Are genetic polymorphisms of glutathione S-Transferase P1 gene associated with urothelial carcinoma of the urinary bladder?

Abstract

Background: Polymorphisms in genes encoding glutathione S-transferase (GST) may affect susceptibility to develop urothelial carcinomas (UCs). One of the extensively studied genes in this group is GST P1 (GSTP1), but studies of the relationship of polymorphisms of GSTP1 and UC of the bladder have been equivocal. Hence, we assessed the association between genetic polymorphism of GSTP1 gene and the development of UC of the urinary bladder. Materials and Methods: This prospective, case–control study was conducted in the departments of urology and clinical genetics at a tertiary care teaching hospital in South India, which included 52 patients with histopathologically confirmed UC bladder and matched with 46 controls from August 2012 to July 2013. The study participants provided a single venous blood sample for extraction of genomic DNA. Laboratory personnel was blinded to sample groups. The primary outcome of the study was to detect association of genetic polymorphism of GSTP1 gene with UC of the bladder. The secondary outcome was to assess if the risk of urothelial bladder cancer is increased in smokers with polymorphism of GSTP1 gene. Statistical Analysis Used: We used the Chi-square or Fisher's (F) exact test to compare discrete variables. Unconditional logistic regression was used to estimate adjusted odds ratios and 95% confidence intervals. Results: Although the heterozygous polymorphic genotype ile/val (AG) was seen more frequently in cancer group (34.6% vs. 23.9%), the difference was not statistically significant (P = 0.202). None of the smokers had homozygous polymorphic valine allele and GSTP1 did not add to the susceptibility of UC bladder even among smokers. Conclusions: A lack of association between GSTP1 313 G/G polymorphism and urothelial cancer of bladder was observed.