Bone Marrow Acid Phosphatase in Staging of Prostatic Cancer: How Reliable is It?

Abstract
To evaluate the reliability of bone marrow acid phosphatase in the staging of prostatic carcinoma, 50 bone marrow samples collected at random were analyzed. The samples were assayed for acid phosphatase content by a colorimetric method using sodium thymolphthalein monophosphate as a substrate and counter immunoelectrophoresis and radioimmunoassay. A high percentage (61%) of falsely positive results was found in patients with various hematological diseases without evidence of prostatic carcinoma by the colorimetric evaluation. All of these patients except 1 had negative immunochemical assays. Until a specific assay for prostatic acid phosphatase is developed for clinical use the use of a single elevation of bone marrow acid phosphatase as a parameter of metastatic disease should be cautioned.