Sentinel Node and Recurrent Breast Cancer (SNARB): results of a nationwide registration study.

BACKGROUND: Knowledge of regional lymph node involvement is important in patients with recurrent breast cancer for obtaining better locoregional control and predicting prognosis. To determine technical feasibility, validity, aberrant drainage rates, and clinical consequences of performing repeat sentinel node biopsy (SNB) in patients with locally recurrent breast cancer we conducted the "Sentinel Node and Recurrent Breast Cancer (SNARB)" study. METHODS: A total of 150 patients with locally recurrent breast cancer underwent lymphatic mapping and SNB. In case of an intact axillary lymph node basin, ipsilateral axillary lymph node dissection (ALND) was performed subsequently. RESULTS: A total of 41 patients previously underwent breast conserving therapy (BCT) with SNB, 82 patients BCT with ALND, and 21 patients a mastectomy, of which 9 with SNB and 12 with ALND. In 95 patients (63.3 %) a sentinel node was identified and in 78 patients (52 %) the sentinel node was successfully removed. In 18 patients (22.8 %) a (micro)metastasis was found on pathologic examination. Confirmation ALND in 18 patients showed no axillary lymph node metastases. Aberrant drainage pathways were visualized in 58.9 % of the patients, significantly more frequently after a previous ALND (79.3 %) than after a previous SNB (25.0 %) (P < .0001). Overall, the result of this repeat SNB led to a change in the adjuvant treatment plan in 16.5 % of the patients with a successful repeat SNB. CONCLUSIONS: Repeat SNB is technically feasible and provides reliable results in patients with locally recurrent breast cancer, leading to change in management in 1 of 6 patients.