The safety and efficacy of immunotherapy and palliative radiotherapy in patients with metastatic non-small cell lung cancer: a systematic review and meta-analysis of 13 prospective studies

Objective Whether palliative RT (pRT) can influence the prognosis of mNSCLC patients who are treated with immune checkpoint inhibitors (ICIs) is still under debate. Therefore, we performed a systematic review and meta-analysis to evaluate the efficacy and safety of pRT plus ICIs in mNSCLC patients.Methods PubMed, Cochrane, and Embase databases were searched, and only prospective studies and randomized controlled trials (RCTs) were included. All data were analyzed with Stata 14.0 and Review Manager Version 5.4 software.Results A total of 13 studies were included. The combined ORRs for the ICIs group, cRT plus ICIs group, and SBRT plus ICIs group were 0.22 (95% CI: 1.27, 4.04), 0.26 (95% CI: 0.04, 0.49), and 0.29 (95% CI: 0.17, 0.40), respectively. And PFS were 2.21 (95% CI: 1.71, 2.70), 4.63 (95% CI: 2.16, 7.09), and 7.38 (95% CI: 2.16, 12.60) months, respectively. OS was 5.96 (95% CI: 3.85, 8.07), 9.04 (95% CI: 6.49, 11.59), and 7.96 (95% CI: 4.02, 11.91) months for the above groups, respectively. For safety terms, patients receiving ICIs plus SBRT had an incidence of 5% (95% CI: 2%, 9%) for pneumonia.Conclusion Patients with mNSCLC may benefit from the combination of ICIs and pRT therapy, but these findings need further validation.