e16054 Background: This study aimed to explore whether immunonutrition therapy could enhance the efficacy of gastric cancer immunotherapy by reshaping the tumor immune microenvironment, providing new ideas and schemes for the neoadjuvant therapy of locally advanced gastric cancer (LAGC). Methods: This study is a pragmatic, open label, single-center randomized controlled study. Suitable LAGC patients were screened and randomly assigned in a 1:1 ratio to the control group - neoadjuvant chemotherapy (NAC) and the intervention group - neoadjuvant chemotherapy combined with immunotherapy (tislelizumab) and oral immunonutrition (oral impact, NACII). The primary endpoint is pathological complete response (pCR) after 3 cycle treatment. The following secondary endpoints will be evaluated: R0 resection rate; lymph node status after neoadjuvant therapy; The safety of the treatment plan. The accompanying changes in the immune status and tumor microenvironment is set as the exploratory endpoint. 76 LAGC at least is expected to include in this study. Results: As of January 26 2026, a total of 43 participants were included, among which 23 were in the NAC group and 20 were in the NACII group. A total of 36 subjects underwent radical gastrectomy for gastric cancer (20 in the NAC group and 16 in the NACII group). The pCR rate in the NAC group was significantly lower than that in the NACII group (0% vs 35%, p < 0.001), while there was no significant statistical difference in the R0 resection rate between the two groups. After three cycles of immunotherapy combined with oral immunonutritional supplementation treatment, it was able to significantly reduce the proportions of ypT stage (p < 0.001), intravascular tumor thrombus (p = 0.024), and nerve invasion (p = 0.023), and also reduce the proportion of postoperative complications (p = 0.001). Through multiple immunostaining, it was found that the number of infiltrating lymphocytes within the cancer nests in the NACII group was significantly higher than that in the NAC group, especially the infiltration of DC cells was more pronounced. Conclusions: Immunotherapy combined with oral immune nutritional supplementation can significantly increase the postoperative PCR rate of neoadjuvant treatment for LAGC and achieve tumor downstaging. Immunonutrition therapy can reshape the tumor immune microenvironment, so as to further enhance the immunotherapy effect of advanced gastric cancer. The specific mechanism needs to be further studied. Clinical trial information: ChiCTR2300077461.
Chen et al. (Thu,) studied this question.