| Objective To explore the predictive value of systemic immune inflammation index(SII), serum pepsinogen(PG) and gastrin-17(G-17) in gastric cancer. Methods A total of 108 patients with GC who were newly diagnosed and underwent surgical treatment in Jiangsu Provincial Hospital of Traditional Chinese Medicine from January 2023 to August 2024 were selected as GC group. In addition, 296 patients with benign gastric diseases were selected, including 80 patients with active gastric ulcer(GU) as the GU group, 106 patients with chronic atrophic gastritis(CAG) as the CAG group, and 110 patients with chronic non-atrophic gastritis(CNAG) as the CNAG group. Another 100 healthy subjects in the hospital during the same period were included in the control group. The differences in the levels of each index between the GC group and other groups were compared and analyzed. The patients with gastric cancer in the GC group were clinically staged, and the differences in the levels of each index in GC patients at different stages were compared. The differences in preoperative SII, PGⅠ, PGⅡ and G-17 levels in different clinicopathological features of GC were compared. The receiver operating characteristic(ROC) curve was drawn to compare the predictive efficacy of each index for GC. In addition, 70 patients with GC who were newly diagnosed in the hospital from September 2024 to April 2025 were selected for cross-validation. Results The level of SII in GC group was higher than that in benign gastric disease groups and control group(P< 0.05), and the levels of PGⅠ and PGⅡ in GC group were lower than those in benign gastric disease groups and control group(P<0.05). The levels of SII, G17, CEA, CA724 and CA199 in patients with stage Ⅲ/Ⅳ were higher than those in patients with stage Ⅰ/Ⅱ(P<0.05). The level of PGⅠ in patients with stage Ⅲ/Ⅳ was lower than that in patients with stage Ⅰ/Ⅱ(P<0.05). In GC patients with Hp infection, the larger the tumor, the deeper the depth of invasion, the more lymph node metastasis, and distant organ metastasis, the higher the preoperative SII and G-17 levels, while the PGⅠ level was the opposite(P<0.05). The larger the tumor, the lower the preoperative PGⅡ level(P<0.05). Patients with tumors located in the cardia/gastric fundus had lower PGⅠ levels(P<0.05), and patients with tumors located in the gastric antrum/pylorus had lower G-17 levels(P<0.05). The area under the curve(AUC) of combined detection of SII, PGⅠ, CEA and CA724 in predicting GC was 0.976(95 % CI : 0.964-0.990), which was higher than that of SII, PGⅠ, PGⅡ, G17, CEA, CA199, CA724 and HP alone in predicting GC(Z = 5.843, 5.642, 8.939, 8.557, 4.709, 6.653, 5.199, 10.290, P< 0.05). The results of cross-validation showed that the true positive rate of each index in the diagnosis of GC was in good agreement with the sensitivity obtained by AUC curve. The true positive rate of SII, PGⅠ, CEA and CA724 combined detection was the highest, and the false negative rate was the lowest, 95.71 % and 4.29 %, respectively. Conclusion SII, PG and G-17 have good predictive value for GC, which can provide help for clinical diagnosis of GC and formulation of personalized treatment plan. |