Role of CD4(+)T, CD8(+)T Cells, and CD4(+)T/CD8(+)T Cell Ratio in Gastric Cancer and Its Clinical Significance

OBJECTIVE: To study the expression and clinical importance of CD4(+)T, CD8(+)T cells, and CD4(+)T/CD8(+)T cell percentage in gastric cancer (GC) patients. METHODS: The blood count of CD4(+)T and CD8(+)T lymphocytes was ascertained via flow cytometry before surgery in 93 GC patients undergoing gastrectomy. The CD4(+)T, CD8(+)T, and Foxp3(+)T lymphocytes in cancerous and normal adjacent tissues and the presence of PD-L1 in cancerous tissues were detected via immunohistochemistry. The link between the permeation of CD4(+)T, CD8(+)T lymphocytes in venous blood, and cancer and normal adjacent tissues was analyzed. RESULTS: Lauren histotype, TNM stage, lymphatic/nervous invasion, and NLR level were all considerably associated with peripheral CD4(+)T and CD8(+)T cell levels, whereas CD8(+)T lymphocytes were also associated with vascular invasion (p < 0.05). The CD4(+)T lymphocyte counts, CD4(+)T, and CD8(+)T cell percentage in GC tissues were found to have been decreased when compared to normal adjacent tissues, whereas the CD8(+)T and Foxp3(+)T lymphocyte count was higher in GC tissues (p < 0.05). According to a Spearman analysis, the CD4(+)T and CD8(+)T cell counts in tumor tissues were positively related to the Foxp3(+)T lymphocyte count (p < 0.05). Greater peripheral CD4(+)T lymphocyte counts and increased level of CD4(+)T/CD8(+)T percentage corresponded with greater CD4(+)T cell levels and increased CD4(+)T/CD8(+)T quantity in normal adjacent tissues. Higher levels of peripheral CD8(+)T cells corresponded with higher quantities of CD8(+)T cells in cancer tissues. A reduced CD4(+)T lymphocyte count, together with a reduced CD4(+)T/CD8(+)T percentage in venous blood, was consistent with a diminished CD4(+)T cell count along with a reduced CD4(+)T/CD8(+)T lymphocyte ratio in cancer and normal adjacent tissues. CONCLUSION: The peripheral quantity of CD4(+)T and CD8(+)T lymphocytes in GC patients can partly reflect the infiltrating state of these lymphocytes in cancer and normal adjacent tissues and can preliminarily predict immunotherapy response to a certain extent.