05 and < 0.01 respectively). Vasectomy exhibited an inverse association (P-value < 0.01), thus behaving as a protective factor for PCa.