Objective: To investigate the relationship between the gene polymorphism of metabolizing enzymes and the genetic susceptibility to lung cancer as well as to study the synergistic effects between smoking and the genes.
Methods: A case-control study (case = 217, control = 200) was carried out to compare the frequent distribution of CYP1A1, 2E1, 2D6 and GSTM1 genotypes between the lung cancer group and the control group with a polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) method and to analyze the relationship between these genes and smoking.
Results: GSTM1-null genotype frequency was 58.5% in the lung cancer group and 47.5% in the control group with significant difference (P = 0.02). The frequent distribution of CYP1A1, 2E1, 2D6 genotypes was not significantly different in the two groups (P > 0.05). Synergistic effects were found between smoking and GSTM1 but not between smoking and CYP1A1, 2E1, 2D6.
Conclusion: Smoking and GSTM1-null genotype seemed to be the risk factors of lung cancer. Those who carrying GSTM1-null genotype and smoking cigarettes were prone to suffer from lung cancer to become the high-risk population of the disease.