Immunotherapy in operable non-small cell lung cancer: a systematic review and network meta-analysis of efficacy between neoadjuvant immunochemotherapy and perioperative immunotherapy.

Background: A series of randomized controlled trials (RCTs) have demonstrated the promising prospect of immunotherapy in operable non-small cell lung cancer (NSCLC) and further changed the clinical practice. However, current studies still yet to answer which immunotherapy mode is the optimal strategy, and there is currently a lack of direct comparison between neoadjuvant immunochemotherapy and perioperative immunotherapy ("sandwich mode", including neoadjuvant immunochemotherapy and adjuvant immunotherapy). Thus, we conducted a network meta-analysis (NMA) to evaluate the efficacy between neoadjuvant immunochemotherapy and perioperative immunotherapy. Methods: We performed a Bayesian NMA (PROSPERO registration number: CRD42024495955) by retrieving relevant eligible studies from PubMed, EMBASE, Cochrane Library, ClinicalTrials.gov, and major international conferences until December 31, 2023. Phase II or III RCTs that evaluated the efficacy of different strategies of immunotherapy in operable NSCLC, including neoadjuvant immunochemotherapy and perioperative immunotherapy ("sandwich mode"), were retrieved for analysis. The patients were grouped into neoadjuvant chemotherapy alone (arm A), neoadjuvant immunotherapy plus chemotherapy (arm B); neoadjuvant immunotherapy plus chemotherapy followed by surgery and adjuvant immunotherapy (arm C), respectively. The endpoint was event-free survival (EFS) in different subgroups. Results: Seven studies of 2,934 patients were selected for this NMA finally. Compared with neoadjuvant chemotherapy, both neoadjuvant immunochemotherapy [hazard ratio (HR) 0.61, 95% confidence interval (CI): 0.36-0.98] and perioperative immunotherapy (HR 0.56, 95% CI: 0.42-0.71) significantly improved the EFS in intention-to-treat population, but there was no statistical difference between these two treatments (HR 1.1, 95% CI: 0.62-1.9). There was no statistical difference between perioperative immunotherapy and neoadjuvant immunochemotherapy in all subgroup analysis of EFS. However, in patients with non-squamous disease, programmed cell death-ligand 1 (PD-L1) expression more than 50%, or stage III disease, both neoadjuvant immunotherapy [(HR 0.50, 95% CI: 0.26-0.97), (HR 0.24, 95% CI: 0.061-0.96), (HR 0.50, 95% CI: 0.39-0.63)] and perioperative immunotherapy [(HR 0.64, 95% CI: 0.46-0.87), (HR 0.40, 95% CI: 0.21-0.71), (HR 0.54, 95% CI: 0.34-0.85)] improved EFS significantly compared with neoadjuvant chemotherapy. Conclusions: Both neoadjuvant immunochemotherapy and perioperative immunotherapy significantly increased EFS compared with neoadjuvant chemotherapy. There is no evidence that perioperative immunotherapy is better than neoadjuvant immunochemotherapy in EFS. Patients with non-squamous disease, PD-L1 expression more than 50%, or stage III disease can try the neoadjuvant immunochemotherapy mode.