A simple stratification factor prognostic for survival in advanced cancer:The Good/Bad/Uncertain index

Purpose: This article summarizes the third step of a research program to id entify variables that supplement the predictive power of the the Eastern Co operative Oncology Group (ECOG) performance status (PS) for survival. The o bjective was to produce a simple, practical, stratification factor for phas e III oncology clinical trials involving patients with advanced malignant d isease. Patients and 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, neutra l, 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 pos itive 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 quar tile index and PS alone and increased the accuracy of survival classificati on 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 an d .0001, respectively). Conclusion: The GBU index may be recommended as a supplementary stratificat ion factor for certain future phase III trials in metastatic lung or colore ctal cancer where patient heterogeneity is a particular concern. The GBU re presents a relatively modest increase to the cost and patient burden of a c linical trial given the additional control that is achieved over the potent ially confounding concomitant to the treatment variable.