Axillary ultrasonography combined with pre-operative wire localisation of clipped node in nodal restaging after neoadjuvant chemotherapy in node positive breast cancer patients: a pilot study

Abstract

Objective: To evaluate the role of axillary ultrasonography (axUS) and ultrasound-guided pre-operative wire localisation of pre-treatment positive clipped node (CN) for prediction of nodal response to neoadjuvant chemotherapy (NACT) in node positive breast carcinoma patients.

Methods and materials: A prospective study was conducted between June 2018 and August 2020 after Ethics Committee approval. Breast carcinoma patients (cT1-cT4b) with palpable axillary nodes (cN1-cN3) and suitable for NACT were recruited after written informed consent. Single, most suspicious node was biopsied and clipped. Nodal response to NACT was assessed on axUS. Wire localisation of CN was performed prior to axillary lymph node dissection (ALND). Diagnostic performances of axUS and CN excision were assessed.

Results: Of the 69 patients evaluated, 32 patients (mean age, 43.5 ± 11.8 years; females, 31/32 [97%]; pre-menopausal, 18/32 [56.3%]) with metastatic nodes who received NACT were included. Nodal pathological complete response rate was 34.4% (11/32) overall and 70% (7/10) in patients with ≤2 suspicious nodes on pre-NACT axUS. False-negative rates (FNRs) of axUS and CN excision were 4.8% and 28.6% respectively. Combination of post-NACT axUS and CN excision had an FNR of 4.8% overall and 0% in patients with ≤2 suspicious nodes on pre-NACT axUS.

Conclusion: Combination of AxUS and ultrasound-guided wire localisation of pre-treatment positive CN has high diagnostic accuracy for nodal restaging after NACT in node positive breast cancer patients.

Advances in knowledge: Addition of axUS assessment to wire localisation of CN reduces its FNR for detecting residual metastasis after NACT.

Figure 1.

Ultrasound-guided pre-operative wire localisation of clipped lymph node after neoadjuvant chemotherapy. (a, b) Ultrasonography images show placement of localisation wire (arrows in a & b) in the clipped node (asterisks in a & b) prior to surgery. The clip (arrowhead in b) is well visualized within the cortex of the node in image (b). (c) Post-procedure clinical photograph showing the localisation wire in the right axilla.

Figure 2.

Flowchart of the recruitment process. NACT, neoadjuvant chemotherapy.

Figure 3.

Complete pathologic nodal response to neoadjuvant chemotherapy. (a) Baseline ultrasonography image of a 61-year-old lady with cT3N1 breast cancer showing the metastatic axillary node (arrow) with diffuse cortical thickening and abnormal round shape. (b) The same node (arrow), after neoadjuvant chemotherapy, shows normal morphology with metallic clip within (arrowhead) suggesting complete response. No other suspicious nodes were seen on ultrasonography. (c) Photomicrograph of the lymph node (haematoxylin and eosin stain) shows absence of metastatic tumour cells in the excised lymph node.

Figure 4.

Partial nodal response to neoadjuvant chemotherapy. (a) Baseline ultrasonography image of a 45-year-old lady with T3N1 breast cancer showing metastatic axillary node (arrow) with cortical thickening, loss of fatty hilum and round shape. (b) After completion of neoadjuvant chemotherapy, the same findings are persisting in the same node (arrow) suggesting residual metastasis. The clip (arrowhead) is also seen within. (c) Photomicrograph (haematoxylin and eosin stain) of the lymph node shows residual metastatic cells within (arrow) confirming the findings of ultrasonography.