Sentinel lymph node biopsy after neoadjuvant systemic therapy

Sentinel node biopsy is becoming an alternative to axillary node dissection for axillary staging of Stage 1-11 breast cancers. Similarly, operable breast cancer is increasingly treated with neoadjuvant chemotherapy. Sentinel node biopsy's feasibility and accuracy following neoadjuvant chemotherapy are important because chemotherapy downstages axillary lymph nodes in 30% to 40% of patients. Small studies had addressed this issue, but in the NSABP B-27 trial over 400 patients underwent lymphatic mapping and an attempt for sentinel node biopsy following neoadjuvant chemotherapy. Sentinel node biopsy achieved results comparable to those in multicenter trials of its use after diagnosis and before systemic therapy, supporting its usefulness in patients who have received neoadjuvant chemotherapy and justifying the expanded use of neoadjuvant chemotherapy for its potential to decrease the extent of surgery in the axilla.