Early Prediction of Therapy Response to Abiraterone Acetate Using PSA Subforms in Patients with Castration Resistant Prostate Cancer.
The purpose of this study was to evaluate the prognostic ability of early changes of total prostate specific antigen (tPSA), free PSA (fPSA), [-2]proPSA and the Prostate Health Index (PHI) following initiation of Abiraterone-therapy in men with castration resistant prostate cancer (mCRPC). In 25 patients, PSA-subforms were analyzed before and at 8-12 weeks under therapy as prognosticators of progression-free-survival (PFS) and overall survival (OS). Comparing patients with a PFS < vs. ≥12 months by using Mann-Whitney-Wilcoxon Tests, the relative-median-change of tPSA (-0.1% vs. -86.8%; p = 0.02), fPSA (12.1% vs. -55.3%; p = 0.03) and [-2]proPSA (8.1% vs. -59.3%; p = 0.05) differed significantly. For men with ≤ vs. >15 months of OS there was a non-significant trend for a difference in the relative-median-change of fPSA (17.0% vs. -46.3%; p = 0.06). In Kaplan-Meier analyses, declining fPSA and [-2]proPSA were associated with a longer median PFS (13 months, 95% confidence interval (CI): 9.6-16.4 vs. 10 months, 95% CI: 3.5-16.5; p = 0.11), respectively. Correspondingly, decreasing fPSA and [-2]proPSA values indicated an OS of 32 months (95% CI: not reached (NR)) compared to 21 months in men with rising values (95% CI: 7.7-34.3; p = 0.14), respectively. We concluded that the addition of fPSA- and [-2]proPSA-changes to tPSA-information might be further studied as potential markers of early Abiraterone response in mCRPC patients.
['Schlack|Katrin|K|', 'Krabbe|Laura-Maria|LM|', 'Fobker|Manfred|M|', 'Schrader|Andres Jan|AJ|', 'Semjonow|Axel|A|', 'Boegemann|Martin|M|']
D000069501:Abiraterone Acetate D000368:Aged D000970:Antineoplastic Agents D018572:Disease-Free Survival D006801:Humans D008297:Male D008875:Middle Aged D011379:Prognosis D017430:Prostate-Specific Antigen D064129:Prostatic Neoplasms, Castration-Resistant D016019:Survival Analysis D016896:Treatment Outcome
abiraterone acetate prostate cancer prognosticators tPSA fPSA PHI mCRPC [−2]proPSA surrogate biomarker