Measurement of serum zinc improves prostate cancer detection efficiency in patients with PSA levels between 4 ng/mL and 10 ng/mL.
OBJECTIVE
To investigate whether the measurement of serum zinc may improve the detection of prostate cancer (PCa) in men who had total prostate-specific antigen (PSA) levels higher than 4.1 ng/mL.


METHODS
A mass screening for PCa of 3940 men over 50 years old was undertaken using total serum PSA. Of the 190 men (4.8%) with elevated PSA, 143 (3.6%) underwent a transrectal ultrasonography (TRUS)-guided biopsy of the prostate, and 42 men (1% of total and 29.3% of men undergoing biopsy) were found to have cancer. The areas under the receiver operating characteristic curves (ROC-AUC) were used to compare the diagnostic power of cancer detection by means of serum zinc, and free PSA/total PSA ratio (f/t).


RESULTS
The men with levels of serum zinc that ranged from 40 ng/mL-60 ng/mL, had an age-adjusted odds ratios(OR) of 5.0. A cutoff value of 100 microg/mL for serum zinc concentration provided a sensitivity of 90.5% and a specificity of 32.7% in elevated PSA range, and a sensitivity of 93.3% and specificity of 27.1% in gray zone, respectively. In the gray zone ranges of 4.1 ng/mL-10.0 ng/mL, the ROC-AUC for zinc was 73.0% higher than 62.7% of f/t PSA ratio and 56.7% of total PSA.


CONCLUSIONS
PCa displays a lower serum zinc concentration. The measurement of zinc levels improves PCa detection in the gray zone compared with the f/t PSA ratio and total PSA.
Li
Xiao-Meng
XM
Department of Pathophysiology, School of Basic Medical Sciences, Jilin University, 2 Xinmin Street, Changchun 130021, China.
Zhang
Ling
L
Li
Jiang
J
Li
Yang
Y
Wang
Hong-Liang
HL
Ji
Guo-Yi
GY
Kuwahara
Masaaki
M
Zhao
Xue-Jian
XJ
D019540:Area Under Curve; D001706:Biopsy / Q000379:methods; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D012372:ROC Curve; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D015032:Zinc / Q000097:blood*
D017430:Prostate-Specific Antigen; D015032:Zinc