Implementation of the American College of Surgeons Oncology Group Z1071 Trial Data in Clinical Practice: Is There a Way Forward for Sentinel Lymph Node Dissection in Clinically Node-Positive Breast Cancer Patients Treated with Neoadjuvant Chemotherapy?

For clinically node-positive breast cancer patients receiving neoadjuvant chemotherapy, approximately 40 % will be found to be pathologically node negative. The American College of Surgeons Oncology Group Z1071 trial was therefore conducted to evaluate sentinel lymph node dissection (SLND) in these patients. The trial's primary end point was to determine the false-negative rate (FNR) among patients with clinical N1 disease in whom at least 2 sentinel lymph nodes (SLNs) were identified. The FNR was 12.6 %, which exceeded the prespecified end point of 10.0 %. After data publication, our multidisciplinary team discussed the trial results and how we may incorporate the findings into clinical practice. Patient selection and surgical technique are critical. As an example, when dual tracer technique was used, the FNR was 10.8 %. Data from the trial presented at the San Antonio Breast Cancer Symposium suggested that the FNR could be improved if a clip was placed in the biopsy-proven positive lymph node and removal of that node during SLND was confirmed. Taking this into consideration, we have proposed an approach to surgical management of the axilla in clinically node-positive patients receiving neoadjuvant chemotherapy termed targeted axillary dissection (TAD). TAD involves placing a clip at the time a lymph node is determined to be positive. After completion of neoadjuvant chemotherapy, the clipped node is localized by using a wire or radioactive seed, and during the SLND procedure, all SLNs and the clipped node are removed. We are currently evaluating the efficacy of TAD in axillary staging after neoadjuvant chemotherapy.