The Clinical Usefulness of Serum Prostate Specific Antigen in the Prostatic Disease

Park, Kwang Sung; Min, Byung Kap

Abstract

A new serum marker of prostatic cancer, prostate specific antigen(PSA), has shown promising results in clinical trials. The concentration of PSA in serum was measured using a Tandem-Re radioimmunometric assay and prostate acid phosphatase(PAP), the reference serum marker, was measured using a enzymatic assay, in 149 patients including 23 patients with prostatic cancer, 94 patients with benign prostatic hyperplasia(BPH), and 32 controls free of prostate disorders. The following results were obtained. 1. In normal control group, the mean(+/-SD) PSA value was 1.21+/-0.96ng/ml(range, 0.1 to 3.7), and the mean PAP value was 0.29+/-0.13ng/ml(range, 0.1 to 0.5). 2. The mean PSA levels were 63.07ng/ml and 6.27ng/ml in patients with prostatic cancer and BPH, respectively(p<0.01). 3. PSA was increased in 39.4 percent and PAP in 4.3 percent of patients with BPH. 4. The levels of PSA were elevated in 6.4 percent of the patients with stage A, 64.68 percent with stage C and 73.29 percent with stage D prostatic carcinoma whereas those of PAP were elevated in 30.4 percent of the patients above stage C. 5. The sensitivity and specificity for PSA were 91.3 percent and 60.6 percent, respectively. We conclude that PSA is more sensitive than PAP in the detection of prostatic cancer and will probably be more useful serum marker in monitoring therapy for prostatic carcinoma.