title: A web-based prognostic tool for extremity and trunk wall soft tissue sarcomas and its external validation.
abstract: BACKGROUND
  We developed a web-based, prognostic tool for extremity and trunk wall soft tissue sarcoma to predict 10-year sarcoma-specific survival. External validation was performed.
  
  
  METHODS
  Patients referred during 1987-2002 to Helsinki University Central Hospital are included. External validation was obtained from the Lund University Hospital register. Cox proportional hazards models were fitted with the Helsinki data. The previously described model (SIN) includes size, necrosis, and vascular invasion. The extended model (SAM) includes the SIN factors and in addition depth, location, grade, and size on a continuous scale. Models were statistically compared according to accuracy (area under the ROC curve=AUC) of 10-year sarcoma-specific survival prediction.
  
  
  RESULTS
  The AUC of the SAM model in 10-year survival prediction in the Helsinki patient series was 0.81 as compared with 0.74 for the SIN model (P=0.0007). The corresponding AUCs in the external validation series were 0.77 for the SAM model and 0.73 for the SIN model (P=0.03). A web-based calculator for the SAM model is available at http://www.prognomics.org/sam.
  
  
  CONCLUSIONS
  Addition of grade, depth, and location as well as tumour size on a continuous scale significantly improved the accuracy of the prognostic model when compared with a model that includes only size, necrosis, and vascular invasion.
authors.affiliation: Department of Pathology, HUSLAB and University of Helsinki, PO Box 400, HUCH-00029, Helsinki, Finland. mika.sampo@helsinki.fi
authors.forename: M
authors.initials: M
authors.lastname: Sampo
authors.forename: M
authors.initials: M
authors.lastname: Tarkkanen
authors.forename: E
authors.initials: E
authors.lastname: Tukiainen
authors.forename: P
authors.initials: P
authors.lastname: Popov
authors.forename: P
authors.initials: P
authors.lastname: Gustafson
authors.forename: M
authors.initials: M
authors.lastname: Lundin
authors.forename: T
authors.initials: T
authors.lastname: Böhling
authors.forename: C
authors.initials: C
authors.lastname: Blomqvist
authors.forename: J
authors.initials: J
authors.lastname: Lundin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D002138:Calibration; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009862:Online Systems; D011379:Prognosis; D016016:Proportional Hazards Models; D012372:ROC Curve; D012509:Sarcoma / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D047368:Tumor Burden; D055815:Young Adult