Evaluation of prostate-specific antigen in prostate cancer

Prostate-specific antigen (PSA) was assayed retrospectively in 131 prostate cancer patients. Pretreatment levels at primary tumor diagnosis were above 5 ng/ml in 13/16 (81%) of stage B and C patients and in 28/28 (100%) of stage D (D1 and D2) patients. At the discovery of metastasis in treated patients, they were above this value in 12/17 (71%) of patients. To determine the value of PSA assays when physical exams were negative, 52 patients were reevaluated at a maximum interval of 12 months as a function of their initial PSA concentration. When the initial PSA was negative, there was no clinical evolution during the next 6 months; when PSA was positive, patients had a 55% risk of progression in the next 4 months. All PSA assays were coupled with prostatic acid phosphatase (PAP) measurements. No PAP values were positive when PSA was negative.