Sentinel lymphadenectomy in breast cancer: identification of sentinel lymph node and detection of metastases

Sentinel lymphadenectomy is a useful way of assessing axillary status and o bviating axillary dissection in patients with node-negative breast cancer. However, controversies remain concerning the optimal method to identify the sentinel lymph node (SLN) and detect micrometastases in this lymph node. W e reviewed the literature concerning sentinel lymphadenectomy in breast can cer and reached the following conclusions: (a) A combination of preoperativ e lymphoscintigraphy with intraoperative dye-guided and gamma probe-guided methods achieves a higher rate of identification of SLN than any of these t echniques alone. (b) Immediate and reliable intraoperative assessment of se ntinel node status is vital to the technique's success. However, the reliab ility of sentinel node diagnosis using frozen sections is questionable, bec ause micrometastatic foci cannot always be identified. (c) Hematoxylin and eosin (H&E) staining and/or immunohistochemistry on permanent sections are useful for the detection of micrometastases in the sentinel node. Although a reverse transcriptase-polymerase chain reaction (RT-PCR) method is more s ensitive than H&E staining and immunohistochemistry, it would not distingui sh benign from malignant epithelial cells in the SLN. Therefore, further study is required before sentinel lymphadenectomy gains general acceptance for patients with primary breast cancer.