title: A simple stratification factor prognostic for survival in advanced cancer: the good/bad/uncertain index.
abstract: OBJECTIVE
  This article summarizes the third step of a research program to identify variables that supplement the predictive power of the the Eastern Cooperative Oncology Group (ECOG) performance status (PS) for survival. The objective was to produce a simple, practical, stratification factor for phase III oncology clinical trials involving patients with advanced malignant disease.
  
  
  METHODS
  A questionnaire was administered to 729 patients with metastatic colorectal or lung cancers. Patients provided a Karnofsky index and appetite rating while physicians provided a survival estimate and the ECOG-PS. Scores for each item were categorized as having a positive, neutral, or negative indication for survival. A patient was classified as having a relatively good prognosis if three or more of the four items showed a positive indication, a bad prognosis if three or more items were negative, and an uncertain prognosis otherwise (Good/Bad/Uncertain [GBU] index).
  
  
  RESULTS
  The GBU index improved on the prognostic power of a Cox model quartile index and PS alone and increased the accuracy of survival classification estimates by 5% to 10% more than ECOG-PS alone. For patients with PS of 0 or 1, significant survival patterns exist between GBU groups (P=.002 and.0001, respectively).
  
  
  CONCLUSIONS
  The GBU index may be recommended as a supplementary stratification factor for certain future phase III trials in metastatic lung or colorectal cancer where patient heterogeneity is a particular concern. The GBU represents a relatively modest increase to the cost and patient burden of a clinical trial given the additional control that is achieved over the potentially confounding concomitant to the treatment variable.
authors.affiliation: Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA. jsloan@mayo.edu
authors.forename: J A
authors.initials: JA
authors.lastname: Sloan
authors.forename: C L
authors.initials: CL
authors.lastname: Loprinzi
authors.forename: J A
authors.initials: JA
authors.lastname: Laurine
authors.forename: P J
authors.initials: PJ
authors.lastname: Novotny
authors.forename: D
authors.initials: D
authors.lastname: Vargas-Chanes
authors.forename: J E
authors.initials: JE
authors.lastname: Krook
authors.forename: M J
authors.initials: MJ
authors.lastname: O'Connell
authors.forename: J W
authors.initials: JW
authors.lastname: Kugler
authors.forename: M T
authors.initials: MT
authors.lastname: Tirona
authors.forename: C G
authors.initials: CG
authors.lastname: Kardinal
authors.forename: M
authors.initials: M
authors.lastname: Wiesenfeld
authors.forename: L K
authors.initials: LK
authors.lastname: Tschetter
authors.forename: A K
authors.initials: AK
authors.lastname: Hatfield
authors.forename: P L
authors.initials: PL
authors.lastname: Schaefer
mesh_terms: D000368:Aged; D017326:Clinical Trials, Phase III as Topic / Q000379:methods; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality* / Q000503:physiopathology; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016019:Survival Analysis