Selecting Node-Positive Patients for Axillary Downstaging with Neoadjuvant Chemotherapy

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Axillary lymph node dissection (ALND) is a standard procedure for node-positive breast cancer patients.
• Neoadjuvant chemotherapy (NAC) can lead to axillary downstaging, potentially allowing avoidance of ALND.
• Retrieval of three or more negative sentinel lymph nodes (SLNs) is a criterion for avoiding ALND in node-positive patients post-NAC.

Purpose of the Study:

• To evaluate the rate at which node-positive patients avoid ALND after NAC.
• To identify predictors for achieving three or more negative SLNs.
• To identify predictors for nodal pathological complete response (pCR) and subsequent ALND avoidance.

Main Methods:

• Retrospective analysis of a prospectively maintained database from November 2013 to July 2019.
• Inclusion of patients with biopsy-proven N1 tumors (cT1-3) who converted to cN0 after NAC.
• SLN biopsy (SLNB) with dual mapping performed on eligible patients.

Main Results:

• 91% of eligible patients converted to cN0 and underwent SLNB; 93% had three or more SLNs identified.
• Lower rates of identifying three or more SLNs were associated with lymphovascular invasion (LVI) and higher body mass index (BMI).
• 41% of patients avoided ALND, with rates varying by tumor grade, receptor status, and LVI. Nodal pCR was achieved in 46% of patients.

Conclusions:

• ALND avoidance is feasible in 41% of cN1 breast cancer patients following NAC.
• BMI and LVI are significant factors negatively impacting SLN retrieval.
• Tumor grade, receptor status, and LVI are key predictors for ALND avoidance, aiding in patient selection.