The relationship between pneumonitis and programmed cell death-1/programmed cell death ligand 1 inhibitors among cancer patients: A systematic review and meta-analysis.

Background: We put the meta-analysis into practice to reveal the relationship between the incidence risk of immune-related pneumonitis and the use of programmed cell death-1 (PD-1) and ligand 1 (PD-L1) inhibitors related pneumonitis in cancer patients. Method: The meta-analysis was put into practice according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Odds ratio (OR) was evaluated by random effect model. Results: After screening and eligibility assessment, 33 clinical trials involving 19,854 patients were selected and used for the final meta-analysis after selection criteria checked. Compared with chemotherapy, the use of PD-1/PD-L1 inhibitors alone increased the incidence risk of all-grade (OR = 4.29, 95% confidence interval: [2.97, 6.19],P < .00001) and grade 3 to 5 immune-related pneumonitis (OR = 3.53, 95% confidence interval: [2.04, 6.11],P < .00001). Similar trend could also be found when PD-1/PD-L1 inhibitors were prescribed alone or in combination with other anti-tumor therapies. Conclusion: Whether PD-1/PD-L1 inhibitors were used alone or combined with other antitumor drugs, the incidence risk of immune-related pneumonitis would be increased.