Improved Axillary Evaluation Following Neoadjuvant Therapy for Patients With Node-Positive Breast Cancer Using Selective Evaluation of Clipped Nodes: Implementation of Targeted Axillary Dissection

Abstract

Purpose: Placing clips in nodes with biopsy-confirmed metastasis before initiating neoadjuvant therapy allows for evaluation of response in breast cancer. Our goal was to determine if pathologic changes in clipped nodes reflect the status of the nodal basin and if targeted axillary dissection (TAD), which includes sentinel lymph node dissection (SLND) and selective localization and removal of clipped nodes, improves the false-negative rate (FNR) compared with SLND alone.

Methods: A prospective study of patients with biopsy-confirmed nodal metastases with a clip placed in the sampled node was performed. After neoadjuvant therapy, patients underwent axillary surgery and the pathology of the clipped node was compared with other nodes. Patients undergoing TAD had SLND and selective removal of the clipped node using iodine-125 seed localization. The FNR was determined in patients undergoing complete axillary lymphadenectomy (ALND).

Results: Of 208 patients enrolled in this study, 191 underwent ALND, with residual disease identified in 120 (63%). The clipped node revealed metastases in 115 patients, resulting in an FNR of 4.2% (95% CI, 1.4 to 9.5) for the clipped node. In patients undergoing SLND and ALND (n = 118), the FNR was 10.1% (95% CI, 4.2 to 19.8), which included seven false-negative events in 69 patients with residual disease. Adding evaluation of the clipped node reduced the FNR to 1.4% (95% CI, 0.03 to 7.3; P = .03). The clipped node was not retrieved as an SLN in 23% (31 of 134) of patients, including six with negative SLNs but metastasis in the clipped node. TAD followed by ALND was performed in 85 patients, with an FNR of 2.0% (1 of 50; 95% CI, 0.05 to 10.7).

Conclusion: Marking nodes with biopsy-confirmed metastatic disease allows for selective removal and improves pathologic evaluation for residual nodal disease after chemotherapy.

Fig 1.

Ability of pathologic evaluation of the clipped node to predict nodal status of remaining axillary nodes following neoadjuvant therapy. Pathology of the clipped node was compared with other lymph nodes in patients undergoing axillary lymphadenectomy (ALND) to determine the false-negative rate of the evaluation of the clipped node. *False-negative, clipped node showed no metastases but other nodes had residual disease.

Fig 2.

Ability of sentinel lymph-node dissection (SLND) plus evaluation of the clipped node to predict nodal status after neoadjuvant therapy. Pathologic results of sentinel lymph nodes (SLN) and clipped nodes were compared with pathology of the remaining axillary nodes to determine false-negative rates. ALND, axillary lymphadenectomy.

Fig 3.

Iodine-125 seed localized removal of clipped axillary lymph nodes. Targeted axillary dissection involves not only removal of all sentinel nodes but also selective localization and removal of clipped nodes. (A) An iodine-125 seed is placed within the clipped node by a breast radiologist 1 to 5 days before surgery under ultrasound guidance. Mammogram performed after seed placement shows the clip and the seed within the node. (B) Once the localized node is removed, a specimen radiograph is performed to ensure that the clip and seed have been removed.

Fig 4.

Ability of targeted axillary dissection (TAD) to predict nodal response after neoadjuvant therapy. Pathologic results of nodes removed from TAD were compared with other lymph nodes in patients who underwent axillary lymphadenectomy (ALND) to determine the false-negative rate of TAD. SNL, sentinel lymph node.