Lack of association of GSTT1, GSTM1, GSTO1, GSTP1 and CYP1A1 polymorphisms for susceptibility and outcome in Brazilian prostate cancer patients.

The polymorphic inheritance of human drug-metabolizing enzymes, such as those encoded by the GST and CYP systems, has been implicated in both cancer risk and prognostic. In an effort to increase our understanding of the interaction between potential environmental exposure, lifestyle, and genetic factors in the predisposition and response to radiotherapy of prostate cancer patients, we examined GSTT1, GSTM1, GSTO1, GSTP1 and CYP1A1 genotypes in a Brazilian population. We studied 125 prostate cancer patients and 100 benign prostatic hyperplasia patients paired for ethnic and lifestyle characteristics. Lifetime occupational history, dietary patterns, cigarette-smoking, and other anamnestic data were obtained through interviews. Outcome was evaluated in 42 stage <or= T2a patients presenting a Gleason score <or= 6, PSA <or= 10 ng/ml, treated with radiotherapy and followed up for 12 to 34 months (15 +/- 8 months). None of the studied polymorphisms was found associated to prostate cancer risk either considered separately or in combination, in uni- or multivariate regression logistic analysis. Also, there was no association between genotypes and possible clinical factors of risk or any parameter of tumour aggressiveness at diagnosis or during follow-up. Patients' response to radiotherapy treatment was not associated to any genotype. In conclusion, our data suggest that GST and CYP1A1 genotypes are not associated with the susceptibility to prostate cancer or its outcome in the Brazilian population.