When the pathological analysis will diagnose a metastatic SLN, complete axillary lymph node dissection (ALND) will immediately be performed. In the case of negative SLN, serial sections and detection of cytokeratine (AE1/AE3; Dako, Zymed, CA, USA) will be performed during standard pathological analysis. Macrometastases will be defined as clusters of cancer cells ≥2 mm, micrometastases as clusters of cancer cells ≥0.2 mm and <2 mm, and isolated cancer cells as clusters of cancer cells <0.2 mm. ALND will be performed in cases of macro- or micrometastases.