Intraepithelial Effector (CD3+)/Regulatory (FoxP3+) T-Cell Ratio Predicts a Clinical Outcome of Human Colon Carcinoma

Abstract

Background & Aims: Regulatory T cells (Tregs) express the forkhead box transcription factor (FoxP3) and suppress the antitumor immune response. We investigated whether the intratumoral densities of FoxP3+ and effector CD3+ lymphocytes are associated with prognosis of patients with colon cancer. Methods: FoxP3 and CD3 expression and location were determined in stage II and III colon carcinomas (n = 160) and normal mucosa (n = 25) by immunohistochemistry; CD4 and FoxP3 were localized by dual immunofluorescence microscopy. T-cell markers were compared with pathological variables, DNA mismatch repair status, and patient survival using Cox proportional hazards models. Results: FoxP3+ and CD3+ T-cell densities were increased in carcinomas compared with autologous normal mucosa (P