A simple stratification factor prognostic for survival in advanced cancer: the good/bad/uncertain index.
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.
Sloan
J A
JA
Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA. jsloan@mayo.edu
Loprinzi
C L
CL
Laurine
J A
JA
Novotny
P J
PJ
Vargas-Chanes
D
D
Krook
J E
JE
O'Connell
M J
MJ
Kugler
J W
JW
Tirona
M T
MT
Kardinal
C G
CG
Wiesenfeld
M
M
Tschetter
L K
LK
Hatfield
A K
AK
Schaefer
P L
PL
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