Prostatic acid phosphatase by radioimmunoassay tumor marker in bone marrow

Detection of tumor cells in bone marrow of patients with prostatic carcinoma by immunocytochemical techniques

We used a mixture of antisera to prostatic specific acid phosphatase, prostatic specific antigen, epithelial membrane antigen and cytokeratin to examine multiple marrow aspirates from patients with local (15) and metastatic prostatic carcinoma (15), and benign prostatic hypertrophy (10). We found moderate to large numbers of tumor cells in the bone marrow of 11 of 15 (73 per cent) patients with known metastatic disease and small numbers of abnormal cells in 2 of 15 (13 per cent) patients with apparently local disease. No tumor cells were found in patients with benign prostatic hypertrophy, and only 2 patients with metastatic disease had tumor cells in the bone marrow when conventional hematomorphological preparations were examined. These findings suggest that immunocytochemistry can increase the detection rate of metastatic prostatic carcinoma cells. Further followup of larger numbers of patients with local carcinoma will reveal whether the presence of micrometastases denotes a poor prognosis.

Bone marrow prostatic specific antigen and prostatic acid phosphatase levels: are they helpful in staging prostatic cancer?

We analyzed serum and bone marrow levels of prostatic specific antigen and prostatic acid phosphatase quantified by double antibody radioimmunoassay in 70 patients. Of the patients 36 had prostatic cancer, including 23 with metastatic disease. There was a significant correlation between the serum and bone marrow levels of prostatic specific antigen and prostatic acid phosphatase independently of the metastases (p less than 0.001). No patient with prostatic cancer and positive bone marrow prostatic specific antigen or prostatic acid phosphatase levels had normal serum levels. Quantification of bone marrow prostatic specific antigen and prostatic acid phosphatase does not provide more information than does serum determination.

Bone metastases: pathogenesis, treatment, and rationale for use of resorption inhibitors

Tumors in bone are usually metastatic, with breast, prostate, and lung tumors accounting for more than 80 percent of clinically manifest lesions. Untreated, such metastases can produce the symptoms that most concern cancer patients--pain, pathologic fractures, and paralysis through epidural cord compression. Recent advances in the understanding of the metastatic cascade and the regulation of bone formation and resorption provide unique therapeutic approaches for prevention and treatment of these lesions. This article reviews the prevalence, distribution, diagnosis, and treatment of metastatic cancer in the skeleton, as well as the processes involved in the development of such metastases, the local mediators responsible for some of the destructive changes in bone, and their pathologic results. In addition to considering some of the conventional therapeutic approaches, a rationale for the use of bone resorption inhibitors, such as the diphosphonates (bisphosphonates), is presented for the prevention and amelioration of the pathologic consequences of skeletal metastases.

The detection and evaluation of human tumor metastases

Many biochemical indices are purported to have clinical utility in the detection and management of neoplasia. Experience gained during the past decade tends to indicate their having a more important role in the detection and monitoring of metastases than of the primary lesion. From this present review of some of the commoner human tumours, it is concluded that such marker substances are important adjuncts in the management of germ cell and certain endocrine and endocrine-related tumours. The carcinoembryonic antigen (CEA) provides a marker for many gastrointestinal cancers, but there are no presently available substances with clinical usefulness for either breast or lung neoplasms. Alternative approaches to the detection of metastases are also presented. The particular use of antibody probes at an immunohistochemical level has been claimed to be able to detect micrometastastic disease in bone marrow or tumour-related monoclonal antibody probes may have application to other cancers in the future.

A critical evaluation of a specific radioimmunoassay for prostatic acid phosphatase

A radioimmunoassay (RIA) method for acid phosphatase detection was compared to a standard enzyme assay using sera from 210 normal volunteers and 285 patients with prostatic disease. Statistical and clinical comparisons were made between defined subgroups. All 55 normal females had RIA detectable serum acid phosphatase, implying that this assay cannot be entirely specific for enzyme of prostatic origin. Urinary catheterization did not affect acid phosphatase levels. In all stages of carcinoma there were more acid phosphatase elevations by the RIA method than enzyme method, but neither assay could differentiate intracapsular cancer from benign prostatic hyperplasia. A small number of patients with biopsy proven negative nodules had marginally elevated values, suggesting as obligation for closer follow-up. The RIA method may be superior for monitoring patients with more advanced malignancy. Additional practical advantages of the RIA include relative simplicity and elimination of the special serum handling required for the enzyme assay.

Radioimmunoassayable prostate-specific acid phosphatase in peripheral and bone marrow sera compared in diagnosis of prostatic cancer patients

Measurements of human prostate-specific acid phosphatase by radioimmunoassay in peripheral and bone marrow sera were compared. We studied 20 patients with benign prostatic hyperplasia, 27 with untreated prostatic cancer without bone metastases and 11 with metastases, in addition to 7 with cancer treated by hormonal therapy. The prostate-specific acid phosphatase concentrations in peripheral and bone marrow serum samples were equal and did not exceed the upper limit of our health-associated reference interval, 2.8 microgram. per 1. (mean plus 2 standard deviations) in patients with prostatic hyperplasia. Of 27 prostatic cancer patients without bone metastases the concentration of prostate-specific acid phosphatase was elevated in the peripheral sera of 20 and in the bone marrow sera of 21, and 21 had an extracapsular tumor (stage T3 to T4). Prostate-specific acid phosphatase concentrations were elevated in peripheral and bone marrow serum specimens of all 11 patients with metastases and bone marrow cytology studies were positive in 2. There was no difference in prostate-specific acid phosphatase concentrations in peripheral and bone marrow serum specimens from prostatic cancer patients undergoing hormonal treatment. We conclude that the use of bone marrow serum for the measurement of radioimmunoassayable prostate-specific acid phosphatase in prostatic cancer patients does not provide any further information in regard to the detection of prostatic cancer compared to the use of peripheral serum specimens. Falsely positive findings in bone marrow specimens were not observed with the method used.

Radioimmunoassay versus counterimmune electrophoresis for measurement of serum prostatic acid phosphatase

Radioimmunoassay (RIA) kits obtained from commercial sources were evaluated and compared with a standard counterimmunoelectrophoretic (CIE) assay for the measurement of prostatic acid phosphatase (PAP) in serum. None of the radioimmunoassays was found to be more sensitive than the CIE assay in detecting elevated serum PAP. Both immunoassays were somewhat more effective clinically in measuring prostatic specific acid phosphatase than an enzyme colorimetric assay. The results obtained by CIE agreed with the results obtained by RIA in 96 per cent of the tests. The number of positive results in patients with confirmed prostate adenocarcinoma increased with disease progression. The low number of positive tests in localized adenocarcinoma (Stages A and B) suggests that neither the CIE nor any RIA procedure is useful for screening unselected populations for adenocarcinoma of the prostate.

Serum and bone marrow radioimmunoassay of acid phosphatase in prostatic cancer

Use of radioimmunoassay (RIA) for determinations of prostatic acid phosphatase has recently received considerable attention because of reported higher sensitivity and specificity than previous enzymatic assays. We have compared the sensitivity and specificity of a commercially available RIA to a highly specific enzymatic assay (thymolphthalein monophosphate) using 37 patients with prostatic cancer and 34 patients with surgically proved benign prostatic hyperplasia. Seventeen of the cancer patients and all 34 of the BPH patients were studied prospectively. We further evaluated specificity by performing the RIA on 25 specimens of bone marrow from patients with nonprostatic disease. Our results indicate the radioimmunoassay is not, at this time, an adequate screening tool, and we question its accuracy in staging patients anymore reliably than by enzymatic assay.

Bone marrow acid phosphatase by radioimmunoassay: 3 years of experience

Clinical followup of 112 patients staged by the immunochemical determination of prostatic acid phosphatase from bone marrow aspirates is presented. This represents a 94 per cent (112 of 118) retrieval rate of a group studied more than 2 years previously. Of the 11 patients judged to be at high risk 4 (36 per cent) have suffered bony metastases, whereas only 3 of 86 patients (3 per cent) with normal bone marrow acid phosphatase by radioimmunoassay have done so. An additional 184 patients with carcinoma and 77 controls have been studied. Although radioimmunoassay greatly improves specificity in bone marrow aspirates a few falsely positive results can occur. This finding may be secondary to cross reaction from leukocyte acid phosphatase and/or interference from lipid.

A solid-phase immunoadsorbent assay for serum prostatic acid phosphatase

A solid-phase immunoadsorbent assay for serum prostatic acid phosphatase (PAP) measurement has been developed as modified from our previously reported immunofluoroassay, utilizing the specific anti-PAP antibodies conjugated to CNBr-activated Sepharose 4B. The serum prostatic acid phosphatase was bound, and separated from other acid phosphatases and serum proteins, by the solid-phase anti-PAP IgG Sepharose 4B. The enzyme activity was quantitated by measuring the enzyme hydrolytic product, alpha-naphthol, from a primary standard solution. The entire procedure could be performed within four hours. The sensitivity of this method was 0.22 I.U./l of enzyme activity or 0.88 ng of prostatic acic phosphatase protein per ml of serum. Normal range of serum prostatic acid phosphatase as determined by this assay was found to be 0.4--2.4 I.U./l of enzyme activity (or 1.60--9.60 ng of enzyme protein per ml of serum). Initial clinical evaluation showed that 19 of 25 patients with early stages of prostatic cancer and 12 of 14 patients with metastatic prostatic cancer exhibited an elevated enzyme level (overall 79%), as compared with only six and eight patients, respectively (overall 36%), by a conventional chemical method.

Clinical significance of serum and bone marrow acid phosphatase

Currently available immunochemical assays for the determination of serum prostatic acid phosphatase have improved the reliability of this biological marker in carcinoma of the prostate. Although the value of such methods for screening the general population is questionable, a certain percentage of elevated serum levels is observed in patients with localized disease. The significance of such findings is unclear at the present time. Recent evidence suggests that in elevated bone marrow acid phosphatase, using these methods is of predictive value in the future development of metastatic disease.