The involvement of axillary reverse mapping nodes in patients with node-positive breast cancer

Axillary reverse mapping (ARM) procedure is useful in reducing lymphedema. However, concerns regarding oncologic safety have limited the adoption of the ARM procedure. This study aimed to evaluate the involvement of ARM nodes in node-positive breast cancer patients.

Two hundred twenty-three node-positive patients were enrolled in this study: 90 were clinically node-negative, but had one or more positive sentinel lymph nodes (SLNs) (SLN-positive group); 68 were clinicopathologically node-positive (CpN-positive group); and 65 had confirmed nodal involvement and received neoadjuvant chemotherapy (NAC) (NAC group). All patients underwent axillary lymph node dissection with fluorescent ARM.

ARM nodes were involved in 33 (36.7%) patients of the SLN-group. Residual ARM nodes after SLN biopsy were involved in 11 patients (12.2%), including 5 patients (19.2%) with crossover type nodes and 6 patients (9.4%) with non-crossover type nodes. However, the difference in involvement rates between the two types was not high enough to be significant. Of these 11 patients, moreover, four patients had three or more than 3 involved SLNs. On the other hand, the involvement rate of ARM nodes in the NAC group was significantly lower than that of the CpN-positive group (35.4% vs. 64.7%: p < 0.01). Despite lower involvement, the risk of metastases in the ARM nodes was still too high to spare ARM nodes in both the NAC group and CpN-positive group.

Suspicious or involved ARM nodes should be removed even when detected in ARM procedure, particularly in NAC-group and CpN-positive-group patients.