Krag et al., NEJM 1998 — “The Sentinel Node in Breast Cancer: A Multicenter Validation Study.”

Rodrigo Arrangoiz MS, MD, FACS, FSSO

  • What did they asked?
    • Can a radioisotope-guided sentinel lymph node (SLN) biopsy accurately predict the status of the axilla in breast cancer across multiple surgeons and practice settings? 
  • Methods:
    • Population and setting:
      • 443 women with breast cancer:
        • Treated by 11 surgeons at varied centers
      • Everyone underwent complete axillary lymph node dissection (ALND) so SLNB performance could be verified
    • Technique:
      • Peritumoral / pericavity injection of:
        • 4 mL technetium-99m sulfur colloid (≈1 mCi / 37 MBq):
          • Intraoperative hand-held gamma probe to find “hot spots,” then SLN excision followed by ALND
  • Key performance metrics:
    • Identification (“hot-spot”) rate:
      • 93% (413 / 443)
    • Accuracy vs full axillary histology:
      • 97% (392 / 405)
    • Sensitivity:
      • 89% (101/114):
        • False-negative rate ≈ 11% among node-positive cases
      • Specificity / PPV:
        • 100% (no false positives)
      • NPV:
        • 96% (291/304)
    • Anatomic insight:
      • SLNs were outside the axilla in 8% and outside level I in 11%
      • 3% of positive SLNs were in non-axillary locations
  • Why it mattered?
    • Provided the first large, multicenter, surgeon-diverse validation:
      • Showing SLN biopsy is a highly accurate predictor of axillary status:
        • Establishing the foundation for replacing routine ALND in cN0 patients and enabling the de-escalation pathway:
          • Later confirmed by trials like NSABP B-32 and Z0011
  • Nuances and caveats the paper raised:
    • Learning curve / variability:
      • Success varied by surgeon and patient factors, underscoring the need for technique standardization and training
    • Technique scope:
      • Study used radioisotope only (no blue dye in the protocol):
        • Which many centers later combined with blue dye to further enhance identification and lower FNR:
          • Background reviews consistently show higher detection and lower FNR with combined mapping
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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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