Polymorphisms of co-inhibitory molecules (CTLA-4/PD-1/PD-L1) and the risk of non-small cell lung cancer in a Chinese population.
AIM To evaluate the correlation between a polymorphism of PD-L1 gene and the susceptibility of non-small cell lung cancer (NSCLC) in a Chinese population. METHODS A total of 293 Chinese patients with NSCLC and 293 age and sex matched controls of the same ethnic origin were enrolled in this study. A/C polymorphism at position 8923 in intron 4 of PD-L1 gene was typed using the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP). The interactions between A/C genotype, allele frequency and NSCLC susceptibility were analyzed. RESULTS The A/C genotype frequencies were significantly different between NSCLC patients and controls. The AC and CC frequencies were higher in NSCLC patients than in controls (16.4 vs 8.9%, 1.0 vs 0.3%, respectively). The C-allele frequency was higher in NSCLC patients than in controls (9.2 vs 4.8%). Significant differences in the A and C allele frequencies were noted between the two groups (χ(2) = 8.864, P = 0.003). More risk of NSCLC was found in individuals carrying the C allele than in those carrying the A allele (OR = 2.203; 95% CI 1.262-3.242). In both light smokers (≤20 pack-years) and heavy smokers (>20 pack-years), individuals carrying the C-allele had more risk of NSCLC than those carrying the A-allele (light smokers OR = 1.847, 95% CI 1.001-3.409; heavy smokers OR = 3.252, 95% CI 1.196-8.845, respectively). CONCLUSION An A/C polymorphism at position 8923 in the PD-L1 gene is associated with NSCLC susceptibility. The PD-L1 polymorphism plays a role in NSCLC, especially in patients with the C-allele.