Infiltrating regulatory T cell numbers is not a factor to predict patient's survival in oesophageal squamous cell carcinoma

Abstract

CD4/8 status has been previously reported to be a critical factor in the prognosis of oesophageal squamous cell carcinoma (OSCC). In the current study, we investigated the effect of regulatory T cells (T_reg; Foxp3⁺ lymphocytes) on the status of CD4⁺ and CD8⁺ T cells in 122 patients with OSCC. Immunohistochemical analysis of T_reg was performed using an antibody against Foxp3. The survival rate for low Foxp3 patients was significantly lower than for high Foxp3 patients (P=0.0028 by log-rank test), but Foxp3 status did not significantly correlate with prognosis in CD4/8(+/+) patients or CD4/8(+/−) or (−/+) patients (P=0.5185 and 0.8479, respectively, by log-rank test). We also found that Foxp3 status correlated with CD4/8 status (P=0.0002 by χ² test) and that the variance of CD8/CD4 ratio in patients with low Foxp3 was larger than in patients with high Foxp3 (Preg suppress anti-tumour immunity in patients with OSCC. Rather, the CD8/CD4 ratio and CD4/8 status appear to be critical factors in anti-tumour immunity. Furthermore, T_reg numbers correlate with both the CD8/CD4 ratio and the CD4/8 status, suggesting that T_reg number is not a factor to predict patient's survival in OSCC.