Tumor-infiltrating CD45RO+ memory cells are associated with a favorable prognosis breast cancer

Background CD45RO is a marker for memory lymphocytes. Whether CD45RO + tumor-infiltrating lymphocytes (TILs) prevent breast cancer recurrence is unclear. Methods In the present study, we evaluated CD45RO expression in TILs as a predictor of prognosis in 98 patients with breast cancer who underwent radical surgery without neoadjuvant chemotherapy. Patients were classified as CD45RO + /TILs High or CD45RO + /TILs Low based on median immunohistochemistry levels. Results CD45RO + /TILs High were associated with smaller tumor size. The CD45RO + /TILs High group also had significantly fewer metastatic lymph nodes ( P = 0.0082) and fewer peritumoral lymphatic invasions ( P = 0.0284). The CD45RO + /TILs High group enjoyed longer recurrence-free survival ( P = 0.0453) but not cancer-specific survival ( P = 0.0640) in univariate analysis. Conclusions These results suggested that CD45RO + effector cells may both help eradicate local tumors and prevent metastases to the lymphatic systems in breast cancer patients. High ratio of CD45RO expressing TILs was associated with recurrence-free survival improvement and a trend toward cancer-specific survival improvement in breast cancer patients.