T-Lymphocyte Subsets in Patients with AJCC Stage III Gastric Cancer during Postoperative Adjuvant Chemotherapy

BACKGROUND AND AIMS: Advanced neoplastic diseases alter the immune response in cancer patients. The aim of this study was to evaluate the changes of T-lymphocyte subsets during postoperative adjuvant chemotherapy, and the relationship between T-lymphocyte subsets and tumor recurrence in AJCC stage III gastric cancers. MATERIAL AND METHODS: Analysis of T-lymphocyte subsets was performed in 39 patients with stage III gastric adenocarcinoma who had undergone a curative gastric resection and postoperative chemotherapy. CirculatingT-lymphocyte subsets were measured on venous blood by using flow cytometry and monoclonal antibodies on preoperative day 1, and postoperative months 1, 3, and 6. RESULTS: The 5-year disease-free survival rates of patients with stage 3a and 3b gastric cancer were 57.1% and 33.3%, respectively (p = 0.06). Values of CD3+ and CD4+ T-cells, and CD4+/CD8+ ratios were consistently lower in the recurrence group throughout the observation period. CD4+ T-cell counts were significantly lower in the recurrence group on preoperative day 1, and postoperative months 1 and 6. However, most values of the T-lymphocyte subsets showed no statistically significant difference when comparing the stage 3a and 3b disease patient groups. CONCLUSIONS: The results of this study suggest that immunosuppression associated with CD3+ and CD4+ T-cell depression is a risk factor for postoperative recurrence in patients with stage III gastric cancer.