title: Inclusion of KI67 significantly improves performance of the PREDICT prognostication and prediction model for early breast cancer.
abstract: BACKGROUND
  PREDICT (http://www.predict.nhs.uk) is a prognostication and treatment benefit tool for early breast cancer (EBC). The aim of this study was to incorporate the prognostic effect of KI67 status in a new version (v3), and compare performance with the Predict model that includes HER2 status (v2).
  
  
  METHODS
  The validation study was based on 1,726 patients with EBC treated in Nottingham between 1989 and 1998. KI67 positivity for PREDICT is defined as >10% of tumour cells staining positive. ROC curves were constructed for Predict models with (v3) and without (v2) KI67 input. Comparison was made using the method of DeLong.
  
  
  RESULTS
  In 1274 ER+ patients the predicted number of events at 10 years increased from 196 for v2 to 204 for v3 compared to 221 observed. The area under the ROC curve (AUC) improved from 0.7611 to 0.7676 (p=0.005) in ER+ patients and from 0.7546 to 0.7595 (p=0.0008) in all 1726 patients (ER+ and ER-).
  
  
  CONCLUSIONS
  Addition of KI67 to PREDICT has led to a statistically significant improvement in the model performance for ER+ patients and will aid clinical decision making in these patients. Further studies should determine whether other markers including gene expression profiling provide additional prognostic information to that provided by PREDICT.
authors.forename: Gordon C
authors.initials: GC
authors.lastname: Wishart
authors.forename: Emad
authors.initials: E
authors.lastname: Rakha
authors.forename: Andrew
authors.initials: A
authors.lastname: Green
authors.forename: Ian
authors.initials: I
authors.lastname: Ellis
authors.forename: Hamid Raza
authors.initials: HR
authors.lastname: Ali
authors.forename: Elena
authors.initials: E
authors.lastname: Provenzano
authors.forename: Fiona M
authors.initials: FM
authors.lastname: Blows
authors.forename: Carlos
authors.initials: C
authors.lastname: Caldas
authors.affiliation: Department of Oncology, University of Cambridge, Strangeways Research Laboratory, Worts Causeway, Cambridge CB1 8RN, UK. pp10001@medschl.cam.ac.uk.
authors.forename: Paul D P
authors.initials: PD
authors.lastname: Pharoah
mesh_terms: D000328:Adult; D019540:Area Under Curve; D001943:Breast Neoplasms / Q000737:chemistry* / Q000401:mortality / Q000473:pathology*; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D008962:Models, Theoretical; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D011960:Receptors, Estrogen / Q000032:analysis; D047368:Tumor Burden
chemical_list: D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; C508053:ERBB2 protein, human