Is regional nodes radiotherapy an alternative to surgery?

Sentinel node biopsy (SN) in breast cancer treatment was introduced in the mid-1990s in order to be able to stage patients before decision of definitive surgery. Since then, both the pathological examinations of the SN and the systemic adjuvant treatment have improved and cause new challenges in the correct decision making regarding whether or not to radically treat the axilla in case of a positive SN. In SN positive patients, current St. Gallen guidelines support no completion ALND (axillary lymph node dissection) in clinically node-negative patients with 1-2 macrometastatic sentinel nodes operated with breast conservation and receiving tangential field adjuvant radiotherapy (RT). ALND is being questioned due to increased morbidity compared with SN biopsy alone, and to limited long term benefit on disease free survival in selected patients. An alternative to ALND is treating the axilla with nodal RT although this treatment is mostly used as adjuvant treatment after ALND in high risk patients. Few studies have investigated the benefit of nodal RT compared to ALND, and no consensus has yet been reached. Clinical decision making regarding treating the axilla should be based on relevant data, and in this review studies aiming at deciding whether or not and how the axilla should be treated in SN positive patients will be discussed. Furthermore treatment choice will be discussed, since besides ALND, both breast irradiation and nodal irradiation might cure residual disease after SN. Also the issue of improved systemic adjuvant treatment will be discussed in relation to eventually no regional axillary treatment.