Background: Although, in general, immunoperoxidase staining for prostate-specific antigen (PSA) and prostate-specific acid phosphatase (PSAP) cannot distinguish between benign and malignant prostatic epithelium, immunoreactivity of these antigens may be helpful in predicting prognosis of prostate cancer. The purpose of this study was to evaluate intensity and extent of immunoperoxidase staining for PSA and PSAP as a prognostic tool in prostate adenocarcinomas.
Methods: We studied radical prostatectomy specimens from 68 patients with the following stages: organ-confined, 34.3%; focal capsular penetration, 38.8%; established capsular penetration, 25.3%; and seminal vesicle invasion, 1.6%. Ninety-one percent of cases were Gleason score 5-7. The mean follow-up for those men without progression was 8.9 years, compared to 3.5 years for those with progression. Progression was defined as an elevated postoperative serum PSA level (> 0.2 ng/ml). Intensity of PSA and PSAP staining was recorded and based on a scale of 0-3 (0, no staining; 1, weak; 2, moderate; 3, intense). Extent was quantitated on a scale of 0-4 (0, 0-5% staining; 1, 6-35%; 2, 36-65%; 3, 65-95%; 4, 95-100%). A score (0-12) was computed by multiplying intensity and extent of the stain in the tumor area.
Results and conclusions: Intensity and extent of PSA and PSAP immunoreactivity did not predict progression in adenocarcinomas of the prostate following radical prostatectomy.