Biological half-life of prostate-specific antigen after radical prostatectomy.

The disappearance pattern of prostate-specific antigen from serum after a standard radical prostatectomy was studied in eight patients with cancer confined to the prostate. The results were used to plot an elimination curve and calculate the best fit. A biphasic pattern was found with an average biological half-life of 1.63 hours in the alpha-phase, and 4.63 days in the beta-phase. Based on these results it is concluded that determination of prostate-specific antigen concentrations less than one month after a standard radical prostato-vesiculectomy has no value for the detection or exclusion of residual malignant processes.