This is a retrospective, observational, multicentric and no profit study. The study involves patients with diagnosis of cN+ breast cancer who underwent neoadjuvant treatment and then treated with lymph node biopsy or axillary lymphadenectomy, referring to the participating centers.
For each patient the following clinical-anamnestic information will be collected: age, pre-NAC blood cell count, tumor dimension, clinical staging (cT, cN), histological information (tumor subtype, grading, receptors' status, Ki-67 value), neoadjuvant treatment regimen, clinical and radiological local response after NAC, clinical and radiological nodal response after NAC, type of surgery, number of examined lymph nodes, number of positive lymph nodes, pathological staging after surgery (ypT, ypN).
