Predictive and prognostic value of combined detection of sTim-3, PG and PD-L1 in immune checkpoint inhibitor therapy for advanced gastric cancer.

[OBJECTIVE] To investigate the value of combined detection of T-cell immunoglobulin mucin molecule 3 (sTim-3), pepsinogen (PG) and programmed death receptor 1 (PD-L1) in evaluating treatment efficacy and predicting the prognosis of immunosuppressant therapy in advanced gastric cancer.

[METHODS] A retrospective study was conducted on the data of 90 patients with advanced gastric cancer who were treated at the First Affiliated Hospital of Changsha Medical University from January 2019 to February 2021. Patients were divided into effective and ineffective groups based on treatment response. Logistic regression was used to identify the factors affecting the efficacy of immune checkpoint inhibitors in treating progressive gastric cancer. ROC curves were drawn to assess the predictive value of serum sTim-3, PG, and PD-L1 alone or in combination. Serum levels of sTim-3, PG, PD-L1 were compared between the survival and death groups, and univariate and Cox proportional risk regression analyses were conducted to identify factors affecting prognosis of patients with progressive gastric cancer. Survival curves were plotted using the Kaplan-Meier method, and ROC curves were used to assess the prognostic value of combined and individual testing of sTim-3, PG, and PD-L1.

[RESULTS] No statistically significant difference were observed between the effective and ineffective groups in terms of gender, age, body mass index, smoking history, alcohol consumption history, KPS score, tumor site, presence of ascites, or use of other therapies (all >0.05). The levels of sTim-3, PG II, and PD-L1 were higher in the ineffective group than those in the effective group, while PG I was lower than that in the effective group (all <0.05). Logistic regression analysis showed that sTim-3 (=2.408), PG I (=1.779) and PD-L1 (=1.844) were independent risk factors for treatment efficacy of immune checkpoint inhibitors in advanced gastric cancer (all <0.05). The AUC value of combined detection of serum sTim-3, PG I and PD-L1 for treatment efficacy was higher than their individual detection (<0.05). The serum levels of sTim-3 and PD-L1 in the death group were higher than those in the survival group, while PG I was lower than that in the survival group. The levels of sTim-3 (=2.686), PG I (=2.782) and PD-L1 (=2.018) were independent prognostic factors in patients with advanced gastric cancer. The AUC of the combined detection of sTim-3, PG I and PD-L1 in predicting the prognosis of patients with advanced gastric cancer was significantly higher than their individual detection (all P<0.05). Log-rank test showed that the 3-year survival rates of patients with high sTim-3 and PD-L1 levels were significantly higher than those with low levels (all <0.05).

[CONCLUSION] sTim-3, PG and PD-L1 have significant clinical value in predicting treatment efficacy and prognosis of advanced gastric cancer patients undergoing immunosuppressive therapy.