Efficacy of PD-1/PD-L1 immunotherapy on brain metastatic non-small-cell lung cancer and treatment-related adverse events: A systematic review

Background: Recent evidence suggests that PD-1/PD-L1 immunotherapy improves outcomes in patients with brain metastatic non-small cell lung cancer.

Methods: Records were searched electronically on MEDLINE, Embase and BIOSIS. Hazard ratios and their 95% confidence intervals for overall survival and progression free survival, and treatment-related adverse events data were extracted. Risk of bias was assessed in included studies using the Cochrane Collaboration's revised tool to assess risk of bias in randomized trials.

Results: PD-1/PD-L1 immunotherapy increased overall survival by 33% and progression free survival by 47% compared with chemotherapy. Two studies had a high risk of bias. Treatment-related adverse events were reported in 95%, 89% and 65% of patients receiving chemoimmunotherapy,chemotherapy and single agent immunotherapy, respectively.

Conclusion: PD-1/PD-L1 inhibitors alone or in addition to chemotherapy increase overall and progression free survival when compared with chemotherapy alone. Chemoimmunotherapy and chemotherapy patients experienced the most treatment-related adverse events.