Implication of PD‑L1 polymorphisms rs2297136 on clinical outcomes of patients with advanced NSCLC who received PD‑1 blockades: A retrospective exploratory study

Clinically, programmed death-1 (PD-1) blockades have demonstrated promising therapeutic outcomes for patients with advanced non-small cell lung cancer (NSCLC). The present study aimed to examine the impact of programmed death-ligand 1 (PD-L1) polymorphism on clinical outcomes of patients with advanced NSCLC who were treated with PD-1 blockades therapy. The present study was designed as a retrospective analysis, where a consecutive screening of 89 patients with advanced NSCLC who received PD-1 blockades monotherapy were screened. Biological specimens were collected to determine the presence of polymorphism and PD-L1 mRNA expression through genotyping. The analysis focused on examining the relationship between the genotype status of PD-L1 polymorphism and clinical outcomes. Among the 89 patients with advanced NSCLC, the use of PD-1 blockades monotherapy resulted in objective response rate (ORR) of 22.5%, a median progression-free survival (PFS) of 3.4 months [95% Confidence Interval (CI): 1.80-5.00) and a median overall survival (OS) of 11.3 months (95% CI: 7.93-14.67). The analysis of polymorphism indicated that only rs2297136 had clinical significance. Among the 89 patients with NSCLC, the prevalence of rs2297136 was as follows: A total of 58 cases (65.2%) had the AA genotype, 28 cases (31.5%) had the AG genotype and 3 cases (3.4%) had the GG genotype. This resulted in a minor allele frequency of 0.19, which was in consistent with Hardy-Weinberg Equilibrium (P=0.865). The correlation analysis between genotype status of rs2297136 and clinical outcomes indicated that patients with the AA genotype had an ORR of 19.0%, while those with the AG/GG genotype had an ORR of 29.0% (P=0.278). Additionally, the median PFS for the AA genotype was 2.95 months, compared with 5.30 months for the AG/GG genotype (P=0.038). Accordingly, median OS of the AA and AG/GG genotypes was 8.8 and 18.4 months, respectively (P=0.011). The mRNA expression of PD-L1 was significantly higher in patients with AG/GG genotype compared with those with AA genotype (P