Abstract
Sentinel lymph nodes (SLN) biopsy is currently the standard procedure for axillary staging in patients with invasive breast cancer and clinically negative lymph nodes (cN0). Historically, all patients with a positive sentinel lymph node (SLN) undergo classical axillary lymph node dissection (ALND). A randomized clinical trial in patients with breast cancer with clinical T1-2N0M0, with positive SLN afterwards undergo classical ALND showed that women diagnosed with T1-T2 and cN0 who underwent breast-conserving surgery and radiation therapy can safely avoid ALND. The main goal of SLN examination should be the detection of all macrometastases (> 2 mm). The role and timing of SLN in patients who received neoadjuvant polychemotherapy is still controversial and continues being studied in clinical trials.