Local and regional control in breast cancer: role of sentinel node biopsy

The development and acceptance of the SLND has profoundly affected the management of breast cancer. SLND has supplanted ALND as a highly accurate and less-morbid axillary staging procedure in patients with clinically node-negative early-stage breast cancer. SLND alone is associated with less than 1% isolated axillary recurrence in patients with node-negative disease and provides excellent regional nodal control. Historically, ALND has been the recommended treatment for patients with SLN metastases. ALND was thought to offer prognostic information, prevent axillary local recurrence, and possibly render a small survival benefit. However, resection of nonsentinel nodes with metastases may not affect survival, and not all axillary metastases progress to become clinically evident. Furthermore, with increased understanding of tumor biology, nodal status and number of involved lymph nodes are no longer the only determinants of systemic therapy. As improved breast cancer screening allows identification of early-stage disease localized to the breast, and because treatment plans are more often made on the basis of tumor biology, the role of completion ALND may be less critical. The low LRR rates seen in the ACOSOG Z0011 trial, several other randomized trials, and retrospective reviews suggest that SLND alone may provide adequate locoregional control and provide adequate information to guide adjuvant systemic therapy in selected women with clinically node-negative early-stage breast cancer.