Comparison of Classic and International Society of Urological Pathology 2005 Modified Gleason grading using needle biopsies from the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial.

CONTEXT: Use of the International Society of Urological Pathology (ISUP) 2005 modified Gleason score may result in higher scores compared with the classic Gleason scoring system. OBJECTIVE: To compare scores derived using the 2 scoring systems. DESIGN: On-study and for-cause biopsies were centrally reviewed and assigned a classic Gleason score in the Reduction by Dutasteride of prostate Cancer Events trial. Positive biopsies were reviewed by an independent pathologist in a secondary review using the ISUP 2005 modified Gleason score. The independent pathologist also recorded a classic Gleason score. RESULTS: In total, 1482/1507 (98%) positive biopsy results were independently reviewed. Scores assigned by the 2 pathologists (classic versus modified) agreed in 83% (1230 of 1481) of cases; 99% (1471 of 1481) of cancers were within ±1 of their previous score. Of discordant cases, similar numbers of biopsies were upgraded and downgraded in the secondary review, with minor differences in the score distributions. Interobserver agreement was good, with κ values ranging from 0.62 (95% confidence interval [CI], 0.56-0.67) to 0.70 (95% CI, 0.65-0.76). The overall number of high-grade tumors (Gleason score 8-10; n = 48) remained constant between reviews, with 3 fewer cases in the placebo group (n = 16) and 3 more in the dutasteride group (n = 32) in the secondary review. When comparing the independent pathologist's modified scores versus the classic, 17 of 1481 cancers (1.1%) were upgraded (including 9 of 17 upgrades [53%] to high-grade tumors). CONCLUSIONS: This analysis showed similar score distributions between the classic and modified Gleason scoring systems. The differences seen between the 2 pathologists' scores likely reflect differences in interpretation rather than the scoring system chosen.

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 ß-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 (ß = 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.

Genome-wide association study identifies loci at ATF7IP and KLK2 associated with percentage of circulating free PSA.

BACKGROUND: Percentage of free-to-total prostate-specific antigen (%fPSA) is an independent predictor of risk for prostate cancer among men with modestly elevated level of total PSA (tPSA) in blood. Physiological and pathological factors have been shown to influence the %fPSA value and diagnostic accuracy. MATERIALS/METHODS: To evaluate genetic determinants of %fPSA, we conducted a genome-wide association study of serum %fPSA by genotyping 642,584 single nucleotide polymorphisms (SNPs) in 3192 men of European ancestry, each with a tPSA level of 2.5 to 10 ng/ml, that were recruited in the REduction by DUtasteride of Prostate Cancer Events study. Single nucleotide polymorphisms (SNPs) with P < 10(-5) were further evaluated among the controls of a population-based case-control study in Sweden (2899 prostate cancer cases and 1722 male controls), including 464 controls having tPSA levels of 2.5 to 10 ng/ml. RESULTS: We identified two loci that were associated with %fPSA at a genome-wide significance level (P <5 x 10(-8)). The first associated SNP was rs3213764 (P = 6.45 x 10(-10)), a nonsynonymous variant (K530R) in the ATF7IP gene at 12p13. This variant was also nominally associated with tPSA (P = .015). The second locus was rs1354774 (P = 1.25 x 10(-12)), near KLK2 at 19q13, which was not associated with tPSA levels, and is separate from the rs17632542 locus at KLK3 that was previously associated with tPSA levels and prostate cancer risk. Neither rs3213764 nor rs1354774 was associated with prostate cancer risk or aggressiveness. CONCLUSIONS: These findings demonstrate that genetic variants at ATF7IP and KLK2 contribute to the variance of %fPSA.

Genome-wide association study identifies a new locus JMJD1C at 10q21 that may influence serum androgen levels in men.

Circulating androgen levels are often used as indicators of physiological or pathological conditions. More than half of the variance for circulating androgen levels is thought to be genetically influenced. A genome-wide association study (GWAS) has identified two loci, SHBG at 17p13 and FAM9B at Xp22, for serum testosterone (T) levels; however, these explain only a small fraction of inter-individual variability. To identify additional genetic determinants of androgen levels, a GWAS of baseline serum T and dihydrotestosterone (DHT) levels was conducted in 3225 men of European ancestry from the REduction by DUtasteride of Prostate Cancer Events (REDUCE) study. Cross-validation was used to confirm the observed associations between the drug (n = 1581) and placebo (n = 1644) groups of REDUCE. In addition to confirming the associations of two known loci with serum T levels (rs727428 in SHBG: P = 1.26 × 10(-12); rs5934505 in FAM9B: P = 1.61 × 10(-8)), we identified a new locus, JMJD1C at 10q21 that was associated with serum T levels at a genome-wide significance level (rs10822184: P = 1.12 × 10(-8)). We also observed that the SHBG locus was associated with serum DHT levels (rs727428: P = 1.47 × 10(-11)). Moreover, two additional variants in SHBG [rs72829446, in strong linkage equilibrium with the missense variant D356N (rs6259), and rs1799941] were also independently associated with circulating androgen levels in a statistical scale. These three loci (JMJD1C, SHBG and FAM9B) were estimated to account for ~5.3 and 4.1% of the variance of serum T and DHT levels. Our findings may provide new insights into the regulation of circulating androgens and potential targets for androgen-based therapy.

A comparison of Bayesian and frequentist approaches to incorporating external information for the prediction of prostate cancer risk.

We present the most comprehensive comparison to date of the predictive benefit of genetics in addition to currently used clinical variables, using genotype data for 33 single-nucleotide polymorphisms (SNPs) in 1,547 Caucasian men from the placebo arm of the REduction by DUtasteride of prostate Cancer Events (REDUCE®) trial. Moreover, we conducted a detailed comparison of three techniques for incorporating genetics into clinical risk prediction. The first method was a standard logistic regression model, which included separate terms for the clinical covariates and for each of the genetic markers. This approach ignores a substantial amount of external information concerning effect sizes for these Genome Wide Association Study (GWAS)-replicated SNPs. The second and third methods investigated two possible approaches to incorporating meta-analysed external SNP effect estimates - one via a weighted PCa 'risk' score based solely on the meta analysis estimates, and the other incorporating both the current and prior data via informative priors in a Bayesian logistic regression model. All methods demonstrated a slight improvement in predictive performance upon incorporation of genetics. The two methods that incorporated external information showed the greatest receiver-operating-characteristic AUCs increase from 0.61 to 0.64. The value of our methods comparison is likely to lie in observations of performance similarities, rather than difference, between three approaches of very different resource requirements. The two methods that included external information performed best, but only marginally despite substantial differences in complexity.

Potential impact of adding genetic markers to clinical parameters in predicting prostate biopsy outcomes in men following an initial negative biopsy: findings from the REDUCE trial.

BACKGROUND: Several germline single nucleotide polymorphisms (SNPs) have been consistently associated with prostate cancer (PCa) risk. OBJECTIVE: To determine whether there is an improvement in PCa risk prediction by adding these SNPs to existing predictors of PCa. DESIGN, SETTING, AND PARTICIPANTS: Subjects included men in the placebo arm of the randomized Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial in whom germline DNA was available. All men had an initial negative prostate biopsy and underwent study-mandated biopsies at 2 yr and 4 yr. Predictive performance of baseline clinical parameters and/or a genetic score based on 33 established PCa risk-associated SNPs was evaluated. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Area under the receiver operating characteristic curves (AUC) were used to compare different models with different predictors. Net reclassification improvement (NRI) and decision curve analysis (DCA) were used to assess changes in risk prediction by adding genetic markers. RESULTS AND LIMITATIONS: Among 1654 men, genetic score was a significant predictor of positive biopsy, even after adjusting for known clinical variables and family history (p = 3.41 × 10(-8)). The AUC for the genetic score exceeded that of any other PCa predictor at 0.59. Adding the genetic score to the best clinical model improved the AUC from 0.62 to 0.66 (p<0.001), reclassified PCa risk in 33% of men (NRI: 0.10; p=0.002), resulted in higher net benefit from DCA, and decreased the number of biopsies needed to detect the same number of PCa instances. The benefit of adding the genetic score was greatest among men at intermediate risk (25th percentile to 75th percentile). Similar results were found for high-grade (Gleason score ≥ 7) PCa. A major limitation of this study was its focus on white patients only. CONCLUSIONS: Adding genetic markers to current clinical parameters may improve PCa risk prediction. The improvement is modest but may be helpful for better determining the need for repeat prostate biopsy. The clinical impact of these results requires further study.

Prostate cancer risk in men with baseline history of coronary artery disease: results from the REDUCE Study.

BACKGROUND: Coronary artery disease (CAD) and prostate cancer (PCa) are not only common diseases, but share many risk factors. To date, only a few studies have explored the relationship between CAD and PCa risk, with conflicting results. METHODS: The four-year REDUCE study tested dutasteride 0.5 mg daily for PCa risk reduction in men with prostate specific antigen (PSA) of 2.5 to 10.0 ng/mL and a negative biopsy. Among men who underwent at least one on-study biopsy (n = 6,729; 82.8%), the association between CAD and overall PCa risk and disease grade was examined with logistic and multinomial logistic regression adjusting for clinicopathologic features, respectively. RESULTS: Overall, 547 men (8.6%) had a history of CAD. Men with CAD were significantly older and had higher body mass index, PSA, and larger prostate volumes and were more likely to have diabetes, hypertension, and hypercholesterolemia and take aspirin and statins. On multivariate analysis, CAD was associated with a 35% increased risk of PCa diagnosis (OR = 1.35, 95% CI: 1.08-1.67, P = 0.007), while elevating risk of both low- (OR = 1.34, 95% CI: 1.05-1.73, P = 0.02) and high-grade disease (OR = 1.34, 95% CI: 0.95-1.88, P = 0.09). CONCLUSIONS: In a post hoc hypothesis developing secondary analysis of the REDUCE study, CAD was significantly associated with increased PCa diagnosis. IMPACT: If confirmed in other studies, this suggests CAD may be a novel PCa risk factor and suggests common shared etiologies. Whether lifestyle changes shown to reduce CAD risk (i.e., weight loss, exercise, cholesterol reduction, etc.) can reduce PCa risk, warrants further study.

Dutasteride in localised prostate cancer management: the REDEEM randomised, double-blind, placebo-controlled trial.

BACKGROUND: We aimed to investigate the safety and efficacy of dutasteride, a 5α-reductase inhibitor, on prostate cancer progression in men with low-risk disease who chose to be followed up with active surveillance. METHODS: In our 3 year, randomised, double-blind, placebo-controlled study, undertaken at 65 academic medical centres or outpatient clinics in North America, we enrolled men aged 48-82 years who had low-volume, Gleason score 5-6 prostate cancer and had chosen to be followed up with active surveillance. We randomly allocated participants in a one-to-one ratio, stratified by site and in block sizes of four, to receive once-daily dutasteride 0·5 mg or matching placebo. Participants were followed up for 3 years, with 12-core prostate biopsy samples obtained after 18 months and 3 years. The primary endpoint was time to prostate cancer progression, defined as the number of days between the start of study treatment and the earlier of either pathological progression (in patients with ≥1 biopsy assessment after baseline) or therapeutic progression (start of medical therapy). This trial is registered with ClinicalTrials.gov, number NCT00363311. FINDINGS: Between Aug 10, 2006, and March 26, 2007, we randomly allocated 302 participants, of whom 289 (96%) had at least one biopsy procedure after baseline and were included in the primary analysis. By 3 years, 54 (38%) of 144 men in the dutasteride group and 70 (48%) of 145 controls had prostate cancer progression (pathological or therapeutic; hazard ratio 0·62, 95% CI 0·43-0·89; p=0·009). Incidence of adverse events was much the same between treatment groups. 35 (24%) men in the dutasteride group and 23 (15%) controls had sexual adverse events or breast enlargement or tenderness. Eight (5%) men in the dutasteride group and seven (5%) controls had cardiovascular adverse events, but there were no prostate cancer-related deaths or instances of metastatic disease. INTERPRETATION: Dutasteride could provide a beneficial adjunct to active surveillance for men with low-risk prostate cancer. FUNDING: GlaxoSmithKline.

Usefulness of prostate-specific antigen (PSA) rise as a marker of prostate cancer in men treated with dutasteride: lessons from the REDUCE study.

OBJECTIVES: To determine if dutasteride-treated men can be monitored safely and adequately for prostate cancer based on data from the Reduction by Dutasteride in Prostate Cancer Events (REDUCE) study. To analyse whether the use of treatment-specific criteria for repeat biopsy maintains the usefulness of prostate-specific antigen (PSA) level for detecting high grade cancers. PATIENTS AND METHODS: The REDUCE study was a randomized, double-blind, placebo-controlled investigation of whether dutasteride (0.5 mg/day) reduced the risk of biopsy-detectable prostate cancer in men with a previous negative biopsy. The usefulness of PSA was evaluated using biopsy thresholds defined by National Comprehensive Cancer Network guidelines in the placebo group and any rise in PSA from nadir (the lowest PSA level achieved while in the study) in the dutasteride group. The number of cancers detected on biopsy in the absence of increased/suspicious PSA level as well as sensitivity, specificity, positive predictive value and negative predictive value for high grade prostate cancer detection were analysed by treatment group. Prostate cancer pathological characteristics were compared between men who did and did not meet biopsy thresholds. RESULTS: Of 8231 men randomized, 3305 (dutasteride) and 3424 (placebo) underwent at least one prostate biopsy during the study and were included in the analysis. If only men meeting biopsy thresholds underwent biopsy, 25% (47/191) of Gleason 7 and 24% (7/29) of Gleason 8-10 cancers would have been missed in the dutasteride group, and 37% (78/209) of Gleason 7 and 22% (4/18) Gleason 8-10 cancers would have been missed in the placebo group. In both groups, the incidence of Gleason 7 and Gleason 8-10 cancers generally increased with greater rises in PSA. Sensitivity of PSA kinetics was higher and specificity was lower for the detection of Gleason 7-10 cancers in men treated with dutasteride vs placebo. Men with Gleason 7 and Gleason 8-10 cancer meeting biopsy thresholds had greater numbers of positive cores, percent core involvement, and biopsy cancer volume vs men not meeting thresholds. CONCLUSION: Using treatment-specific biopsy thresholds, the present study shows that the ability of PSA kinetics to detect high grade prostate cancer is maintained with dutasteride compared with placebo in men with a previous negative biopsy. The sensitivity of PSA kinetics with dutasteride was similar to (Gleason 8-10) or higher than (Gleason 7-10) the placebo group; however, biopsy decisions based on a single increased PSA measurement from nadir in the dutasteride group resulted in a lower specificity compared with using a comparable biopsy threshold in the placebo group, indicating the importance of confirmation of PSA measurements.

Dutasteride reduces prostatitis symptoms compared with placebo in men enrolled in the REDUCE study.

PURPOSE: Men at risk for prostate cancer may concurrently experience chronic prostatitis or pelvic pain. We evaluated the effect of dutasteride on prostatitis-like symptoms in the REDUCE study population. MATERIALS AND METHODS: REDUCE was a 4-year, randomized, double-blind, placebo controlled study of prostate cancer risk reduction with 0.5 mg dutasteride vs placebo in men 50 to 75 years old with prostate specific antigen 2.5 to 10 ng/ml and a negative prostate biopsy in the previous 6 months. In this analysis we investigated change from baseline in Chronic Prostatitis Symptom Index in men with prostatitis-like pain (Chronic Prostatitis Symptom Index pain subscore 5 or greater) and prostatitis-like syndrome (perineal or ejaculatory pain plus Chronic Prostatitis Symptom Index pain subscore 4 or greater), the proportion of subjects with at least a moderate Chronic Prostatitis Symptom Index response (6-unit or greater improvement) and reports of new onset clinical prostatitis. RESULTS: Of 5,379 men with a total baseline Chronic Prostatitis Symptom Index score 678 (12.6%) had prostatitis-like pain and 427 (7.9%) had prostatitis-like syndrome. Chronic Prostatitis Symptom Index total score decreased significantly at 48 months in the dutasteride group vs placebo in men with prostatitis-like pain (p <0.0001) and with prostatitis-like syndrome (t test p = 0.03). There were significantly more Chronic Prostatitis Symptom Index responders with dutasteride vs placebo in the prostatitis-like pain (49% vs 37%, respectively, p = 0.0033) and prostatitis-like syndrome (46% vs 35%, Fisher's exact test p = 0.0265) subgroups. Prostatitis was reported as an adverse event by significantly more men randomized to placebo (3.6%) than to dutasteride (2.5%, p = 0.003). CONCLUSIONS: Long-term dutasteride therapy resulted in improvement in prostatitis related symptoms in older men with an increased prostate specific antigen.

Prostate cancer gene 3 score predicts prostate biopsy outcome in men receiving dutasteride for prevention of prostate cancer: results from the REDUCE trial.

OBJECTIVES: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Dutasteride improves outcomes of benign prostatic hyperplasia when evaluated for prostate cancer risk reduction: secondary analysis of the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial.

OBJECTIVE: To investigate the effect of dutasteride versus placebo on the symptoms and associated complications of male lower urinary tract symptoms and benign prostatic hyperplasia (BPH) across a range of prostate volumes and BPH symptoms in men evaluated for prostate cancer risk reduction in the 4-year REduction by DUtasteride of prostate Cancer Events (REDUCE) trial. METHODS: REDUCE was a multicenter, randomized, double-blind, placebo-controlled study of prostate cancer risk reduction with daily dutasteride 0.5 mg or placebo. Eligible men were aged 50-75 years, with a prostate-specific antigen level of 2.5-10 ng/mL and a prostate volume of ≤80 cm3. The prespecified and post hoc analyses were performed on the incidence of acute urinary retention, BPH-related surgery, and urinary tract infections, as well as on changes in prostate volume, International Prostate Symptom Score, BPH Impact Index, and maximal urinary flow rate (Qmax). RESULTS: A total of 8122 men were included in the efficacy population. During the 4-year study, the International Prostate Symptom Score increased in placebo-treated patients, while dutasteride-treated patients had a stabilized or decreased International Prostate Symptom Score and improved BPH Impact Index and quality of life due to urinary symptom scores across all prostate volume quintiles (including prostate glands smaller than those studied in previous dutasteride trials). 48 months, the incidence of acute urinary retention or BPH-related surgery was significantly less in the dutasteride group (2.5%) than in the placebo group (9%) overall (P<.001) and in each baseline prostate volume quintile (P<.01). CONCLUSION: During the 4-year study, dutasteride was associated with a decreased risk of BPH progression in men with mild-to-moderate symptoms and normal or enlarged prostates.

Comparison of dutasteride and finasteride for treating benign prostatic hyperplasia: the Enlarged Prostate International Comparator Study (EPICS).

OBJECTIVE: • To assess the efficacy and safety of dutasteride compared with finasteride in treating men with symptomatic benign prostatic hyperplasia (BPH) for 12 months. PATIENTS AND METHODS: • The Enlarged Prostate International Comparator Study was a multicentre, randomized, double-blind, 12-month, parallel-group study. • Men aged ≥ 50 years with a clinical diagnosis of BPH received once-daily treatment with dutasteride 0.5 mg (n= 813) or finasteride 5 mg (n= 817). After a 4-week placebo run-in period, patients were randomized to receive dutasteride or finasteride for 48 weeks, followed by an optional 24-month, open-label phase, during which patients received dutasteride 0.5 mg once daily. • The primary endpoint was change in prostate volume, and the secondary endpoints included improvement in American Urological Association Symptom Index (AUA-SI) scores, improvement in maximum urinary flow rate (Q(max)) and long-term safety in the 24-month open-label phase. RESULTS: • Both dutasteride and finasteride were effective at reducing prostate volume with no significant difference between the two treatments during the study. • Similar reductions in mean AUA-SI scores and Q(max) were also observed for men in both treatment groups. • A similar percentage of adverse events was experienced by patients of both treatment groups, and no new adverse events were reported in the open-label phase. CONCLUSION: • Dutasteride and finasteride, when administered for 12 months, were similarly effective in reducing prostate volume and improving Q(max) and urinary symptoms associated with BPH in men with an enlarged prostate.

Chemoprevention of prostate cancer.

Over the past two decades, many more men are diagnosed with prostate cancer then die of the disease. This increase in diagnosis has led to aggressive treatment of indolent disease in many individuals and has been the impetus for finding a means of reducing the risk of prostate cancer. In the past decade, there have been eight large trials of prostate cancer risk reduction using dietary supplements, 5α-reductase inhibitors, or anti-estrogens. The only two trials which have demonstrated efficacy are those involving 5α-reductase inhibitors: the PCPT (finasteride) and REDUCE (dutasteride). This review examines prostate cancer risk reduction, with emphasis on conclusions that can be drawn from these two landmark studies.

Biopsy misidentification identified by DNA profiling in a large multicenter trial.

PURPOSE: The Reduction by Dutasteride of Prostate Cancer Events (REDUCE) prostate cancer risk reduction study randomly assigned 8,231 men to dutasteride or placebo for 4 years. Protocol-mandated biopsies were obtained after 2 and 4 years. After the discovery of three cases of biopsy sample misidentification in the first 2 years, all protocol-mandated biopsy samples were DNA tested to verify biopsy identity. METHODS: Biopsy and blood DNA profiling was performed retrospectively for the year 2 scheduled biopsies and prospectively for the year 4 scheduled biopsies. Toward the end of year 2, multiple changes were made to improve sample handling and chain of custody. RESULTS: Of the 6,458 year 2 and 4,777 year 4 biopsies, 26 biopsies reflecting 13 sample handling errors at year 2 (0.4%) and one biopsy reflecting one sample handling error at year 4 (0.02%) were confirmed to be mismatched to the patient for whom they were originally submitted. Of 6,733 reference blood samples profiled, 31 (0.5%) were found to be mismatched to the patient's verified identity profile. Sample identification errors occurred at local research sites and central laboratories. CONCLUSION: Biopsy misidentification is a potential problem in clinical laboratories and clinical trials. Until now, biopsy misidentification has not been studied in the setting of a large, multinational clinical trial. In the REDUCE study, process improvement initiatives halfway through the trial dramatically reduced biopsy mismatches. The potential for biopsy mismatches in clinical trials and clinical practice is an under-recognized problem that requires rigorous attention to details of chain of custody and consideration of more widespread DNA identity testing.

Effect of dutasteride on prostate biopsy rates and the diagnosis of prostate cancer in men with lower urinary tract symptoms and enlarged prostates in the Combination of Avodart and Tamsulosin trial.

BACKGROUND: A 23% relative risk reduction (RRR) in prostate cancer (PCa) was shown in men receiving dutasteride in the 4-yr Reduction by Dutasteride of Prostate Cancer Events study, in whom biopsies were protocol dependent. OBJECTIVE: Our aim was to explore PCa risk reduction in men with benign prostatic hyperplasia (BPH) from the Combination of Avodart and Tamsulosin (CombAT) study, in which biopsies were undertaken for cause. DESIGN, SETTING, AND PARTICIPANTS: CombAT was a 4-yr randomized double-blind parallel group study in 4844 men ≥50 yr of age with clinically diagnosed moderate to severe BPH, International Prostate Symptom Score ≥12, prostate volume ≥30 ml, and serum prostate-specific antigen (PSA) 1.5-10 ng/ml. Men underwent annual PSA measurement and digital rectal examination (DRE), and prostate biopsies were performed for cause. INTERVENTION: All patients took tamsulosin 0.4 mg/d, dutasteride 0.5 mg/d, or a combination of both. MEASUREMENTS: The primary end point was incidence of PCa. Secondary end points included postbaseline prostate biopsy rates and Gleason score of cancers. RESULTS AND LIMITATIONS: Dutasteride (alone or in combination with tamsulosin) was associated with a 40% RRR of PCa diagnosis compared with tamsulosin monotherapy (95% confidence interval, 16-57%; p=0.002) and a 40% reduction in the likelihood of biopsy. There were similar reductions in low- and high-grade Gleason score cancers. The biopsy rate in the groups receiving dutasteride trended toward a higher diagnostic yield (combination: 29%, dutasteride: 28%, tamsulosin: 24%). One limitation was the lack of a standardized approach to PCa diagnosis and grading. CONCLUSIONS: Dutasteride, alone or in combination with tamsulosin, significantly reduced the relative risk of PCa diagnosis in men with BPH undergoing annual DRE and PSA screening. Consistent with the increased usefulness of PSA for PCa detection, men receiving dutasteride had a numerically lower biopsy rate and higher yield of PCa on biopsy. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT00090103 (http://www.clinicaltrials.gov/ct2/show/NCT00090103).

The effect of dutasteride on the usefulness of prostate specific antigen for the diagnosis of high grade and clinically relevant prostate cancer in men with a previous negative biopsy: results from the REDUCE study.

PURPOSE: We assessed whether dutasteride enhances the usefulness of total prostate specific antigen for diagnosing clinically significant prostate cancer. MATERIALS AND METHODS: The 4-year REDUCE study evaluated the efficacy and safety of 0.5 mg dutasteride daily for prostate cancer risk reduction in men with a prostate specific antigen of 2.5 to 10.0 ng/ml and a negative prostate biopsy. Specificity, sensitivity, and positive and negative predictive values of prostate specific antigen for the diagnosis of prostate cancer were assessed. RESULTS: Final prostate specific antigen before biopsy and change from month 6 to final prostate specific antigen performed better for the diagnosis of Gleason score 7-10 tumors in men who received dutasteride vs placebo as assessed by the area under the ROC curves (0.700 vs 0.650, p = 0.0491; and 0.699 vs 0.593, p = 0.0001, respectively). Increases in prostate specific antigen were associated with a higher likelihood of biopsy detectable, Gleason score 7-10 and clinically significant (modified Epstein criteria) prostate cancer. Percentage decreases in prostate specific antigen from baseline to month 6 in the dutasteride arm did not predict prostate cancer overall or Gleason score 7-10 cancer. CONCLUSIONS: In men with a previously negative prostate biopsy, prostate specific antigen performed better during the 4-year study as a marker of prostate cancer in men who received dutasteride vs placebo. The degree of prostate specific antigen increase after 6 months was a better indicator of clinically significant cancer in the dutasteride arm than in the placebo arm. Conversely, the initial decrease in prostate specific antigen in men taking dutasteride did not predict the likelihood of prostate cancer.

Low serum testosterone levels are poor predictors of sexual dysfunction.

OBJECTIVE: • To identify predictors of sexual dysfunction using baseline data from the reduction by dutasteride of prostate cancer events (REDUCE) study. PATIENTS AND METHODS: • REDUCE was a 4-year randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of once-daily dutasteride 0.5 mg in over 8000 men aged 50-75 years with a prostate-specific antigen (PSA) level of 2.5-10 ng/mL (50-60 years) or 3.0-10 ng/mL (>60 years) and a negative prostate biopsy within 6 months of enrolment. • Baseline values (mean serum testosterone, age, International Prostate Symptom Score [IPSS], total prostate volume [TPV], body mass index [BMI], and presence of diabetes/glucose intolerance) were compared in subjects with and without sexual dysfunction (sexual inactivity, impotence, decreased libido or a Problem Assessment Scale of the Sexual Function Index [PAS-SFI] score <9). RESULTS: • Multivariate logistic regression showed that baseline age and IPSS were significant predictors of all four sexual function criteria examined (P < 0.0001). • BMI was a significant predictor of decreased libido, impotence and a PAS-SFI score <9, while diabetes/glucose intolerance was a significant predictor of sexual inactivity, impotence and a PAS-SFI score <9. • Testosterone and TPV were not significant predictors of any sexual function criterion examined. CONCLUSIONS: • Age, IPSS, BMI and diabetes/glucose intolerance, but not serum testosterone or TPV, were significant independent predictors of sexual dysfunction in the REDUCE study population. • The lack of association between sexual dysfunction and serum testosterone questions the value of modestly reduced or low normal testosterone levels as criteria for choosing testosterone replacement in older men with sexual dysfunction.

Effect of dutasteride on the risk of prostate cancer.

BACKGROUND: We conducted a study to determine whether dutasteride reduces the risk of incident prostate cancer, as detected on biopsy, among men who are at increased risk for the disease. METHODS: In this 4-year, multicenter, randomized, double-blind, placebo-controlled, parallel-group study, we compared dutasteride, at a dose of 0.5 mg daily, with placebo. Men were eligible for inclusion in the study if they were 50 to 75 years of age, had a prostate-specific antigen (PSA) level of 2.5 to 10.0 ng per milliliter, and had had one negative prostate biopsy (6 to 12 cores) within 6 months before enrollment. Subjects underwent a 10-core transrectal ultrasound-guided biopsy at 2 and 4 years. RESULTS: Among 6729 men who underwent a biopsy or prostate surgery, cancer was detected in 659 of the 3305 men in the dutasteride group, as compared with 858 of the 3424 men in the placebo group, representing a relative risk reduction with dutasteride of 22.8% (95% confidence interval, 15.2 to 29.8) over the 4-year study period (P<0.001). Overall, in years 1 through 4, among the 6706 men who underwent a needle biopsy, there were 220 tumors with a Gleason score of 7 to 10 among 3299 men in the dutasteride group and 233 among 3407 men in the placebo group (P=0.81). During years 3 and 4, there were 12 tumors with a Gleason score of 8 to 10 in the dutasteride group, as compared with only 1 in the placebo group (P=0.003). Dutasteride therapy, as compared with placebo, resulted in a reduction in the rate of acute urinary retention (1.6% vs. 6.7%, a 77.3% relative reduction). The incidence of adverse events was similar to that in studies of dutasteride therapy for benign prostatic hyperplasia, except that in our study, as compared with previous studies, the relative incidence of the composite category of cardiac failure was higher in the dutasteride group than in the placebo group (0.7% [30 men] vs. 0.4% [16 men], P=0.03). CONCLUSIONS: Over the course of the 4-year study period, dutasteride reduced the risk of incident prostate cancer detected on biopsy and improved the outcomes related to benign prostatic hyperplasia. (ClinicalTrials.gov number, NCT00056407.)

Prostate needle biopsy quality in reduction by dutasteride of prostate cancer events study: worldwide comparison of improvement with investigator training and centralized laboratory processing.

OBJECTIVES: To compare biopsy quality factors among study sites worldwide at entry and at year 2 in the reduction by dutasteride of prostate cancer events study. The accuracy of prostate cancer detection is influenced by the length and number of biopsy cores. METHODS: Biopsy quality factors at entry and at year 2 were compared for subjects enrolled from 6 geographic regions: North America, South America, Western Europe, Central/Eastern Europe, Australia, and Africa. Investigator training was provided for prostate biopsy collection before year 2, emphasizing core length and number of cores obtained. RESULTS: Data were collected prospectively from 4649 subjects at entry and 6267 subjects at year 2. At entry, the aggregate length, number of cores, and mean length of cores differed significantly among regions. Aggregate length was longest in biopsies from Australia, and number of cores was highest from South America. At year 2, each region collected the protocol-required 10 cores, and aggregate length and mean length of cores were greater than for entry biopsies; site variance was reduced for all factors. CONCLUSIONS: There were significant differences in aggregate length, number of cores, and mean length of cores among regions at study entry. After investigator training by the study sponsor and use of a central laboratory for standardized processing, year 2 biopsies showed an increase in all 3 quality factors when compared with entry biopsies. Variance in biopsy quality can be reduced by investigator training and standardization of collection and processing, thereby optimizing detection of cancer. Biopsy quality may be a useful comparative measure in urologic practice.