Background
Gastric cancer, death, malignancy, cancer, mismatch repair deficiency
GASTRIC CANCER, CANCER, MICROSATELLITE INSTABILITY
Gastric cancer (GC) has become the sixth most common malignancy and the third leading cause of cancer-related death globally [For the second-line chemotherapy drugs recommended in the guideline, paclitaxel or irinotecan, the objective response rate (ORR) is only about 10–20.9% with a median progression-free survival (PFS) of 2.1 to 3.6 months, and a median overall survival (OS) of 5.3 to 9.5 months [Recent studies suggested that anti-angiogenic therapeutic strategy such as ramucirumab or apatinib in combination with chemotherapy could achieve favorable results [Increasing evidence of clinical studies support the use of immune checkpoint inhibitors (ICIs) in the treatment of GC, especially for patients with mismatch repair deficiency or microsatellite instability–high cancer [Although immunotherapy has showed a partial curative effect on GC, the above studies showed that the efficacy of single-agent PD-1 monoclonal antibody was limited. Many studies have revealed a synergistic effect of PD-1/PD-L1 antibody plus chemotherapy or VEGFR2 inhibitor [