A chart review performed at the Department of Internal Medicine, University of Alberta, Edmonton, AB. concluded that the a quick rate of initial PSA decline in men with hormone refractory prostate cancer receiving docetaxel chemotherapy (chemo) predicts an increased overall survival (OS).
Studies have demonstrated that docetaxel chemotherapy does prolong survival in metastatic hormone-refractory prostate cancer (mHRPC), but not all men benefit from this therapy. Prostate Specific Antigen (PSA) decline and the rate of PSA decline following chemotherapy treatment differs from one man to another. This review demonstrated that men who managed to achieve a rapid rate of PSA decline, measured as a shorter PSA half-life (PSAHL), can hope to experience a longer overall survival (OS) than those who achieve a slower rate of PSA decline.
The review was performed on the hospital charts from January 2000 to May 2006. At 42 days (after 2 cycles of chemo) and 84 days (after 4 cycles of chemo), PSA response and PSAHL were determined. PSAHL could only be determined in men with a PSA drop from their baseline. Optimal PSAHL values for OS stratification were determined using the log-rank chi-square statistic. Survival analysis was performed by using Kaplan-Meier curves and regression analysis.
The researchers were able to use the data from 154 men who fulfilled the inclusion criteria. Using 42-day post-docetaxel data, no associations with OS could be demonstrated. Using 84-day post-docetaxel data, patients stratified by PSAHL demonstrated a significant difference in OS (15 months vs. 25 months) and this relationship remained following multivariate analysis (hazard ratio 0.08 [0.021-0.34]).
A more rapid rate of PSA decline (PSAHL < 70 days) measured after 4 cycles of chemotherapy was associated with a longer over all survival. This result was independent of other known markers of survival.
Can Urol Assoc J. 2009 Oct;3(5):369-74., Hanninen M, Venner P, North S.
Joel T Nowak MA, MSW