Prostate specific antigen: not detectable despite tumor progression after radical prostatectomy.

Prostate specific antigen was not detectable in 2 men with documented prostate cancer progression after radical prostatectomy. Possible explanations for prostate specific antigen remaining zero in these situations are discussed. We conclude that while monitoring prostate specific antigen is of great value in the followup of patients with prostatic cancer, it has not replaced more standard means of followup.