Lymph-node dissection in breast cancer.

Abstract

Along with the ongoing modifications in treatment of primary breast cancer, the purpose and extent of lymph-node dissection has changed. The following is an overview of the current knowledge and practice of lymph-node dissection in breast cancer, with special regard to expected developments in the near future. Axillary dissection is described as a ten-step procedure, including dissection of level-I and -II and Rotter's nodes, without level-III nodes, providing at least ten lymph nodes for accurate staging information. Axillary dissection still offers the most efficient local control in node-positive patients, whereas, in primarily node-negative patients, irradiation seems to be equally effective. In general, lymph-node dissection does not alter overall survival but there is no doubt that surgical therapy still contributes to cure in early-breast-cancer patients and seems to be curative for certain patients with stage-I carcinoma. The lymph node status of the axilla is crucial for the indication of adjuvant therapy in early invasive breast cancer, but an increasing number of clinical node-negative patients could be managed with information based on features of the primary tumor, regardless of the nodal status. The most promising new concept for the selection of node-positive patients, while avoiding unnecessary morbidity of axillary dissection in early-breast-cancer patients, is the sentinel-node concept. The principle is based on the identification of the first "sentinel" lymph node reached by lymphatic flow. Thus, only proven node-positive patients undergo axillary dissection. Local failure of internal mammary lymph nodes is rarely recognized; however, internal mammary lymph nodes seem to have an underestimated prognostic significance in about 10-20% of axillary node-negative patients. This may lead to the withholding of systemic therapy for patients with early breast cancer. Nevertheless, there is no indication for a routine parasternal dissection today. The sentinel-node concept may also support the selection of diagnostic internal lymph-node biopsy and subsequent adjuvant therapy in cases with no axillary lymph-node metastases but with internal lymph-node metastases.