A meta-analysis on neoadjuvant immunochemotherapy in stage III-IVa (oligometastatic) non-small cell lung cancer

<bold>Abstract</bold> <bold>Background and Objectives:</bold> The majority of patients with non-small cell lung cancer (NSCLC) are diagnosed at locally advanced or advanced stages, which are associated with poor prognosis at the time of initial diagnosis. The emergence of immunotherapy has introduced a shift in the characterization of patients with stage III and IVa oligometastatic disease (OMD) NSCLC, making them a potentially resectable population eligible for downstaging surgery following translational therapy. In this study, a meta-analysis was performed using published data to systematically assess the efficacy and safety of neoadjuvant immunochemotherapy for stage III-IVa OMD. <bold>METHODS:</bold> A comprehensive search was conducted on the Cochrane Library, PubMed, Web of Science, and Embase databases from January 1, 2000 to May 1, 2023, to identify studies concentrated on neoadjuvant immunochemotherapy followed by surgery for treating stage III-IVa NSCLCs. Data analysis was conducted using R 4.1.3 software, and P < 0.05 was considered statistically significant. <bold>RESULTS:</bold> Totally, 19 articles, encompassing 667 patients, were finally included in this study, of whom 546 cases underwent surgery. The combined meta-analysis yielded a stage III-IVa NSLCLC major pathological response (MPR) rate of 65% (95% confidence interval (CI): [60%-71%], I2:32%), P=0.10), a pathological complete response (pCR) rate of 41% (95%CI: [35-50%]), I2:71%, P＜0.01), an objective response rate (ORR): of 76% (95% CI: [65-85%]), I2:84%, P<0.01). <bold>Conclusion:</bold> Neoadjuvant immunochemotherapy demonstrates clinical benefits for patients with stage III-IVA NSCLC, and TRAEs are tolerable.