Clinical usefulness of prostate-specific antigen and prostatic acid phosphatase in patients with prostatic cancer.

Serum prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) levels were measured in 70 patients with benign prostatic hypertrophy (BPH) and in 70 patients with prostatic cancer. PSA was increased above the cutoff level of 10 ng/ml in 13% of patients with BPH and in 87% of patients with prostatic cancer. In contrast, abnormal PAP levels were found in 14 and 76% of patients, respectively. We concluded that, due to its high specificity, PSA is a useful marker in the management of patients with prostatic carcinoma and that it surpasses PAP in this regard.