The serum acid phosphatase (SAP) level is often valuable as an aid in establishing the diagnosis of prostatic carcinoma, but it is a poor substitute for a positive biopsy. The availability of semispecific tests like the SAP determination often prevent the logical progression of diagnostic events that are so often employed in establishing a diagnosis as serious as carcinoma. Certainly, a reasonable effort to obtain histologic proof of prostatic carcinoma is essential, particularly since the prostate is exceedingly available for biopsy, the morbidity and mortality are virtually nil, and the chance of success quite high.
Systematic analysis of populations with prostatic carcinoma demonstrate that, in general, the more tumor tissue present, the more likely it is that the SAP level will be elevated. Woodard34 and Fraley and Howard,35 using a modification of the Bodansky36 and Babson and Read37 techniques, respectively, reported levels of activity in patients;