Background: Sentinel lymph node (SN) biopsy is a technique for identifying axillary metastases from primary breast cancer. The present paper reports our results with the method.
Material and methods: SN biopsies have been routinely performed at Ullevål University Hospital since 2000 and the results have been prospectively recorded. 1409 patients with breast cancer or ductal carcinoma in situ grade 3, were injected with peritumoral radiocolloid the day before the biopsy and with blue dye per-operatively to detect the SN.
Results: The SN was detected in 90 % of the operations. Metastases to SN were detected in 25 % of the patients and 52 % of these had no further positive nodes in the axilla. Thus, axillary lymph node clearance was omitted in 948 patients. Three patients had local recurrence in the axilla within one year after the successful SN procedure. Ductal carcinoma in situ grade 3 was diagnosed preoperatively in 162 patients (cytology); 88 had the diagnosis after histology and the rest had invasive cancer or combinations with in situ lesions of other grades. Axillary metastases were found in 4.8 % of these patients. Isolated tumour cells (< 0.2 mm diameter) were found in 9 patients for whom axillary clearance has not been performed.
Interpretation: SN biopsy has replaced routine axillary clearance as a routine operation in breast cancer. The method is safe when performed correctly, as metastases in the axilla after a negative SN rarely occur.