PCA3 molecular urine assay correlates with prostate cancer tumor volume: implication in selecting candidates for active surveillance.
OBJECTIVE
Prostate cancer gene 3 (PCA3) has shown promise as a molecular marker in prostate cancer detection. We assessed the association of urinary PCA3 score with prostatectomy tumor volume and other clinical and pathological features.


METHODS
Urine specimens were collected after digital rectal examination from 59 men scheduled for prostate biopsy and 83 men scheduled for radical prostatectomy. Prostatectomy findings were evaluable for 96 men. PCA3 and prostate specific antigen mRNAs were quantified with Gen-Probe DTS 400 System. The PCA3 score was defined as the ratio of PCA3 mRNA/prostate specific antigen mRNA x10(3).


RESULTS
The PCA3 score in men with negative biopsies (30) and positive biopsies (29) were significantly different (median 21.1 and 31.0, respectively, p = 0.029). The PCA3 score was significantly correlated with total tumor volume in prostatectomy specimens (r = 0.269, p = 0.008), and was also associated with prostatectomy Gleason score (6 vs 7 or greater, p = 0.005) but not with other clinical and pathological features. The PCA3 score was significantly different when comparing low volume/low grade cancer (dominant tumor volume less than 0.5 cc, Gleason score 6) and significant cancer (p = 0.007). On multivariate analysis PCA3 was the best predictor of total tumor volume in prostatectomy (p = 0.001). Receiver operating characteristic curve analysis showed that the PCA3 score could discriminate low volume cancer (total tumor volume less than 0.5 cc) well with area under the curve of 0.757.


CONCLUSIONS
The PCA3 score appears to stratify men based on prostatectomy tumor volume and Gleason score, and may have clinical applicability in selecting men who have low volume/low grade cancer.
Nakanishi
Hiroyuki
H
Department of Urology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Groskopf
Jack
J
Fritsche
Herbert A
HA
Bhadkamkar
Viju
V
Blase
Amy
A
Kumar
S Vikas
SV
Davis
John W
JW
Troncoso
Patricia
P
Rittenhouse
Harry
H
Babaian
R Joseph
RJ
D000368:Aged; D000951:Antigens, Neoplasm / Q000652:urine*; D014408:Biomarkers, Tumor / Q000652:urine*; D001707:Biopsy, Needle; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011467:Prostate / Q000473:pathology; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000652:urine; D012680:Sensitivity and Specificity; D047368:Tumor Burden
D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C479341:prostate cancer antigen 3, human