Axillary Surgery in Breast Cancer: Evidence-Based De-escalation Across Upfront and Post-Neoadjuvant Settings

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Axillary surgery for breast cancer has evolved from radical clearance to de-escalation.
• Sentinel lymph node biopsy (SLNB) replaced axillary lymph node dissection (ALND), reducing morbidity.
• Recent trials question the necessity of SLNB in select patients, favoring optimized interventions.

Purpose of the Study:

• To review evidence on de-escalating axillary surgery in breast cancer.
• To analyze the impact of sentinel lymph node metastasis burden on treatment decisions.
• To explore the potential omission of axillary surgery in specific patient groups.

Main Methods:

• Review of randomized trials categorized by sentinel lymph node metastasis burden (micrometastasis, mixed, macrometastasis).
• Analysis of studies comparing observation versus SLNB in clinically node-negative patients.
• Examination of neoadjuvant treatment data and ongoing trials exploring complete axillary surgery omission.

Main Results:

• Omitting axillary lymph node dissection (ALND) is safe for patients with micrometastases or 1-2 positive sentinel lymph nodes (SLNB) when systemic therapy and radiotherapy are administered.
• ALND omission is also safe for patients with 1-2 macrometastases.
• Observation may be non-inferior to SLNB in clinically node-negative, imaging-negative tumors.
• Complete omission of axillary surgery is being investigated in neoadjuvant settings for excellent responders.

Conclusions:

• Axillary surgery de-escalation is supported by robust evidence across varying sentinel lymph node metastasis burdens.
• Optimizing axillary surgery based on disease biology, systemic therapy response, and patient quality of life is the current trend.
• Further research is ongoing to potentially omit axillary surgery entirely in select breast cancer patients.