Intratumoral FOXP3+VEGFR2+ regulatory T cells are predictive markers for recurrence and survival in patients with colorectal cancer.

Previously, we have shown that CD8(+)T/FOXP3(+) cell ratio but not FOXP3(+) cell number alone is an independent prognostic factor for colorectal cancer. In the present study, we evaluated whether the number of intratumoral FOXP3(+)VEGFR2(+) (itFOXP3(+)VEGFR2(+)) T cells alone could be a predictive factor for survival prognosis in patients with colorectal cancer. Distribution of regulatory T cells (Tregs) at tumor sites derived from 88 patients with primary colorectal cancer was fluorescence-immunohistochemically examined. Relatively low number of itFOXP3(+)VEGFR2(+) cells significantly correlated with better [corrected] disease-free survival (DS) and overall survival (OS); multivariate analysis indicated that number of itFOXP3(+)VEGFR2(+) cells is an independent predictive and prognostic factor of DS and OS while neither intratumoral FOXP3(+) cell number nor intratumoral FOXP3(+)VEGFR2(-) cell number alone showed significant correlation with DS or OS. These results suggest that FOXP3(+)VEGFR2(+) may be a better predictive Treg marker than FOXP3(+) alone for recurrence and survival in patients with colorectal cancer.