Selection for axillary clearance in breast cancer (ultrasound negative, sentinel node positive patients have low rates of further metastases)

BACKGROUND: The aim of this study was to determine whether we could identify a subset of axillary clearance patients in whom the procedure yielded negative nodes and was therefore of no therapeutic benefit.

METHODS: Over a three year period 138 patients underwent axillary clearance at our unit. The axillae of all patients were assessed preoperatively with clinical examination, ultrasound (USS) and FNAC if suspicious nodes identified. Patients with clinically malignant nodes or positive FNAC underwent axillary node clearance where appropriate, whilst completion axillary node clearance was performed in those who had no preoperative evidence of metastatic axillary disease but positive sentinel node biopsy (SNB)/axillary node sample (ANS).

RESULTS: Of the 138 patients, the indications for axillary clearance were positive FNAC or clinically malignant nodes in 89 and positive SNB/ANS in the remaining 49. Patients with preoperative evidence of axillary metastases had significantly more positive nodes compared to those who underwent SNB and completion ANC 4.6 vs. 3.1 p = 0.037. Of the patients with ultrasonographically normal axillae but positive SNB, 8.7% had further nodal metastases at completion ANC. This was significantly less than in those with abnormal USS (negative FNAC) and positive SNB (41.7%); p = 0.033.

CONCLUSIONS: Preoperative ultrasound in conjunction with FNAC and clinical judgement identifies most patients with positive axillary nodes and such patients have more widespread disease. The additional value of completion axillary ANC in patients with ultrasonographically normal axillae but positive SNB appears small as sentinel node 'biopsy' serves to clear the axilla of metastases in most of these patients.