Positive and negative aspects of sentinel lymph node biopsy in breast cancer.

The sentinel lymph node (SLN) is the first lymph node to receive lymphatic drainage from a tumor. SLN biopsy has become a mainstay of breast cancer management and is used when the axilla is clinically clear of disease. Staging of the axilla in breast cancer is used to predict prognosis and in planning adjuvant treatment. SLN biopsy is not used where there has been previous axillary or breast radiotherapy or surgery, locally advanced or inflammatory disease and stage IV disease. Controversies remain in several specific clinical situations, including management of the axilla following detection of a positive SLN. There are no sufficiently robust predictive tumor features to prevent completion axillary dissection in these cases. However, there is evidence that immediate axillary surgery for operable, clinically node-negative breast cancer provides no survival benefit and may be unnecessary for many women. SLN biopsy may have a role after neoadjuvant chemotherapy, sparing some women from axillary node dissection. Further work is required to ascertain SLN biopsy sensitivity prior to its routine use in the clinic for multicentric and multifocal disease.