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

Abstract

Introduction: The axillary lymph node status is one of the most important prognostic factors in breast cancer. For locally advanced tumors, neoadjuvant chemotherapy favors higher rates of breast lumpectomy and downstaging tumor burden of axilla. The aim of this study was to evaluate the use of a standardized image-guided protocol after neoadjuvant chemotherapy to enable sentinel node dissection in patients with axillary downstaging, avoiding axillary dissection. Methods: Retrospective cohort study of data collected from medical records of patients who underwent neoadjuvant chemotherapy in a single center, from January 2014 to December 2018. The protocol comprises the placement of a metal clip in positive axillary lymph node, in patients with up to two clinically abnormal lymph nodes presented on imaging. After neoadjuvant chemotherapy, and once a radiologic complete response was achieved, sentinel node dissection was performed using blue dye and radiotracer. Axillary dissection were avoided in patients whose clipped sentinel node were negative for metastasis and in patients with three identified and negative sentinel node dissection. Results: A total of 471 patients were analyzed for this study: 303 before and 165 after the implementation of the protocol; 3 cases were excluded. The rate of sentinel node dissection in clinical nodes positive patients was statistically higher in this group when compared to patients treated before the protocol implementation (22.8% vs. 40.8%; p=0.001). Patients with triple negative and HER2-positive tumors underwent sentinel node dissection more frequently when compared to luminal tumors (p=0.03). After multivariate analysis, the variables that were associated with a greater chance of performing sentinel node dissection were clinical staging, type of surgery performed and implementation of the axillary assessment protocol. Conclusions: The results showed that the use of an easily and accessible image-guided protocol can improve sentinel node dissection in selected patients, even if the lymph node was positive previously to neoadjuvant treatment.