title: A preoperative nomogram to predict the risk of synchronous distant metastases at diagnosis of primary breast cancer.
abstract: BACKGROUND
  The detection of synchronous metastases at primary diagnosis of breast cancer (BC) affects its initial management. A risk calculator that incorporates many factors to evaluate an individual's risk of harbouring synchronous metastases would be useful to adapt cancer management.
  
  
  METHODS
  Patients with primary diagnosis of BC were identified from three institutional databases sharing homogeneous work-up recommendations. A risk score for synchronous metastases was estimated and a nomogram was constructed using the first database. Its performance was assessed by receiver characteristic (ROC) analysis. The nomogram was externally validated in the two independent cohorts.
  
  
  RESULTS
  A preoperative nomogram based on the clinical tumour size (P<0.001), clinical nodal status (P<0.001), oestrogen (P=0.17) and progesterone receptors (P=0.04) was developed. The nomogram accuracy was 87.3% (95% confidence interval (CI), 84.45-90.2%). Overall, the area under the ROC curve (AUC) was 86.1% for the validation set from the Institut Curie-René Huguenin, and 63.8% for the MD Anderson validation set. The negative predictive value (NPV) was high in the three cohorts (97-99%).
  
  
  CONCLUSIONS
  We developed and validated a strong metastasis risk calculator that can evaluate with high accuracy an individual's risk of harbouring synchronous metastases at diagnosis of primary BC.
  
  
  CONCLUSIONS
  A nomogram to predict synchronous metastases at diagnosis of breast cancer was developed and externally validated. This tool allows avoiding unnecessary expensive work-up.
authors: Department of Breast and Medical Oncology, Institut Gustave Roussy, Villejuif 94805, France.
authors: C
authors: C
authors: Boutros
authors: Department of Surgery, Division of Breast and Plastic Surgery, Institut Gustave Roussy, Villejuif 94805, France.
authors: C
authors: C
authors: Mazouni
authors: Department of Breast and Medical Oncology, Institut Curie, Hôpital René Huguenin, Saint-Cloud, France.
authors: F
authors: F
authors: Lerebours
authors: Department of Breast and Medical Oncology, Institut Curie, Hôpital René Huguenin, Saint-Cloud, France.
authors: D
authors: D
authors: Stevens
authors: Department of Biostatistics, MD Anderson Cancer Center, Houston, TX, USA.
authors: X
authors: X
authors: Lei
authors: Department of Breast Medical Oncology, University of Texas, MD Anderson Cancer Center, Houston, TX, USA.
authors: A M
authors: AM
authors: Gonzalez-Angulo
authors: Department of Breast and Medical Oncology, Institut Gustave Roussy, Villejuif 94805, France.
authors: S
authors: S
authors: Delaloge
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009378:Neoplasms, Multiple Primary / Q000175:diagnosis* / Q000473:pathology*; D049451:Nomograms; D057234:Preoperative Period; D012372:ROC Curve; D012306:Risk; D055815:Young Adult