[Prostate-specific antigen. A new biological serum marker for prostatic adenocarcinoma]

Prostate-specific antigen (PSA) was measured by polyclonal radioimmunoassay in 45 untreated patients with prostatic cancer and 14 patients with benign prostatic hyperplasia. Prostatic acid phosphatase (PAP) was determined in 35 patients with prostatic cancer and 14 patients with benign hyperplasia. Serum PSA was raised in 42 patients with cancer of the prostate, but only 14 of 35 patients showed increased serum levels of PAP. Half the patients with benign prostate hyperplasia had PSA greater than 4 micrograms/l and one third had PSA greater than 10 micrograms/l. PAP was slightly elevated in two patients with benign prostatic hyperplasia. Serum PSA increased with the clinical stage of prostatic cancer. However, preoperative levels of PSA were not sufficiently reliable to predict the final pathological stage for each individual patient. After radical prostatectomy for cancer confined to the prostate, serum PSA fell to an undetectable level.