Sentinel lymph node biopsy (SLNB) vs. axillary lymph node dissection (ALND) in the current surgical treatment of early stage breast cancer

The identification and biopsy of the sentinel lymph node has become a standard method of treatment for stage I and II breast cancer in the last decades, taking into account the fact that the management of the axilla in patients with breast cancer has evolved from the routine lymphadenectomy to a selective attitude, based on the histopathological evaluation of the sentinel lymph node, as well as on the tumor and on the patients’ characteristics. Since the introduction of the method into clinical practice, in 1994, different methods of identification have been used (radioisotope injection, vital blue dye, or, more recently, lipophilic contrast agent for ultrasound visualization or paramagnetic nanoparticles (NPs) or the method of indocyanine green fluorescence), each presenting certain limits, but the radioisotopic method proving the most accurate. Moreover, during the development of the method, beside the standard indications specific for T1 or T2 breast tumor, without clinical or imagistic axillary adenopathies, their extension to a series of other particular situations such as the following, has been tried: ductal carcinoma in situ, multicentre tumors, after excisional biopsy or tumors preoperatively treated by neoadjuvant chemotherapy. The aim of the paper is to present the progress made regarding the current stage in the use of sentinel lymph node technique in breast cancer, while mentioning the established indications, as well as the ones that are still debating and need further studies. Likewise, the cases in which the axillary lymph node dissection remains the major indication for treatment of the axilla, in patients with early stage breast cancer, will be discussed.