Cavalcante FP, Millen EC, Zerwes FP, Novita GG. Role of Axillary Surgery After Neoadjuvant Chemotherapy. JCO Glob Oncol. 2020 Feb;6:238-241.
“In a US study, associating selective localization and removal of clipped nodes with SLN dissection, known as targeted axillary dissection, reduced false-negative rates to approximately 2% compared with 4% with removal of the clipped lymph node alone.  However, patients are required to undergo two procedures: placement of the clip before systemic treatment and marking it to identify the lymph node during surgery. A retrospective analysis showed that in patients with clipped lymph nodes who were referred for preoperative marking, the clip failed to be identified in 20% of those patients, even when computed tomography was used, with the additional risk of the clip not being removed during surgery.  Therefore, the use of clips is controversial, because it is sometimes impossible to remove the clip alone. Despite the association between the number of lymph nodes and false-negative rates, there are still no convincing data regarding clinical outcome.”
Caudle AS, Yang WT, Krishnamurthy S, et al. Improved Axillary Evaluation Following Neoadjuvant Therapy for Patients With Node-Positive Breast Cancer Using Selective Evaluation of Clipped Nodes: Implementation of Targeted Axillary Dissection. J Clin Oncol. 2016 Apr 1;34(10):1072-8.
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.