Inadequacy of free prostate-specific antigen parameters in the prediction of pathologic extent of prostate cancer in Japanese men.
OBJECTIVE
To evaluate free prostate-specific antigen (PSA) and free to total PSA ratio as predictors of pathologic extent in Japanese patients with prostate cancer.


METHODS
By TOSOH assay, pretreatment serum serologic markers of free PSA, total PSA, free to total PSA ratio, and PSA density (PSAD) were determined for 108 patients subsequent to radical prostatectomy for resectable prostate cancer. Serum values for these markers were compared with pathologic findings and tumor volume on 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 margin 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 volume or specimen Gleason score. Free PSA and free to total PSA ratio were not found to be any more useful than total PSA and PSAD for predicting pT3 disease by receiver operating characteristic curve analysis. Multivariate logistic regression analysis and log likelihood ratio test results indicated little additional value of these parameters for predicting pT3 disease.


CONCLUSIONS
Contrary to previous reports, free PSA and the free to total PSA ratio are of little use subsequent to the diagnosis of prostate cancer.
Egawa
S
S
Department of Urology, Kitasato University School of Medicine, Kanagawa, Japan.
Suyama
K
K
Soh
S
S
Kuwao
S
S
Uchida
T
T
Koshiba
K
K
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D007564:Japan; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000208:ethnology / Q000473:pathology* / Q000601:surgery; D012372:ROC Curve
D017430:Prostate-Specific Antigen