Pretreatment PSA velocity as a predictor of disease outcome following radical radiation therapy.
OBJECTIVE
Pretreatment prostate-specific antigen velocity (PSAV) greater than 2.0 ng/mL/year has been identified as a predictor of disease-specific survival (DSS) and overall survival (OS) after radiotherapy for prostate adenocarcinoma. This study aimed to independently verify if pretreatment PSAV is associated with biochemical disease-free survival (bDFS), DSS, or OS in men undergoing radiation therapy.


METHODS
A total of 473 patients treated with radiation therapy for localized prostate cancer formed the study cohort. No men received neoadjuvant or adjuvant hormones. Kaplan-Meier and Cox regression analysis were used to evaluate if PSAV predicted disease endpoints.


RESULTS
Men with a PSAV greater than 2.0 ng/mL/year had a shorter bDFS compared with men with a PSAV of 2.0 ng/mL/year or less (median, bDFS 68 months vs. 97 months; p = 0.0003). However, on multivariate analysis, PSAV was no longer a significant predictor of bDFS in the entire cohort (p = 0.09). PSAV did not predict DSS or OS (p = 0.55 and p = 0.99, respectively). In patients with high-risk disease, PSAV predicted bDFS on univariate (p = 0.0002) and multivariate (p = 0.02) analysis, but not DSS or OS.


CONCLUSIONS
Pretreatment PSAV greater than 2.0 ng/mL/year is associated with reduced bDFS. However, PSAV is an independent predictor of bDFS only in high-risk patients. PSAV does not predict survival outcomes.
Palma
David
D
Radiation Oncology Program, British Columbia Cancer Agency, Vancouver, British Columbia, Canada. dpalma@bccancer.bc.ca
Tyldesley
Scott
S
Blood
Paul
P
Liu
Mitchell
M
Morris
James
J
Pickles
Tom
T
D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000401:mortality / Q000532:radiotherapy*; D020266:Radiotherapy, Conformal; D012008:Recurrence; D012044:Regression Analysis
D017430:Prostate-Specific Antigen