Sentinel node biopsy (SNB) is the standard procedure for axillary staging in patients with clinically lymph node negative invasive breast cancer. Completion axillary lymph node dissection (c-ALND) may not be necessary for all patients as a significant number of patients have no further metastases in non-sentinel nodes (nonSN) and c-ALND may not improve survival. | Determinants for non-sentinel node metastases in primary invasive breast cancer A population-based cohort study of 602 consecutive patients with sentinel node metastases