The short-term efficacy of neoadjuvant SOX versus SOX plus immune checkpoint inhibitor following laparoscopic gastrectomy for locally advanced gastric cancer: a multicenter retrospective cohort study in China

Background This study aims to evaluate the short-term efficacy for locally advanced gastric cancer (LAGC) who accepted laparoscopic gastrectomy (LG) after neoadjuvant SOX versus SOX plus immune checkpoint inhibitors (ICIs). Methods LAGC patients who accepted LG after neoadjuvant SOX (SOX-LG, n = 169) and SOX plus ICIs (SOX + ICIs-LG, n = 140) in three medical centers between Jan 2020 and Mar 2024 were analyzed. We compared the tumor regression, treatment-related adverse events (TRAEs), perioperative safety between two groups, and explored the risk factors of postoperative complications (POCs) for LG after neoadjuvant therapy. Results The baseline characteristics were comparable between two groups (P > 0.05). SOX + ICIs-LG group acquired a higher proportion of objective response (63.6% vs. 46.7%, P = 0.003), major pathological response (43.6% vs. 31.4%, P = 0.001), and pathological complete response (17.9% vs. 9.5%, P = 0.030). There were no significant differences in the TRAEs rates, operation time, R0 resection, retrieved lymph nodes, postoperative first flatus, and hospitalized days, overall and severe POCs between two groups (P > 0.05). Patients in the SOX-ICIs-LG group had lower estimated blood loss (EBL) compared with SOX-LG (P = 0.001). Multivariate analysis showed that more EBL (P = 0.003) and prognostic nutritional index (PNI) < 40 (P = 0.005) were independent risk factors of POCs for LG after neoadjuvant therapy. Conclusion Neoadjuvant SOX plus ICIs brings better tumor regression and similar TRAEs compared with SOX alone for LAGC. SOX + ICIs-LG is safe and feasible to conduct with less EBL. Surgeons should focus on the perioperative management to control POCs for patients with PNI < 40 and more EBL.