Paradigm shift in axilla surgery for breast cancer patients treated with sentinel node biopsy

Sentinel node biopsy (SNB) is a standard technique for the diagnosis of regional lymph node metastases in clinically node-negative breast cancer patients. In the case of pathologically negative sentinel lymph nodes (SLN), axillary lymph node dissection (ALND) can be avoided.

Recent clinical studies on SNB in breast cancer were reviewed regarding the pathological and molecular diagnosis of SLN, the tools used to predict non-SLN metastases, the prognostic significance of isolated tumor cells (ITC) and micrometastases (MIC), and axilla surgery.

ITC or MIC in SLN was associated with worse survival in patients treated with SNB alone or SNB followed by ALND. However, this effect was limited and adjuvant therapy improved survival. If T1 and one SLN-positive breast cancer patients are treated with whole-breast irradiation and adjuvant therapy, additional ALND may not be necessary.

SNB without ALND can be adopted for patients with a small number of SLN metastases. Although the lack of apparent regional lymph node recurrence, similar to tumor dormancy, cannot be fully explained, ALND should be performed in cases that are highly suspected to be non-SLN metastases.