Prognostic Significance of T Helper 1 and 2 and T Cytotoxic 1 and 2 Cells in Patients with Non-small Cell Lung Cancer

Background: We report the prognostic significance of peripheral and tumor-infiltrating Th1, Th2, Tc1 and Tc2 cells in lung cancer patients. Materials and Methods: We evaluated the rates of interferon (IFN)-γ+/CD4+ cells (Th1), interleukin (IL)-4+ /CD4+ cells (Th2), IFN-γ+/CD8+ cells (Tc1), IL-4+ /CD8+ cells (Tc2), and the ratio of Th1 to Th2 and that of Tc1 to Tc2 among peripheral blood lymphocytes (PBL) and tumor-infiltrating lymphocytes (TIL), in 51 consecutive patients with non-small cell lung cancer, by detecting the intracellular cytokine production using three-color flow cytometry. Results: Patients with a low Th1/Th2 ratio in peripheral blood lymphocytes had a significantly better prognosis than those with a high Th1/Th2 ratio (5-year survival rate: low: 74.7% vs. high: 50.3%; p=0.038). Patients with a low Th1/Th2 ratio in peripheral blood had a significantly better prognosis than those with a high Th1/Th2 ratio in pathological Stage II or III (5-year survival rate: low: 66.6% vs. high: 18.2%; p=0.018). Conclusion: A high Th1/Th2 ratio in peripheral blood is a negative prognostic factor, especially in pathological Stage II or III non-small cell lung cancer patients.