ARM: axillary reverse mapping - The need for selection of patients

Axillary reverse mapping (ARM) is a technique that discerns axillary lymphatic drainage of the arm from the breast. This study was performed to evaluate both the feasibility of this technique and the proportion of metastatic involvement of ARM-nodes.Patients with invasive breast cancer and an indication for axillary lymph node dissection (ALND) were enrolled in the study: patients with a tumor-positive sentinel lymph node (SLN(+)-group) and patients who had axillary metastases proven by preoperative cytology (CP-N(+)-group) were distinguished. ARM was performed in all patients by injecting blue dye. During surgery ARM-nodes were identified and removed first, followed by ALND.Between October 2009 and June 2011 93 patients underwent ARM. There were 43 patients in the SLN(+)-group and 50 patients in the CP-N(+)-group. No significant differences in visualization rate of ARM-nodes between the groups (86 vs 94% respectively, P = 0.196) were identified. In the SLN(+)-group none of the ARM-nodes contained metastases versus 11 patients (22%) in the CP-N(+)-group (P = 0.001). Patients receiving neoadjuvant systemic therapy had a significantly lower risk of additional axillary lymph node metastases (24.6 vs 44.4%, P = 0.046).The ARM procedure is technically feasible with a high visualization rate. The proportion of patients with metastases in the ARM-nodes was significantly higher in patients with proven axillary metastases than in patients with a positive SLN. Patients with SLN metastases appear to be good candidates for the ARM technique and possibly also patients with proven axillary metastases receiving neoadjuvant chemotherapy.