[Analysis of the results of percent free prostate specific antigen detection among the men without prostate diseases in Xi'an].
OBJECTIVE
To measure the percentage of free prostate specific antigen (fPSA) among the men without prostate diseases in Xi'an, and understand the age-related changes in percent fPSA and its association with the pathological grade and clinical stage of prostate cancer, so as to determine the reference range of percent fPSA in Chinese men.


METHODS
A total of 829 men (including 775 men without prostate disease and 54 with prostate cancer) were enrolled into the study and the serum PSA and fPSA levels were measured for calculating the percent fPSA. The 775 prostate disease-free subjects were divided into 5 age groups to study the relations of PSA, fPSA and percent fPSA with age. In the 54 patients with prostate cancer, the relations of pathological grade and clinical stage with percent fPSA were investigated with reference to the related data of the men without prostate disease to establish the appropriate reference range of percent fPSA for Chinese men.


RESULTS
Serum PSA or fPSA levels, but not the percent fPSA, were correlated to age. In patients with prostate cancer, the percent fPSA was also correlated to the pathological grade and clinical stage. Among the men without prostate disease we investigated, the percent fPSA was significantly lower than that reported in other countries. The reference range of percent fPSA for Chinese men was > or =15%.


CONCLUSIONS
The percent fPSA is not correlated to age and has greater clinical value than PSA measurement in the detection of prostate cancer. The percent fPSA decreases in prostate cancer patients with lowered pathological grade, advanced clinical stage, and therefore increased malignancy. The reference range of percent fPSA reported in other countries does not apply to Chinese men, and according to our investigation, the reference range of percent fPSA> or =15% is appropriate for Chinese men.
Zhang
Peng
P
Department of Urology, Department of Medical Laboratory, Second Affiliated Hospital, Xi'an Jiaotong University College of Medicine, Xi'an 710004, China. zpbill@yahoo.com.cn
Wang
Zi-ming
ZM
Zhong
Tie
T
Zhao
Li-hua
LH
D000328:Adult; D000368:Aged; D000375:Aging; D044466:Asian People; D014408:Biomarkers, Tumor / Q000097:blood; D002681:China; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis; D012016:Reference Values
D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen