Safety and efficacy of immunotherapy plus chemotherapy as neoadjuvant treatment for patients with locally advanced gastric cancer: a retrospective cohort study.

backgroundThe combined use of programmed death receptor-1 (PD-1) inhibitors and chemotherapy has reshaped the treatment landscape of advanced or metastatic gastric cancer (GC). This study aimed to assess the efficacy and safety of PD-1 inhibitors combined with chemotherapy in a neoadjuvant setting for locally advanced GC (LAGC).

methodsPatients diagnosed with clinical stage II-III GC undergoing neoadjuvant PD-1 inhibitors plus chemotherapy were enrolled from December 2019 to July 2022. Clinicopathological characteristics, pathological information, and survival data were recorded and analyzed.

resultsA total of 42 eligible patients were enrolled, of whom 37 (88.1%) had clinical stage III disease. All the patients underwent surgery, and the R0 resection rate was 90.5%. Major pathological response (MPR) and pathological complete response (pCR) rates were 42.9% and 26.2%, respectively. The overall TNM downstaging rate was 76.2%. A total of 36 (85.7%) patients received adjuvant chemotherapy. With a median follow-up of 23.1 months, four patients died after tumor recurrence, and three were alive with recurrence. The 1-year overall survival (OS) and disease-free survival (DFS) rates were 94.4% and 89.5%, respectively, and the median OS and DFS were not reached. Neoadjuvant treatment was well tolerated with no grade 4-5 treatment-related adverse events (TRAEs) observed. The most common grade 3 TRAEs were anemia and alanine aminotransferase increase (n = 2 each, 9.6%).

conclusionsPD-1 inhibitors plus chemotherapy demonstrated promising efficacy, with encouraging pCR and survival outcomes in a neoadjuvant setting for patients with LAGC. The combined therapy also showed a good safety profile.