CCR4 Expression in Tumor-Infiltrating Regulatory T Cells in Patients with Squamous Cell Carcinoma of the Lung: A Prognostic Factor for Relapse and Survival.

To clarify the prognostic impact of tumor-infiltrating effector regulatory T cells (eTregs) in non-small cell lung cancer (NSCLC), eTregs were evaluated by immunohistochemical detection of CCR4 and Foxp3 in 108 consecutive surgical NSCLC tumors. Multivariate analysis showed that a high ratio of CCR4(+) eTregs to total Tregs (40%) was the only independent risk factor for relapse-free survival (odds ratio [OR]: 6.54, 95% confidence interval: 1.67-25.7, p=.007) and overall survival (OR: 3.76, p=.037) in lung squamous cell carcinoma (SqCC). These results highlight the prognostic importance of the balance of tumor-infiltrating Tregs in resected lung SqCC.