Changing Practices in Axillary Surgery After Neoadjuvant Breast Cancer Therapy: Insights From the EUSOMA European...

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Sentinel lymph node biopsy (SLNB) is a viable option for axillary staging post-neoadjuvant treatment (NAT) in both clinically node-negative (cN0) and node-positive (cN+) breast cancer patients.
• The efficacy of NAT in downstaging axillary lymph nodes has led to increased consideration of SLNB.

Purpose of the Study:

• To evaluate the trends and utilization of SLNB in a large European population of breast cancer patients who have undergone NAT.
• To analyze the shift in surgical axillary management strategies following NAT over time.

Main Methods:

• Analysis of prospectively collected data from 17,321 breast cancer patients who received NAT between 2010 and 2021, sourced from the EUSOMADB database.
• Stratification of patients into clinically node-negative (cN0) and clinically node-positive (cN+) groups.
• Evaluation of SLNB and direct axillary dissection (AD) rates over two distinct periods (2010-2015 and 2016-2021).

Main Results:

• A significant increase in SLNB utilization was observed for cN0 patients (86% to 94%) and cN+ patients (25% to 40%) from the earlier to the later period.
• Correspondingly, direct axillary dissection (AD) rates decreased significantly in both cN0 (14% to 6%) and cN+ (75% to 60%) patient groups.
• Higher SLNB rates were noted for triple-negative and HER2-enriched subtypes, with significant increases across all subtypes over time. Predictors included later surgery period, specific molecular subtypes, breast-conserving surgery, and NAT type.

Conclusions:

• There is a substantial and growing trend favoring SLNB as the primary surgical approach for axillary staging after NAT in breast cancer.
• This shift indicates a move towards less invasive surgical procedures, driven by the effectiveness of NAT in managing axillary lymph node involvement.