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.
Keywords: Breast cancer; CD45RO; Prognosis; Tumor-infiltrating lymphocytes.