Prognostic implications of disappearance rate of biologic markers following radical prostatectomy

Six patients with localized prostatic carcinoma undergoing radical prostatectomy were studied by serial sample collection from the time of surgical removal of the prostate up to one week in the postoperative period. Of the three markers studied (PAP, PSA, LASA), half-life of specific prostatic markers were calculated. Half-life of PAP was found to be 7.25 hours +/- SE of 0.7 hours. For PSA the half-life could be obtained in 4 of 6 patients and was found to be 45.5 hours +/- SE 4.9 hours. In 2 patients PSA did not fall in a regular fashion and half-life could not be obtained. In both patients metastatic disease has developed within six months of surgery. LASA demonstrated progressive increase following surgery, most likely due to associated inflammatory reaction. These studies confirm previous observations that PSA is a more sensitive marker than PAP, and that the presence of an elevated PSA after radical prostatectomy denotes the presence of residual disease.