Genetic Polymorphisms Of Glutathione S-transferase M1 And T1 Gene Related With The Susceptibility To Lung Cancer

Objective: The individual carcinoma risk assessment was undertaken to analyze susceptibility to lung cancer associated with the genotype of glutathione S-transferase Ml (GSTM1) or Tl (GSTT1), which could provide academic basis for the prevention of lung neoplasm, particularly for the screen of susceptibles to lung neoplasm.Methods: The genetic polymorphisms of GSTM1 and GSTT1 were detected with the method of multiplex polymerase chain reaction. A category matching case-control study of epidemiology was carried out to examine the relationship between the polymorphisms of these two genotypes and the occurrence of lung cancer.Results: The frequencies of GSTM1 and GSTT1 deficient genotypes were 58.40% and 46.00% in the case group while 55.80% and 43.60% in the control group, respectively. No significant difference of these two genotypes was found between the case and control group (AT2=0.23, P=.632; X2=0.18, P=0.673). The stratification analysis implied that non-smokers in cases, especially women and urban residents who never smoke had a higher proportion of GSTM1 null genotype than those in controls ( x2=4.02, P=0.045, OR=2.0, 95%CI: 1.01-3.96; x2=3.98, P=0.046, OR=2.56, 95%C7: 1.00-6.50; x2=5.25, P=0.022, OR=2.16, 95%CI : 1.14-6.73). Furthermore, GSTM1 deficient genotype was significantly overrepresented in adenocarcinoma patients who were elders (age 60 years or over) or non-smokers ( x2=5.30, P=0.021, OR=3.05, 95%CI: 1.15-8.08; x2=5.28, 7M).022, OR=2.67, 95%CI: 1.14-6.26).Binary Logistic regression analysis suggested GSTM1 null genotype, not GSTTl null genotype (Score=0.28, P=0.598), was associated with an increased risk of lung carcinoma, especially the adenocarcinoma (Wald=4.63, P=0.031, OR=1.91, 95%CI: 1.06-3.43; Wald=4.49, P=0.034, OR=2.24, 95%CJ: 1.06-4.71). At the same time, all the tested interactional covariates including GSTMIXGSTTl, GSTM1XSI and GSTTl XSI did not reach statistical significance (Score=0.28, P=0.594; Score=0.46, P=0.496; Score=0.11, P=0.743).Conclusions: Compared with the previous reports, there was a higher level of GSTM 1 and GSTTl homozygous deletions in the surveyed Chinese population of Han nationality in Guangdong Province. The lack of GSTM 1 confered increased susceptibility to lung neoplasm in nonsmokers, particularly in women and urban residents who never smoke. Furthermore, the homozygous null deletion in GSTM1 was related to a greater susceptibility to adenocarcinoma in aged people (age 60 years or over). GSTM1 deficient genotype was associated with the susceptibility to lung cancer, mainly to adenocarcinoma, while GSTTl genotype was unlikely to be linked with lung cancer susceptibility. In addition, the results of this study did not reveal any gene-gene or gene-smoking interaction in the development of lung carcinoma.