Prognostic Impact of Residual T and N Status After Neoadjuvant Therapy in Breast Cancer

Background/Aim: Residual disease after neoadjuvant systemic therapy (NST) is strongly associated with prognosis in breast cancer. However, currently available indices such as the Residual Cancer Burden (RCB) and Neo-Bioscore are complex and not readily applicable in daily clinical practice. This study aimed to evaluate the prognostic significance of residual tumor morphology using only pathological T and N factors as a simple and clinically implementable index. Patients and Methods: Among 327 patients who received NST at our institution, 174 non-pathological complete response (non-pCR) cases who underwent axillary lymph node dissection were analyzed. Patients were classified according to the presence or absence of residual T and/or N factors (ypT+/ypN+, ypT+/ypN−, ypT−/ypN+). Disease-free survival (DFS) and cancer-specific survival (CSS) were assessed using Kaplan–Meier and Cox regression analyses. Results: Patients who achieved pCR had significantly better DFS and CSS (p