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

Axillary reverse mapping (ARM) is a technique to map and preserve upper extremity lymphatic drainage during axillary lymph node dissection (ALND) in breast cancer patients. We prospectively evaluated the metastatic involvement of ARM-nodes in patients who underwent an ALND for clinically node positive disease following (neo)adjuvant chemotherapy (NAC) in comparison to patients in whom primary ALND was performed without NAC.

Patients with clinically node positive invasive breast cancer, confirmed by fine needle aspiration cytology and scheduled for primary ALND were enrolled in the study. Patients were separated into two groups: one group treated with NAC (NAC+ group) and one group not treated with NAC (NAC- group). ARM was performed in all patients by injecting blue dye into the ipsilateral upper extremity. During ALND, ARM-nodes were first identified and removed separately, followed by a standard ALND.

91 patients were included in the NAC+ and 21 patients in the NAC- group. There was no difference in the ARM visualization rate between the two groups (86.8% for NAC+ group versus 90.5% for NAC- group, P = 0.647). In the NAC+ group 16.5% of the patients had metastatic involvement of the ARM-nodes versus 36.8% of the patients in the NAC- group (P = 0.048).

The risk of metastatic involvement of ARM-nodes in clinically node positive breast cancer patients is significantly lower in patients who have received NAC.