title: A Novel Clinical Prediction Model for Prognosis in Malignant Pleural Mesothelioma Using Decision Tree Analysis.
abstract: BACKGROUND
  Malignant pleural mesothelioma (MPM) is a rare cancer with a heterogeneous prognosis. Prognostic models are not widely utilized clinically. Classification and regression tree (CART) analysis examines the interaction of multiple variables with a given outcome.
  
  
  METHODS
  Between 2005 and 2014, all cases with pathologically confirmed MPM had routinely available histological, clinical, and laboratory characteristics recorded. Classification and regression tree analysis was performed using 29 variables with 18-month survival as the dependent variable. Risk groups were refined according to survival and clinical characteristics. The model was then tested on an external international cohort.
  
  
  RESULTS
  A total of 482 cases were included in the derivation cohort; the median survival was 12.6 months, and the median age was 69 years. The model defined four risk groups with clear survival differences (p < 0.0001). The strongest predictive variable was the presence of weight loss. The group with the best survival at 18 months (86.7% alive, median survival 34.0 months, termed risk group 1) had no weight loss, a hemoglobin level greater than 153 g/L, and a serum albumin level greater than 43 g/L. The group with the worst survival (0% alive, median survival 7.5 months, termed risk group 4d) had weight loss, a performance score of 0 or 1, and sarcomatoid histological characteristics. The C-statistic for the model was 0.761, and the sensitivity was 94.5%. Validation on 174 external cases confirmed the model's ability to discriminate between risk groups in an alternative data set with fair performance (C-statistic 0.68).
  
  
  CONCLUSIONS
  We have developed and validated a simple, clinically relevant model to reliably discriminate patients at high and lower risk of death using routinely available variables from the time of diagnosis in unselected populations of patients with MPM.
authors.affiliation: Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Perth, Australia; School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; Institute for Respiratory Health, Perth, Australia. Electronic address: fraserbrims@uwa.edu.au.
authors.forename: Fraser J H
authors.initials: FJ
authors.lastname: Brims
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; National Centre for Asbestos Related Diseases, University of Western Australia, Perth, Australia; Department of Medical Oncology, Sir Charles Gairdner Hospital, Perth, Australia.
authors.forename: Tarek M
authors.initials: TM
authors.lastname: Meniawy
authors.affiliation: Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Perth, Australia.
authors.forename: Ian
authors.initials: I
authors.lastname: Duffus
authors.affiliation: Department of Respiratory Medicine, North Bristol National Health Service Trust, Bristol, United Kingdom.
authors.forename: Duneesha
authors.initials: D
authors.lastname: de Fonseka
authors.affiliation: PathWest Laboratory Medicine, Queen Elizabeth II Medical Campus, Perth, Australia.
authors.forename: Amanda
authors.initials: A
authors.lastname: Segal
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; National Centre for Asbestos Related Diseases, University of Western Australia, Perth, Australia.
authors.forename: Jenette
authors.initials: J
authors.lastname: Creaney
authors.affiliation: Department of Respiratory Medicine, North Bristol National Health Service Trust, Bristol, United Kingdom.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Maskell
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; National Centre for Asbestos Related Diseases, University of Western Australia, Perth, Australia.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Lake
authors.affiliation: Telethon Kids Institute, University of Western Australia, Perth, Australia.
authors.forename: Nick
authors.initials: N
authors.lastname: de Klerk
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Australia; National Centre for Asbestos Related Diseases, University of Western Australia, Perth, Australia; Department of Medical Oncology, Sir Charles Gairdner Hospital, Perth, Australia.
authors.forename: Anna K
authors.initials: AK
authors.lastname: Nowak
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003663:Decision Trees; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology; D008297:Male; D008654:Mesothelioma / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology; D000086002:Mesothelioma, Malignant; D015233:Models, Statistical; D010997:Pleural Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology; D011379:Prognosis
keywords: Decision trees; Mesothelioma; Prognosis; Survival