Objective To investigate the prognostic value of the platelet-lymphocyte ratio (PLR) in non-small cell lung cancer patients treated with PD-1/PD-L1 inhibitors.

Methods PubMed, EMBASE, Web of Science, Medline, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database, VIP, WanFang and other databases were searched online for eligible studies about evaluating the relation between PLR and the prognosis of NSCLC patients treated with PD-1/PD-L1 inhibitors from the establishment of database to April 2020. The relevant data of literatures that met the inclusion criteria were extracted. Pooled estimates of HR and 95%CI were calculated using Stata 15.0.

Results We included six studies involving 551 patients. Elevated PLR was associated with worse OS and PFS of NSCLC patients treated with PD-1/PD-L1 inhibitors. The subgroup analysis of OS showed the prognostic value of high PLR in Caucasian race, cutoff value ≤169.05, PLR cutoff value determination according to previous literature and multi-center retrospective study (P < 0.05). Subgroup analysis of PFS showed the prognostic value of high PLR in East Asian race, cutoff value ≤169.05, PLR cutoff value determination according to previous literature and single-center retrospective study (P < 0.05).

Conclusion Among NSCLC patients treated with PD-1/PD-L1 inhibitors, elevated blood PLR is associated with shorter OS and PFS, indicating that it may be a potential biomarker for PD-1/PD-L1 treatment on NSCLC patients.