Axillary Reverse Mapping in Clinically Node-Positive Breast Cancer Patients.

Background: Axillary reverse mapping (ARM) nodes are involved in a significant proportion of clinically node-positive (cN+) breast cancer patients. However, neoadjuvant chemotherapy (NAC) is effective at decreasing the incidence of nodal metastases in cN+ patients.

Patients And Methods: One hundred forty-five cN+ patients with confirmed nodal involvement on ultrasound-guided fine needle aspiration cytology were enrolled in this study: one group underwent axillary lymph node dissection (ALND) without NAC (upfront surgery group), and the other group underwent ALND following NAC (NAC group). The patients underwent F-FDG-positron emission tomography/computed tomography (F-FDG-PET/CT) before surgery, as well as an ARM procedure during ALND.

Results: the rates of involvement of ARM nodes in the NAC group were significantly lower than those of the upfront surgery group (36.6% vs. 62.2%, < 0.01). Notably, involvement was significantly decreased after NAC in non-luminal-type tumors as compared to the luminal-type (18.4% vs. 48.5%: < 0.01). Moreover, there was a significant difference in ARM node involvement after NAC between patients with or without axillary uptake of F-FDG (61.5% vs. 32.5%: < 0.01).

Conclusions: NAC significantly decreased the risk of ARM node metastases in cN+ patients, but F-FDG-PET/CT was not suitable to detect residual metastatic disease of the axilla after NAC.