The effect of local immunity on gastric cancer prognosis

Aim . To study the state of local immunity in patients with gastric adenocarcinoma. Materials and methods. From 2017 to 2018, 45 previously untreated patients with gastric adenocarcinoma (25 with stage I–III, 20 with stage IV) received surgical/combined treatment or chemotherapy, respectively, at the Blokhin Scientific Research Center of Oncology. Tumor tissue was taken before treatment. By using flow cytometry there were evaluated the percentage of tumor tissue infiltration by lymphocytes (CD45+CD14-TIL); T cells (CD3+CD19-TIL); B cells (CD3-CD19+TIL); NK cell (CD3-CD16+CD56+TIL); effector cells CD16 (CD16+Perforin+TIL) and CD8 (CD8+Perforin+TIL) with their cytotoxic potential – active CD16TIL and active CD8TIL; subpopulations of regulatory T cells – NKT cells (CD3+CD16+CD56+TIL), regulatory cells CD4 (CD4+CD25+CD127-TIL) and CD8 (CD8+CD11b-CD28-TIL). The prognostic value of immune cells for overall survival (OS) and progression-free survival (PFS) was assessed. Results. A favorable prognosis factor for progression-free survival in patients with local and locally advanced forms of gastric cancer was an increase in the number of CD3-CD19+TIL (HR 0.862, 95% CI 0.782–0.957, p =0.005), and an unfavorable prognosis was an increase in NK cells (CD3-CD16+CD56+TIL); HR 1.382, 95% CI 1.087–1.758, p =0.008. The negative effect of the relative content of NK cells (CD3-CD16+CD56+TIL) and NKT cells (CD3+CD16+CD56+TIL) on OS of patients with metastatic gastric cancer noted (HR 1.249, 95% CI 0.997–1.564, p =0.053; HR 1.127, 95% CI 1.025–1.239, p =0.013). At the same time, an increase in the percentage of tumor tissue infiltration by lymphocytes (CD45+CD14-TIL) and an increase in the age of patients (HR 1.005, 95% CI 1.002–1.008, p =0.003; HR 1.098, 95% CI 1.031–1.170, p =0.004) reduce the incidence of PFS in patients with metastatic gastric carcinoma. Conclusion. Indices of local immunity can serve as additional prognostic factors for gastric carcinoma.