The potential therapeutic effect of sentinel lymphadenectomy

Sentinel lymph node (SLN) biopsy in a minimally invasive staging procedure for early breast cancer patients that is currently being investigated in many institutional and multi-institutional studies. Its main perspectives are the omission of axillary dissection in sentinel lymph node-negative patients and an improved staging as a result of more intensive histopathological methods for the detection of nodal involvement. The hypothesis presented in this article suggests that sentinel lymphadenectomy may also serve as a therapeutic intervention in some patients. The background for this comes from historical studies before the general use of systemic adjuvant treatment, which suggest that some node-positive breast cancer patients seem to be curable by locoregional treatment alone. Recent studies show that many patients have nodal metastases limited to the SLNs, where (considering the sigmoid growth model of solid tumours) small metastases may grow faster than larger ones. Large metastases are associated with worse prognosis. It is suggested that, in consequence of its expected therapeutic effects, sentinel lymphadenectomy, i.e. the removal of the lymph nodes most likely to harbour metastases, should be preferred to the omission of axillary dissection, or any other surgical staging procedure based on predictive models of nodal involvement derived from primary tumour characteristics.