AMAROS (EORTC 10981-22023)

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • AMAROS (EORTC 10981-22023):
    • If a positive SLN needs axillary treatment, axillary RT (ART) gives equivalent control to ALND with far less lymphedema
  • Design & who it applies to:
    • Population: 
      • cT1 to cT2, clinically node-negative invasive breast cancer with a positive sentinel lymph node (SLN):
        • Patients underwent BCT or mastectomy:
          • Unlike Z0011, which was BCT-only
        • Randomized to ALND (levels I to II) vs axillary radiotherapy (levels I to III ± supraclavicular fossa)
    • Primary endpoint: 
      • Non-inferiority of 5-year axillary recurrence (ARR)
    • Key results:
      • 5-year (primary report, Lancet Oncol 2014):
        • Axillary recurrence: 
          • 0.43% ALND vs 1.19% ART:
            • Non-inferiority test underpowered due to very few events, but absolute ARR was low in both arms
      • Lymphedema at 5 years: 
        • 23% ALND vs 11% ART (significantly less with ART)
    • 10-year update (JCO 2023):
      • Cumulative axillary recurrence: 
        • 0.93% ALND vs 1.82% ART (HR 1.71, 95% CI 0.67–4.39):
          • No meaningful difference
      • Overall survival: 
        • 84.6% ALND vs 81.4% ART (HR 1.17, 95% CI 0.89–1.52):
          • No difference
      • Disease-free survival: 
        • 75.0% ALND vs 70.1% ART (HR 1.19, 95% CI 0.97–1.46):
          • No difference
      • Updated 5-year lymphedema: 
        • 24.5% ALND vs 11.9% ART (P<.001):
          • Quality of life similar
  • Clinical takeaways:
    • For SLN-positive patients who still require axillary treatment:
      • Choose ART over ALND to achieve the same axillary control and survival with substantially less lymphedema:
        • This applies to both BCT and mastectomy cohorts (AMAROS included both):
          • If you’re uncomfortable omitting axillary therapy (e.g., features beyond Z0011 scope):
            • ART is preferred over ALND to minimize morbidity
    • Avoid combined ALND + ART when possible:
      • Stacking treatments markedly raises lymphedema risk:
        • General morbidity data and reviews echo this principle
    • Field/Dose (typical in AMAROS): 
      • Axilla levels I to III ± SCV, ~ 50 Gy in conventional fractions; most modern clinics use tangents / high tangents plus nodal fields as indicated. (Protocol details in trial reports.)
  • Bottom line: 
    • ART = ALND for control, with less arm morbidity:
      • So when axillary therapy is needed after a positive SLN:
        • ART is the preferred option
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Published by Rodrigo Arrangoiz MS, MD, FACS, FSSO

My name is Rodrigo Arrangoiz I am a breast surgeon/ thyroid surgeon / parathyroid surgeon / head and neck surgeon / surgical oncologist that works at Center for Advanced Surgical Oncology in Miami, Florida. I was trained as a surgeon at Michigan State University from (2005 to 2010) where I was a chief resident in 2010. My surgical oncology and head and neck training was performed at the Fox Chase Cancer Center in Philadelphia from 2010 to 2012. At the same time I underwent a masters in science (Clinical research for health professionals) at the University of Drexel. Through the International Federation of Head and Neck Societies / Memorial Sloan Kettering Cancer Center I performed a two year head and neck surgery and oncology / endocrine fellowship that ended in 2016. Mi nombre es Rodrigo Arrangoiz, soy cirujano oncólogo / cirujano de tumores de cabeza y cuello / cirujano endocrino que trabaja Center for Advanced Surgical Oncology en Miami, Florida. Fui entrenado como cirujano en Michigan State University (2005 a 2010 ) donde fui jefe de residentes en 2010. Mi formación en oncología quirúrgica y e n tumores de cabeza y cuello se realizó en el Fox Chase Cancer Center en Filadelfia de 2010 a 2012. Al mismo tiempo, me sometí a una maestría en ciencias (investigación clínica para profesionales de la salud) en la Universidad de Drexel. A través de la Federación Internacional de Sociedades de Cabeza y Cuello / Memorial Sloan Kettering Cancer Center realicé una sub especialidad en cirugía de cabeza y cuello / cirugia endocrina de dos años que terminó en 2016.

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