Prostate Cancer Gene 3 Assay Research Articles

Clinical evaluation of prostate cancer gene 3 score in diagnosis among Chinese men with prostate cancer and benign prostatic hyperplasia.

BackgroundProstate cancer is the second most common diagnosed cancer in men. Due to the low specificity of current diagnosis methods for detecting prostate cancer, identification of new biomarkers is highly desirable. The study was conducted to determine the clinical utility of the prostate cancer gene 3 (PCA3) assay to predict biopsy-detected cancers in Chinese men.MethodsThe study included men who had a biopsy at The Affiliated Sixth People’s Hospital of Shanghai Jiao Tong University from January 2013 to December 2013. Formalin-fixed, paraffin-embedded tissue blocks were used to test PCA3 and prostate-specific antigen (PSA) mRNA. The diagnostic accuracy of the PCA3 score for predicting a positive biopsy outcome was studied using sensitivity and specificity, and it was compared with PSA.ResultsThe probability of a positive biopsy increased with increasing PCA3 scores. The mean PCA3 score was significantly higher in men with prostate cancer (198.03, 95 % confidence interval [CI] 74.79–321.27) vs benign prostatic hyperplasia (BPH) (84.31, 95 % CI 6.47–162.15, P < 0.01). The PCA3 score (cutoff 35) had a sensitivity of 85.7 % and specificity of 62.5 %. Receiver operating characteristic analysis showed higher areas under the ROC curve for the PCA3 score vs PSA, but without statistical significance.ConclusionsIncreased PCA3 in biopsy tissue correlated with prostate cancer and the PCA3 assay may improve the diagnosis efficacy as the PCA3 score being independent of PSA level. The diagnostic significance of urinary PCA3 testing should be explored in future study to determine the prediction value in guiding biopsy decision as the clinical relevance of current study was limited for PCA3 testing based on biopsy tissue in a limited number of Chinese men.

Genome-wide Association Study Identifies Genetic Determinants of Urine PCA3 Levels in Men

Prostate cancer gene 3 (PCA3) is a non-coding gene specifically overexpressed in prostate cancer (PCa) that has great potential as a clinical biomarker for predicting prostate biopsy outcome. However, genetic determinants of PCA3 expression level remain unknown. To investigate the association between genetic variants and PCA3 mRNA level, a genome-wide association study was conducted in 1371 men of European descent in the REduction by DUtasteride of prostate Cancer Events trial. First-voided urine specimens containing prostate cells were obtained after digital rectal examination. The PROGENSA PCA3 assay was used to determine PCA3 score in the urinary samples. A linear regression model was used to detect the associations between (single nucleotide polymorphisms) SNPs and PCA3 score under an additive genetic model, adjusting for age and population stratification. Two SNPs, rs10993994 in β-microseminoprotein at 10q11.23 and rs10424878 in kallikrein-related peptidase 2 at 19q13.33, were associated with PCA3 score at genome-wide significance level (P = 1.22 x 10-9 and 1.06 x 10-8, respectively). Men carrying the rs10993994 “T” allele or rs10424878 “A” allele had higher PCA3 score compared with men carrying rs10993994 “C” allele or rs10424878 “G” allele (β = 1.25 and 1.24, respectively). This is the first comprehensive search for genetic determinants of PCA3 score. The novel loci identified may provide insight into the molecular mechanisms of PCA3 expression as a potential marker of PCa.

Clinical utility of the prostate cancer gene 3 (PCA3) urine assay in Japanese men undergoing prostate biopsy

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: It is known that a prostate cancer gene 3 (PCA3) urine assay is superior to serum PSA level or PSA-related indices for predicting a positive biopsy result in European and US men. This is the first report on PCA3 in a large cohort of Japanese men. The diagnostic value of the PCA3 score in Japanese men was similar to those reported in European and US men. The study concludes that a combination of PSA density and PCA3 score may be useful for selecting patients who could avoid an unnecessary biopsy. To examine the diagnostic performance of the prostate cancer gene 3 (PCA3) score for prostate cancer in Japanese men undergoing prostate biopsy. This Japanese, multicentre study included 647 Asian men who underwent extended prostate biopsy with elevated prostate-specific antigen (PSA) and/or abnormal digital rectal examination (DRE). Urine samples were collected after DRE. The PCA3 score was determined using a PROGENSA PCA3 assay and correlated with biopsy outcome. Its diagnostic accuracy was compared with that of serum PSA level, prostate volume (PV), PSA density (PSAD), and free/total PSA ratio (f/t PSA). A total of 633 urine samples were successfully analysed (the informative rate was 98%). Median PSA was 7.6 ng/mL. Biopsy revealed cancer in 264 men (41.7%). The PCA3 score for men with prostate cancer was significantly higher than that for men with negative biopsies (median PCA3 score: 49 vs. 18; P < 0.001). The rate of positive biopsy was 16.0% in men with a PCA3 score of <20 and 60.6% in those with a PCA3 score of ≥50. Using a PCA3 score threshold of 35, sensitivity and specificity were 66.5 and 71.6%, respectively. The area under the curve of the PCA3 score was significantly higher than that of the f/t PSA in men with PSA 4-10 ng/mL (0.742 vs 0.647; P < 0.05). In men with PSAD < 0.15 and PCA3 < 20, only three (4.2%) out of 72 men had prostate cancer. The PCA3 score was significantly superior to f/t PSA in predicting a positive biopsy result for prostate cancer in Japanese men with PSA 4-10 ng/mL. The combination of PSAD and PCA3 score may be useful for selecting patients who could avoid an unnecessary biopsy.

Relationship between prostate cancer gene 3 (PCA3) and characteristics of tumor aggressiveness

Data supporting prostate cancer gene 3 (PCA3) as prognostic marker are still inconsistent. With special emphasis to Gleason pattern specific tumor volumes (TVs) the relationships between PCA3 score and different characteristics of tumor aggressiveness were meticulously analyzed. In 127 patients treated with radical prostatectomy for clinically localized prostate cancer, urinary PCA3 score was quantified using Progensa™ PCA3 assay. Total TV and Gleason patterns' specific tumor volumes (GPTV) were assessed by computer-assisted planimetry. Spearman's rank correlations coefficients (r) were calculated to assess relationships between PCA3 and TV as well as GPTV. Regression analyses were performed to estimate the relationship between PCA3 and TV as well as non-organ confined disease. Mean patients' age was 60.8 years. Patients showed a mean PSA level of 8.1 ng/ml and a mean PCA3 score of 68.5. PCA3 was not significantly correlated with TV (r = 0.131, P = 0.142). Stratified by Gleason score groups ≤ 6, 7, and ≥ 8, PCA3 showed no significant correlations with TV. In a subgroup analysis of 50 patients with different primary and secondary Gleason patterns there was neither a correlation with the primary GPTV (r = 0.071, P = 0.626) nor with the secondary GPTV (r = 0.052, P = 0.722). The PCA3 score was neither an independent predictor for TV nor for non-organ confined disease. The PCA3 score did not show any significant correlation with TV, primary or secondary GPTV. Moreover, the PCA3 score was not an independent predictor for TV or for non-organ confined disease. Thus, the PCA3 score had no impact for the prediction of aggressive prostate cancers.

The relationship between Prostate CAncer gene 3 (PCA3) and prostate cancer significance

To evaluate the relationship between Prostate CAncer gene 3 (PCA3) and prostate cancer significance. Clinical data from two multi-centre European open-label, prospective studies evaluating the clinical utility of the PCA3 assay in guiding initial and repeat biopsy decisions were analysed. First-catch urine was collected after digital rectal examination (three strokes per lobe) and the PCA3 score was determined using the PROGENSA(®) PCA3 assay. Transrectal ultrasound-guided biopsy (≥8 cores) and radical prostatectomy (RP) specimens were analysed by the local pathologist. The relationship between biopsy and RP outcomes with the PCA3 score was assessed. Of the 1009 men enrolled, 348 (34%) had a positive biopsy. The median and mean PCA3 scores were statistically significantly lower in men with biopsy Gleason score <7 vs ≥7, with clinical stage T1c vs T2a-T2c, T3a cancers, with ≤33% vs >33% positive biopsy cores and with 'biopsy indolent' vs 'biopsy significant' prostate cancer (indolent prostate cancer defined by biopsy Epstein criteria). In all, 175 men with a positive biopsy had a RP: median and mean PCA3 scores were statistically significantly lower in men with pathological Gleason score <7 vs ≥7, and with pathological stage T2a-T2c vs T3a-T3b cancers. The PCA3 score may combined with traditional tools aid in identifying men with clinically insignificant prostate cancer, as shown by biopsy and RP pathological features including biopsy Epstein criteria, who could be candidates for active surveillance. Treatment selection should be based on a combination of clinical and pathological variables. If one wants to use a threshold point to guide treatment decisions in clinical practice, a PCA3 score threshold of 20 may have the highest utility for selecting men with clinically insignificant prostate cancer in whom active surveillance may be appropriate; a PCA3 score threshold of 50 may be used to identify men at high risk of harbouring significant prostate cancer who are candidates for RP. Although the association between the PCA3 score and prostate cancer aggressiveness needs further evaluation, the inclusion of the PCA3 score into patient management strategies may provide clinicians with another tool to more accurately determine the course of treatment.

Prostate Cancer Gene 3 Score Predicts Prostate Biopsy Outcome in Men Receiving Dutasteride for Prevention of Prostate Cancer: Results From the REDUCE Trial

To examine the ability of the urinary prostate cancer gene 3 (PCA3) assay to predict biopsy-detected cancers in men receiving dutasteride in the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study cohort. Urine and serum samples from 930 men in the active arm were acquired at years 2 and 4 of the biopsy visits. In addition to univariate logistic regression and receiver operating characteristic analysis, multivariate analysis for association with biopsy outcome was performed for PCA3 score in the presence of serum prostate-specific antigen (PSA), age, prostate volume, and family history of prostate cancer. At year 2, the univariate PCA3 score area under the receiver operating characteristic curve (AUC) was 0.668 versus 0.603 for PSA. At year 4, the PCA3 assay significantly predicted the biopsy outcome (AUC 0.628, 95% confidence interval 0.556-0.700), and the PSA level was not predictive (AUC 0.556, 95% confidence interval 0.469-0.642). The year 2 multivariate model yielded an AUC of 0.712. Removing the PCA3 score decreased the AUC to 0.660 (P = .0166 vs the full model). The median PCA3 scores in the dutasteride arm were not different from those in the 1072 men in the placebo arm (16.2 and 17.2 at year 2, P = .1755; and 18.8 and 18.1 at year 4, P = .2340, respectively). However, the PSA values were reduced >50% in the dutasteride arm at both visits (both P < .0001 vs placebo). At a PCA3 score cutoff of 35, the sensitivity and specificity were equivalent between the 2 arms. In the present study, the PCA3 assay outperformed PSA for cancer detection in men undergoing dutasteride treatment and improved the diagnostic accuracy when combined with the PSA level and other clinical variables. In addition, no adjustment in PCA3 score was needed to yield equivalent clinical performance between the dutasteride and placebo arms. These findings are particularly important in light of the potential role of dutasteride for prostate cancer chemoprevention.

Biopsy and treatment decisions in the initial management of prostate cancer and the role of PCA3; a systematic analysis of expert opinion

The Prostate CAncer gene 3 (PCA3) assay may guide prostate biopsy decisions and predict prostate cancer (PCa) aggressiveness. This study explored the appropriateness of (1) PCA3 testing; (2) biopsy; (3) active surveillance (AS) and the value of the PCA3 Score for biopsy and AS decisions. Using the RAND/UCLA appropriateness method, 12 urologists assessed the appropriateness of PCA3, biopsy and AS for theoretical patient profiles, constructed by combining clinical variables. They individually scored the appropriateness for all profiles using a 9-point scale. Based on the median score and extent of agreement, the appropriateness for each profile was calculated. The PCA3 Assay was mainly considered appropriate in men with ≥1 negative biopsy, PSA ≥ 3 ng/mL and life expectancy (LE) ≥10 years. A LE < 10 years, ≥2 negative biopsies and PCA3 Score <20 decreased biopsy appropriateness, while PSA ≥ 3 ng/mL and PCA3 Score >50 increased it. In men without a prior biopsy, LE ≥ 10 years and a suspicious DRE, PCA3 did not affect biopsy appropriateness. In other men, a PCA3 Score <20 discouraged biopsy, while a value ≥35 supported biopsy. AS was mainly considered appropriate if LE < 10 years, T1c PCa, ≤20% positive cores and PSA < 3 ng/mL. A PCA3 Score <20 pleads for and higher scores (particularly >50) against AS. These findings illustrate in which men PCA3 can be of additional value when taking biopsy and treatment decisions in clinical practice.

The role of the PCA3 assay in predicting prostate biopsy outcome in a South African setting

What's known on the subject? and What does the study add? The PCA3 assay has shown significant potential amongst the initial studies carried out in Western countries. This assay performed in line with previous studies. We have shown this marker to perform independent of prostatic volume and have identified potential indications for its use in our setting. However, we have not observed the PCA3 assay to outperform the PSA level across the risk spectrum. • To evaluate the investigational role, ideal threshold and indications of the Prostate CAncer gene 3 (PCA3) assay in a South African context. • To better define the universality of the above marker since this is the pioneer study on the continent of Africa. • We prospectively evaluated 105 consecutive South African men referred for a prostate biopsy at two tertiary centres in the capital city, Pretoria. • Sequentially, PSA levels and post DRE urine samples were taken within 24 h before prostate biopsy. • The urine specimen was tested using the PROGENSA™ PCA3 assay and a score was generated as (PCA3 mRNA/PSA mRNA) × 1000. • The performance of this assay in predicting biopsy outcome was assessed, and compared with that of serum PSA. • Median patient age was 67 years with a positive biopsy incidence of 42.9%. • The higher the PCA3 score the greater the probability of a positive biopsy (P = 0.003). • This score performed independently of prostatic volume (P = 0.3889) or the presence of a concurrent primary malignancy (P = 0.804). • A threshold of 60 revealed a positive predictive value of 60% with an odds ratio of 4, whereas setting a limit of 35 revealed a positive predictive value of 54% and odds ratio of 3.5. • Using receiver operating characteristics for overall performance comparison, the PSA level (area under the curve 0.844) performed better than the PCA3 score (area under the curve 0.705). • PCA3 assay has shown consistency and performed in line with previous studies but it did not surpass serum PSA in this population. • A PCA3 assay threshold of 60 performed better than the conventional limit of 35. • This assay may have a potential niche in a certain subset of South African men that includes patients with larger glands, previous negative biopsies and altered baseline PSA levels.

Prostate cancer gene 3 urine assay for prostate cancer in Japanese men undergoing prostate biopsy

To examine the clinical utility of the prostate cancer gene 3 (PCA3) urine test in predicting prostate cancer in Japanese men undergoing prostate biopsy. The study group included 105 men who underwent extended prostate biopsy based on an elevated serum prostate-specific antigen (PSA). In all cases, the patients' race was Asian. Urine specimens were collected after digital rectal examination, and PCA3 score (PCA3/PSA mRNA) was determined in the urine using the APTIMA PCA3 assay. PCA3 score was investigated for a correlation with serum PSA, prostate volume (PV), PSA density and biopsy outcome. All urine samples collected were successfully analyzed (i.e. the informative specimen rate was 100%). Biopsy showed prostate cancer in 38 men (36%). The PCA3 score was not associated with serum PSA nor PV. The median PCA3 score in prostate cancer was significantly higher than that in negative biopsy (59.5 vs 14.2 P<0.0001). The probability of prostate cancer was 69% at a PCA3 score of more than 50 and 5% at a PCA3 score of less than 20. On multivariable logistic regression, PSA density (P<0.05) and PCA3 score (P<0.0001) were the independent predictors for prostate cancer. There was no significant difference in AUC between PCA3 score and PSA density. The combination of PCA3 score and PSA density increased the AUC from 0.72 for PSA alone to 0.88. The specificity of the PCA3 urine assay for prostate cancer was excellent in Japanese men undergoing biopsy. PCA3 score could improve the prediction for prostate cancer and help to better select men who might benefit from prostate biopsy.

The Prostate Cancer gene 3 assay: indications for use in clinical practice

The Prostate CAncer gene 3 (PCA3) assay is a novel tool that might aid in the diagnosis of prostate cancer and that might indicate the significance of the disease. In this review we discuss five clinical cases in which the PCA3 assay can be considered, based on scientific evidence and key patient cases from real-life clinical practice. The PCA3 assay might be used to guide biopsy decisions in: (i) Men with an elevated serum total prostate specific antigen (tPSA) level and one or more previous negative biopsies; (ii) men with a normal tPSA level and a family history of prostate cancer; (iii) men with an elevated tPSA level (2.5-10 ng/mL) and no previous biopsy; (iv) men with an elevated tPSA level and a concomitant urinary condition. In addition, in men diagnosed with prostate cancer, the PCA3 assay could aid in the decision of whether active therapy is needed or active surveillance is appropriate.

Prostate Cancer Gene 3 (PCA3): Development and Internal Validation of a Novel Biopsy Nomogram

Urinary prostate cancer gene 3 (PCA3) represents a promising novel marker of prostate cancer detection. To test whether urinary PCA3 assay improves prostate cancer (PCa) risk assessment and to construct a decision-making aid in a multi-institutional cohort with pre-prostate biopsy data. PCA3 assay cut-off threshold analyses were followed by logistic regression models which used established predictors to assess PCa-risk at biopsy in a large multi-institutional data set of 809 men at risk of harboring PCa. Regression coefficients were used to construct four sets of nomograms. Predictive accuracy (PA) estimates of biopsy outcome predictions were quantified using the area under the curve of the receiver operator characteristic analysis in models with and without PCA3. Bootstrap resamples were used for internal validation and to reduce overfit bias. The extent of overestimation or underestimation of the observed PCa rate at biopsy was explored graphically using nonparametric loss-calibration plots. Differences in PA were tested using the Mantel-Haenszel test. Finally, nomogram-derived probability cut-offs were tested to assess the ability to identify patients with or without PCa. PCA3 was identified as a statistically independent risk factor of PCa at biopsy. Addition of a PCA3 assay improved bootstrap-corrected multivariate PA of the base model between 2% and 5%. The highest increment in PA resulted from a PCA3 assay cut-off threshold of 17, where a 5% gain in PA (from 0.68 to 0.73, p=0.04) was recorded. Nomogram probability-derived risk cut-off analyses further corroborate the superiority of the PCA3 nomogram over the base model. PCA3 fulfills the criteria for a novel marker capable of increasing PA of multivariate biopsy models. This novel PCA3-based nomogram better identifies men at risk of harboring PCa and assists in deciding whether further evaluation is necessary.

Clinical Utility of the PCA3 Urine Assay in European Men Scheduled for Repeat Biopsy

BackgroundThe Prostate CAncer gene 3 (PCA3) assay has shown promise as an aid in prostate cancer (pCA) diagnosis in identifying men with a high probability of a positive (repeat) biopsy. ObjectiveThis study evaluated the clinical utility of the PROGENSA PCA3 assay. Design, setting, and participantsThis European prospective, multicentre study enrolled men with one or two negative biopsies scheduled for repeat biopsy. MeasurementsAfter digital rectal examination (DRE), first-catch urine was collected to measure PCA3 mRNA concentration and to calculate the PCA3 score. The PCA3 score was compared to biopsy outcome. The diagnostic accuracy of the PCA3 assay was compared to percent of free prostate-specific antigen (%fPSA). Results and limitationsIn 463 men, the positive repeat biopsy rate was 28%. The higher the PCA3 score, the greater the probability of a positive repeat biopsy. The PCA3 score (cut-off of 35) had a greater diagnostic accuracy than %fPSA (cut-off of 25%). The PCA3 score was independent of the number of previous biopsies, age, prostate volume, and total prostate-specific antigen (PSA) level. Moreover, the PCA3 score was significantly higher in men with high-grade prostate intraepithelial neoplasia (HGPIN) versus those without HGPIN, clinical stage T2 versus T1, Gleason score ≥7 versus <7, and “significant” versus “indolent” (clinical stage T1c, PSA density [PSAD] <0.15ng/ml, Gleason score in biopsy ≤6, and percent positive cores ≤33%) pCA. ConclusionsThe probability of a positive repeat biopsy increases with rising PCA3 scores. The PCA3 score was superior to %fPSA for predicting repeat prostate biopsy outcome and may be indicative of clinical stage and significance of pCa.

A multicenter evaluation of the PCA3 molecular urine test: Pre-analytical effects, analytical performance, and diagnostic accuracy

BackgroundMeasurement of prostate cancer gene 3 (PCA3) mRNA normalized to prostate-specific antigen (PSA) mRNA in urine has been proposed as a marker for prostate cancer. MethodsWe investigated pre-analytical effects, analytical performance, and diagnostic accuracy of a quantitative assay for PCA3. ResultsUrine specimens collected without prostate manipulation demonstrated low informative rates. However, specimens collected following digital rectal examinations of 3 or 8 strokes per prostate lobe demonstrated informative rates >94%. Across all urine specimen types, median PCA3 results did not show statistically significant differences (P>0.8). Measurements of controls of known mRNA content demonstrated percent recoveries of 100±15% for both PCA3 and PSA mRNAs. PCA3 mRNA total, intra-assay, inter-assay, and inter-site CVs were ≤17.1%, ≤14.0%, ≤9.9%, and ≤3.2%, respectively. Corresponding CVs for PSA mRNA assay were ≤11.5%, ≤8.6%, ≤7.9%, and ≤8.3%. Blinded assay of urines from 72 men with known prostate biopsy outcomes yielded areas under the curve from receiver-operating characteristic analysis of 0.7 at both research sites. Deming regression of individual PCA3 results between sites yielded slope=0.94, intercept=0.48, R=0.9677 (P<0.0001). ConclusionsThe PCA3 assay is insensitive to pre-analytical factors, performs well analytically and correctly classifies a high percent of subjects with known prostate cancer status across research sites.

PCA3 Molecular Urine Assay for Prostate Cancer in Men Undergoing Repeat Biopsy

Men with elevated serum prostate-specific antigen (PSA) levels and negative prostate biopsy findings present a dilemma because of the lack of an accurate diagnostic test. We evaluated the potential utility of the investigational prostate cancer gene 3 (PCA3) urine assay to predict the repeat biopsy outcome. Urine was collected after digital rectal examination (three strokes per lobe) from 233 men with serum PSA levels persistently 2.5 ng/mL or greater and at least one previous negative biopsy. The specimens were collected from April 2004 to January 2006. The PCA3 scores were determined using a highly sensitive quantitative assay with transcription-mediated amplification. The ability of the PCA3 score to predict the biopsy outcome was assessed and compared with the serum PSA levels. The RNA yield was adequate for analysis in the urine samples from 226 of 233 men (ie, the informative specimen rate was 97%). Repeat biopsy revealed prostate cancer in 60 (27%) of the of 226 remaining subjects. Receiver operating characteristic curve analysis yielded an area under the curve of 0.68 for the PCA3 score. In contrast, the area under the curve for serum PSA was 0.52. Using a PCA3 score cutoff of 35, the assay sensitivity was 58% and specificity 72%, with an odds ratio of 3.6. At PCA3 scores of less than 5, only 12% of men had prostate cancer on repeat biopsy; at PCA3 scores greater than 100, the risk of positive biopsy was 50%. In men undergoing repeat prostate biopsy to rule out cancer, the urinary PCA3 score was superior to serum PSA determination for predicting the biopsy outcome. The high specificity and informative rate suggest that the PCA3 assay could have an important role in prostate cancer diagnosis.

APTIMA PCA3 Molecular Urine Test: Development of a Method to Aid in the Diagnosis of Prostate Cancer

Prostate cancer gene 3 (PCA3) encodes a prostate-specific mRNA that has shown promise as a prostate cancer diagnostic tool. This report describes the characterization of a prototype quantitative PCA3-based test for whole urine. Whole-urine specimens were collected after digital rectal examination from 3 groups: men scheduled for prostate biopsy (n = 70), healthy men (<45 years of age with no known prostate cancer risk factors; n = 52), and men who had undergone radical prostatectomy (n = 21). PCA3 and prostate-specific antigen (PSA) mRNAs were isolated, amplified, and quantified by use of Gen-Probe DTS400 Systems. Prostate biopsy results were correlated with the PCA3/PSA mRNA ratio, and PSA mRNA concentrations were used to normalize PCA3 signals and confirm the yield of prostate-specific RNA. Assay precision, specimen stability, and mRNA yield were also evaluated. The specimen informative rate (fraction of specimens yielding sufficient RNA for analysis) was 98.2%. In this clinical research study, ROC curve analysis of prebiopsy specimens yielded an area under the curve of 0.746; sensitivity was 69% and specificity 79%. Serum PSA assay specificity was 28% for this same group. PCA3 and PSA mRNAs were undetectable in postprostatectomy specimens except for one man with recurrent prostate cancer. Assay interrun CVs were < or =12%. Both mRNAs were stable in processed urine up to 5 days at 4 degrees C and after 5 freeze-thaw cycles. The APTIMA PCA3 assay combines simple specimen processing with precise assays and existing instruments and could add specificity to the current algorithm for prostate cancer diagnosis.