Prospective Registry Trial Assessing the Use of Magnetic Seeds to Locate Clipped Nodes After Neoadjuvant Chemotherapy for Breast Cancer Patients

Background Targeted axillary dissection (TAD) involves locating and removing both clipped nodes and sentinel nodes for assessment of the axillary response to neoadjuvant chemotherapy (NAC) by clinically node-positive breast cancer patients. Initial reports described radioactive seeds used for localization, which makes the technique difficult to implement in some settings. This trial was performed to determine whether magnetic seeds can be used to locate clipped axillary lymph nodes for removal. Methods This prospective registry trial enrolled patients who had biopsy-proven node-positive disease with a clip placed in the node and treatment with NAC. A magnetic seed was placed under ultrasound guidance in the clipped node after NAC. All the patients underwent TAD. Results Magnetic seeds were placed in 50 patients by 17 breast radiologists. All the patients had successful seed placement at the first attempt (mean time for localization was 6.1 min; range 1-30 min). The final position of the magnetic seed was within the node (n = 44, 88%), in the cortex (n = 3, 6%), less than 3 mm from the node (n = 2, 4%), or by the clip when the node could not be adequately visualized (n = 1, 2%). The magnetic seed was retrieved at surgery from all the patients. In 49 (98%) of the 50 cases, the clip and magnetic seed were retrieved from the same node. Surgeons rated the transcutaneous and intraoperative localization as easy for 43 (86%) of the 50 cases. No device-related adverse events occurred. Conclusions Localization and selective removal of clipped nodes can be accomplished safely and effectively using magnetic seeds

Nomograms for Predicting Axillary Response to Neoadjuvant Chemotherapy in Clinically Node-Positive Patients with Breast Cancer

Background: Many patients with clinically node-positive breast cancer receive neoadjuvant chemotherapy (NAC). Recent trials suggest the potential for limiting axillary surgery in patients who convert to pathologically node-negative disease. The authors developed a nomogram to predict axillary response to NAC in patients with cN1 disease that can assist clinicians in treatment planning. Methods: Patients with cT1\u20134N1M0 breast cancer who received NAC and underwent axillary lymph node dissection from 2001 through 2013 were identified (n\ua0=\ua0584). Uni- and multivariate logistic regression analyses were performed to determine factors predictive of nodal conversion. A nomogram to predict the likelihood of nodal pathologic complete response (pCR) was constructed based on clinicopathologic variables and validated using an external dataset. Results: Axillary pCR was achieved for 217 patients (37\ua0%). Patients presenting with high nuclear grade [grade 3 vs. 1, odds ratio (OR) 13.4], human epidermal growth factor receptor 2-positive (OR 4.7), estrogen receptor (ER)-negative (OR 3.5), or progesterone receptor-negative (OR 4.3) tumors were more likely to achieve nodal pCR. These factors, together with clinically relevant factors including presence of multifocal/centric disease, clinical T stage, and extent of nodal disease seen on regional nodal ultrasound at diagnosis were used to create nomograms predicting nodal conversion. The discrimination of the nomogram using ER+ status (>1\ua0% staining) versus ER 12 status [area under the curve (AUC) 78\ua0%] was improved slightly using the percentage of ER staining (AUC 78.7\ua0%). Both nomograms were validated using an external cohort. Conclusion: Nomograms incorporating routine clinicopathologic parameters can predict axillary pCR in node-positive patients receiving NAC and may help to inform treatment decisions