Axillary Sentinel Lymph Node Biopsy

Excerpt

Staging for breast cancer involves the evaluation of the regional lymph nodes. Sentinel lymph node biopsy was developed to allow for assessment of the axillary lymph node status without a formal axillary dissection. The principle of sentinel node identification and removal is that the sentinel node(s) will be affected by regional lymph node tumor spread before the rest of the lymph nodes in that regional nodal basin. The identification, removal, and careful analysis of those lymph nodes can allow for the classification of the spread of the tumor and allow for prognostication. Traditionally, when a sentinel lymph node was positive, that was a trigger for performing a formal axillary dissection and removing all lymph nodes from the axilla. However, more recent evidence suggests that complete axillary dissection is not necessary for certain circumstances, even with a positive sentinel node. This fact is important because axillary dissection is a morbid procedure, with complications including lymphedema, nerve injury, ongoing pain, and lymphangiosarcoma. To safely forego completion axillary dissection with a positive sentinel node, a patient should have a T1 or T2 primary tumor and less than three nodes involved with tumor.