Sentinel lymphadenectomy for the staging of clinical axillary node-negative breast cancer before neoadjuvant chemotherapy

Abstract

e11604 Background: Several authors reported sentinel lymph node biopsy after neoadjuvant chemotherapy. Nevertheless, the ideal time of sentinel lymph node biopsy is still a matter of debate. Methods: We evaluated the feasibility and the accuracy of sentinel lymph node biopsy before neoadjuvant chemotherapy using a combined procedure (blue dye and radio-labelled detection) in a homogeneous cohort study with clinically axillary node-negative breast cancer. Study candidates were patients referred to the Institut Paoli-Calmettes Cancer Center (Marseille, France) for the treatment of invasive breast cancer. Patients were included in the study if they had tumor more than 3 cm in diameter without palpable axillary lymph node for which a neoadjuvant chemotherapy was indicated in order to enhance the likelihood of breast conservation. An axillary lymph node dissection was performed after completion of neoadjuvant chemotherapy. Results: From September 2005 to September 2007, thirty-one women with T2 or T3 invasive breast cancer without palpable axillary lymph node underwent sentinel lymph node biopsy before neoadjuvant chemotherapy and an axillary lymph node dissection after neoadjuvant chemotherapy. Among the 20 women who had metastatic sentinel lymph node biopsy (65%), 4 (20%) had additional metastatic node on axillary lymph node dissection. By contrast, all the 11 women who had no metastatic sentinel lymph node biopsy had no involved nodes in the axillary lymph node dissection. The sentinel lymph node biopsy identification rate before neoadjuvant chemotherapy was 100% with any false negative. Conclusions: Sentinel lymph node biopsy before neoadjuvant chemotherapy is a feasible and an accurate diagnostic tool to predict the pre-therapeutic axilla status. These findings suggest that axillary lymph node dissection may be avoided in patients with a negative sentinel lymph node biopsy performed before neoadjuvant chemotherapy. No significant financial relationships to disclose.