Benefits of a standardized protocol for axillary management after neoadjuvant chemotherapy in a single center.

Abstract Purpose: Axillary lymph node status is one of the most important prognostic factors in breast cancer. Neoadjuvant chemotherapy (NACT) has been indicated for locally advanced tumors, and for HER2-positive and triple negative tumors larger than 2.0 and 1.0 cm, respectively, regardless of axillary status. NACT allows clinicians to assess the biological responses of the tumor, predicting prognosis and permitting more conservative surgeries in breast and axilla.Objective: evaluate the use of a standardized protocol after NACT to enable, sentinel node dissection (SLND) in patients with axillary downstaging, avoiding axillary dissection (ALND).Methods: retrospective cohort study of data collected from medical records of patients who underwent NACT in a single center, from January 2014 to December 2018. 471 patients were included in this study: 303 patients before and 165 patients after the implementation of this protocol. This protocol comprises a placement of a metal clip in biopsied lymph node, in patients with up to 2 clinically lymph nodes. After NACT, if a radiologic complete response were achieved, SLND was performed using blue die and tecnecion99. ALDN were avoided in patients whose clipped sentinel node were negative for metastasis. Trial registration number 2786/19, october,19, 2019, retrospectively registered.Results: Protocol avoided ALDN in 18% of selected patients (p< 0.05). Also, patients with triple negative and HER2 positive tumors underwent SLND most frequently, when compared to Luminal tumors (p 0.03).This results showed that the proposed protocol can improve SLND in selected patients when axillary targeted dissection cannot be performed.