Higher Tumor Mutation Burden Was a Predictor for Better Outcome for NSCLC Patients Treated with PD-1 Antibodies: A Systematic Review and Meta-analysis

This study was conducted to evaluate the predictive efficacy of tumor mutation burden (TMB) in patients with non-small-cell lung cancer (NSCLC) receiving PD-1 antibodies. Embase, PubMed, Ovid Medline, and the Cochrane Library were systematically searched until May 24, 2020. The keywords included "PD-1," "TMB," and "NSCLC." Overall survival (OS) and progression-free survival (PFS) were summarized and combined using the hazard ratio (HR) and 95% confidence interval. Twenty-one studies with 9883 patients were included in the meta-analysis. The overall relapse rate ranged from 39.3% to 64.3% in the higher TMB group as compared with 0% to 40% in the lower TMB group. The median OS ranged from 2.9 to 23 mo in the higher TMB group as compared with 4.3 to 16.2 mo in the lower TMB group. Patients with a higher TMB had a better OS as compared with patients with a lower TMB (HR = 0.61, P < 0.001). Similarly, a higher TMB was also a good predictor of PFS in patients treated with PD1/PDL1 antibodies (HR = 0.55, P < 0.001). Our results suggest that among NSCLC patients receiving PD1/PDL1 antibodies, patients with higher TMB could have a better survival outcome.