INADEQUACY OF FREE PROSTATE-SPECIFIC ANTIGEN PARAMETERS IN THE PREDICTION OF PATHOLOGICAL EXTENT OF PROSTATE-CANCER IN JAPANESE MEN

Objectives. To evaluate free prostate-specific antigen (PSA) and free to total PSA ratio as predictors of pathologic extent in Japanese pati ents with prostate cancer. Methods. By TOSOH assay, pretreatment serum serologic markers of free PSA, total PSA, free to total PSA ratio, an d PSA density (PSAD) were determined for 108 patients subsequent to ra dical prostatectomy for resectable prostate cancer. Serum values for t hese markers were compared with pathologic findings and tumor volume o n the basis of pathologic assessment of whole mount section histology. Results. Mean total PSA, free PSA, free to total PSA ratio, and PSAD significantly differed for pathologically confined (pT2 or lower) and advanced (pT3 or higher) cancers (P < 0.05). Total PSA, free PSA, and PSAD provided indication of seminal vesicle involvement, surgical marg in status, nodal involvement, and total tumor volume (P < 0.05). Free PSA was more closely correlated with total tumor volume than the free to total PSA ratio; this ratio was not correlated with total tumor vol ume or specimen Gleason score. Free PSA and free to total PSA ratio we re not found to be any more useful than total PSA and PSAD for predict ing pT3 disease by receiver operating characteristic curve analysis. M ultivariate logistic regression analysis and log likelihood ratio test results indicated little additional value of these parameters for pre dicting pT3 disease. Conclusions. Contrary to previous reports, free P SA and the free to total PSA ratio are of little use subsequent to the diagnosis of prostate cancer. UROLOGY 52: 230-236, 1998. (C) 1998, El sevier Science Inc. All rights reserved.