In Switzerland, 5'500 women and 30 to 40 men are diagnosed with breast cancer every year. It accounts for one third of all cancer diagnoses among women, and causes approximately 1'350 deaths per year. Around 1'200 patients per year need axillary lymph node dissection (ALND) as part of their surgical treatment. ALND is indicated primarily for node-positive breast cancer. Patients are identified either by pre-operative evaluation of the axilla or by intraoperative sentinel lymph node biopsy (SLNB).