Intraoperative lymphatic mapping and sentinel lymph node dissection in breast cancer

Because the tumor status of the regional lymph nodes is the most important prognostic factor in patients with early-stage breast cancer, accurate histopathologic assessment of these nodes is essential for optimal management, including the selection of candidates for adjuvant systemic therapies. Intraoperative lymphatic mapping using a vital blue dye, with or without a radiocolloid, can identify the first axillary node to receive lymphatic drainage from a primary breast carcinoma. Focused histopathologic assessment of this sentinel node can be used to determine the tumor status of the entire axillary basin. The minimal morbidity and high accuracy of sentinel lymph node dissection (SLND) in breast cancer have been validated by multiple independent investigators, and the data suggest that this surgical technique may eventually replace complete lymph node dissection as the preferred axillary procedure for the management of early-stage disease. In experienced hands, SLND can be successfully performed in more than 90% of eligible breast cancer patients; the tumor status of the sentinel node accurately predicts the status of all axillary nodes in more than 95% of cases. This article reviews the current status, controversies, and future directions of SLND as a staging technique for patients with primary breast carcinoma.