GASTRIC CANCER IMMUNOTHERAPY

Gastric cancer (GC) takes 5th place among the malignant neoplasms by incidence in the world. Mortality from GC is high, since in most cases the disease is diagnosed in the late stages, with distant metastases, the five-year survival in GC does not exceed 25–30 %. The standard for GC therapy is surgery with chemotherapy. There is a high resistance to chemotherapy in the late stages of GC, and this circumstance requires a fundamentally new therapy. Recently, studies have been actively conducted on the therapy of GC with the immune control point inhibitors. At the moment, the most studied are monoclonal antibodies against PD-1 (Programmed cell death 1, CD279) / PDL1 (Programmed death-ligand 1, CD274), CTLA-4 (Cytotoxic T-lymphocyte-associated protein 4, CD152). The article discusses the characteristics of PD-1, PD-L1, CTLA-4 molecules and their significance in suppressing the T-cell response, as well as the antitumor effect of immune control point inhibitors. The results of clinical studies of GC therapy with monoclonal antibodies against PD-1 / PD-L1, CTLA-4 were analyzed. The immune control point inhibitors are used as both first-line therapy and subsequent ones. The negative side of immunotherapy is immune-mediated adverse events that can affect the tissues of the kidneys, heart, gastrointestinal tract, liver, lungs, skin and endocrine glands. Biomarkers of the effectiveness of the immune control point inhibitors for GC are considered, among which one can distinguish PD-L1 expression, microsatellite instability, gene expression profile, tumor mutational load and composition of the intestinal microbiome.