广泛期小细胞肺癌（ES-SCLC）是一种具有高度侵袭性和致命性、治疗选择有限且预后不良的疾病。本研究旨在系统评估免疫检查点抑制剂联合化疗（ICIs+ChT）与单独化疗（ChT）在ES-SCLC一线治疗中的疗效和安全性。我们在PubMed、Cochrane图书馆、Embase、CNKI和其他数据库中进行了一项与"ICIs+ChT"与"ChT"在ES-SCLC一线治疗中相关的随机对照试验（RCT）的文献搜索。使用RevMan 5.4软件进行具有风险比（HR）和相对风险（RR）的荟萃分析。采用SAS 9.4软件进行生存结果的混合效应模型荟萃分析和绘制生存曲线。本研究纳入了6个RCT的2,638名ES-SCLC患者，其中1,341名患者接受"ICIs+ChT"方案，1,297名患者接受ChT。根据混合效应模型提供的荟萃分析结果，与接受单独化疗的患者相比，接受"ICIs+ChT"方案的患者在总体生存期（OS）（HR = 0.800，95% CI = 0.731-0.876，P < 0.001）和无进展生存期（PFS）（HR = 0.815，95% CI = 0.757-0.878，P < 0.001）方面显著延长。与ChT相比，"ICIs+ChT"既未改善客观缓解率（ORR）（RR = 1.06，95% CI = 1.00-1.12，P = 0.06），也未改善疾病控制率（DCR）（RR = 0.97，95% CI = 0.92-1.03，P = 0.35）。尽管在"ICIs+ChT"亚组中，三级至五级的治疗相关不良事件（trAEs）的发生率并未增加（RR = 1.16，95% CI = 0.97-1.39，P = 0.11），但三级至五级的免疫相关不良事件（irAEs）的发生率显著增加（RR = 4.29，95% CI = 1.73-10.61，P < 0.00001）。与单独化疗相比，ICIs联合化疗在ES-SCLC患者一线治疗中能够显著延长OS和PFS。尽管"ICIs+ChT"亚组的irAEs发生率较"ChT"亚组高，但两个亚组的trAEs发生率相似。免疫检查点抑制剂联合化疗是ES-SCLC一线治疗的良好选择。PROSPERO，识别号：CRD42022348496。版权所有©2023 Zheng, Deng, Huang和Chen.

Extensive-stage small cell lung cancer (ES-SCLC) is a highly invasive and fatal disease with limited therapeutic options and poor prognosis. Our study aims to systematically evaluate the efficacy and safety of immune checkpoint inhibitors combined with chemotherapy (ICIs+ChT) vs. chemotherapy alone (ChT) in the first-line treatment of ES-SCLC.A literature search was performed for randomized controlled trials (RCTs) related to "ICIs+ChT" vs. "ChT" in the first-line treatment of ES-SCLC in PubMed, Cochrane Library, Embase, CNKI, and other databases. RevMan 5.4 software was used to perform meta-analyses with hazard ratio (HR) and relative risk (RR). SAS 9.4 software was applied to conduct a mixed-effect model meta-analysis of the survival outcomes and draw survival curves.A total of 2,638 patients with ES-SCLC from 6 RCTs were included, of which 1,341 patients received "ICIs+ChT" and 1,297 received ChT. Based on the meta-analysis results provided by the mixed-effect model, patients receiving the "ICIs+ChT" regimen had a significantly longer overall survival (OS, HR = 0.800, 95% CI = 0.731-0.876, P < 0.001) and progression-free survival (PFS, HR = 0.815, 95% CI = 0.757-0.878, P <0.001) in comparison to those receiving ChT only. Compared with ChT, "ICIs+ChT" did neither improve the objective response rate (ORR, RR = 1.06, 95% CI = 1.00-1.12, P = 0.06) nor did it improve the disease control rate (DCR, RR = 0.97, 95% CI = 0.92-1.03, P = 0.35). Although the incidence of grade 3 to 5 treatment-related adverse events (trAEs) in the "ICIs+ChT" subgroup did not increase (RR = 1.16, 95% CI = 0.97-1.39, P = 0.11), the incidence of grade 3 to 5 immune-related adverse events (irAEs) increased significantly (RR = 4.29, 95% CI = 1.73-10.61, P < 0.00001).ICIs+ChT regimen could significantly prolong OS and PFS in patients with ES-SCLC compared with ChT alone. Although the incidence of irAEs in "ICIs+ChT" is higher than that in the "ChT" subgroup, the incidence of trAEs is similar within the two subgroups. ICIs combined with chemotherapy demonstrated a good choice as first-line treatment for ES-SCLC.PROSPERO, identifier: CRD42022348496.Copyright © 2023 Zheng, Deng, Huang and Chen.