Sentinel Lymph Node Biopsy in Breast Cancer: Initial Experience at Memorial Sloan-Kettering Cancer Center

Background: Sentinel node biopsy (SNB) has emerged as a potential alternative to routine axillary dissection in clinically node-negative breast cancer. Study Design: From September 1995 to June 1996 at Memorial Sloan-Kettering Cancer Center, 60 patients with clinically node-negative cancer underwent SNB, which was immediately followed by standard axillary dissection. Both blue dye and radioisotope were used to identify the sentinel node. SNB was compared with standard axillary dissection for its ability to accurately reflect the final pathologic status of the axillary nodes. Results: The sentinel node was successfully identified by lymphoscintigraphy in 75% (42 of 56), by blue dye in 75% (44 of 59), by isotope in 88% (52 of 59), and by the combination of blue dye and isotope in 93% (55 of 59) of all 59 evaluable patients. Of the 55 patients in this study where sentinel nodes were identified, 20 (36%) were histologically positive. The sentinel node was falsely negative in three patients, yielding an accuracy of 95%. SNB was more accurate for T1 (98%) than for T2–T3 tumors (82%). Conclusions: Lymphatic mapping is technically feasible, reliably identifies a sentinel node in most cases, and appears more accurate for T1 tumors than for larger lesions. Blue dye and radioisotope are complementary techniques, and the overall success of the procedure is maximized when the two are used together.