[Demonstration of the sentinel lymph node in axillary dissection for breast cancer]

The sentinel node is defined as the first-line axillary lymphatic drainage node in breast cancer. If the sentinel node can be identified, during axillary dissection for breast cancer, resection could be limited reducing subsequent morbidity. However, before modifying the standard dissection procedure, it is important to prove that the sentinel node is representative of the metastatic status of other axillary nodes.

Between March and December 1996, 86 patients (mean age 58 years, range 32-82) underwent amputation (n = 20), tumorectomy with dissection (n = 56) or tumorectomy followed by secondary dissection (n = 10) for breast cancer. Ten ml of diluted patent blue was injected either into the peripheral portion of the tumor or the tumorectomy cavity. Node dissection was performed 10 to 20 minutes after injection. The blue sentinel node was identified prior to standard dissection.

A mean 12 nodes were removed (range 4-21). Seventy-nine sentinel nodes were identified (91%) and in 7 cases (8%) a sentinel node could not be identified. In 7 other cases the sentinel node was a false negative, i.e. non malignant despite metastases in other dissected nodes. In all the other cases, the status of the sentinel node predicted the status of the other nodes, i.e. a non-metastatic sentinel node associated with other metastatic nodes. Finally, in 7 cases, the sentinel node was the only invaded node among the nodes dissected. During the last 3 months of the study, the sentinel node was identified in 100% of the cases and was representative of the overall dissection.

Identifying the sentinel node is an alternative to standard axillary node dissection procedures. The method requires a training period and identification can be improved with radioimmunologic guidance. Patient selection within the framework of a rigorous multidisciplinary protocol is indispensable. A nationwide study is currently being conducted to validate these preliminary results.