OBJECTIVE: To probe into the efficacy of carrelizumab combined with amlotinib in the treatment of advanced gastric cancer and its effect on short-term prognosis

so as to provide reference for clinical treatment.METHODS: From Jan. 2019 to Jan. 2020

100 patients with stage ⅢB to Ⅳ gastric cancer who failed the second-line treatment in this hospital were extracted to be divided into the control group and the observation group via the random number table. Patients in the control group（ n = 50） received anlotinib 10 mg orally from the 1 st to 14 th day of treatment for 4 cycles（ 3 weeks as a treatment cycle）. The observation group（ n = 50） was additionally given 200 mg carrelizumab intravenously on the 1 st day of treatment for 4 cycles（ 3 weeks as a treatment cycle）

and follow-up was maintained after discharge. The efficacy

safety

survival time

serum vascular endothelio genic factor（ VEGF） level and programmed cell death receptor 1（ PD-1） expression on CD4

+

T cells and CD8

+

T cells in peripheral blood were compared between two groups. The above indicators of patients with different microsatellite instability（ MSI） status were observed（ MSI-H for high MSI

MSI-L for low MSI

and MSS for no MSI）. RESULTS: Eighty-eight patients were enrolled for the results analysis.（ 1） The disease control rate in the observation group[79. 07%（ 34/43） ] was significantly higher than that in the control group[57. 78%（ 26/45） ]

the difference was statistically significant（ P

<

0. 05）. In the observation group

the objective effective rate of MSI-H + MSI-L patients[50. 00%（ 6/12） ]was significantly higher than that of MSS patients[6. 45%（ 2/31） ]

the difference was statistically significant（ P

<

0. 05）.（ 2） After treatment

the levels of serum VEGF

peripheral blood CD4

+

T cells PD-1 and CD8+T cells PD-1 in the observation group were significantly lower than those in the control group

with statistically significant difference（ P

<

0. 05）. After treatment

CD4

+

T cells PD-1 and CD8

+

T cells PD-1 in peripheral blood of MSI-H + MSI-L patients were significantly lower than those of MSS patients in the observation group

with statistically significant differences（ P

<

0. 05）

while there was no statistically significant difference in serum VEGF level between MSI-H +MSI-L patients and MSS patients（ P

>

0. 05）.（ 3） There was no significant difference in the incidence of grade Ⅲ or above adverse drug reactions between two groups（ P

>

0. 05）.（ 4） The median follow-up was 16（ from 12 to 20）months

and 9 cases were lost to follow-up. The median progression-free survival time and median overall survival time in the observation group were longer than those in the control group

and the median progression-free survival time and median overall survival time in MSI-H + MSI-L patients were longer than those in MSS patients in the observation group

with statistically significant difference（ P

<

0. 05）. CONCLUSIONS: Carrelizumab combined with amlotinib in the treatment of advanced gastric cancer can improve the rates of DCR and prolong the survival time with higher safety

especially in MSI-H + MSI-L patients.