A Genetic Score Can Identify Men at High Risk for Prostate Cancer Among Men With Prostate-Specific Antigen of 1–3 ng/ml

Background

The diagnostic performance of a genetic score based on single nucleotide polymorphisms (SNPs) is unknown in the prostate-specific antigen (PSA) range of 1–3 ng/ml. A substantial proportion of men in this PSA span have prostate cancer (PCa), but biomarkers to determine who should undergo a prostate biopsy are lacking.

Objective

To evaluate whether a genetic risk score identifies men in the PSA range of 1–3 ng/ml who are at higher risk for PCa.

Design, setting, and participants

Men aged 50–69 yr with PSA 1–3 ng/ml and without a previous prostate biopsy were selected from the STHLM2 cohort. Of 2696 men, 49 SNPs were genotyped, and a polygenic risk score was calculated. Of these men, 860 were invited according to risk score, and 172 underwent biopsy.

Outcome measurements and statistical analysis

The risk of PCa was assessed using univariate and multivariate logistic regression analysis.

Results and limitations

PCa was diagnosed in 47 of 172 participants (27%), with Gleason sum 6 in 36 of 47 men (77%) and Gleason sum ≥7 in 10 of 47 men (21%); one man had intraductal cancer. The genetic score was a significant predictor of a positive biopsy (p = 0.028), even after adjusting for PSA, ratio of free to total PSA, prostate volume, age, and family history. There was an increase in the odds ratio of 1.60 (95% confidence interval, 1.05–2.45) with increasing genetic risk score. The absolute risk difference of positive biopsy was 19 percentage points, comparing the high and low genetic risk group (37% vs 18%).

Conclusions

A risk score based on SNPs predicts biopsy outcome in previously unbiopsied men with PSA 1–3 ng/ml. Introducing a genetic-based risk stratification tool can increase the proportion of men being classified in line with their true risk of PCa.     

Initial Prostate Biopsy: Development and Internal Validation of a Biopsy-specific Nomogram Based on the Prostate Cancer Antigen 3 Assay

Background

Urinary prostate cancer antigen 3 (PCA3) assay in combination with established clinical risk factors improves the identification of men at risk of harboring prostate cancer (PCa) at initial biopsy (IBX).

Objective

To develop and validate internally the first IBX-specific PCA3-based nomogram that allows an individual assessment of a man's risk of harboring any PCa and high-grade PCa (HGPCa).

Design, setting, and participants

Clinical and biopsy data including urinary PCA3 score of 692 referred IBX men at risk of PCa were collected within two prospective multi-institutional studies.

Intervention

IBX (≥10 biopsy cores) with standard risk factor assessment including prebiopsy urinary PCA3 measurement.

Outcome measurements and statistical analysis

PCA3 assay cut-off thresholds were investigated. Regression coefficients of logistic risk factor analyses were used to construct specific sets of PCA3-based nomograms to predict any PCa and HGPCa at IBX. Accuracy estimates for the presence of any PCa and HGPCa were quantified using area under the curve of the receiver operator characteristic analysis and compared with a clinical model. Bootstrap resamples were used for internal validation. Decision curve analyses quantified the clinical net benefit related to the novel PCA3-based IBX nomogram versus the clinical model.

Results and limitations

Any PCa and HGPCa were diagnosed in 46% (n = 318) and 20% (n = 137), respectively. Age, prostate-specific antigen, digital rectal examination, prostate volume, and PCA3 were independent predictors of PCa at IBX (all p < 0.001). The PCA3-based IBX nomograms significantly outperformed the clinical models without PCA3 (all p < 0.001). Accuracy was increased by 4.5–7.1% related to PCA3 inclusion. When applying nomogram-derived PCa probability thresholds ≤30%, only a few patients with HGPCa (≤2%) will be missed while avoiding up to 55% of unnecessary biopsies. External validation of the PCA3-based IBX-specific nomogram is warranted.

Conclusions

The internally validated PCA3-based IBX-specific nomogram outperforms a clinical prediction model without PCA3 for the prediction of any PCa, leading to the avoidance of unnecessary biopsies while missing only a few cases of HGPCa. Our findings support the concepts of a combination of novel markers with established clinical risk factors and the superiority of decision tools that are specific to a clinical scenario.     

The Added Value of Percentage of Free to Total Prostate-specific Antigen,PCA3, and a Kallikrein Panel to the ERSPC Risk Calculator for Prostate Cancer in Prescreened Men

Background

Prostate-specific antigen (PSA) testing has limited accuracy for the early detection of prostate cancer (PCa).

Objective

To assess the value added by percentage of free to total PSA (%fPSA), prostate cancer antigen 3 (PCA3), and a kallikrein panel (4k-panel) to the European Randomised Study of Screening for Prostate Cancer (ERSPC) multivariable prediction models: risk calculator (RC) 4, including transrectal ultrasound, and RC 4 plus digital rectal examination (4+DRE) for prescreened men.

Design, setting, and participants

Participants were invited for rescreening between October 2007 and February 2009 within the Dutch part of the ERSPC study. Biopsies were taken in men with a PSA level ≥3.0 ng/ml or a PCA3 score ≥10. Additional analyses of the 4k-panel were done on serum samples.

Outcome measurements and statistical analysis

Outcome was defined as PCa detectable by sextant biopsy. Receiver operating characteristic curve and decision curve analyses were performed to compare the predictive capabilities of %fPSA, PCA3, 4k-panel, the ERSPC RCs, and their combinations in logistic regression models.

Results and limitations

PCa was detected in 119 of 708 men. The %fPSA did not perform better univariately or added to the RCs compared with the RCs alone. In 202 men with an elevated PSA, the 4k-panel discriminated better than PCA3 when modelled univariately (area under the curve [AUC]: 0.78 vs 0.62; p = 0.01). The multivariable models with PCA3 or the 4k-panel were equivalent (AUC: 0.80 for RC 4+DRE). In the total population, PCA3 discriminated better than the 4k-panel (univariate AUC: 0.63 vs 0.56; p = 0.05). There was no statistically significant difference between the multivariable model with PCA3 (AUC: 0.73) versus the model with the 4k-panel (AUC: 0.71; p = 0.18). The multivariable model with PCA3 performed better than the reference model (0.73 vs 0.70; p = 0.02). Decision curves confirmed these patterns, although numbers were small.

Conclusions

Both PCA3 and, to a lesser extent, a 4k-panel have added value to the DRE-based ERSPC RC in detecting PCa in prescreened men.

Patient summary

We studied the added value of novel biomarkers to previously developed risk prediction models for prostate cancer. We found that inclusion of these biomarkers resulted in an increase in predictive ability.     

Prostate Cancer (PCa) Risk Variants and Risk of Fatal PCa in the National Cancer Institute Breast and Prostate Cancer Cohort Consortium

Background

Screening and diagnosis of prostate cancer (PCa) is hampered by an inability to predict who has the potential to develop fatal disease and who has indolent cancer. Studies have identified multiple genetic risk loci for PCa incidence, but it is unknown whether they could be used as biomarkers for PCa-specific mortality (PCSM).

Objective

To examine the association of 47 established PCa risk single-nucleotide polymorphisms (SNPs) with PCSM.

Design, setting, and participants

We included 10 487 men who had PCa and 11 024 controls, with a median follow-up of 8.3 yr, during which 1053 PCa deaths occurred.

Outcome measurements and statistical analysis

The main outcome was PCSM. The risk allele was defined as the allele associated with an increased risk for PCa in the literature. We used Cox proportional hazards regression to calculate the hazard ratios of each SNP with time to progression to PCSM after diagnosis. We also used logistic regression to calculate odds ratios for each risk SNP, comparing fatal PCa cases to controls.

Results and limitations

Among the cases, we found that 8 of the 47 SNPs were significantly associated (p < 0.05) with time to PCSM. The risk allele of rs11672691 (intergenic) was associated with an increased risk for PCSM, while 7 SNPs had risk alleles inversely associated (rs13385191 [C2orf43], rs17021918 [PDLIM5], rs10486567 [JAZF1], rs6465657 [LMTK2], rs7127900 (intergenic), rs2735839 [KLK3], rs10993994 [MSMB], rs13385191 [C2orf43]). In the case-control analysis, 22 SNPs were associated (p < 0.05) with the risk of fatal PCa, but most did not differentiate between fatal and nonfatal PCa. Rs11672691 and rs10993994 were associated with both fatal and nonfatal PCa, while rs6465657, rs7127900, rs2735839, and rs13385191 were associated with nonfatal PCa only.

Conclusions

Eight established risk loci were associated with progression to PCSM after diagnosis. Twenty-two SNPs were associated with fatal PCa incidence, but most did not differentiate between fatal and nonfatal PCa. The relatively small magnitudes of the associations do not translate well into risk prediction, but these findings merit further follow-up, because they may yield important clues about the complex biology of fatal PCa.

Patient summary

In this report, we assessed whether established PCa risk variants could predict PCSM. We found eight risk variants associated with PCSM: One predicted an increased risk of PCSM, while seven were associated with decreased risk. Larger studies that focus on fatal PCa are needed to identify more markers that could aid prediction.     

Neoadjuvant Hormonal Therapy Use and the Risk of Death in Men with Prostate Cancer Treated with Brachytherapy Who Have No or at Least a Single Risk Factor for Coronary Artery Disease

Background

Neoadjuvant hormone therapy (NHT) use is associated with an increased risk of all-cause mortality (ACM) in men with a history of coronary artery disease (CAD)–induced congestive heart failure (CHF) or myocardial infarction (MI). However, its effect in men with no or at least a single risk factor for CAD stratified by prostate cancer (PCa) aggressiveness is unknown.

Objective

To assess whether NHT use affects the risk of ACM in men with low-, intermediate-, and high-risk PCa treated with brachytherapy who have no or at least a single risk factor for CAD.

Design, setting, and participants

This retrospective study cohort consisted of 5411 men with low-risk PCa (prostate-specific antigen [PSA] <10 ng/ml, Gleason score 6, and clinical stage T1–T2a); 4365 men with intermediate-risk PCa (PSA 10–20 ng/ml or Gleason score <8 or clinical stage <T3); and 1360 men with localized or locally advanced, high-risk PCa consecutively treated in a community-based, multi-institutional setting between 1991 and 2006. CAD risk factors included at least a history of diabetes mellitus, hypercholesterolemia, or hypertension. The median follow-up for men with low-, intermediate-, and high-risk PCa were 4.1, 4.4, and 4.6 yr, respectively.

Interventions

Men were treated with or without a median duration of 4 mo of NHT followed by brachytherapy with or without supplemental external-beam radiation therapy (EBRT).

Outcome measurements and statistical analysis

Cox regression multivariable analyses were performed to assess whether NHT use affected the risk of ACM in men with low-, intermediate-, and high-risk PCa, adjusting for age; year of brachytherapy; supplemental EBRT use; the presence of CAD risk factors; treatment propensity score; and known PCa prognostic factors, including pretreatment PSA level, biopsy Gleason score, and clinical stage.

Results and limitations

NHT use was associated with a significantly increased risk of ACM in men with low-risk PCa (adjusted hazard ratio [HR]: 1.27; 95% confidence interval [CI], 1.07–1.51; p < 0.01) but not in men with intermediate-risk (adjusted HR: 1.13; 95% CI, 0.96–1.35; p = 0.15) or high-risk PCa (adjusted HR: 0.86; 95% CI, 0.66–1.13; p = 0.28). Using an interaction model for the low-risk group, NHT use was associated with a significantly increased risk of ACM in the subgroup of men with at least a single CAD risk factor (adjusted HR: 1.36; 95% CI, 1.07–1.74; p = 0.01) but not for men with no CAD risk factors (adjusted HR: 1.19; 95% CI, 0.95–1.51; p = 0.13).

Conclusions

For men with no or at least a single risk factor for CAD, NHT use is associated with an increased risk of ACM in the setting of low-risk but not intermediate- or high-risk PCa. This effect is driven by the subgroup of men with at least a single risk factor for CAD. These results warrant prospective validation given the widespread use of NHT for prostate downsizing prior to brachytherapy.     

Performance of the Prostate Cancer Antigen 3 (PCA3) Gene and Prostate-Specific Antigen in Prescreened Men: Exploring the Value of PCA3 for a First-line Diagnostic Test

Background

The performance characteristics of serum prostate-specific antigen (PSA) as a diagnostic test for prostate cancer (PCa) are poor. The performance of the PCa antigen 3 (PCA3) gene as a primary diagnostic is unknown.

Objective

Assess the value of PCA3 as a first-line diagnostic test.

Design, setting and participants

Participants included men aged 63–75 who were invited for rescreening in the period from September 2007 to February 2009 within the European Randomised Study of Screening for Prostate Cancer, Rotterdam section.

Interventions

Lateral sextant biopsies were performed if the serum PSA value was ≥3.0 ng/ml and/or the PCA3 score was ≥10.

Measurements

Measurements included distribution and correlation of PSA value and PCA3 score and their relation to the number of cases and the characteristics of PCa detected. Additional value of PCA3 was included in men with previous negative biopsy and/or PSA <3.0 ng/ml.

Results and limitations

In 721 men, all biopsied, 122 PCa cases (16.9%) were detected. Correlation between PSA and PCA3 is poor (Spearman rank correlation: ρ = 0.14; p < 0.0001). A PSA ≥3.0 ng/ml misses 64.7% of the total PCa that can be detected with the sextant biopsy technique and 57.9% of serious PCa (T2a or higher and/or Gleason grade ≥4, n = 19), and 68.2% of biopsies could have been avoided; the respective data for PCA3 ≥35 are 32%, 26.3%, and 51.7%. Performance of PCA3 in men with low PSA (area under the curve [AUC]: 0.63) and/or previous negative biopsy (AUC: 0.68) is unclear but has limited reliability due to small numbers.

Conclusions

PCA3 as a first-line screening test shows improvement of the performance characteristics and identification of serious disease compared with PSA in this prescreened population.     

Prospective Multicentre Evaluation of PCA3 and TMPRSS2-ERG Gene Fusions as Diagnostic and Prognostic Urinary Biomarkers for Prostate Cancer

Background

Prostate cancer antigen 3 (PCA3) and v-ets erythroblastosis virus E26 oncogene homolog (TMPRSS2-ERG) gene fusions are promising prostate cancer (PCa) specific biomarkers that can be measured in urine.

Objective

To evaluate the diagnostic and prognostic value of Progensa PCA3 and TMPRSS2-ERG gene fusions (as individual biomarkers and as a panel) for PCa in a prospective multicentre setting.

Design, setting, and participants

At six centres, post–digital rectal examination first-catch urine specimens prior to prostate biopsies were prospectively collected from 497 men. We assessed the predictive value of Progensa PCA3 and TMPRSS2-ERG (quantitative nucleic acid amplification assay to detect TMPRSS2-ERG messenger RNA [mRNA]) for PCa, Gleason score, clinical tumour stage, and PCa significance (individually and as a marker panel). This was compared with serum prostate-specific antigen and the European Randomised Study of Screening for Prostate Cancer (ERSPC) risk calculator. In a subgroup (n = 61) we evaluated biomarker association with prostatectomy outcome.

Outcome measurements and statistical analysis

Univariate and multivariate logistic regression analysis and receiver operating curves were used.

Results and limitations

Urine samples of 443 men contained sufficient mRNA for marker analysis. PCa was diagnosed in 196 of 443 men. Both PCA3 and TMPRSS2-ERG had significant additional predictive value to the ERSPC risk calculator parameters in multivariate analysis (p < 0.001 and resp. p = 0.002). The area under the curve (AUC) increased from 0.799 (ERSPC risk calculator), to 0.833 (ERSPC risk calculator plus PCA3), to 0.842 (ERSPC risk calculator plus PCA3 plus TMPRSS2-ERG) to predict PCa. Sensitivity of PCA3 increased from 68% to 76% when combined with TMPRSS2-ERG. TMPRSS2-ERG added significant predictive value to the ERSPC risk calculator to predict biopsy Gleason score (p < 0.001) and clinical tumour stage (p = 0.023), whereas PCA3 did not.

Conclusions

TMPRSS2-ERG had independent additional predictive value to PCA3 and the ERSPC risk calculator parameters for predicting PCa. TMPRSS2-ERG had prognostic value, whereas PCA3 did not. Implementing the novel urinary biomarker panel PCA3 and TMPRSS2-ERG into clinical practice would lead to a considerable reduction of the number of prostate biopsies.     

Serum Testosterone and Dihydrotestosterone and Prostate Cancer Risk in the Placebo Arm of the Reduction by Dutasteride of Prostate Cancer Events Trial

Background

Findings of studies on the association between androgens and prostate cancer (PCa) are mixed. Androgens may affect prostate-specific antigen (PSA) levels, thereby influencing biopsy recommendations. Also, androgens may stimulate prostate growth at very low levels with no additional effects at higher levels (saturation model).

Objective

To test whether androgens were associated with PCa risk in the placebo arm of a prospective study in which biopsies were performed regardless of PSA level.

Design, setting, and participants

Of 8122 men in the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial, 4073 men (50.1%) received placebo. Key entry criteria were PSA 2.5–10 ng/ml and one prior negative biopsy.

Intervention

Per-protocol biopsies at 2 and 4 yr; for-cause biopsies at physician discretion.

Outcome measurements and statistical analysis

Multivariable logistic regression was used to test the association between baseline log-transformed testosterone and dihydrotestosterone (DHT) levels and the risk of detecting either PCa or low-grade PCa (Gleason score <6) compared with high-grade PCa (Gleason score >7). In secondary analysis, we stratified the analysis by low baseline androgen levels (testosterone <10 nmol/l; DHT <0.76 nmol/l) compared with normal baseline androgen levels.

Results and limitations

Of 4073 men, 3255 (79.9%) had at least one biopsy after randomization and were analyzed. Androgen levels tested continuously or by quintiles were generally unrelated to PCa detection or grade. PCa detection was similar among men with low compared with normal baseline testosterone levels (25.5% and 25.1%; p = 0.831). In secondary analysis, higher testosterone levels at baseline were associated with higher PCa detection (odds ratio: 1.23; 95% confidence interval, 1.06–1.43; p = 0.006) only if men had low baseline testosterone (<10 nmol/l). For men with normal baseline testosterone (≥10 nmol/l), higher testosterone levels at baseline were unrelated to PCa risk (p = 0.33). No association was found for DHT and PCa (all p > 0.85).

Conclusions

Baseline serum testosterone and DHT levels were unrelated to PCa detection or grade. Our findings of the lowest testosterone levels being associated with the lowest PCa risk with no further changes with higher testosterone support a saturation model but must be confirmed in future studies using an a priori defined hypothesis.

ClinicalTrials.gov identifier

NCT00056407.     

External Validation of Urinary PCA3-Based Nomograms to Individually Predict Prostate Biopsy Outcome

Background

Prior to safely adopting risk stratification tools, their performance must be tested in an external patient cohort.

Objective

To assess accuracy and generalizability of previously reported, internally validated, prebiopsy prostate cancer antigen 3 (PCA3) gene-based nomograms when applied to a large, external, European cohort of men at risk of prostate cancer (PCa).

Design, setting, and participants

Biopsy data, including urinary PCA3 score, were available for 621 men at risk of PCa who were participating in a European multi-institutional study.

Intervention

All patients underwent a ≥10-core prostate biopsy. Biopsy indication was based on suspicious digital rectal examination, persistently elevated prostate-specific antigen level (2.5–10 ng/ml) and/or suspicious histology (atypical small acinar proliferation of the prostate, >/= two cores affected by high-grade prostatic intraepithelial neoplasia in first set of biopsies).

Measurements

PCA3 scores were assessed using the Progensa assay (Gen-Probe Inc, San Diego, CA, USA). According to the previously reported nomograms, different PCA3 score codings were used. The probability of a positive biopsy was calculated using previously published logistic regression coefficients. Predicted outcomes were compared to the actual biopsy results. Accuracy was calculated using the area under the curve as a measure of discrimination; calibration was explored graphically.

Results and limitations

Biopsy-confirmed PCa was detected in 255 (41.1%) men. Median PCA3 score of biopsy-negative versus biopsy-positive men was 20 versus 48 in the total cohort, 17 versus 47 at initial biopsy, and 37 versus 53 at repeat biopsy (all p ≤ 0.002). External validation of all four previously reported PCA3-based nomograms demonstrated equally high accuracy (0.73–0.75) and excellent calibration. The main limitations of the study reside in its early detection setting, referral scenario, and participation of only tertiary-care centers.

Conclusions

In accordance with the original publication, previously developed PCA3-based nomograms achieved high accuracy and sufficient calibration. These novel nomograms represent robust tools and are thus generalizable to European men at risk of harboring PCa. Consequently, in presence of a PCA3 score, these nomograms may be safely used to assist clinicians when prostate biopsy is contemplated.     

Prospective Evaluation of an Extended 21-Core Biopsy Scheme as Initial Prostate Cancer Diagnostic Strategy

Background

The debate on the optimal number of prostate biopsy core samples that should be taken as an initial strategy is open.

Objective

To prospectively evaluate the diagnostic yield of a 21-core biopsy protocol as an initial strategy for prostate cancer (PCa) detection.

Design, setting, and participants

During 10 yr, 2753 consecutive patients underwent a 21-core biopsy scheme for their first set of biopsy specimens.

Intervention

All patients underwent a standardized 21-core protocol with cores mapped for location.

Outcome measurements and statistical analysis

The PCa detection rate of each biopsy scheme (6, 12, or 21 cores) was compared using a McNemar test. Predictive factors of the diagnostic yield achieved by a 21-core scheme were studied using logistic regression analyses.

Results and limitations

PCa detection rates using 6 sextant biopsies, 12 cores, and 21 cores were 32.5%, 40.4%, and 43.3%, respectively. The 12-core procedure improved the cancer detection rate by 19.4% (p = 0.004), and the 21-biopsy scheme improved the rate by 6.7% overall (p < 0.001). The six far lateral cores were the most efficient in terms of detection rate. The diagnostic yield of the 21-core protocol was >10% in prostates with volume >70 ml, in men with a prostate-specific antigen level < 4 ng/ml, with a prostate-specific antigen density (PSAD) <0.20 ng/ml per gram. A PSAD <0.20 ng/ml per gram was the strongest independent predictive factor of the diagnostic yield offered by the 21-core scheme (p < 0.001). The 21-core protocol significantly increased the rate of PCa eligible for active surveillance (62.5% vs 48.4%; p = 0.036) than those detected by a 12-core scheme without statistically increasing the rate of insignificant PCa (p = 0.503).

Conclusions

A 21-core biopsy scheme improves significantly the PCa detection rate compared with a 12-core protocol. We identified a cut-off PSAD (0.20 ng/ml per gram) below which an extended 21-core scheme might be systematically proposed to significantly improve the overall detection rate without increasing the rate of detected insignificant PCa.     

Prognostic Parameters,Complications, and Oncologic and Functional Outcome of Salvage Radical Prostatectomy for Locally Recurrent Prostate Cancer after 21st-Century Radiotherapy

Background

Salvage radical prostatectomy (SRP) for radiorecurrent prostate cancer (PCa) is a second local treatment with curative intent in patients with true organ-confined recurrent PCa.

Objective

We evaluated preoperative prognostic risk factors to predict organ-confined, locally recurrent PCa after primary radiotherapy (RT).

Design, setting, and participants

Fifty-five men with biopsy-proven, locally recurrent PCa underwent SRP and extended pelvic lymph node dissection (ePLND) after external-beam radiotherapy (EBRT) or low- or high-dose brachytherapy.

Measurements

Prostate-specific antigen (PSA), clinical stage, biopsy Gleason score prior to RT and SRP, PSA nadir, time to recurrence, PSA doubling time (PSA DT), PSA prior to surgery, and pathohistology of the SRP specimen were analysed to predict organ-confined recurrent disease. Uni- and multivariate statistical analysis was performed.

Results and limitations

Forty (72.7%) and 15 (27.3%) patients demonstrated organ-confined and locally advanced PCa, respectively. Eleven patients (20%) and seven patients (12.7%) had lymph node metastases and positive surgical margins (PSM), respectively. On multivariate analysis, biopsy Gleason score prior to SRP (p = 0.02), <50% positive biopsy cores (p = 0.001), PSA DT >12 mo (p = 0.001), and low-dose brachytherapy (p = 0.001) were significant predictors of organ-confined PCa with negative surgical margins (NSM). Limitations of the study are its retrospective nature and the relatively low number of patients.

Conclusions

SRP is a surgically challenging but effective secondary local treatment of radiorecurrent PCa with curative intent. The identified predictive parameters will help to select patients most suitable for SRP with long-term cure and good functional outcome.     

Outcome Following Active Surveillance of Men with Screen-detected Prostate Cancer. Results from the Göteborg Randomised Population-based Prostate Cancer Screening Trial

Background

Active surveillance (AS) has emerged as a treatment strategy for reducing overtreatment of screen-detected, low-risk prostate cancer (PCa).

Objective

To assess outcomes following AS of men with screen-detected PCa.

Design, setting, and participants

Of the 968 men who were diagnosed with screen-detected PCa between 1995 and 2010 in the Göteborg randomised, population-based PCa screening trial, 439 were managed with AS and were included in this study. Median age at diagnosis was 65.4 yr of age, and median follow-up was 6.0 yr from diagnosis.

Intervention

The study participants were followed at intervals of 3–12 mo and were recommended to switch to deferred active treatment in case of a progression in prostate-specific antigen, grade, or stage.

Outcome measurements and statistical analysis

The end points—overall survival (OS), treatment-free survival, failure-free (no relapse after radical treatment) survival, and cancer-specific survival—were calculated for various risk groups (very low, low, intermediate, and high) with Kaplan-Meier estimates. A Cox proportional hazards model as well as a competing risk analysis were used to assess whether risk group or age at diagnosis was associated with failure after AS.

Results and limitations

Forty-five per cent of all screen-detected PCa were managed with AS, and very low-risk and low-risk PCa constituted 60% of all screen-detected PCa. Thirty-seven per cent (162 of 439) switched from surveillance to deferred active treatment, and 39 men failed AS. The 10-yr OS, treatment-free survival, and failure-free survival were 81.1%, 45.4%, and 86.4%, respectively (Kaplan-Meier estimates). Men with low-, intermediate-, and high-risk tumours had a hazard ratio for failure of 2.1 (p = 0.09), 3.6 (p = 0.002), and 4.6 (p = 0.15), respectively, compared to very low-risk tumours (Cox regression). Only one PCa death occurred, and one patient developed metastasis (both in the intermediate-risk group). The main limitation of this study is the relatively short follow-up.

Conclusions

A large proportion of men with screen-detected PCa can be managed with AS. AS appears safe for men with low-risk PCa.     

Gonadotropin-releasing Hormone Agonists and Acute Kidney Injury in Patients with Prostate Cancer

Background

Androgen deprivation therapy (ADT) might increase the risk of acute kidney injury (AKI) in patients with prostate cancer (PCa).

Objective

To examine the impact of ADT on AKI in a large contemporary cohort of patients with nonmetastatic PCa representing the US population.

Design, setting, and participants

Overall, 69 292 patients diagnosed with nonmetastatic PCa between 1995 and 2009 were abstracted from the Surveillance Epidemiology and End Results–Medicare database.

Outcomes measurements and statistical analyses

Patient in both treatment arms (ADT vs no ADT) were matched using propensity-score methodology. Ten-year AKI rates were estimated. Competing-risks regression analyses tested the association between ADT and AKI, after adjusting for the risk of death during follow-up.

Results and limitations

Overall, the 10-yr AKI rates were 24.9% versus 30.7% for ADT-naive patients versus those treated with ADT, respectively (p < 0.001). When patients were stratified according to the type of ADT, the 10-yr AKI rates were 31.1% versus 26.0% for men treated with gonadotropin-releasing hormone (GnRH) agonists and bilateral orchiectomy, respectively (p < 0.001). In multivariable analyses, the administration of GnRH agonists (hazard ratio [HR]: 1.24; 95% confidence interval [CI], 1.18–1.31; p < 0.001), but not bilateral orchiectomy (HR: 1.11; 95% CI, 0.96–1.29; p = 0.1), was associated with the risk of experiencing AKI. Our study is limited by its retrospective design.

Conclusions

ADT is associated with an increased risk of AKI in patients with nonmetastatic PCa. In particular, the administration of GnRH agonists, but not surgical castration, may substantially increase the risk of experiencing AKI. These observations should help provide physicians with better patient selection to reduce the risk of AKI.

Patient summary

The administration of gonadotropin-releasing hormone agonists, but not bilateral orchiectomy, increases the risk of acute kidney injury (AKI) in patients with prostate cancer (PCa). These observations should help provide physicians with better patient selection to reduce the risk of AKI in PCa patients.     

Health-Related Quality of Life in the Finnish Trial of Screening for Prostate Cancer

Background

Evidence of the potential impact of systematic screening for prostate cancer (PCa) on health-related quality of life (HRQoL) at a population-based level is currently scarce.

Objective

This study aims to quantify the long-term HRQoL impact associated with screening for PCa.

Design, setting, and participants

Postal questionnaire surveys were conducted in 1998, 2000, 2004, and 2011 among men in the Finnish PCa screening trial diagnosed with PCa (total n = 7011) and among a random subsample of the trial population (n = 2200). In 2011, for example, 1587 responses were received from men with PCa in the screening arm and 1706 from men in the control arm. In addition, from the trial subsample, 549 men in the screening arm and 539 in the control arm provided responses.

Outcome measurements and statistical analysis

Health-state-value scores were compared between the intervention and control arms using three distinct HRQoL measures (15D, EQ-5D, and SF-6D), and statistical significance was assessed using t tests. In addition, differences over repeated assessments of HRQoL between groups were evaluated using generalised estimating equations.

Results and limitations

In the 2011 survey, a small but statistically significant difference emerged between the trial arms among men diagnosed with PCa (mean scores, screening vs control arm: 15D: 0.872 vs 0.866, p = 0.14; EQ-5D: 0.852 vs 0.831, p = 0.03; and SF-6D: 0.763 vs 0.756, p = 0.06). Such differences in favour of the screening arm were not found among the sample of men from the trial (15D: 0.889 vs 0.892, p = 0.62; EQ-5D: 0.831 vs 0.852, p = 0.08; and SF-6D: 0.775 vs 0.777, p = 0.88). The slight advantage with screening among men with PCa was reasonably consistent across time in the longitudinal analysis and was strongest among men with early-stage disease.

Conclusions

These results show some long-term HRQoL benefit from screening for men with PCa but suggest little impact overall in the trial population.     

Primary Gleason Grade 4 at the Positive Margin Is Associated with Metastasis and Death Among Patients with Gleason 7 Prostate Cancer Undergoing Radical Prostatectomy

Background

The presence of a positive surgical margin (PSM) at radical prostatectomy (RP) has been linked to an increased risk of biochemical recurrence and receipt of secondary therapy; however, its association with other oncologic end points remains controversial.

Objective

To evaluate the association of primary Gleason grade (GG) at the site of PSM with subsequent clinical progression and mortality among patients with Gleason score (GS) 7 prostate cancer (PCa).

Design, setting, and participants

We identified 1036 patients who underwent RP between 1996 and 2002. A single uropathologist re-reviewed all specimens noted to have a PSM to record GG at the margin.

Outcome measurements and statistical analysis

Survival was estimated using the Kaplan-Meier method. Cox models were used to analyze the association of margin primary GG with outcome.

Results and limitations

Overall, 338 men (33%) had a PSM; of those, 242 had PSM GG3 and 96 had PSM GG4. Median postoperative follow-up was 13 yr. Compared with men with PSM GG3 or a negative SM, we noted that men with PSM GG4 had significantly worse 15-yr systemic progression-free survival (74% vs 90% vs 93%, respectively; p < 0.001) and cancer-specific survival (86% vs 96% vs 97%, respectively; p = 0.002). On multivariable analysis, the presence of PSM GG4 was associated with increased risks of systemic progression (hazard ratio [HR]: 2.77; p = 0.003) and death from PCa (HR: 3.93; p = 0.02) among men with a PSM. Limitations include the relatively small rate of disease recurrence.

Conclusions

PSM primary GG4 was independently associated with adverse oncologic outcomes among men with GS7 PCa. Pending external validation, GG at the PSM may be considered for inclusion in pathologic reports and risk stratification following RP.

Patient summary

Among patients with Gleason grade 7 prostate cancer and a positive surgical margin at the time of prostatectomy, we found that higher Gleason grade at the margin was associated with worse oncologic outcomes.     

Screening for Prostate Cancer Decreases the Risk of Developing Metastatic Disease: Findings from the European Randomized Study of Screening for Prostate Cancer (ERSPC)

Background

Metastatic disease is a major morbidity of prostate cancer (PCa). Its prevention is an important goal.

Objective

To assess the effect of screening for PCa on the incidence of metastatic disease in a randomized trial.

Design, setting, and participants

Data were available for 76 813 men aged 55–69 yr coming from four centers of the European Randomized Study of Screening for Prostate Cancer (ERSPC). The presence of metastatic disease was evaluated by imaging or by prostate-specific antigen (PSA) values >100 ng/ml at diagnosis and during follow-up.

Intervention

Regular screening based on serum PSA measurements was offered to 36 270 men randomized to the screening arm, while no screening was provided to the 40 543 men in the control arm.

Outcome measurements and statistical analysis

The Nelson-Aalen technique and Poisson regression were used to calculate cumulative incidence and rate ratios of M+ disease.

Results and limitations

After a median follow-up of 12 yr, 666 men with M+ PCa were detected, 256 in the screening arm and 410 in the control arm, resulting in cumulative incidence of 0.67% and 0.86% per 1000 men, respectively (p < 0.001). This finding translated into a relative reduction of 30% (hazard ratio [HR]: 0.70; 95% confidence interval [CI], 0.60–0.82; p = 0.001) in the intention-to-screen analysis and a 42% (p = 0.0001) reduction for men who were actually screened. An absolute risk reduction of metastatic disease of 3.1 per 1000 men randomized (0.31%) was found. A large discrepancy was seen when comparing the rates of M+ detected at diagnosis and all M+ cases that emerged during the total follow-up period, a 50% reduction (HR: 0.50; 95% CI, 0.41–0.62) versus the 30% reduction. The main limitation is incomplete explanation of the lack of an effect of screening during follow-up.

Conclusions

PSA screening significantly reduces the risk of developing metastatic PCa. However, despite earlier diagnosis with screening, certain men still progress and develop metastases.The ERSPC trial is registered under number ISRCTN49127736.     

Alcohol Intake Increases High-grade Prostate Cancer Risk Among Men Taking Dutasteride in the REDUCE Trial

Background

Although most studies found no association between alcohol intake and prostate cancer (PCa) risk, an analysis of the Prostate Cancer Prevention Trial found that high alcohol intake significantly increased PCa risk among men randomized to the 5α-reductase inhibitor (5-ARI) finasteride.

Objective

Determine whether alcohol affects PCa risk among men taking the 5-ARI dutasteride.

Design, settings, and participants

Reduction by Dutasteride of Prostate Cancer Events was a 4-yr, multicenter, randomized, double-blind, placebo-controlled trial to compare PCa after dutasteride administration (0.5 mg/d) with placebo. Participants had a baseline prostate-specific antigen between 2.5 and 10.0 ng/ml and a recent negative prostate biopsy. Alcohol intake was determined by baseline questionnaire, and participants underwent a prostate biopsy to determine PCa status at 2 yr and 4 yr of follow-up.

Outcome measurements and statistical analysis

Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between alcohol intake and low-grade (Gleason <7) and high-grade (Gleason >7) PCa.

Results and limitations

Of 6374 participants in our analysis, approximately 25% reported no alcohol consumption, 49% were moderate drinkers (one to seven drinks per week), and 26% were heavy drinkers (more than seven drinks per week). Alcohol intake was not associated with low- or high-grade PCa in the placebo arm and was not associated with low-grade PCa among men taking dutasteride. In contrast, men randomized to dutasteride and reporting more than seven drinks per week were 86% more likely to be diagnosed with high-grade PCa (p = 0.01). Among alcohol abstainers, dutasteride was associated with significantly reduced risk of high-grade PCa (OR: 0.59; 95% CI, 0.38–0.90), but dutasteride was no longer associated with reduced high-grade PCa among men reporting high alcohol intake (OR: 0.99; 95% CI, 0.67–1.45).

Conclusions

Alcohol consumption negated a protective association between dutasteride and high-grade PCa.

Patient summary

We confirmed a prior study that alcohol affects PCa prevention in patients taking 5-ARIs. Patients taking 5-ARIs may wish to eliminate alcohol intake if they are concerned about PCa.     

The Effect of Benign Lower Urinary Tract Symptoms on Subsequent Prostate Cancer Testing and Diagnosis

Background

Lower urinary tract symptoms (LUTS) are common and have been associated with the subsequent diagnosis of prostate cancer (PCa) in population cohorts.

Objective

To determine whether the association between LUTS and PCa is due to the intensity of PCa testing after LUTS diagnosis.

Design, setting, and participants

We prospectively followed a representative, population-based cohort of 1922 men, aged 40–79 yr, from 1990 until 2010 with interviews, questionnaires, and abstracting of medical records for prostate outcomes. Men were excluded if they had a previous prostate biopsy or PCa diagnosis. Self-reported LUTS was defined as an American Urological Association symptom index score >7 (n = 621). Men treated for LUTS (n = 168) were identified from review of medical records and/or self report. Median follow-up was 11.8 yr (interquartile range: 10.7–12.3).

Outcome measurements and statistical analysis

Associations between self-reported LUTS, or treatment for LUTS, and risk of subsequent prostate biopsy and PCa were estimated using Cox proportional hazard models.

Results and limitations

Fifty-five percent of eligible men enrolled in the study. Men treated for LUTS were more likely to undergo a prostate biopsy (hazard ratio [HR]: 2.4; 95% confidence interval [CI], 1.7–3.3). Men younger than 65 yr who were treated for LUTS were more likely to be diagnosed with PCa (HR: 2.3, 95% CI, 1.5–3.5), while men aged >65 yr were not (HR: 0.89, 95% CI, 0.35–1.9). Men with self-reported LUTS were not more likely to be biopsied or diagnosed with PCa. Neither definition of LUTS was associated with subsequent intermediate- to high-risk cancer. The study is limited by lack of histologic or prostate-specific antigen level data for the cohort.

Conclusions

These results indicate that a possible cause of the association between LUTS and PCa is increased diagnostic intensity among men whose LUTS come to the attention of physicians. Increased symptoms themselves were not associated with intensity of testing or diagnosis.     

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

Background

Urinary prostate cancer gene 3 (PCA3) represents a promising novel marker of prostate cancer detection.

Objective

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.

Design, setting, and participants

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.

Measurements

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.

Results and limitations

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.

Conclusions

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.