[Clinical evaluation of prostate antigen (PA) in prostate cancer]

Prostate antigen (PA) which was isolated at 1979 and may have a probability to be a tumor marker of prostate cancer has been evaluated clinically using an EIA for detection method. From mean +3 S.D. of normal male subjects, upper cut-off values of Americans and Japanese have been decided as 2.5 and 1.2 ng/ml, respectively. Of a total of 1,109 assayed serum PA, positive rate in prostate cancer were 78% in Americans (n = 570) and 61% in Japanese (n = 45), whereas false positive rate was lower in Japanese. Serum PA values could be used for speculation of patients' prognosis and monitoring in prostate cancer.