Prostate cancer and glutathione S-transferase deletions

Abstract

GSTM1 and GSTT1 gene polymorphisms have been studied in many populations to evaluate their association with prostate cancer risk with contrasting results. The current study was aimed to find out the association of GSTM1 and GSTT1 gene polymorphisms with prostate cancer in Pakistani men. This case control study included pathologically confirmed prostate cancer patients and age matched male controls. Epidemiological data was collected by a standard questionnaire and presence or absence of GSTM1 and GSTT1 gene was observed by multiplex PCR using CYP1A1 as housekeeping gene. Prostate cancer was more prevalent in age of >60 years and most of the patients were at stage IV (70 %) and have undergone surgery. Family history of cancer, smoking, metastasis and surgery were found to be significant (P<0.05) risk factors in prostate cancer development. Gleason score 7 was most prevalent (40.5 %) in prostate cancer patients. Source of drinking water, residential area, occupation, eating habits and number of family members had no association (P>0.05) with prostate cancer risk. No significant association was found when comparing GSTM1 (OR=0.78) and GSTT1 (OR=0.89) gene deletions with prostate cancer risk. Smoking and TNM staging were also not associated with deletion of GSTM1 and GSTT1 genes. Comparison of dual null deletion of both genes with prostate cancer also showed nonsignificant associations. Deletion of GSTM1 gene at stage IV prostate cancer patients was significantly higher compared with other stages of cancer while no significance was shown by GSTT1 gene deletion. GSTM1, GSTT1 and deletion of both GSTM1 and GSTT1 genes do not contribute towards increased risk of prostate cancer in Pakistani population.