This meta-analysis investigated the clinical benefits of chemo-immunotherapy in extensive-stage small-cell lung cancer (ES-SCLC). Seven randomized controlled trials with a total of 2862 patients were analyzed. Compared with chemotherapy alone, chemo-immunotherapy provided a better progression-free survival (PFS) with a hazard ratio (HR) of 0.81, p < 0.00001, and overall survival (OS) with a HR of 0.82, p < 0.0001; however, the incidence of treatment-related adverse effects (TRAEs) was significantly increased. Subgroup analyses showed that good performance status, cisplatin-based chemotherapy, without brain metastases at baseline and non-Asian populations were associated with greater benefits in OS from chemo-immunotherapy. Chemo-immunotherapy demonstrated better PFS and OS compared with chemotherapy alone as first line treatment in ES-SCLC, but additional TRAEs should be closely monitored.
