Axillary reverse mapping (ARM) in clinically node positive breast cancer patients

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Axillary reverse mapping (ARM) is a technique used in breast cancer surgery to identify and preserve lymphatic drainage from the upper extremity during axillary lymph node dissection (ALND).
• Evaluating metastatic involvement in ARM nodes is crucial for understanding cancer spread and guiding treatment decisions, particularly in clinically node-positive patients.

Purpose of the Study:

• To prospectively assess the rate of metastatic involvement in ARM nodes in breast cancer patients who received neoadjuvant chemotherapy (NAC) prior to ALND.
• To compare the metastatic involvement of ARM nodes in patients treated with NAC versus those who underwent primary ALND without NAC.

Main Methods:

• Patients with clinically node-positive invasive breast cancer scheduled for ALND were enrolled.
• Patients were divided into two groups: those who received NAC (NAC+ group) and those who did not (NAC- group).
• ARM was performed by injecting blue dye into the upper extremity, and ARM nodes were identified and removed separately during ALND.

Main Results:

• A total of 91 patients were in the NAC+ group and 21 in the NAC- group.
• ARM visualization rates were similar between groups (86.8% for NAC+ vs. 90.5% for NAC-, P = 0.647).
• Metastatic involvement of ARM nodes was significantly lower in the NAC+ group (16.5%) compared to the NAC- group (36.8%, P = 0.048).

Conclusions:

• Neoadjuvant chemotherapy significantly reduces the risk of metastatic involvement in ARM nodes for clinically node-positive breast cancer patients.
• ARM node status may be influenced by prior NAC, suggesting a potential role for NAC in reducing axillary micrometastasis.