GLUTATHIONE-S-TRANSFERASE M1 (GSTM1) AND T1 (GSTT1) POLYMORPHISMS ANDLUNG-CANCER RISK AMONG NORTHWESTERN MEDITERRANEANS

Several polymorphic genes including those encoding for glutathione S-t ransferases (GST) have been reported to be involved in modifying lung cancer risk in smokers, The gene GSTM1 is frequently deleted in humans and a possible association between the nub genotype and lung cancer r isk is controversial, Another polymorphic gene of the same supergene f amily, GSTT1, is also involved in the detoxification of some environme ntal carcinogens, Both genes were genotyped in (a) a group of lung can cer patients (ia = 160); (b) a group of healthy smokers (n = 120); (c) a group of blood donors from the general population (ii = 192), All p atients and controls were Northwestern Mediterranean Caucasians, The r esults show that the GSTM1 null genotype (GSTM10/GSTM1*0) was slightl y over represented in the lung cancer patients (frequency of 58%; OR: 1.40, 95% CI: 0.74-2.61, referred to healthy smokers), The histologica l type most clearly modified was small cell carcinoma (frequency of 62 .2%, OR: 1.91, CI: 0.78-4.69), The subdivision of the patients with on e or two copies of the GSTM1 gene according to a GSTM1A, GSTM1*B or G STM1A A/B genotype (frequencies of 28.2%, 11.2%, 2.5% respectively) r evealed no significant differences between the cases and both control groups, The frequency of the deleted GSTT1 genotype among the lung can cer patients (24%) was not significantly increased (OR: 1.08, CI: 0.57 -2.05, referred to healthy smokers), The results showed that 14.4% of the patients presented homozygous deletion of both GSTT1 and GSTM1 (12 .5% among healthy smokers) suggesting no potentiation between null gen otypes for lung cancer risk.