Performance of prostate-specific antigen mass in estimation of prostate volume in Japanese men with benign prostate hyperplasia.
OBJECTIVE
Obese men with benign prostate hyperplasia might have lower serum prostate-specific antigen because of hemodilution, resulting in underestimation of total prostate volume by serum prostate-specific antigen. The aim of this study was to compare the performance of prostate-specific antigen mass as the absolute amount of prostate-specific antigen protein secreted into circulation with that of serum prostate-specific antigen in the prediction of total prostate volume.


METHODS
A total of 1517 men with serum prostate-specific antigen up to 10 ng/mL, including 1425 with biopsy-proven benign prostate hyperplasia, were enrolled in this study. Height and weight were used to estimate body mass index, body surface area and plasma volume. Prostate-specific antigen mass was calculated as serum prostate-specific antigen multiplied by plasma volume. The association between serum prostate-specific antigen or prostate-specific antigen mass and transrectal ultrasound-measured total prostate volume were evaluated by Pearson's correlation coefficient (Υ), linear regression analyses and receiver operating characteristic curves.


RESULTS
Serum prostate-specific antigen had an inverse relationship with plasma volume, decreasing as plasma volume increased, after adjustment of total prostate volume. Larger total prostate volume per serum prostate-specific antigen was found in men with higher body mass index or plasma volume. Among all participants, the correlation (Υ = 0.456) between prostate-specific antigen mass and total prostate volume was apparently stronger than that (Υ = 0.442) between serum prostate-specific antigen and total prostate volume. Prostate-specific antigen mass outperformed serum prostate-specific antigen at estimating total prostate volume cut-off values of 30 and 40 mL. These findings were more significant in men aged ≥60 years.


CONCLUSIONS
Prostate-specific antigen mass performs better than serum prostate-specific antigen in estimating TPV, especially in men aged ≥60 years.
Department of Urology, Graduate School of Tokyo Medical and Dental University, Tokyo, Japan. hi-masu.uro@tmd.ac.jp
Hitoshi
H
Masuda
Satoru
S
Kawakami
Mizuaki
M
Sakura
Yasuhisa
Y
Fujii
Fumitaka
F
Koga
Kazutaka
K
Saito
Noboru
N
Numao
Junji
J
Yonese
Iwao
I
Fukui
Kazunori
K
Kihara
D000367:Age Factors; D000368:Aged; D019540:Area Under Curve; D044466:Asian People; D015992:Body Mass Index; D001830:Body Surface Area; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D010953:Plasma Volume; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000097:blood* / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D012372:ROC Curve; D012189:Retrospective Studies; D014463:Ultrasonography
D017430:Prostate-Specific Antigen