title: Validation and limitations of use of a breast cancer nomogram predicting the likelihood of non-sentinel node involvement after positive sentinel node biopsy.
abstract: BACKGROUND
  Axillary lymph node dissection (ALND) for patients with positive sentinel lymph nodes (SLNs) is currently under discussion in the literature. The breast cancer nomogram (BCN), an online tool developed by the Memorial Sloan-Kettering Cancer Center (MSKCC), aims to predict the risk of positive non-SLN in SLN-positive patients. The purpose of this study was to test the accuracy of the nomogram on patients with macrometastatic and micrometastatic SLN-positive biopsy findings.
  
  
  METHODS
  Patient characteristics, tumor pathology, and positive SLN characteristics were collected on 588 consecutive patients who underwent completion ALND. The MSKCC BCN tool was used to calculate risk of metastases for all 588 cases that included a subgroup of the 213 patients with SLN micrometastases. The BCN was performed for positive SLN biopsy findings regardless of the method of metastasis detection. Evaluation of the BCN was performed by the area under the curve method.
  
  
  RESULTS
  The BCN applied to all 588 patients achieved an area under the receiver operating characteristic curve (ROC) of .724 (range, .677-.771) compared with .76 in the MSKCC study. When the tool was applied solely to micrometastases found by hematoxylin and eosin staining and metastases found by immunohistochemistry, the area under the ROC was .538 (range, .423-.653).
  
  
  CONCLUSIONS
  The MSKCC nomogram has been validated for all the patients having a metastatic SLN at the Institut Curie. However, this model was not reliably predictive for positive non-SLN in cases with micrometastic positive SLN.
authors.affiliation: Department of Surgical Oncology, Institut Curie, 26 rue d'Ulm, 75005 Paris, France. severine.alran@curie.net
authors.forename: Séverine
authors.initials: S
authors.lastname: Alran
authors.forename: Yann
authors.initials: Y
authors.lastname: De Rycke
authors.forename: Virginie
authors.initials: V
authors.lastname: Fourchotte
authors.forename: Hélène
authors.initials: H
authors.lastname: Charitansky
authors.forename: Fatima
authors.initials: F
authors.lastname: Laki
authors.forename: Marie Christine
authors.initials: MC
authors.lastname: Falcou
authors.forename: Myriam
authors.initials: M
authors.lastname: Benamor
authors.forename: Paul
authors.initials: P
authors.lastname: Freneaux
authors.forename: Rémy Jacques
authors.initials: RJ
authors.lastname: Salmon
authors.forename: Brigitte
authors.initials: B
authors.lastname: Sigal-Zafrani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001365:Axilla / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006651:Histocytochemistry; D006801:Humans; D007150:Immunohistochemistry; D016013:Likelihood Functions; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009367:Neoplasm Staging; D049451:Nomograms; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D021701:Sentinel Lymph Node Biopsy; D047368:Tumor Burden