Incidence risk of PD-1/PD-L1-related pneumonia and diarrhea in non-small cell lung cancer (NSCLC) patients: a systematic review and meta-analysis of randomized controlled trials.

Programmed cell death-1 (PD-1) and programmed cell death ligand-1(PD-L1) inhibitor therapy have been approved for the treatment of many cancers, although their incidence of some side effects was high. We aim to fully investigate the incidence risk of PD-1/PD-L1 inhibitors–related pneumonia and diarrhea in NSCLC patients, as well as treatment-related deaths. PubMed, Medline, Cochrane Library, and Clinical trials.gov databases were searched up to Sep 17, 2020, for clinical trials of PD-1 inhibitors and PD-L1 inhibitors in the treatment of NSCLC. Randomized controlled trials and their references were screened. Seventeen trials were included in our meta-analysis, including 11,363 patients. PD-1/PD-L1 inhibitors significantly increased the risk of developing all-grade and high-grade (grade ≥ 3) pneumonia (risk ratio [RR] = 2.28; 95% CI: 1.39–3.76; P < 0.01; RR = 2.38; 95% CI: 1.72–3.29; P < 0.01, respectively). The use of PD-1/PD-L1 inhibitor did not increase the risk of developing all-grade and high-grade diarrhea (RR = 0.79; 95% CI: 0.62–1.01; P = 0.06; RR = 0.96; 95% CI: 0.70–1.31; P = 0.78, respectively). There was no significant difference between the rate of death in PD-1 and PD-L1 inhibitors (P = 0.079). These data suggest that PD-1/PD-L1 inhibitors significantly increase the risk of all-grade and high-grade pneumonia in NSCLC patients and PD-1/PD-L1 monotherapy increases the risk of all-grade pneumonia in NSCLC patients compared to PD-1/PD-L1 inhibitor combination regimens. Physicians should pay more attention to NSCLC patients who treated with PD-1/PD-L1 inhibitors.