Development of the Biological Prognostic Score in patients with advanced cancer and prospective verification of its external validity: Comparison with the Palliative Prognostic Index

Abstract

Objective: To develop and confirm the validity of a Biological Prognostic Score using only blood test results for prediction of prognosis in patients with advanced cancer. Methods: We conducted parametric survival time analysis using blood test results, age, sex, and primary diagnosis as independent variables, and event of death as a dependent variable, among patients in a palliative care unit (a development cohort). We then developed the Biological Prognostic Score (BPS). Thereafter, we confirmed the accuracy of the BPS and the Palliative Prognostic Index (PPI) prospectively among patients, who withdrew or withheld further curative or life-prolonging therapies, in other facilities (a validation cohort). Results: We developed the BPS, which consists of cholinesterase, blood urea nitrogen, and total iron-binding capacity, from 122 patients in a development cohort. We then examined 195 patients in a validation cohort and found that the area under the receiver operating characteristic curve for 1-9 week survival prediction was BPS=0.76-0.86 and PPI=0.69-0.73. Discussion: Our results suggest that the BPS was valid. It will be necessary to perform further examinations in multiple facilities and to explore more generalized parameters that could replace total iron-binding capacity in our BPS.