[CD8 and FOXP3 expression in stromal tumor-infiltrating lymphocytes of triple-negative breast carcinomas: a...

To investigate the relationship between stromal tumor-infiltrating lymphocytes (TIL) and CD8 or FOXP3 positive lymphocytes in triple-negative breast carcinoma.

A total of 160 triple-negative breast carcinomas were collected from the First Affiliated Hospital of Nanjing Medical University during 2012 to 2014. All were surgical excision or biopsy specimens from patients without prior chemotherapy and radiotherapy. Histopathologic analysis of stromal TIL was performed on hematoxylin and eosin-stained sections, and MaxVision immunohistochemical method was used for detection of CD8 and FOXP3 protein expression.

Stromal TILs were positively correlated with Ki-67 labeling index (P=0.002). The density of CD8(+) cytotoxic T-lymphocyte (CTL) was negatively correlated with tumor size (P=0.009), and positively correlated with Ki-67 index (P=0.021). The density of FOXP3(+) regulatory T-lymphocyte (Treg) was inversely correlated with the patient age (P=0.030), and positively correlated with histological grade (P=0.026). Stromal TILs were positively correlated with the density of CD8(+) CTL (P=0.014).

The percentage of stromal TILs and density of CD8(+) CTL are associated with tumor cell proliferation of triple-negative breast cancers. The density of FOXP3(+) Treg is significantly associated with poor prognosis. Stromal TIL is positively correlated with the density of CD8(+) CTL. Stromal TIL may provide a potential marker for pathological diagnosis and a target for guiding adjuvant therapy in patients with triple-negative breast cancers.