Association of GSTM3 intron 6 variant with cigarette smoking, tobacco chewing and alcohol as modifier factors for prostate cancer risk.

Variations in glutathione-S-transferases (GSTs) genes may alter the catalytic efficiency of GST isoenzymes leading to potential increase in susceptibility to carcinogens present in cigarette smoke and tobacco. The present study aimed to explore the association of GSTM3 intron 6 polymorphism with susceptibility to prostate cancer (PCa), and to assess risks associated with cigarette smoking, tobacco chewing and alcohol consumption in PCa patients of North India. The study included 135 PCa patients and 169 controls. All subjects were genotyped for 3-bp deletion in intron 6 of GSTM3. Risk of developing prostate cancer associated with GSTM3 AB + BB was 2.5-fold (OR = 2.51, P = 0.028) as compared to AA genotype. Patients who were either smokers and/or had alcohol habits demonstrated a strong association with GSTM3 (AB + BB) genotype (OR = 4.11, P = 0.046; OR = 4.38, P = 0.027, respectively). Our results suggested GSTM3 (AB + BB) genotype to be significantly associated with PCa risk. The risk was even more apparent in case of cigarette smokers and alcohol consumers.