Interactions between GSTM1, GSTT1 and GSTP1 polymorphisms and smoking and intake of fruit and vegetables in relation to lung cancer

Polymorphisms in glutathione S-transferases (GST) are weakly associated with risk for lung cancer. We examined gene-environment interactions in relation to lung cancer in 430 cases and 767 comparison persons identified within a prospective cohort of 57,053 persons. We used assays capable of discriminating heterozygous individuals from those with two functional alleles and homozygous deletions in GSTM1 and GSTT1. There was no overall association between the GST polymorphisms and lung cancer. We found that fruit and vegetables reduced the risk of lung cancer only among carriers of at least one functional GSTM1 allele, and among carriers of two GSTP1 Val alleles. There were no significant interactions between the GST polymorphisms and smoking.