Keywords: breast cancer, positive lymph nodes, axillary node dissection

The presence of axillary lymph node metastases is an important prognostic indicator in patients with invasive breast cancer. Diagnostic procedures for axillary lymph nodes are ultrasound-guided axillary lymph node biopsy and sentinel node biopsy. If metastases are found in the axillary lymph nodes, an axillary lymph node dissection is performed. However, this procedure may be associated with serious complications and side effects. Recent studies have shown that deciding not to perform an axillary lymph node dissection is not always associated with a poorer prognosis. This dissertation shows that the various patient groups with positive lymph nodes largely differ from each other in terms of tumour characteristics and prognosis. Axillary lymph node dissection remains necessary in specific patient groups.