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

Background: 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.

Methods: 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.

Results: 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).

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