To observe the clinical efficacy and safety of combination of sintilimab injection and chemotherapy on patients with advanced gastric cancer.

Patients with advanced gastric cancer in gastrointestinal tumor center of the hospital were retrospectively analyzed and divided into control group and treatment group. Control group was given XELOX chemotherapy regimen (intravenous drip of 130 mg·m^-2 oxaliplatin injection on the 1st day of each cycle; oral administration of 1 000 mg·m^-2 capecitabine tablets in the morning and evening, continuous medication from the 1st day to the 14th day of each cycle, 21 days as a cycle). On the basis of control group, treatment group was given 200 mg of sintilimab injection by intravenous drip on the 1st day of each cycle, and were treated no more than 8 cycles (21 days as a cycle), and received maintenance regimen (control group was given single drug treatment, 1 000 mg·m^-2 capecitabine tablets orally in the morning and evening, for 14 consecutive days and 7 days of discontinuation, 21 days as a cycle; on the basis of control group, treatment group was given 200 mg of sintilimab injection, intravenous drip, on the first day of each cycle, 21 days as a cycle) after disease control. The patients were followed up until death. The remission rate, blood markers including matrix metalloproteinase-9 (MMP-9), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) and survival prognosis were compared between the two groups, and the safety was evaluated.

A total of 86 patients with advanced gastric cancer were selected from the hospital information system. According to the different treatment regimens, they were classified into control group and treatment group, with 43 cases in each group. After excluding those who changed the drug dose or changed the treatment method due to personal reasons during treatment process, 38 cases were included in control group and 42 cases were included in treatment group. After treatment, the levels of MMP-9 in treatment group and control group were (230.74±54.37) and (311.95±69.76) μg·L^-1, the NLR were 1.44±0.37 and 1.82±0.47, the PLR were 134.42±17.55 and 162.46±17.17, respectively, and there were statistical significantly differences in the above indexes between treatment group and control group (all P<0.05). The objective remission rates in treatment group and control group were 54.76% (23 cases/42 cases) and 31.58% (12 cases /38 cases), and the disease control rates were 96.83% (40 cases/42 cases) and 78.95% (30 cases/38 cases), respectively, the above indicators in treatment group were statistically significantly different from those in control group (all P<0.05). The median progression-free survival [95% confidence interval (CI)] values in treatment group and control group were 19.00 (95%CI: 16.89-21.11) and 12.00 (95%CI: 12.74-17.26) months, and the median overall survival (95%CI) values were 25.00 (95%CI: 23.78-26.22) and 20.00 (95%CI: 16.98-23.02) months, respectively, the above indicators revealed statistical significantly differences between treatment group and control group (all P<0.05). The incidence rates of myelosuppression in treatment group and control group were 45.24% (19 cases/42 cases) and 60.53% (23 cases/38 cases), and the incidence rates of gastrointestinal reaction were 35.71% (15 cases/42 cases) and 39.47% (15 cases/38 cases), and incidence rates of liver function injury were 26.19% (11 cases/42 cases) and 21.05% (8 cases/38 cases), and the incidence rates of hand-foot syndrome were 21.43% (9 cases/42 cases) and 15.79% (6 cases/38 cases), and the incidence rates of neurotoxicity were 40.48% (17 cases/42 cases) and 52.63% (20 cases/38 cases), and the incidence rates of thyroid dysfunction were 7.14% (3 cases/42 cases) and 0.00% (0 cases/38 cases), respectively, without statistical significantly differences (all P>0.05).

The application of sintilimab injection combined with XELOX chemotherapy regimen in patients with advanced gastric cancer can effectively enhance the remission rate, reduce the levels of serum MMP-9, NLR and PLR, and improve the survival prognosis, with good safety.