Polymorphism in glutathione S-transferases: Susceptibility and treatment outcome for head and neck cancer

The study investigates the association of polymorphism in glutathione S-transferases (GSTs) with susceptibility for head and neck squamous cell carcinoma (HNSCC) and its sites as well as treatment response in cases receiving chemotherapy (CT) and combination of CT-radiotherapy (CT-RT). The case-control study included 500 male cases and an equal number of healthy male controls. Odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated for the association between genotypes and cancer risk. An increase in the risk for HNSCC and cancers of oral cavity, larynx or pharynx was observed in cases with null genotypes of GSTM1 or GSTT1. The interaction of alcohol or tobacco with variant genotypes of GSTM1 or GSTT1 also resulted in a significant increase in the risk for HNSCC. Further, HNSCC cases carrying the null genotypes of GSTM1 and GSTT1 or variant genotypes of GSTP1 showed a significant and superior treatment response. The present data thus provides evidence for the association of polymorphisms in GSTs with risk for HNSCC and its treatment response.