Glutathione S-transferase M1 gene polymorphism is related to COPD in patients with non-small-cell lung cancer.

OBJECTIVE

Oxidative stress contributes to the development of both lung cancer and chronic obstructive pulmonary disease (COPD). Antioxidative enzymes may protect against such damage. We hypothesized that genetic variations in glutathione S-transferase M1 and/or T1 genes (GSTM1 and GSTT1, respectively) may influence susceptibility to COPD in patients with non-small-cell lung cancer.

PATIENTS AND METHODS

The polymorphisms in GSTM1 and GSTT1 genes were examined in 110 patients (age: 63+/-1 years) with newly diagnosed non-small-cell lung cancer using the polymerase chain reaction. Respiratory function was assessed by bodyplethysmography.

RESULTS

In the GSTM1 null (-/-) genotype, both FEV1 and FEV1/FVC were significantly lower than in the GSTM1 plus genotype (GSTM1 -/+ or +/+) (75.8+/-2.5 versus 86.6+/-3.6%, p<0.02; 69.1+/-1.6 versus 77.0+/-2.4, p<0.01, respectively). Among the patients with GSTM1 null genotype, 49% suffered from COPD as opposed to 21% of patients with GSTM1 plus genotype. In contrast, no differences were seen in FEV1 or FEV1/FVC when comparing patients with GSTT1 null genotype and GSTT1 plus genotype (81.4+/-4.9 versus 79.3+/-2.3, p=NS; 71.1+/-2.9 versus 72.2+/-1.6, p=NS). Multiple stepwise regression analysis identified the GSTM1 genotype (p<0.02) as a significant independent predictor of FEV1 in this group of patients.

CONCLUSION

The present study suggests that in patients with non-small-cell lung cancer the presence of at least one active allele in GSTM1 has a protective effect against the development of COPD.