Post-neoadjuvant chemotherapy sentinel node biopsy and axillary sampling for node negative (N0) axilla.

1108 Background: Post neoadjuvant chemotherapy (NACT) sentinel node biopsy (SNB) is not a standard of care due to the wide variability in false negative rate (FNR), varying from 5.7% to 33%. In operable breast cancer (OBC), FNR of less than 10% is acceptable. We attempted to find out the reliability of low axillary sampling(LAS), with dissection limited below the first intercostobrachial nerve, to correctly identify the node negative axilla in the post NACT clinically node negative (N0) patients. Methods: Women with large operable (LOBC) and locally advanced breast cancer (LABC), post-NACT clinically N0, underwent concomitant blue dye-colloid guided SNB and LAS. The identification rate, FNR, and negative predictive value (NPV) of both procedures were compared. Results: Post-NACT 209 eligible women underwent combined LAS and SNB procedure. At presentation, the tumors were large (median 5.0 cm) with 70% clinically palpable nodes. All patients received 4 cycles of neo-adjuvant anthracycline-based chemotherap...