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.
Department of Urology, Prostate Center, University Hospital Muenster, Albert-Schweitzer-Campus 1, GB A1, Muenster D-48149, Germany. katrin.schlack@ukmuenster.de.
Katrin
K
Schlack
Department of Urology, Prostate Center, University Hospital Muenster, Albert-Schweitzer-Campus 1, GB A1, Muenster D-48149, Germany. laura-maria.krabbe@ukmuenster.de.|Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9110, USA. laura-maria.krabbe@ukmuenster.de.
Laura-Maria
LM
Krabbe
Center for Laboratory Medicine, University Hospital Muenster, Albert-Schweitzer-Campus 1, GB A1, Muenster D-48149, Germany. manfred.fobker@ukmuenster.de.
Manfred
M
Fobker
Department of Urology, Prostate Center, University Hospital Muenster, Albert-Schweitzer-Campus 1, GB A1, Muenster D-48149, Germany. andresjan.schrader@ukmuenster.de.
Andres Jan
AJ
Schrader
Department of Urology, Prostate Center, University Hospital Muenster, Albert-Schweitzer-Campus 1, GB A1, Muenster D-48149, Germany. axel.semjonow@ukmuenster.de.
Axel
A
Semjonow
Department of Urology, Prostate Center, University Hospital Muenster, Albert-Schweitzer-Campus 1, GB A1, Muenster D-48149, Germany. martin.boegemann@ukmuenster.de.
Martin
M
Boegemann
D000069501:Abiraterone Acetate / Q000008:administration & dosage* / Q000627:therapeutic use; D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000378:metabolism*; D064129:Prostatic Neoplasms, Castration-Resistant / Q000188:drug therapy* / Q000378:metabolism; D016019:Survival Analysis; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D017430:Prostate-Specific Antigen; D000069501:Abiraterone Acetate
PHI; [−2]proPSA; abiraterone acetate; fPSA; mCRPC; prognosticators; prostate cancer; surrogate biomarker; tPSA