Prognostic role of serum prostatic acid phosphatase for 103Pd-based radiation for prostatic carcinoma.
OBJECTIVE
To establish the prognostic role of serum enzymatic prostatic acid phosphatase (PAP) in patients treated with palladium (103Pd) and supplemental external beam irradiation (EBRT) for clinically localized, high-risk prostate carcinoma.


METHODS
One hundred twenty-four consecutive patients with Stage T2a-T3 prostatic carcinoma were treated from 1992 through 1995. Each patient had at least one of the following risk factors for extracapsular disease extension: Stage T2b or greater (100 patients), Gleason score 7-10 (40 patients), pretreatment prostate specific antigen (PSA) >15 ng/ml (32 patients), or elevated serum PAP (25 patients). Patients received 41 Gy conformal EBRT to a limited pelvic field, followed 4 weeks later by a 103Pd boost (prescription dose 80 Gy). Biochemical failure was defined as a PSA greater than 1 ng/ml (normal <4 ng/ml).


RESULTS
The overall, actuarial freedom from biochemical failure at 4 years after treatment was 79%. In Cox-proportional hazard multivariate analysis, the strongest predictor of failure was elevated pretreatment acid phosphatase (p = 0.02), followed by Gleason score (p = 0.1), and PSA (p = 0.14).


CONCLUSIONS
PAP was the strongest predictor of long-term biochemical failure. It may be a more accurate indicator of micrometastatic disease than PSA, and as such, we suggest that it be reconsidered for general use in radiation-treated patients.
Dattoli
M
M
Department of Radiology, University Community Hospital, Tampa, FL 33613, USA.
Wallner
K
K
True
L
L
Sorace
R
R
Koval
J
J
Cash
J
J
Acosta
R
R
Biswas
M
M
Binder
M
M
Sullivan
B
B
Lastarria
E
E
Kirwan
N
N
Stein
D
D
D000135:Acid Phosphatase / Q000097:blood*; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009363:Neoplasm Proteins / Q000097:blood*; D009367:Neoplasm Staging; D010165:Palladium / Q000627:therapeutic use*; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology / Q000532:radiotherapy*; D011868:Radioisotopes / Q000627:therapeutic use*; D017211:Treatment Failure
D009363:Neoplasm Proteins; D011868:Radioisotopes; D010165:Palladium; D000135:Acid Phosphatase; D017430:Prostate-Specific Antigen