Intratumoural FOXP3-positive regulatory T cells are associated with adverse prognosis in radically resected gastric cancer

We investigated the clinical significance of tumour-infiltrating FOXP3-positive regulatory Tcells (Tregs) in radically resected (R0) gastric cancer. From a single-institution database,tumors of 110 patients who underwent R0 resection for stage II–III disease were studiedfor FOXP3-positive Tregs by immunohistochemistry. The observed median number ofFOXP3-positive Tregs was used as the cut-point in analyses (<6 versus P6 count). Tregswere significantly higher in gastric carcinomas than in normal tissue (P = 0.0001). TregscountP6 was significantly associated with vascular/lymphatic/perineural invasion (VELIPI)in the tumour (P = 0.03). Multivariate analysis showed association between adverse relapsefreesurvival and grading 3, stage III, VELIPI and Tregs count P6 (P = 0.02). Adverse overallsurvival was associated with grading 3, stage III, VELIPI and Tregs count P6 (P = 0.006).FOXP3-positive Tregs may be a novel marker for identifying high-risk gastric cancerpatients. Present findings deserve additional investigation as Tregs may also represent aninnovative therapeutic target.