Accuracy of PCA3 measurement in predicting short-term biopsy progression in an active surveillance program.
OBJECTIVE
PCA3 is a prostate specific noncoding mRNA that is significantly over expressed in prostate cancer tissue. Urinary PCA3 levels have been associated with prostate cancer grade and extent, suggesting a possible role in monitoring patients on active surveillance. We assessed the relationship between PCA3 and prostate biopsy results in men in a surveillance program.


METHODS
Urine specimens were obtained from 294 men with prostate cancer enrolled in the Johns Hopkins surveillance program. The followup protocol included semiannual free and total prostate specific antigen measurements, digital rectal examination and annual surveillance prostate biopsy. Cox proportional hazards regression was used to evaluate the association between PCA3 results and progression on surveillance biopsy (defined as Gleason pattern 4 or 5, more than 2 positive biopsy cores or more than 50% involvement of any core with cancer).


RESULTS
Patients with progression on biopsy (12.9%) had a mean PCA3 score similar to that of those without progression (60.0 vs 50.8, p = 0.131). ROC analysis suggested that PCA3 alone could not be used to identify men with progression on biopsy (AUC 0.589, 95% CI 0.496-0.683, p = 0.076). After adjustment for age and date of diagnosis PCA3 was not significantly associated with progression on biopsy (p = 0.15).


CONCLUSIONS
In men with low risk prostate cancer who were carefully selected for surveillance the PCA3 score was not significantly associated with short-term biopsy progression. Further analysis is necessary to assess the usefulness of PCA3 in combination with other biomarkers or in selected subsets of patients undergoing surveillance.
Tosoian
Jeffrey J
JJ
Department of Urology, Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA.
Loeb
Stacy
S
Kettermann
Anna
A
Landis
Patricia
P
Elliot
Debra J
DJ
Epstein
Jonathan I
JI
Partin
Alan W
AW
Carter
H Ballentine
HB
Sokoll
Lori J
LJ
D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000652:urine*; D001706:Biopsy; D018450:Disease Progression; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011237:Predictive Value of Tests; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000652:urine*; D015203:Reproducibility of Results; D013997:Time Factors
D000951:Antigens, Neoplasm; C479341:prostate cancer antigen 3, human