Prognostic factors for survival of patients with bidimensionally measurable metastatic hormone-refractory prostatic cancer treated with single-agent chemotherapy

Abstract

Background: A range of response proportions have been reported using the same single-agent inpatients with hormone refractory prostatic cancer. To assess whether these results were due to imbalances in prognostic factors, the authors evaluated a series of prognostic factors for survival in patients with prostatic cancer treated with chemotherapy.

Methods: Complete data sets were available in 146 patients, in whom 27 individual variables were considered in univariate analysis. Significant factors (P < 0.05) were then evaluated using regression analysis along with transformations of the data to obtain a Cox and exponential model. The derived model was then evaluated on an independent data set from the National Cancer Institute treated with suramin.

Results: In univariate analysis in order of significance, the serum alkaline phosphate (0.0018), serum lactic dehydrogenase (0.006), prior radiation therapy (0.007), serum aspartate amino transferase (0.02), presence of liver disease (0.033), and pretreatment Karnofsky performance status (0.04) were associated with survival. In the regression analysis, only the log-transformed lactic dehydrogenase (LDH) and normal versus abnormal alkaline phosphatase were significant. This model was confirmed with an independent data set from patients treated with the putative growth factor inhibitor suramin.

Conclusions: This analysis emphasizes important factors that can be used to stratify patients in future phase II and III trials.