Sentinel node biopsy after primary chemotherapy in breast cancer: a note of caution from results of ABCSG-14.
Over the past years, experience has been increasing with lymphatic mapping and sentinel node biopsy (SNB) after preoperative chemotherapy for breast cancer, with a wide range of results reported in the literature and final conclusions on the diagnostic value and clinical consequences of this sequential approach still missing. Between 1999 and 2002, the Austrian Breast and Colorectal Cancer Study Group (ABCSG) conducted a prospective randomized multicenter trial comparing three versus six preoperative cycles of epirubicin/docetaxel + granulocyte colony-stimulating factor for operable breast cancer. Of the 292 patients recruited to the trial overall, 111 were enrolled in a prospective subprotocol for performing LM and SNB in addition to obligatory axillary lymph node dissection (ALND) after PC. SNB after PC identified at least one sentinel node in 100 of 111 patients (identification rate 90%). In six cases, a false-negative SN was identified, resulting in a false-negative rate of 13% (6 of 47). We only found little correlation between patients and tumor characteristics and the identification rate or false-negative rate. Lymphatic mapping and SNB after primary chemotherapy failed to predict histologic infiltration of the sentinel node with sufficient sensitivity. The routine use of SNB after primary chemotherapy should therefore be discouraged.