Predictive value of sentinel lymph node biopsy prior to neoadjuvant chemotherapy in clinically node negative breast cancer

606 Background: Applicability and optimal timing of sentinel node biopsy (SNB) in breast cancer patients treated with neoadjuvant therapy is not yet known. SNB prior to neoadjuvant therapy is relatively untested, while SNB after neoadjuvant therapy is associated with lower mapping success and higher false negative rates. SNB prior to neoadjuvant therapy may give data useful in guiding systemic, radiation and surgical treatment decisions. Methods: 52 T2-T4, N0 breast cancer patients who had SNB prior to neoadjuvant therapy from 7/2000 to 10/2003 were reviewed. Initial 1° tumor size, SNB pathology, clinical response to therapy and findings at definitive surgery were examined. Results: 22 patients (42%) were SNB(-) and 21 had no further axillary treatment. None have recurred locally. 1 SNB(-) patient had tumor progression during chemo and a positive axillary node dissection (ALND). 30 patients (58%) were SNB(+); to date 26 have had ALND after neoadjuvant therapy; 1 with a micromet had no further surgery. At ...