Molecular detection of localized prostate cancer using quantitative methylation-specific PCR on urinary cells obtained following prostate massage.
OBJECTIVE
The diagnosis of localized prostate cancer is difficult due to a lack of cancer-specific biomarkers. Many patients require repeat prostate biopsies to diagnose the disease. We investigated whether aberrant promoter hypermethylation in prostatic fluid could reliably detect prostate cancer.


METHODS
Urine samples were collected after prostate massage from 95 patients with localized prostate cancer undergoing radical prostatectomy (63 pT(1), 31 pT(2), and 1 pT(3)) and from 38 control patients. Ten genes (GSTP1, RASSF1a, ECDH1, APC, DAPK, MGMT, p14, p16, RARbeta2, and TIMP3) were investigated using quantitative real-time methylation-specific PCR. Receiver operator curves were generated.


RESULTS
The frequency of gene methylation ranged from 6.3% (p14) to 83.2% (GSTP1) in prostate cancer patients. At least one gene was hypermethylated in 93% of cancer patients. The specificity of methylation was 0.74. Methylation was significantly more frequent (P < 0.05) in cancer than control patients for all genes except p14 and p16. According to receiver operator curve analysis, the four-gene combination of GSTP1 (0.86), RASSF1a (0.85), RARbeta2 (0.80), and APC (0.74) best discriminated malignant from nonmalignant cases. The sensitivity and accuracy of this four-gene set were 86% and 89%, respectively.


CONCLUSIONS
The presence of aberrant methylation in urinary cells obtained after prostate massage is significantly associated with prostate cancer. A panel of four genes could stratify patients into low and high risk of having prostate cancer and optimize the need for repeat prostatic biopsies.
Rouprêt
Morgan
M
Institute for Cancer Studies and Academic Urology Unit, University of Sheffield, Royal Hallamshire Hospital, Sheffield, UK. mroupret@club-internet.fr
Hupertan
Vincent
V
Yates
David R
DR
Catto
James W F
JW
Rehman
Ishtiaq
I
Meuth
Mark
M
Ricci
Sylvie
S
Lacave
Roger
R
Cancel-Tassin
Géraldine
G
de la Taille
Alexandre
A
Rozet
François
F
Cathelineau
Xavier
X
Vallancien
Guy
G
Hamdy
Freddie C
FC
Cussenot
Olivier
O
D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis / Q000652:urine; D004247:DNA / Q000032:analysis / Q000302:isolation & purification / Q000652:urine; D019175:DNA Methylation; D006801:Humans; D008297:Male; D008405:Massage; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D012680:Sensitivity and Specificity; D014556:Urine / Q000166:cytology*
D014408:Biomarkers, Tumor; D004247:DNA