Repeat sentinel node biopsy in patients with locally recurrent breast cancer: a systematic review and meta-analysis of the literature.

Axillary staging in patients with locally recurrent breast cancer is important for obtaining locoregional control and predicting prognosis. The aim of the present study is to determine technical feasibility, validity, aberrant drainage patterns and clinical consequences of performing repeat sentinel node biopsy (SNB) in these patients. We performed a systematic review and meta-analysis of the literature and included all studies on repeat SNB in locally recurrent breast cancer. A total of 692 patients were described, 301 after a previous SNB, 361 after a previous axillary lymph node dissection (ALND), and 30 with no previous axillary surgery. Sentinel node identification was successful in 452 of the 692 patients (65.3 %), which was significantly higher in patients who had undergone previous SNB compared to previous ALND (81.0 vs. 52.2 %) (P < 0.0001). In 175 of 405 patients with successful lymphatic mapping aberrant drainage pathways were visualized (43.2 %), which were seen more frequently after previous ALND than after previous SNB (69.2 vs. 17.4 %) (P < 0.0001). In 19.2 % of the patients the sentinel node was tumor positive and 27.5 % of these metastases were found in aberrant lymph drainage basins. Overall, 213 patients could be spared an ALND and in 17.9 % of the patients the information derived from the repeat SNB led to a change in adjuvant radiotherapy or systemic treatment plans. The procedure had a false-negative rate of 0.2 %. Repeat SNB is technically feasible and accurate. Next to sparing patients an unnecessary ALND, the information can lead to a change in adjuvant treatment strategy.