N 1953 Fishman and Lerner reported a tech-I nique for the determination of that portion of the serum acid phosphatasc that originates from the prostate.9 T h e method is based on the observation of Abul-Fad1 and King that L-tartrate inhibits prostatic acid phosphatase. Fishman and co-workers77 8 subsequently presented evidence that the L-tartrate-inhibited, or prostatic, fraction of the total serum acid phosphatase may at times be increased in patients with prostatic carcinoma, either lotalized or metastatic, when the total serum acid phosphatase is within normal limits. We have previously described our results with the L-tartrate-inhibiting method as a screening procedure for clinically unsuspected prostatic carcinoma among 366 patients in a cancer-prevention clinic.6 T h e present report is based on a further exploration of total and prostatic serum-acid-phosphatase values in twenty patients with prostatic carcinoma and twenty with benign prostatic enlargement.
MATFRIALS AND MFTHODS
T h e technique for the determination ol total and prostatic serum acid phosphatases described by Fishman and Lerner was employed.9 T e n cubic centimeters of venous blood was drawn from each patient. T h e specimen was centrifuged within an hour after collection, and the serum was placed immediately in the deep lreeze pending the assay. Care was taken not to include specimens ob- tained within sixteen hours after digital rectal