Role of sentinel lymph node dissection in breast cancer

The sentinel node concept is valid for penile cancer, melanoma, breast canc er and is probably also applicable to other solid malignancies. Sentinel no des are the one or two initial nodes in the regional nodal drainage basin e ncountered by the lymphatic effluent from a tumour, which can be identified with an injection of vital dye or other lymphogogue. Sentinel lymph node d issection (SLND), a minimally invasive procedure with negligible morbidity, has therefore been utilized as an alternative to complete axillary lymph n ode dissection (ALND) for staging breast cancer. Examination of sentinel no des provides a focused histopathological assessment of tissue most likely t o harbour metastases, providing enhanced staging accuracy with a low false- negative rate. Tumour-free sentinel nodes are predictive of a tumour-free:a xilla, thereby allowing for the possibility of SLND without ALND and sparin g patients the morbidity of ALND. Most of the experience from SLND has been obtained for axillary sentinel nodes. However, sentinel nodes have been id entified in nonaxillary sites, such as the internal mammary nodes, but data on SLND for these regions is scarce. The ultimate role of SLND in breast c ancer, which may be to identify sentinel-node-negative patients or even tho se with sentinel node metastases who can safely avoid ALND without sacrific ing regional control and possibly gain a therapeutic benefit, cannot: be de fined before we have the results of large trials that are currently in prog ress.