Comparison of enzyme, clinical, radiographic, and radionuclide methods of detecting bone metastases from carcinoma of the prostate.

Patients (219) with prostatic adenocarcinoma were classified on the basis of whether or not their bone scans were positive for metastasis. Acid and alkaline phosphatase determinations and clinical evaluations for bone metastases were reviewed. Of those with proved metastases, 43% had no bone pain, 39% had normal acid phosphatase levels, 23% normal alkaline phosphatase levels, 19% normal levels of both enzymes, and 15% normal enzyme levels without bone pain. Twenty-four per cent of the patients with normal enzyme levels and clinically unsuspected bone metastases had bone scans which proved positive for metastasis; 62% of these had normal radiographs.