Tailored Axillary Surgery With or Without Axillary Lymph Node Dissection Followed by Radiotherapy in Patients With Clinically Node-positive Breast Cancer (TAXIS)

Inclusion Criteria: Inclusion criteria at pre-registration: * Written informed consent according to ICH/GCP regulations prior to any trial specific procedures. * Breast cancer, node positive detected by palpation or imaging (with or without planned neoadjuvant treatment) * Female or male aged ≥ 18 years * Ability to complete the Quality of Life questionnaires Inclusion criteria at registration: * Node-positive breast cancer (histologically or cytologically proven both in primary tumor and in lymph node) AJCC/UICC \[42\] stage II-III (all molecular subtypes allowed): * Node-positivity detected by imaging (iN+) and confirmed by pathology * Node-positivity detected by palpation (cN1-3) and confirmed by pathology * Occult breast cancer is allowed, if biopsy-proven axillary lymphatic metastasis is present * Eligible for primary ALND or sentinel lymph node (SLN) procedure with frozen section and either: * Newly diagnosed * Isolated in-breast recurrence or second ipsilateral breast cancer after previous breast conserving surgery and sentinel procedure and at least 3 years disease free and no prior axillary dissection or axillary RT * Most suspicious axillary lymph node clipped * Baseline Quality of Life questionnaire has been completed * WHO performance status 0-2 * Adequate condition for general anesthesia and breast cancer surgery * Women with child-bearing potential are using effective contraception, are not pregnant or lactating and agree not to become pregnant d…