The correlation between systemic inflammatory markers and efficiency for advanced gastric cancer patients treated with ICIs combined with chemotherapy

Abstract Currently lacking research to explore the correlation between inflammatory markers and the efficacy of immune checkpoint inhibitors (ICIs) combined with chemotherapy in the treatment of advanced gastric cancer. This study is a retrospective study and included patients with advanced gastric cancer who receiving ICIs combined with chemotherapy from January 2020 to December 2022. We analysed the relationship between systemic inflammatory markers and the efficacy of ICIs combined chemotherapy and constructed a clinical prediction model. A nomogram was constructed based on the results of the bidirectional stepwise regression model. A total of 197 patients were enrolled in the training group, with a median follow‐up period of time 26 months. Kaplan Meier analysis showed that the median OS of patients with low systemic immune‐inflammatory index (SII) and low platelet to lymphocyte ratio (PLR) was superior to those with high SII and PLR. Univariate and multivariate Cox regression analysis showed that SII, NLR, PLR, and N stage as independent prognostic factors for OS. Adding SII to the conventional model improved the predictive ability of the 12‐month OS. A total of 95 patients were included in the validation group, and external validation of the SII‐based nomogram showed favourable predictive performance. Baseline SII, PLR, and N stage may serve as independent predictive factors for survival outcomes in advanced gastric cancer patients undergoing ICIs combined with chemotherapy. The SII‐based nomogram can provide intuitive and accurate prognosis prediction of individual patients.