A systematic and genome-wide correlation meta-analysis of PD-L1 expression and targetable NSCLC driver genes.

BACKGROUND: Studies have shown that the ligand of programmed cell death protein 1 (B7-H1, CD274 or PD-L1) is related to lung cancer driver genes. Although studies have examined the association between lung cancer driver gene mutations or expression and PD-L1 expression, the present studies have not been mined the correlation systematically and genome-widely.

METHODS: All relevant published PD-L1 articles with driver genes data and the RNA-seq dataset from The Cancer Genome Atlas (TCGA) were analyzed. We performed meta-analysis for data included in the selected literature, and then independently explored the correlation between genes by co-expression analysis of RNA-seq data in the TCGA database.

RESULTS: A sum of 9,934 lung cancer cases were collected from 34 published studies. Higher PD-L1 expression was associated with wild-type epidermal growth factor receptor (EGFR) [odds ratio (OR): 0.68, 95% confidence interval (CI): 0.48-0.96, P=0.03], Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation (OR: 1.27, 95% CI: 1.02-1.58, P=0.03) or non-adenocarcinoma histology (OR: 0.68, 95% CI: 0.47-0.98, P=0.04). In addition, our analysis from TCGA data indicated that, compared with lung adenocarcinoma, the expression of PD-L1 was significantly higher than that of squamous cell carcinoma patients (P=0.023). The expression of targetable driver genes showed no correlations with PD-L1 expression in non-small cell lung cancer (NSCLC).

CONCLUSIONS: Our results suggest the presence of EGFR wild-type, KRAS gene mutations or squamous cell carcinoma were associated with high PD-L1expression, which provides potential benefited population for the administration of PD-1/PD-L1 blockade in human lung cancer.