Relationship between genetic polymorphisms of GSTM1 as well as GSTT1 and lung cancer

AIM and METHODS: To examine the relationship of glutathione S-transferase M1( GSTM 1) and T1( GSTT 1) with the occurrence of lung cancer, The case-control study was conducted among 161 lung cancer and 165 healthy controls. The genetic polymorphisms of GSTM1 and GSTT1 were detected with the method of multiplex polymerase chain reaction. Logistic regression analyses were used to assess the interaction of between different genotypes as well as between null genotypes and smoking. RESULTS: The frequences of GSTM 1 and GSTT 1 null genotypes had no obvious difference between lung cancer and healthy controls. In non-smoking subjects, the frequence of GSTM 1 null genotype was significantly different between lung cancer and healthy controls. Furthermore, GSTM 1 null genotype was significantly overrepresented in adenocarcinoma patients aged 60 or over, compared with controls.The results from interaction analyses showed although smoking and GSTM 1 deletion were associated with an increased risk of lung cancer, GSTM1 and GSTT 1 null genotypes combined with smoking did not have interaction effect on the risk of lung cancer. The risk for adnocarcinoma in the individuals at the age of 60 or over and in nonsmokers without GSTM1 gene but with GSTT1 functional genotype decreased by 48.5% and 45.3%, respectively. CONCLUSION: Our results suggest that GSTM1 deletion is an important host risk for lung cancer, and imply that GSTT1 functional genotype protects the old (aged 60 or over) and nonsmokers who are lack of GSTM1 gene from the risk of adenocarcinoma.