Efficacy of Immune Checkpoint Inhibitors for Lung Cancer According to Patient Age and Eastern Cooperative Oncology Group Performance Status: A Systematic Review and Meta-analysis

Abstract

Background For treatment of advanced lung cancer, immune checkpoint inhibitors (ICIs) + chemotherapy or the combination of dual ICIs has become the standard first-line treatment in recent years. Considering the differences among patients’ immune systems, the response to ICIs may vary. Therefore, we aimed to evaluate the predictive implications of patient age and Eastern Cooperative Oncology Group (ECOG) performance status (PS) for the efficacy of ICIs for the treatment of lung cancer. Methods We searched the PubMed, Cochrane Library, Web of Science, and EMBASE databases for articles published between January 2010 and September 2020 that compared overall (OS) and progression-free survival (PFS) rates between patients with lung carcinoma who were administered ICIs and control treatments. Results Twenty-four trials including 15,584 patients were selected. ICIs significantly improved the OS rates in patients aged < 65 (hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.65–0.82) and ≥ 65 (0.75 [0.70–0.82]) years, with an age cut-off of 65 years; patients aged < 65 (0.83 [0.72–0.95]) years, when age was classified as < 65, 65–74, and ≥ 75 years; and patients with an ECOG PS score of 0 (0.77 [0.69–0.86]) and 1 (0.78 [0.72–0.85]). However, the differences between the two age groups (p = 0.69), the three age groups (p = 0.43), and the ECOG PS groups (p = 0.82) were not insignificant. Significant advantages of ICIs in terms of PFS rates were found in patients aged < 65 (0.64 [0.52–0.79]) and ≥ 65 (0.73 [0.64–0.84]) years and in those with an ECOG PS score of 0 (0.63 [0.49–0.82]) and 1 (0.66 [0.59–0.75]). No significant difference was observed between the age (p = 0.35) and ECOG PS groups (p = 0.89). Conclusions Younger patients benefited more from ICI administration; however, lung cancer treatment cannot be decided based on age. Patients with different ECOG PS could benefit from ICIs, but data on patients with an ECOG PS score of ≥ 2 are lacking. In future studies, more patients with poor ECOG PS scores should be included.