Sentinel Lymph Node Mapping and Biopsy For Predicting the Axillary Lymph Node Status After Completion of Preoperative Neoadjuvant Systemic Chemotherapy in Patients Who Had Biopsy-Proven Axillary Lymph Node Involvement at Initial Presentation

Multiple retrospective reports have verified the overall utility of post-treatment sentinel lymph node (SLN) mapping and biopsy for assessing the final axillary lymph node status in breast cancer patients who have undergone preoperative neoadjuvant systemic chemotherapy. However, to date, only one report, in abstract form, currently exists within the literature which specifically assesses the utility of post-treatment SLN mapping and biopsy after completion of preoperative neoadjuvant systemic chemotherapy in patients with biopsy-proven positive axillary lymph nodes at initial presentation.

The purpose of the present proposed clinical trial will be to assess the utility of SLN mapping and biopsy for predicting the final axillary status after completion of preoperative neoadjuvant systemic chemotherapy in patients who had biopsy-proven positive axillary lymph nodes at initial presentation.

All eligible patients must have biopsy-proven invasive breast cancer and must also have biopsy-proven involvement of the axillary lymph nodes at initial presentation. Biopsy-proven involvement of the axillary lymph nodes at initial presentation will be based on fine needle aspiration (FNA) cytology, core/Tru-cut biopsy, or pre-treatment SLN biopsy. All eligible patients will have undergone preoperative neoadjuvant systemic chemotherapy.

After completion of preoperative neoadjuvant systemic chemotherapy and on the day of definitive breast cancer surgery, patients will be injected intradermally with approximately 400 microcuries of Tc-99m sulfur colloid. Patients will undergo preoperative lymphoscintigraphy in the nuclear medicine department to access axillary and extra-axillary sites of localization. Intraoperatively, patients will also be injected with approximately 4 to 5 mL of 1% isosulfan blue dye (by intradermal, intraparenchymal, or subareolar route). Patients will undergo intraoperative identification and biopsy of all SLN candidates. A confirmatory axillary lymph node dissection will then be performed on all patients.

The SLN mapping and biopsy procedure that we are proposing to perform on these breast cancer patients with known positive axillary lymph nodes at initial presentation will be done in an identical fashion to the SLN mapping and biopsy procedure that is currently performed as a routine and acceptable standard of care on every breast cancer patient with a clinically negative axilla at presentation.