Efficacy and safety of neoadjuvant treatment with chemotherapy and immune checkpoint blockades for potentially resectable gastric cancer: A retrospective study

The efficacy and safety of adding immune checkpoint inhibitors (ICIs) to neoadjuvant chemotherapy in patients with potentially resectable gastric cancer (GC) are uncertain. This study aimed to retrospectively evaluate the efficacy and safety of neoadjuvant ICIs plus chemotherapy in patients with potentially resectable GC. We retrospectively collected clinical data from patients with potentially resectable GC who received neoadjuvant treatment followed by gastrectomy at the Affiliated Hospital of Qingdao University from 2021 to 2023. The primary aim of this study was to investigate the differences in pathological tumor response (tumor regression grade, TRG) between neoadjuvant programmed cell death-(ligand)1 [PD-(L)1] blockade plus chemotherapy [neoadjuvant immunotherapy (IO) group] and chemotherapy alone (neoadjuvant chemotherapy group). Event-free survival (EFS) and treatment-related adverse events (TRAEs) were also observed. A total of 220 patients were retrospectively included in the analysis, among whom 96 (43.6%) received PD-(L)1 blockade plus chemotherapy as neoadjuvant treatment, and 124 (56.4%) received neoadjuvant chemotherapy. Higher pathological complete response (pCR) rate (21 of 96, 21.9% vs. 9 of 124, 7.2%, <i>P</i> = .004) and TRG0/1 rate (36 of 96, 37.5% vs. 22 of 124, 17.7%, <i>P</i> = .001) were detected in the neoadjuvant IO group. By the last follow-up, the median EFS time had not been reached in the two groups. The combined regimen of PD-(L)1 blockade plus chemotherapy was well-tolerated. In patients with potentially resectable GC, neoadjuvant ICIs plus chemotherapy resulted in higher pCR rates than did neoadjuvant chemotherapy alone. However, the difference in EFS rates was not statistically significant.