Omission of Axillary Lymph Node Dissection in Case of Tumor Spread to Lymph Nodes in the Armpit in Breast Cancer

Inclusion Criteria: * Patients with primary invasive breast cancer clinical stage II-III * Palpable or non-palpable axillary metastases visible by ultrasound (other imaging accepted if confirmatory ultrasound is performed) and confirmed by fine needle aspiration or core biopsy * Written informed consent * Age ≥ 18 years Exclusion Criteria: * Distant metastases * Ipsilateral metastases in internal mammary, infra- or supraclavicular lymph nodes without confirmed axillary nodal involvement * Preoperative suspicion of extensive nodal involvement, i.e. locally advanced disease * Nodes fixed to each other or to neighbouring structures on palpation or imaging * History of contralateral invasive breast cancer within 5 years * Bilateral invasive breast cancer if (i) one side meets any exclusion criteria or (ii) both sides meet all inclusion criteria * Pregnancy * Neoadjuvant systemic treatment (short course of neoadjuvant endocrine therapy \<three months is allowed) * Medical contraindications for or expressed preoperative wish to abstain from radiotherapy or the recommended adjuvant systemic treatment which complies with standard of care, taking age and comorbidity into consideration * Inability to absorb or understand the meaning of the study information; for example, through disability, inadequate language skills or dementia