Elevated Prostatic Acid Phosphatase Levels Research Articles

Bone Scintigraphy, Radiographic Survey and Prostatic Acid Phosphatase in Patients With Prostatic Carcinoma. A Comparison of Sensitivity

In 62 patients with histologically confirmed carcinoma of the prostate bone scintigraphy, radiographic survey and serum prostatic acid phosphatase determinations were carried out to evaluate the progression of the disease and to compare the relative sensitivity of the diagnostic tools. Thirty-five patients had scintigraphic evidence of skeletal metastases, whereas abnormal X-ray survey and elevated prostatic acid phosphatase levels were found in only 4 and 19 patients, respectively, all of whom had positive scintigraphic findings. Radiographic evidence of metastases was not found in any of the patients with normal scintigraphy, while elevated prostatic acid phosphatase was found in two patients. It is concluded that bone scintigraphy is far more sensitive than either radiographic survey or determination of prostatic acid phosphatases in the diagnosis of skeletal involvement in prostatic carcinoma, and should be the method of choice for this purpose.

Clinical utility of serum prostatic acid phosphatase measurements for detection (screening), diagnosis, and therapeutic monitoring of prostatic carcinoma; assessment of monoclonal and polyclonal enzymes and radioimmunoassays.

Serum prostatic acid phosphatase (PAP), measured by three different technics, was used to screen 560 men over 50 years of age for prostatic cancer. All three PAP procedures failed to detect the one subject found to have prostatic cancer on physical examination and confirmed by biopsy, and all assays had a significant number of "falsely" elevated PAP levels. Four PAP assays were assessed in 80 men undergoing prostatic biopsy/removal in whom histologic examination of prostatic tissue was made. Clinical sensitivity and specificity for detecting those patients with and without prostatic cancer ranged from 20-57% and 54-95%, respectively, with the monoclonal enzyme immunoassay being the most sensitive but the least specific, and the traditional enzyme assay being the most specific but insensitive. In men with diagnosed prostatic cancer undergoing radiation or chemotherapy, the assays were useful in distinguishing between those with active and inactive disease. The authors conclude that serum PAP assays, irrespective of the type of procedure used, has no place in screening for prostatic cancer, a minimal role in establishing a definitive diagnosis, but a useful role in monitoring therapy.

LHRH-agonist treatment in metastatic prostate carcinoma

Three patients with metastatic prostatic cancer were treated for 10, 6 and 2 months with the potent LHRH-agonist Buserelin (Hoe 766) as a first-line agent. All showed a fall of elevated prostatic acid phosphatase levels (nearly undetectable after treatment in 2 patients) parallel to plasma testosterone with a relief of complaints after 3–4 weeks of treatment. Two patients had an increment of appetite and body weight. In some patient radiological evidence for objective tumour regression was found by CT scan of the prostate (decrease of 41% in prostate volume), skeletal X-rays and bone scan. In this patient plasma alkaline phosphatase showed a transient increase parallel to disappearance of osteolytic bone lesions (indicating new bone formation) followed by a normalization. It is concluded that LHRH-agonist treatment is effective in patients with metastatic prostatic carcinoma in the absence of serious side-effects.

Radioimmunoassay of serum prostatic acid phosphatase after prostatic massage

The effect of prostatic massage on the concentration of prostatic acid phosphatase (PAP) in blood serum as determined by radioimmunoassay (RIA) was compared with that determined by a standard enzymatic assay (EA). Serum was drawn from 24 men before prostatic massage and after—at specified intervals, up to twenty-four hours. Three of these men were young, normal controls; 10 had biopsy-proved prostate cancer (CA); 11 had histologically confirmed benign prostatic hyperplasia (BPH). After prostatic massage, 3 of the 10 CA patients (30%) had elevation of PAP as determined by EA and 4 of the 11 BPH patients (36%) as determined by RIA. None of the controls showed elevated levels of PAP by either assay. In all patients elevated levels of PAP by both assays had returned to normal twenty-four hours after massage. It was concluded that serum for PAP testing by either assay method should be drawn before or twenty-four hours after rectal examination to prevent false positive results and the need for retesting.

Prostatic Cancer, Acid Phosphatase, Creatine Kinase-Bb and Race: A Prospective Study

To examine the effectiveness of prostatic acid phosphatase and creatine kinase-BB determinations in detecting prostatic cancer serum from 594 men more than 40 years old was assayed for prostatic acid phosphatase with the thymolphthalein monophosphate substrate and a radioimmunoassay kit. Creatine kinase-BB levels also were measured with a radioimmunoassay kit.Patients with benign prostatic hyperplasia had higher prostatic acid phosphatase levels than normal controls. Accordingly, to avoid a high incidence of false positives in patients with benign prostatic hyperplasia the 92.5 percentile level of the patients with benign prostatic hyperplasia (3.9ng./ml.) was chosen as the upper limit of normal. With this critical value elevated prostatic acid phosphatase levels were observed in 6 per cent of the patients with clinical stage A disease, 8 per cent with stage B, 35 per cent with stage C and 68 per cent with stage D. The radioimmunoassay was no more effective than the enzymatic assay in detecting prostatic cancer.A correlation between prostatic acid phosphatase levels and patient race was observed, with 80 per cent of the black patients with extracapsular prostatic cancer having elevated prostatic acid phosphatase levels compared to 34 per cent of the white patients with similar stage disease.Creatine kinase-BB was elevated only in patients with advanced disease and was of little value in the diagnosis of prostatic cancer.

Will Prostatic Acid Phosphatase Determination by Radioimmunoassay Increase The Diagnosis of Early Prostatic Cancer?

The determination of serum prostatic acid phosphatase by radioimmunoassay has received considerable attention as a more sensitive and specific test than its measurement by the usual enzymatic assay. It has been suggested that the increased sensitivity of the radioimmunoassay will improve greatly our ability to diagnose prostatic cancer in the early operative stages.Our study compares prostatic acid phosphatase determination by the radioimmunoassay and enzymatic techniques in 56 untreated and treated patients with prostatic cancer. In addition, 22 patients with biopsy-proved benign prostatic hyperplasia also were studied. The radioimmunoassay used was based on antibodies raised against prostatic acid phosphatase highly purified by 2-stage, ion-specific chromatography and isoelectric focusing techniques. The enzymatic assay used thymolphthalein monophosphate as the substrate.The patients were staged on the basis of digital examination, technetium bone scan and pelvic lymphadenectomy. There were 4 patients with stage A, 12 with stage B, 13 with stage C and 27 with stage D disease. The radioimmunoassay showed an elevated prostatic acid phosphatase in 13 per cent of the patients with intracapsular disease (stages A and B) and in 50 per cent of the patients with extracapsular disease (stages C and D). This finding compares with an enzymatic prostatic acid phosphatase elevation in 13 per cent of the patients with intracapsular and 53 per cent of those with extracapsular disease. There were fewer falsely elevated prostatic acid phosphatase levels by radioimmunoassay (2) than by enzymatic assay (6) in the patients with benign prostatic hyperplasia.Our data show that the radioimmunoassay method provides a reliable and specific measurement of prostatic acid phosphatase. However, the radioimmunoassay measurement of prostatic acid phosphatase does not appear to be more effective as a screening aid in the diagnosis of early stages of prostatic cancer and in our study it was no more helpful than the enzymatic assay.