Research Article

Association study between GSTM1 and GSTT1 genotypes and other possible risk factors in prostate cancer patients in a population from southwest Bahia, Brazil

Published: July 31, 2019
Genet. Mol. Res. 18(3): GMR18296 DOI:


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.