The role of nodal staging in breast cancer. Past, present and future

The axillary nodal status is accepted as the most powerful prognostic tool available for early stage breast cancer. In the past radical removal of level I and level II lymph nodes at axillary node dissection (ALND) has been the most accurate method to assess nodal status, and it is the universal standard; however, it is associated with several adverse long-term sequelae. New diagnostic technologies have helped to individualize diagnostic evaluation and therapy of breast cancer thus improving efficacy and minimizing morbidity of treatment. Lymphatic mapping with sentinel lymph node biopsy has emerged as an effective and safe alternative to the ALND for detecting axillary metastases. Many issues such as indications or technique of performing sentinel node biopsy have been evaluated. Multiple studies now confirm that sentinel lymphadenectomy accurately stages the axilla and is associated with less morbidity than axillary dissection. Blue dye, radiocolloid, or both can be used to identify the sentinel node, and several injection techniques may be used successfully. Sentinel node biopsy is now minimally invasive, highly accurate method of axillary staging, and has replaced routine axillary lymph node dissection as the new standard of care in breast cancer. New technologies for axillary nodal staging include innovative imaging techniques such as single photon emission computerized tomography (SPECT) and modern histopathologic evaluation of sentinel nodes using molecular biologic approaches.