Evidence for a biopsy derived grade artifact among larger prostate glands

Risk factors for Gleason score upgrade from prostate biopsy to radical prostatectomy

Accurate identification of prostate cancer Gleason grade group remains an important component of the initial management of clinically localized disease. However, Gleason score upgrading (GSU) from biopsy to radical prostatectomy can occur in up to a third of patients treated with surgery. Concern for disease undergrading remains a source of diagnostic uncertainty, contributing to both over-treatment of low-risk disease as well as under-treatment of higher-risk prostate cancer. This review examines the published literature concerning risk factors for GSU from time of biopsy to prostatectomy final pathology. Risk factors identified for Gleason upgrading include patient demographic and clinical factors including age, body mass index, race, prostate volume, and biomarker based assays, including prostate-specific antigen (PSA) density, and testosterone values. In addition, prostate magnetic resonance imaging (MRI) findings have also been associated with GSU. Biopsy-specific characteristics associated with GSU include lower number of biopsy cores and lack of targeted methodology, and possibly increasing percent biopsy core positivity. Recognition of risk factors for disease undergrading may prompt confirmatory testing including repeat sampling or imaging. Continued refinements in imaging guided biopsy techniques may also reduce sampling error contributing to undergrading.

Comparing histology between prostate cognitive fusion targeted biopsy and radical prostatectomy: exploring risk factors of Gleason score upgrading in Chinese patients

PURPOSE

To explore and identify the relevant clinical and pathological predictors leading to biopsy Gleason score upgrading (GSU) in cognitive fusion targeted biopsy (COG-TB) in Chinese patients.

METHODS

Clinical and pathological information of 496 patients who underwent COG-TB and radical prostatectomy (RP) in our hospital from January 2020 to September 2023 were retrospectively compiled and analyzed. In this study, we screened valuable predictors through univariable and multivariable logistic regression analyses and then constructed predictive models. We draw nomograms to visualize the predictive models. In addition, the discriminatory power of the model was assessed using receiver operating characteristic (ROC) curves. Finally, calibration curves and decision curve analysis (DCA) were used to evaluate the predictive power of the model and the net benefits it could deliver.

RESULTS

Out of the 496 patients eligible for the study, 279 had a consistent Gleason score (GS) on biopsy and postoperative GS, 191 experienced GSU, and 26 experienced downgrading. Significant associations for GSU were identified for five risk factors through multivariable logistic regression analyses, which included age, prostate volume, BMI, tumor percentage in biopsy tissue, and tumor location. Our model had excellent discriminatory power through ROC analysis. Calibration curves and DCA showed that our model was well calibrated and provided certain benefits for patient treatment decisions.

CONCLUSION

Age, prostate volume, BMI, tumor percentage in biopsy tissue, and tumor location are risk indicators for predicting GSU in COG-TB. Our prediction model is more suitable for Chinese patients and can assist in accurately evaluating biopsy GS and developing effective treatment plans.

5-Alpha Reductase Inhibitor Use and Prostate Cancer Prevention: A Victim of the Times?

Vaselkiv and colleagues present strong evidence of the long-term safety of 5-alpha reductase inhibitor (5-ARI) use. They demonstrated no association with developing advanced prostate cancer, nor dying of prostate cancer. This commentary covers the strengths and weaknesses of the article, and highlights the long and vacillating journey 5-ARIs and prostate cancer prevention have traveled. As 5-ARIs preferentially prevent low-grade prostate cancer, a fact confirmed in the study by Vaselkiv and colleagues, this commentary highlights how 5-ARI chemoprevention may be irrelevant now. With increasing use of active surveillance for low-grade prostate cancers found, and prebiopsy MRI and biomarkers shifting focus to only find those clinically significant cancers, it maybe that 5-ARIs are a victim of the times in their chemoprevention role. See related article by Vaselkiv et al., p. 1460.

Comparison of PI-RADS Versions 2.0 and 2.1 for MRI-based Calculation of the Prostate Volume

RATIONALE AND OBJECTIVES

Prostate gland volume (PGV) should be routinely included in MRI reports of the prostate. The recently updated Prostate Imaging Reporting and Data System (PI-RADS) version 2.1 includes a change in the recommended measurement method for PGV compared to version 2.0. The purpose of this study was to evaluate the agreement of MRI-based PGV calculations with the volumetric manual slice-by-slice prostate segmentation as a reference standard using the linear measurements per PI-RADS versions 2.0 and 2.1. Furthermore, to assess inter-reader agreement for the different measurement approaches, determine the influence of an enlarged transition zone on measurement accuracy and to assess the value of the bullet formula for PGV calculation.

MATERIALS AND METHODS

Ninety-five consecutive treatment-naive patients undergoing prostate MRI were retrospectively analyzed. Prostates were manually contoured and segmented on axial T2-weighted images. Four different radiologists independently measured the prostate in three dimensions according to PI-RADS v2.0 and v2.1, respectively. MRI-based PGV was calculated using the ellipsoid and bullet formulas. Calculated volumes were compared to the reference manual segmentations using Wilcoxon signed-rank test. Inter-reader agreement was calculated using intraclass correlation coefficient (ICC).

RESULTS

Inter-reader agreement was excellent for the ellipsoid and bullet formulas using PI-RADS v2.0 (ICC 0.985 and 0.987) and v2.1 (ICC 0.990 and 0.994), respectively. The median difference from the reference standard using the ellipsoid formula derived PGV was 0.4 mL (interquartile range, -3.9 to 5.1 mL) for PI-RADS v2.0 (p = 0.393) and 2.6 mL (interquartile range, -1.6 to 7.3 mL) for v2.1 (p < 0.001) with a median difference of 2.2 mL. The bullet formula overestimated PGV by a median of 13.3 mL using PI-RADS v2.0 (p < 0.001) and 16.0 mL using v2.1 (p < 0.001). In the presence of an enlarged transition zone the PGV tended to be higher than the reference standard for PI-RADS v2.0 (median difference of 4.7 mL; p = 0.018) and for v2.1 (median difference of 5.7 mL, p < 0.001) using the ellipsoid formula.

CONCLUSION

Inter-reader agreement was excellent for the calculated PGV for both methods. PI-RADS v2.0 measurements with the ellipsoid formula yielded the most accurate volume estimates. The differences between PI-RADS v2.0 and v2.1 were statistically significant although small in absolute numbers but may be of relevance in specific clinical scenarios like prostate-specific antigen density calculation. These findings validate the use of the ellipsoid formula and highlight that the bullet formula should not be used for prostate volume estimation due to systematic overestimation.

Any Correlation Between Prostate Volume and Incidence of Prostate Cancer: A Review of Reported Data for the Last Thirty Years

PURPOSE

Prostate cancer (PCa) is the most common non-skin cancer in men worldwide and more than 80% of men with PCa also have histo-anatomical findings of benign prostate hyperplasia (BPH). It is well documented that BPH develops in the transition zone (TZ), whereas 80-85% of PCa originates in the peripheral zone (PZ) of the prostate. Possible causal links between both disease entities are controversially discussed in the current literature. Some studies have reported that larger prostates have a decreased incidence of PCa compared to smaller prostates. The purpose of this systematic review is to comprehensively summarize studies analyzing any association between prostate gland volume and incidence of PCa.

METHODS

A thorough literature review was performed between 01.01.1990 through 02.28.2020 using PubMed and applying the "PRISMA" guidelines. Inclusion and exclusion criteria were defined.

RESULTS

Our systematic review found 41 articles reporting an inverse (negative) relationship between prostate gland volume and incidence of prostate cancer. Sample sizes ranged from 114 to 6692 patients in these single institutional and multi-institutional studies. Thirty-nine (95%) of the 41 articles showed a statistically significant inverse relationship. In our search, no study was found showing a positive correlation between BPH size and the incidence of PCa.

CONCLUSION

To our knowledge, this is the first systematic review on the important clinical question of interaction between prostate size and the incidence of PCa. The results are demonstrating an inverse relationship, and therefore reveal strong evidence that large prostates may be protective of PCa when compared to smaller prostates.

Can Prostate-Specific Antigen Density Be an Index to Distinguish Patients Who Can Omit Repeat Prostate Biopsy in Patients with Negative Magnetic Resonance Imaging?

Purpose

We evaluated the negative predictive value (NPV) of multiparametric magnetic resonance imaging (mpMRI) in detecting clinically significant prostate cancer (csPCa) according to biopsy setting and prostate-specific antigen density (PSAD) using transperineal template-guided saturation prostate biopsy (TPB) as the reference standard.

Methods

A total of 161 patients with biopsy histories and negative pre-biopsy mpMRI (Prostate Imaging Reporting and Data System version 2 scores of less than 3) participated in the study. TPB was performed on the following indications: “prior negative biopsy” in patients with persistent suspicion of prostate cancer (n = 91) or “confirmatory biopsy” in patients who were candidates for active surveillance (n = 70). The csPCa was defined as a Gleason score of 3 + 4 or greater. We calculated the NPV of mpMRI in detecting csPCa according to biopsy history and prostate-specific antigen density (PSAD) and conducted a logistic regression analysis to determine the clinical predicator for the absence of csPCa.

Results

The detection rate of csPCa was 5.5% in the prior negative biopsy group and 14.3% in the confirmatory biopsy group (P = 0.057). None of the variables in the logistic regression models including PSAD <0.15 ng/mL/cc and prior negative biopsy could predict the absence of csPCa. The NPV of mpMRI in detecting csPCa in patients with a prior negative biopsy worsen from 94.5% to 93.3% when combined with PSAD <0.15 ng/mL/cc.

Conclusion

Patients with negative mpMRI findings may not omit repeat biopsy even if their prior biopsy histories are negative and PSADs are <0.15 ng/mL/cc.

The impact of 5-alpha-reductase inhibitors on mortality in a prostate cancer chemoprevention setting: a meta-analysis

PURPOSE

This study aims to evaluate the impact of 5-alpha-reductase inhibitors (5ARI) for prostate cancer (PCa) primary prevention on specific and overall mortality (primary outcomes), the incidence of PCa diagnosis and disease aggressiveness (secondary outcomes).

METHODS

We searched MEDLINE, EMBASE, Cochrane, ClinicalTrials and BVS through April 2018 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement to identify randomized clinical trials (RCT) and cohort studies (CS). We included articles with data on mortality or PCa incidence for men using 5ARI previously to PCa diagnosis.

RESULTS

Regarding the included studies, nine had data on mortality, 16 on PCa incidence and 12 on Gleason scores (GS). We found that the use of 5ARI had no impact on overall mortality (RR 0.93 95% CI 0.78-1.11) and PCa-related mortality (RR 1.35 95% CI 0.50-3.94), nor on high-grade PCa diagnosis (RR 1.06 95% CI 0.72-1.56). We identified a relative risk reduction of 24% in moderate-grade PCa diagnosis (RR 0.76 95% CI 0.59-0.98) and low-grade PCa diagnosis (RR 0.76 95% CI 0.59-0.97) Also, a reduction of 26% in overall PCa diagnosis was observed in the RCT subgroup analysis (RR 0.74 95% CI 0.65-0.84).

CONCLUSION

5ARI significantly reduced the risk of being diagnosed with PCa, not increasing high-grade disease, overall or cancer-specific mortality. Due to the relatively short mean follow-up of most studies, the mortality analysis is limited.

Development and validation of a novel multivariate risk score to guide biopsy decision for the diagnosis of clinically significant prostate cancer

Objectives

Selecting patients suspected of having prostate cancer (PCa) for a prostate biopsy remains a challenge. Prostate-specific antigen (PSA)-based testing is hampered by its low specificity that often leads to negative biopsy results or detection of clinically insignificant cancers, especially in the 2-10 ng/mL range. The objective was to evaluate a novel diagnostic test called Proclarix incorporating thrombospondin-1 and cathepsin D alongside total and free PSA as well as age for predicting clinically significant PCa.

Patients and methods

The test was developed following a retrospective study design using biobanked samples of 955 men from two reference centres. A multivariate approach was used for model development followed by validation to discriminate significant (grade group ≥2) from insignificant or no cancer at biopsy. The test specificity, positive predictive value (PPV) and negative predictive value (NPV) at a fixed sensitivity of 90% were compared to percent free PSA (%fPSA) alone. The number of avoidable prostate biopsies deemed to be representative of clinical utility was also assessed.

Results

In the targeted patient population, the test displayed increased diagnostic accuracy compared to %fPSA alone. Application of the established model on 955 patients at a fixed sensitivity of 90% for significant disease resulted in a specificity of 43%, NPV of 95% and a PPV of 25%. This is in comparison to a specificity of 17%, NPV of 89% and PPV of 19% for %fPSA alone and had the potential to reduce the total number of biopsies needed to identify clinically significant cancer. Further, the test score correlated with significance of cancer assessed on prostate biopsy.

Conclusions

The Proclarix test can be used as an aid in the decision-making process if to biopsy men in this challenging patient population. The use of the test could reduce the number of biopsies performed avoiding invasive procedures, anxiety, discomfort, pain and complications.

Contemporary Distribution of High-Grade Prostate Cancer in the Circumstances of Opportunistic Testing

Screening has dramatically changed the distribution of the mean age, stage and grade of prostate cancer (PCa) at diagnosis. However, regional-level data that characterize contemporary PCa patients are limited. The aim of the study was to ascertain main clinical and pathological characteristics of PCa at the present time in the circumstances of opportunistic testing.

High-grade PCa according to age, serum prostate specific antigen (PSA), volume prostate, PSA density (PSAD), digital rectal examination (DRE) number of positive cores biopsies and the average percentage of cancer in biopsy at diagnosis has been retrospectively evaluated in 100 men with biopsyproven PCa, at Clinical Centre Kragujevac, from September 2016 until September 2017. PCa were stratified according to Gleason score (GS) into low/intermediate-grade (GS ≤ 7) and high-grade (GS ≥ 8). To identify the determinants associated with high-grade PCa, we performed univariate and multivariate logistic regression.

The most prevalent PCa were the low/intermediate-grade (65%), followed by high-grade (35%). The mean age of the patients was 71.5 (range: 56–88) years and median PSA was 14.6 (range: 1.4–935) ng/ml. There were significant differences in age, PSA, PSAD, DRE, number of positive biopsy and average percentage of cancer in biopsy between patients with or without high-grade GS. Logistic analysis demonstrated the PSAD and age have strong prognostic value of high-grade PCa.

In conclusion, our study has shown the worrying frequency of high-grade PCa in the circumstances of opportunistic testing. Older men and higher level of PSAD had a much higher probability of high-grade PCa.

Multiparametric MRI to improve detection of prostate cancer compared with transrectal ultrasound-guided prostate biopsy alone: the PROMIS study

BACKGROUND

Men with suspected prostate cancer usually undergo transrectal ultrasound (TRUS)-guided prostate biopsy. TRUS-guided biopsy can cause side effects and has relatively poor diagnostic accuracy. Multiparametric magnetic resonance imaging (mpMRI) used as a triage test might allow men to avoid unnecessary TRUS-guided biopsy and improve diagnostic accuracy.

OBJECTIVES

To (1) assess the ability of mpMRI to identify men who can safely avoid unnecessary biopsy, (2) assess the ability of the mpMRI-based pathway to improve the rate of detection of clinically significant (CS) cancer compared with TRUS-guided biopsy and (3) estimate the cost-effectiveness of a mpMRI-based diagnostic pathway.

DESIGN

A validating paired-cohort study and an economic evaluation using a decision-analytic model.

SETTING

Eleven NHS hospitals in England.

PARTICIPANTS

Men at risk of prostate cancer undergoing a first prostate biopsy.

INTERVENTIONS

Participants underwent three tests: (1) mpMRI (the index test), (2) TRUS-guided biopsy (the current standard) and (3) template prostate mapping (TPM) biopsy (the reference test).

MAIN OUTCOME MEASURES

Diagnostic accuracy of mpMRI, TRUS-guided biopsy and TPM-biopsy measured by sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) using primary and secondary definitions of CS cancer. The percentage of negative magnetic resonance imaging (MRI) scans was used to identify men who might be able to avoid biopsy.

RESULTS

Diagnostic study - a total of 740 men were registered and 576 underwent all three tests. According to TPM-biopsy, the prevalence of any cancer was 71% [95% confidence interval (CI) 67% to 75%]. The prevalence of CS cancer according to the primary definition (a Gleason score of ≥ 4 + 3 and/or cancer core length of ≥ 6 mm) was 40% (95% CI 36% to 44%). For CS cancer, TRUS-guided biopsy showed a sensitivity of 48% (95% CI 42% to 55%), specificity of 96% (95% CI 94% to 98%), PPV of 90% (95% CI 83% to 94%) and NPV of 74% (95% CI 69% to 78%). The sensitivity of mpMRI was 93% (95% CI 88% to 96%), specificity was 41% (95% CI 36% to 46%), PPV was 51% (95% CI 46% to 56%) and NPV was 89% (95% CI 83% to 94%). A negative mpMRI scan was recorded for 158 men (27%). Of these, 17 were found to have CS cancer on TPM-biopsy. Economic evaluation - the most cost-effective strategy involved testing all men with mpMRI, followed by MRI-guided TRUS-guided biopsy in those patients with suspected CS cancer, followed by rebiopsy if CS cancer was not detected. This strategy is cost-effective at the TRUS-guided biopsy definition 2 (any Gleason pattern of ≥ 4 and/or cancer core length of ≥ 4 mm), mpMRI definition 2 (lesion volume of ≥ 0.2 ml and/or Gleason score of ≥ 3 + 4) and cut-off point 2 (likely to be benign) and detects 95% (95% CI 92% to 98%) of CS cancers. The main drivers of cost-effectiveness were the unit costs of tests, the improvement in sensitivity of MRI-guided TRUS-guided biopsy compared with blind TRUS-guided biopsy and the longer-term costs and outcomes of men with cancer.

LIMITATIONS

The PROstate Magnetic resonance Imaging Study (PROMIS) was carried out in a selected group and excluded men with a prostate volume of > 100 ml, who are less likely to have cancer. The limitations in the economic modelling arise from the limited evidence on the long-term outcomes of men with prostate cancer and on the sensitivity of MRI-targeted repeat biopsy.

CONCLUSIONS

Incorporating mpMRI into the diagnostic pathway as an initial test prior to prostate biopsy may (1) reduce the proportion of men having unnecessary biopsies, (2) improve the detection of CS prostate cancer and (3) increase the cost-effectiveness of the prostate cancer diagnostic and therapeutic pathway. The PROMIS data set will be used for future research; this is likely to include modelling prognostic factors for CS cancer, optimising MRI scan sequencing and biomarker or translational research analyses using the blood and urine samples collected. Better-quality evidence on long-term outcomes in prostate cancer under the various management strategies is required to better assess cost-effectiveness. The value-of-information analysis should be developed further to assess new research to commission.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN16082556 and NCT01292291.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 39. See the NIHR Journals Library website for further project information. This project was also supported and partially funded by the NIHR Biomedical Research Centre at University College London (UCL) Hospitals NHS Foundation Trust and UCL and by The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research Biomedical Research Centre and was co-ordinated by the Medical Research Council's Clinical Trials Unit at UCL (grant code MC_UU_12023/28). It was sponsored by UCL. Funding for the additional collection of blood and urine samples for translational research was provided by Prostate Cancer UK.

Computer simulations suggest that prostate enlargement due to benign prostatic hyperplasia mechanically impedes prostate cancer growth

Prostate cancer and benign prostatic hyperplasia are common genitourinary diseases in aging men. Both pathologies may coexist and share numerous similarities, which have suggested several connections or some interplay between them. However, solid evidence confirming their existence is lacking. Recent studies on extensive series of prostatectomy specimens have shown that tumors originating in larger prostates present favorable pathological features. Hence, large prostates may exert a protective effect against prostate cancer. In this work, we propose a mechanical explanation for this phenomenon. The mechanical stress fields that originate as tumors enlarge have been shown to slow down their dynamics. Benign prostatic hyperplasia contributes to these mechanical stress fields, hence further restraining prostate cancer growth. We derived a tissue-scale, patient-specific mechanically coupled mathematical model to qualitatively investigate the mechanical interaction of prostate cancer and benign prostatic hyperplasia. This model was calibrated by studying the deformation caused by each disease independently. Our simulations show that a history of benign prostatic hyperplasia creates mechanical stress fields in the prostate that impede prostatic tumor growth and limit its invasiveness. The technology presented herein may assist physicians in the clinical management of benign prostate hyperplasia and prostate cancer by predicting pathological outcomes on a tissue-scale, patient-specific basis.

Questions and answers on prostate multiparameter magnetic resonance imaging: Everything a urologist should know

CONTEXT

For many years, the detection of prostate cancer (PC) and the management of its therapy have been based primarily on prostate-specific antigen, rectal examination and prostate biopsy. However, these parameters have known limitations. Multiparametric magnetic resonance imaging (mpMRI) for prostate cancer has undergone extensive development in recent years, providing morphological and functional information. The aim of this study is to present an updated review of the scope and limitations of prostatic mpMRI for PC, in the framework of a multidisciplinary vision.

ACQUISITION OF EVIDENCE

We conducted a literature review (in PubMed) of articles referencing "mpMRI/staging/ PC/detection/active surveillance/therapy planning/post-therapy". We included 4 systematic reviews and other articles published in high impact-factor journals within the field of radiology and urology.

SUMMARY OF THE EVIDENCE

MpMRI provides morphological and functional information concerning PC. This information is integrated into the Prostate Imaging Report and Date System, classifying the probability of clinically significant carcinoma on a scale from 1 to 5. The usefulness of mpMRI is currently being established for patients with high prostate-specific antigen levels and prior negative prostate biopsy; tumour staging in selected cases; assessment of patients who are candidates for active surveillance; the planning of focal treatments; and the assessment of tumour persistence and recurrence.

CONCLUSIONS

MpMRI currently fills a relevant role in the diagnosis and therapeutic decision-making of PC. More widespread use of the technique requires a cost/benefit analysis.

Association Between Computed Tomographic Features and Kirsten Rat Sarcoma Viral Oncogene Mutations in Patients With Stage I Lung Adenocarcinoma and Their Prognostic Value

BACKGROUND

We investigated the association between computed tomographic (CT) features and Kirsten rat sarcoma viral oncogene (KRAS) mutations in patients with stage I lung adenocarcinoma and their prognostic value.

PATIENTS AND METHODS

A total of 79 patients with pathologic stage I lung adenocarcinoma, available KRAS mutational status, preoperative CT images available, and survival data were included in the present study. Seven CT features, including spiculation, concavity, ground-glass opacity, bubble-like lucency, air bronchogram, pleural retraction, and pleural attachment, were evaluated. The association among the clinical characteristics, CT features, and mutational status was analyzed using Student's t test, the χ(2) test or Fisher's exact test, and logistic regression. The association among CT features, mutational status, and overall survival was analyzed using Kaplan-Meier survival curves with the log-rank test and Cox proportional hazard regression.

RESULTS

The prevalence of KRAS mutations was 41.77%. Spiculation was significantly associated with the presence of KRAS mutations (odds ratio, 2.99; 95% confidence interval [CI], 1.16-7.68). Although KRAS mutational status was not significantly associated with overall survival, the presence of pleural attachment was associated with an increased risk of death (hazard ratio, 2.46; 95% CI, 1.09-5.53). When analyzing KRAS mutational status and pleural attachment combined, patients with wild-type KRAS and no pleural attachment had significantly better survival than did those with wild-type KRAS and pleural attachment (P = .014).

CONCLUSION

These data suggest that spiculation is associated with KRAS mutations and pleural attachment is associated with overall survival in patients with stage I lung adenocarcinoma. Combining the analysis of KRAS mutational status and CT features could better predict survival.

Age is Associated with Upgrading at Confirmatory Biopsy among Men with Prostate Cancer Treated with Active Surveillance

PURPOSE

Active surveillance is increasingly recommended for older men with low risk prostate cancer. Although older men have higher all cause mortality, they also have higher prostate cancer specific mortality. We hypothesized that older age is associated with an increased risk of Gleason score upgrading at confirmatory biopsy when controlling for prostate volume.

MATERIALS AND METHODS

We retrospectively reviewed data on 1,130 patients with prostate cancer who were treated with active surveillance from 1991 through 2011. We included 646 patients with clinical Gleason 6 or less, stage T2a or less prostate cancer, a confirmatory biopsy within 2 years of diagnostic biopsy and prostate magnetic resonance imaging before confirmatory biopsy. The primary outcome was Gleason score upgrading to 7 or greater on confirmatory biopsy. We used logistic regression to estimate the effect of age on upgrading, adjusting for magnetic resonance imaging prostate volume and other potential confounders.

RESULTS

Median age was 66 years (IQR 61-72) and median magnetic resonance imaging prostate volume was 41 ml (IQR 29-55). At confirmatory biopsy disease was upgraded in 55 of 646 patients (9%) and unchanged in 290 (45%) and biopsy was negative in 297 (46%). Older age was associated with higher odds of upgrading (adjusted OR 1.05, 95% CI 1.01-1.09, p=0.009). Larger prostate volume was associated with lower odds of upgrading (adjusted OR 0.80/10 ml increase, 95% CI 0.7-0.9, p=0.012).

CONCLUSIONS

Our findings suggest that older age is associated with an increased risk of misclassification on diagnostic biopsy. Older men who are interested in active surveillance should be counseled about the risks and benefits of confirmatory biopsy.

PROMIS--Prostate MR imaging study: A paired validating cohort study evaluating the role of multi-parametric MRI in men with clinical suspicion of prostate cancer

BACKGROUND

Transrectal ultrasound-guided prostate biopsies are prone to detection errors. Multi-parametric MRI (MP-MRI) may improve the diagnostic pathway.

METHODS

PROMIS is a prospective validating paired-cohort study that meets criteria for level 1 evidence in diagnostic test evaluation. PROMIS will investigate whether multi-parametric (MP)-MRI can discriminate between men with and without clinically-significant prostate cancer who are at risk prior to first biopsy. Up to 714 men will have MP-MRI (index), 10-12 core TRUS-biopsy (standard) and 5mm transperineal template mapping (TPM) biopsies (reference). The conduct and reporting of each test will be blinded to the others.

RESULTS

PROMIS will measure and compare sensitivity, specificity, and positive and negative predictive values of both MP-MRI and TRUS-biopsy against TPM biopsies. The MP-MRI results will be used to determine the proportion of men who could safely avoid biopsy without compromising detection of clinically-significant cancers. For the primary outcome, significant cancer on TPM is defined as Gleason grade >/= 4+3 and/or maximum cancer core length of ≥ 6 mm. PROMIS will also assess inter-observer variability among radiologists among other secondary outcomes. Cost-effectiveness of MP-MRI prior to biopsy will also be evaluated.

CONCLUSIONS

PROMIS will determine whether MP-MRI of the prostate prior to first biopsy improves the detection accuracy of clinically-significant cancer.

Prostate size and adverse pathologic features in men undergoing radical prostatectomy

OBJECTIVE

To investigate the relationship between prostate volume measured from preoperative imaging and adverse pathologic features at the time of radical prostatectomy and evaluate the potential effect of clinical stage on such relationship.

METHODS

In 1756 men who underwent preoperative magnetic resonance imaging and radical prostatectomy from 2000 to 2010, we examined associations of magnetic resonance imaging-measured prostate volume with pathologic outcomes using univariate logistic regression and with postoperative biochemical recurrence using Cox proportional hazards models. We also analyzed the effects of clinical stage on the relationship between prostate volume and adverse pathologic features via interaction analyses.

RESULTS

In univariate analyses, smaller prostate volume was significantly associated with high pathologic Gleason score (P<.0001), extracapsular extension (P<.0001), and positive surgical margins (P=.032). No significant interaction between clinical stage and prostate volume was observed in predicting adverse pathologic features (all P>.05). The association between prostate volume and recurrence was significant in a multivariable analysis adjusting for postoperative variables (P=.031) but missed statistical significance in the preoperative model (P=.053). Addition of prostate volume did not change C-Indices (0.78 and 0.83) of either model.

CONCLUSION

Although prostate size did not enhance the prediction of recurrence, it is associated with aggressiveness of prostate cancer. There is no evidence that this association differs depending on clinical stage. Prospective studies are warranted assessing the effect of initial method of detection on the relationship between volume and outcome.

5α-Reductase inhibitors and risk of high-grade or lethal prostate cancer

IMPORTANCE

5α-Reductase inhibitors (5ARIs) are widely used for benign prostatic hyperplasia despite controversy regarding potential risk of high-grade prostate cancer with use. Furthermore, the effect of 5ARIs on progression and prostate cancer death remains unclear.

OBJECTIVE

To determine the association between 5ARI use and development of high-grade or lethal prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

Prospective observational study of 38,058 men followed up for prostate cancer diagnosis and outcomes between 1996 and 2010 in the Health Professionals Follow-up Study.

EXPOSURES

Use of 5ARIs between 1996 and 2010.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards models were used to estimate risk of prostate cancer diagnosis or development of lethal disease with 5ARI use, adjusting for possible confounders including prostate specific antigen testing.

RESULTS

During 448,803 person-years of follow-up, we ascertained 3681 incident prostate cancer cases. Of these, 289 were lethal (metastatic or fatal), 456 were high grade (Gleason sum [GS] 8-10), 1238 were GS 7, and 1600 were low grade (GS 2-6). A total of 2878 (7.6%) men reported use of 5ARIs between 1996 and 2010. After adjusting for confounders, men who reported ever using 5ARIs over the study period had a reduced risk of overall prostate cancer (hazard ratio [HR], 0.77; 95% CI, 0.65-0.91). 5ARI users had a reduced risk of GS 7 (HR, 0.67; 95% CI, 0.49-0.91) and low-grade (GS 2-6) prostate cancer (HR, 0.74; 95% CI, 0.57-0.95). 5ARI use was not associated with risk of high-grade (GS 8-10) prostate cancer (HR, 0.97; 95% CI, 0.64-1.46) or lethal disease (HR, 0.99; 95% CI, 0.58-1.69). Increased duration of use was associated with significantly lower risk of overall prostate cancer (HR for 1 year of additional use, 0.95; 95% CI, 0.92-0.99), localized (HR, 0.95; 95% CI, 0.90-1.00), and low-grade disease (HR, 0.92; 95% CI, 0.85-0.99). There was no association for lethal, high-grade, or grade 7 disease.

CONCLUSIONS AND RELEVANCE

While 5ARI use was not associated with developing high-grade or lethal prostate cancer, it was associated with a reduction in low-grade, GS 7, and overall prostate cancer. Because the number of patients with high-grade or lethal prostate cancer in our cohort was limited, we cannot rule out potential risk of harm with 5ARI use.

Predicting the risk of harboring high-grade disease for patients diagnosed with prostate cancer scored as Gleason ≤ 6 on biopsy cores

PURPOSE

Biopsy and final pathological Gleason score (GS) are inconstantly correlated with each other. The aim of the current study was to develop and validate a predictive score to screen patients diagnosed with a biopsy GS ≤ 6 prostate cancer (PCa) at risk of GS upgrading.

METHODS

Clinical and pathological data of 1,179 patients managed with radical prostatectomy for a biopsy GS ≤ 6, clinical stage ≤ T2b and preoperative PSA ≤ 20 ng/ml PCa were collected. The population study was randomly split into a development (n = 822) and a validation (n = 357) cohort. A prognostic score was established using the independent factors related to GS upgrading identified in multivariate analysis. The cutoff value derived from the area under the receiver operating characteristic curve of the score.

RESULTS

After RP, the rate of GS upgrading was 56.7%. In multivariate analysis, length of cancer per core > 5 mm (OR 2.938; p < 0.001), PSA level > 15 ng/ml (OR 2.365; p = 0.01), age > 70 (OR 1.746; p = 0.016), number of biopsy cores > 12 (OR 0.696; p = 0.041) and prostate weight > 50 g (OR 0.656; CI; p < 0.007) were independent predictive factors of GS upgrading. A score ranged between -4 and 12 with a cutoff value of 2 was established. In the development cohort, the accuracy of predictive score was 63.7% and the positive predictive value was 71.2%. Results were confirmed in the validation cohort.

CONCLUSION

This predictive tool might be used to screen patients initially diagnosed with low-grade PCa but harboring occult high-grade disease.

Predictors of Gleason score upgrading in patients with prostate biopsy Gleason score ≤6

INTRODUCTION

The discrepancy between prostate biopsy and prostatectomy Gleason scores is common. We investigate the predictive value of prostate biopsy features for predicting Gleason score (GS) upgrading in patients with biopsy Gleason scores ≤6 who underwent radical retropubic prostatectomy (RRP). Our aim was to determine predictors of GS upgrading and to offer guidance to clinicians in determining the therapeutic option.

METHODS

We performed a retrospective study of patients who underwent RRP for clinically localized prostate cancer at 2 major centres between January 2007 and March 2013. All patients with either abnormal digital examination or elevated prostate-specific antigen at screening underwent transrectal ultrasound-guided prostate biopsy. Variables were evaluated among the patients with and without GS upgrading. Our study limitations include its retrospective design, the fact that all subjects were Turkish and the fact that we had a small sample size.

RESULTS

In total, 321 men had GS ≤6 on prostate biopsy. Of these, 190 (59.2%) had GS≤6 concordance and 131 (40.8%) had GS upgrading from ≤6 on biopsy to 7 or higher at the time of the prostatectomy. Independent predictors of pathological upgrading were prostate volume <40 cc (p < 0.001), maximum percent of cancer in any core (p = 0.011), and >1 core positive for cancer (p < 0.001).

CONCLUSIONS

When obtaining an extended-core biopsy scheme, patients with small prostates (≤40 cc), greater than 1 core positive for cancer, and an increased burden of cancer are associated with increased risk of GS upgrading. Patients with GS ≤6 on biopsy with these pathological parameters should be carefully counselled on treatment decisions.

Five-alpha reductase inhibitor influences expression of androgen receptor and HOXB13 in human hyperplastic prostate tissue

OBJECTIVES

Five-alpha reductase inhibitors (5ARIs) are known as chemopreventive agents in prostate cancer with a risk of high-grade disease. This study evaluated the effects of 5ARI on androgen receptor (AR) and proteins involved in prostate cell growth such as HOXB13 expression in human prostate tissue and LNCaP prostate cancer cells.

MATERIALS AND METHODS

We retrospectively selected 21 patients who underwent TURP between March 2007 and February 2010 for previously confirmed BPH by prostate biopsy. They were grouped into control (group 1, n = 9) and 5ARI treatment (group 2, n = 12) before TURP. AR and HOXB13 expression in prostate tissue was evaluated by immunohistochemical staining. We tested the effect of 5ARI on the expression of AR, prostate specific antigen (PSA) and HOXB13 in LNCaP cells. Cells were assessed by Western blot analysis, MTT in vitro proliferation assay, and ELISA.

RESULTS

Group 2 showed stronger reactivity for AR and HOXB13 than those of the group 1. MTT assay showed death of LNCaP cells at 25uM of 5ARI. At the same time, ELISA assay for PSA showed that 5ARI inhibited secretion of PSA in LNCaP cells. Western blot analysis showed that 5ARI did not greatly alter AR expression but it stimulated the expression of HOXB13.

CONCLUSIONS

These results demonstrated that 5ARI influences AR and HOXB13 expression in both LNCaP cells and human prostate tissue. In order to use 5ARI in chemoprevention of prostate cancer, we still need to clarify the influence of 5ARI in ARs and oncogenic proteins and its regulation pathway.

5-alpha reductase inhibitors in patients on active surveillance: do the benefits outweigh the risk?

Prostate cancer (PCa) is a slow, progressive disease. Prostate specific antigen testing, screening, and aggressive case identification has made PCa the most frequently diagnosed cancer. Concerns regarding overdiagnosis and overtreatment flourish on a large scale. In order to avoid overtreatment for those in whom therapeutic intervention is not required, active surveillance for eligible patients with the use of 5-alpha reductase can be considered a safe and a promising approach to delay the progression of the disease with minimal side effects.

The impact of prostate volume, number of biopsy cores and American Urological Association symptom score on the sensitivity of cancer detection using the Prostate Cancer Prevention Trial risk calculator

PURPOSE

We assessed the independent predictive value of prostate volume, number of biopsy cores and AUASS (American Urological Association symptom score) compared to risk factors included in the PCPTRC (Prostate Cancer Prevention Trial risk calculator for prostate cancer) and PCPTHG (Prostate Cancer Prevention Trial risk calculator for high grade cancer [Gleason grade 7 or greater]).

MATERIALS AND METHODS

Of 5,519 PCPT (Prostate Cancer Prevention Trial) participants used to construct the PCPTRC 4,958 with AUASS and prostate specific antigen 10 ng/ml or less were included on logistic regression analysis. Risk algorithms were evaluated in 571 EDRN (Early Detection Research Network) participants using the ROC AUC.

RESULTS

A total of 1,094 participants (22.1%) had prostate cancer, of whom 232 (21.2%) had high grade disease. For prostate cancer prediction higher prostate specific antigen, abnormal digital rectal examination, family history of prostate cancer and number of cores were associated with increased risk, while volume was associated with decreased risk. Excluding prostate volume and number of cores, a history of negative biopsy and increased AUASS were also associated with lower risk. For high grade cancer higher prostate specific antigen, abnormal digital rectal examination, black race and number of cores were associated with increased risk and volume, while AUASS was associated with decreased risk. The AUC of the PCPTRC adjusted for volume and number of cores was 72.7% (using EDRN data), 68.2% when adjusted for AUASS alone and 67.6% PCPTRC. For high grade disease the AUCs were 74.8%, 74.0% and 73.5% (PCPTHG), respectively.

CONCLUSIONS

Adjusted PCPT risk calculators for volume, number of cores and AUASS improve cancer detection.

Temporal changes in the pathologic assessment of prostate cancer

Thirty years have witnessed dramatic changes in the manner in which we diagnose and manage prostate cancer. With prostate-specific antigen screening, there was a shift towards smaller, clinically localized tumors. Tumors are often multifocal and display phenotypic and molecular heterogeneity. Pathologic evaluation of tissue obtained by needle biopsy remains the gold standard for the diagnosis and risk assessment of prostate cancer. Years of experience with grading, along with changes in the amount of biopsy tissue obtained and diagnostic tools available, have produced shifts in grading practices among genitourinary pathologists. Trends in Gleason grading and advances in pathological risk assessment are reviewed with particular emphasis on recent Gleason grading modifications of the International Society of Urologic Pathology. Efforts to maximize the amount of information from pathological specimens, whether it be morphometric, histochemical, or molecular, may improve predictive accuracy of prostate biopsies. New diagnostic techniques are needed to optimize management decisions.

Epidemiology of prostate cancer and treatment remarks

Prostate cancer is one of the most common types of cancer and one of the leading causes of cancer death among men in the Western countries. The aim of the present analysis is to assess the cancer burden in order to ensure accurate strategies for chemoprevention and treatment, including the major therapeutic approaches for localized high-risk disease - surgery and radiation therapy - and quality of life issues related to each option.

Results of a surgically derived nomogram to predict Gleason score upgrading applied to a cohort of patients with "favorable-risk" prostate cancer treated with permanent seed brachytherapy

OBJECTIVE

To examine a 2-year cohort of patients treated with brachytherapy to determine the likelihood of unfavorable pathologic features using a nomogram recently developed at our center to estimate the likelihood of Gleason score upgrading for patients with favorable prostate cancer undergoing radical prostatectomy. The brachytherapy outcomes for patients with a high likelihood of upgrading were compared with those with a lower likelihood to affirm the effectiveness of brachytherapy in this setting. Information on the likelihood of upgrading could help in the selection between active treatment and surveillance for patients with favorable-risk prostate cancer.

METHODS

The records were examined for 259 men undergoing prostate brachytherapy in 2006 to 2007, of whom 217 had favorable risk cancer. The likelihood of Gleason score upgrading (GSU) was predicted using the radical prostatectomy-derived nomogram.

RESULTS

The median age was 62 years (range 44-77), and the median prostate-specific antigen level was 4.71 ng/mL (range 0.56-9.87). Central pathology review was available for 88%, and 83% had undergone extended biopsies. Two men had received androgen deprivation therapy for prostate downsizing. The median predicted likelihood of GSU was 51.2%. The median prostate-specific antigen level for 199 patients without treatment failure after a median follow-up of 4.2 years in this cohort was 0.07 ng/mL (interquartile range undetectable to 0.23).

CONCLUSION

In the present cohort of patients with favorable-risk prostate cancer treated with brachytherapy, the estimated likelihood of GSU using the surgically derived nomogram was substantial. Follow-up with prostate-specific antigen measurement has indicated that brachytherapy is a highly effective treatment option despite less favorable clinical and pathologic factors. Patients should not be discouraged from brachytherapy on the basis of a high likelihood of GSU.

Smaller prostate gland size and older age predict Gleason score upgrading

OBJECTIVES

Gleason score is important for prostate cancer (CaP) risk stratification and prognostication but has a significant rate of upgrading. We examined the effect of prostate size and age on upgrading of Gleason 6 CaP.

MATERIALS AND METHODS

A retrospective review was performed of patients with Gleason 6 CaP who underwent radical prostatectomy from 2001 through 2010. Preoperative clinical and pathologic variables were assessed to determine association with risk of upgrading at prostatectomy.

RESULTS

A total of 1,836 patients were identified with Gleason 6 on prostate biopsy. Upgrading was observed in 543 (29.6%) patients with a final Gleason score of 3+4 in 463 (25.2%), 4+3 in 49 (2.7%), and 8-10 in 31 (1.7%). On univariate logistic regression, age, prostate weight, and PSA were significant predictors of Gleason score upgrading and remained significant on multiple logistic regression. Prostate weight was inversely related to risk of upgrading. To further explore this effect, we performed multiple logistic regression to examine risk of Gleason 6, 7, or 8-10 disease in 2,493 patients with Gleason 6-10 at prostatectomy. After controlling for age and PSA, there was a progressively increased risk of Gleason 6, 7, and 8-10 disease with decreasing prostate weight.

CONCLUSIONS

Older age, higher PSA, and smaller prostate gland size are associated with increased risk of Gleason score upgrading. The inverse relationship of prostate weight to risk of Gleason upgrading may be related to increased high-grade disease in smaller glands.

Prostate size as a predictor of Gleason score upgrading in patients with low risk prostate cancer

PURPOSE

Gleason score upgrading between biopsy and surgical pathological specimens occurs in 30% to 50% of cases. Predicting upgrading in men with low risk prostate cancer may be particularly important since high grade disease influences management decisions and impacts prognosis. We determined whether prostate size predicts Gleason score upgrading in patients with low risk prostate cancer.

MATERIALS AND METHODS

A total of 1,251 consecutive patients with D'Amico low risk disease and complete data available underwent radical prostatectomy at our institution between January 2000 and June 2008. Patients were divided into 3 groups by pathological Gleason score, including no, minor (3 + 4 = 7) and major (4 + 3 = 7 or greater) Gleason score upgrading. We developed bivariate and multivariate models to determine whether prostate size was an important predictor of upgrading while controlling for clinical and biopsy characteristics.

RESULTS

Of 1,251 cases 387 (31.0%) were upgraded, including 324 (26%) and 63 (5%) with minor and major upgrading, respectively. As expected, Gleason score upgrading was associated with worse pathological and cancer control outcomes. On multivariate analysis smaller prostate size was an independent predictor of any and major upgrading (OR 0.58, 95% CI 0.48-0.69, p <0.01 and OR 0.67, 95% CI 0.49-0.96, p = 0.03, respectively). Men with prostate volume at the 25th percentile (36 cm(3)) were 50% more likely to experience upgrading than men with prostate volume at the 75th percentile (58 cm(3)).

CONCLUSIONS

Of low risk cases 31% were upgraded at final pathology. Smaller prostate size predicts Gleason score upgrading in men with clinically low risk prostate cancer. This is important information when counseling patients on management and prognosis.

5-α reductase inhibitors and prostate cancer prevention: where do we turn now?

With the lifetime risk of being diagnosed with prostate cancer so great, an effective chemopreventive agent could have a profound impact on the lives of men. Despite decades of searching for such an agent, physicians still do not have an approved drug to offer their patients. In this article, we outline current strategies for preventing prostate cancer in general, with a focus on the 5-α-reductase inhibitors (5-ARIs) finasteride and dutasteride. We discuss the two landmark randomized, controlled trials of finasteride and dutasteride, highlighting the controversies stemming from the results, and address the issue of 5-ARI use, including reasons why providers may be hesitant to use these agents for chemoprevention. We further discuss the recent US Food and Drug Administration ruling against the proposed new indication for dutasteride and the change to the labeling of finasteride, both of which were intended to permit physicians to use the drugs for chemoprevention. Finally, we discuss future directions for 5-ARI research.

Finasteride upregulates expression of androgen receptor in hyperplastic prostate and LNCaP cells: implications for chemoprevention of prostate cancer

BACKGROUND

Although finasteride is recognized for its role as a chemopreventive agent for prostate cancer, higher grades of malignancy have been reported. It is questioned whether blocking of testosterone conversion to dihydrotestosterone (DHT) by finasteride in prostate tissue will change expression of androgen receptor (AR). Therefore, this study evaluated the effects of finasteride on AR expression in prostate tissue and in the LNCaP cell line.

METHODS

Between January and December 2006, we retrospectively selected and evaluated 47 cases of benign prostatic hyperplasia treated with variable duration of finasteride (5 mg QD) before transurethral resection of the prostate. AR expression in prostate tissue was semiquantified by immunostaining and compared with duration of finasteride treatment. An androgen-dependent prostate cancer cell line (LNCaP) was cultured in charcoal/dextran-treated FBS with DHT or testosterone, and treated with finasteride for 1-3 weeks. Samples of total RNA were collected to analyze expression of AR by real-time quantitative reverse transcription polymerase chain reaction.

RESULTS

Immunohistochemical study revealed significant upregulation of ARs by finasteride treatment for 30-180 days. In cell line study, quantitative real-time reverse transcription polymerase chain reaction revealed significant upregulation of ARs treated by finasteride.

CONCLUSIONS

In our study, finasteride influenced AR expression in benign prostate tissue and prostate cancer cell. Before we can use finasteride in chemoprevention with confidence, we still need to clarify the influence of finasteride in ARs and its regulation pathway.

Molecular targets of phytochemicals for cancer prevention

Although successful for a limited number of tumour types, the efficacy of cancer therapies, especially for late-stage disease, remains poor overall. Many have argued that this could be avoided by focusing on cancer prevention, which has now entered the arena of targeted therapies. During the process of identifying preventive agents, dietary phytochemicals, which are thought to be safe for human use, have emerged as modulators of key cellular signalling pathways. The task now is to understand how these chemicals perturb these pathways by modelling their interactions with their target proteins.

Impact of 5α-reductase inhibitors on men followed by active surveillance for prostate cancer

BACKGROUND

In two large randomized controlled trials, 5α-reductase inhibitors (5-ARIs) were shown to prevent prostate cancer. No prior work had shown the effect of 5-ARIs on those already diagnosed with low-risk prostate cancer.

OBJECTIVE

Our aim was to determine the effect of 5-ARIs on pathologic progression in men on active surveillance.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a single-institution retrospective cohort study comparing men taking a 5-ARI versus no 5-ARI while on active surveillance for prostate cancer.

MEASUREMENTS

Pathologic progression was evaluated and defined as Gleason score >6, maximum core involvement >50%, or more than three cores positive on a follow-up prostate biopsy. Kaplan-Meier analyses were conducted along with multivariable Cox proportional hazard regression modeling for predictors of pathologic progression.

RESULTS AND LIMITATIONS

A total of 288 men on active surveillance met the inclusion criteria. The median follow-up was 38.5 mo (interquartile range: 23.6-59.4) with 93 men (32%) experiencing pathologic progression and 96 men (33%) abandoning active surveillance. Men taking a 5-ARI experienced a lower rate of pathologic progression (18.6% vs 36.7%; p=0.004) and were less likely to abandon active surveillance (20% vs 37.6%; p=0.006). On multivariable Cox proportional hazards analysis, lack of 5-ARI use was most strongly associated with pathologic progression (hazard ratio: 2.91; 95% confidence interval, 1.5-5.6). The main study limitation was the retrospective design and variable duration of 5-ARI therapy.

CONCLUSIONS

The 5-ARIs were associated with a significantly lower rate of pathologic progression and abandonment of active surveillance.

Predicting prostate biopsy outcome: artificial neural networks and polychotomous regression are equivalent models

INTRODUCTION

Complex statistical models utilizing multiple inputs to derive a risk assessment may benefit prostate cancer (PC) detection where focus has been on prostate-specific antigen (PSA). This study develops a polychotomous logistic regression (PR) model and an artificial neural network (ANN) for predicting biopsy results, particularly for clinically significant PC.

METHODS

There were 3,025 men undergoing TRUS-guided biopsy (BX) with PSA <10 ng/ml selected. BX outcome classified as benign, atypical small acinar proliferation or high-grade prostatic intraepithelial neoplasia (ASAP/PIN), non-significant (NSPC) or clinically significant PC (CSPC). PR and ANN models were developed to distinguish between BX categories. Predictors were age, PSA, abnormal digital rectal examination (DRE), positive transrectal ultrasound (TRUS) and prostate volume.

RESULTS

Among the BXs, 44% were benign, 14% ASAP/PIN, 16% NSPC and 25% CSPC. Median age, PSA and volume were 64 years, 5.7 ng/ml and 50 cc. TRUS lesion was present in 47%, and DRE was abnormal in 39%. PR and ANN models did not differ on percentage BX outcomes correctly predicted (55, 57%, respectively) and were equally poor for both ASAP/PIN (0%) and NSPC (2%). For PR and ANN, 74-78% ASAP/PIN predicted benign, 2% NSPC and 20-24% CSPC. For NSPC, 69-71% predicted benign, 27-29% CSPC. Benign outcomes were well identified (86-88%), although 12-13% classified CSPC. CSPC was correctly identified in 65-66% with misclassifications largely benign (33% for PR and ANN).

CONCLUSIONS

Neither PR nor ANN was able to distinguish between the four biopsy outcomes: ASAP/PIN and NSPC were not distinguished from benign or CSPC. ANN did not perform better than PR. Inclusion of additional predictors may increase the performance of statistical models in predicting BX outcome.

Obesity, endogenous hormone metabolism, and prostate cancer risk: a conundrum of "highs" and "lows"

This perspective on the report by Neuhouser et al. (beginning on page 279 in this issue of the journal) examines the associations that have been observed between body mass index, serum insulin, preexisting diabetes, androgen metabolism, and prostate cancer risk. Based on data of the Prostate Cancer Prevention Trial, the observations by Neuhouser et al. plus findings from other studies suggest a complex mix of higher and lower risks for high- and low-grade cancer in association with obesity and endogenous hormone metabolism.

Finasteride to prevent prostate cancer: should all men or only a high-risk subgroup be treated?

PURPOSE Finasteride has been shown to reduce the incidence of prostate cancer. Yet the use of finasteride remains low, likely because of the risk of adverse effects. We sought to determine whether prostate-specific antigen (PSA) levels could identify a high-risk subgroup for which the benefits of finasteride treatment outweigh the potential harms. PATIENTS AND METHODS Raw data from the Prostate Cancer Prevention Trial were used to model chemopreventive treatment strategies: treat all men, treat no men, or treat a high-risk subgroup based on PSA level. We weighted the benefits (reduction in cancer rate) and harms (treatment rate) of each strategy using numbers-needed-to-treat thresholds-the maximum number of men a clinician would treat with finasteride to prevent one cancer. Results Of 9,058 men, 1,957 were diagnosed with prostate cancer during the 7-year study. For the end point of all cancers, including both for-cause and end-of-study biopsies, the optimal strategy is to treat all or nearly all men. To reduce risk of cancers detected through routine care, treating men with PSA > 1.3 or > 2 ng/mL is optimal. For example, treating only men with PSA > 2 ng/mL reduced the treatment rate by 83% and resulted in a cancer rate only 1.1% higher than treating all men. CONCLUSION Clinicians wishing to reduce the risk of any biopsy-detectable prostate cancer should recommend finasteride to all men. Clinicians who believe that it is unnecessary to prevent all cancers, but that preventing those readily detectable by screening would be desirable, would be best off recommending finasteride only to a high-risk subgroup.

Reduction in the risk of prostate cancer: future directions after the Prostate Cancer Prevention Trial

The landmark Prostate Cancer Prevention Trial (PCPT) generated interest in the potential health benefits and cost of reducing prostate cancer risk--specifically, the potential role of 5alpha-reductase inhibitors. However, the PCPT raised several unanswered questions, including the cause and significance of the increased incidence of high-grade tumors associated with finasteride. In the present study, we review the PCPT findings and unanswered questions, next steps in this field, and ongoing prostate cancer prevention trials addressing these unanswered questions. Particular emphasis is placed on the design of the second large-scale trial of a 5alpha-reductase inhibitor, the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial.

Is it time to consider a role for MRI before prostate biopsy?

The use of MRI in prostate cancer management is controversial and current guidelines underplay its role. Technological advances over the past 5 years, however, demand a re-evaluation of this position. In this article, we propose an increased use of MRI, not only in those with a diagnosis of prostate cancer but also for men before a prostate biopsy. The use of MRI before a biopsy can serve as a triage test in men with raised serum prostate-specific antigen levels, in order to select those for biopsy with significant cancer that requires treatment. This strategy could avoid biopsy, and hence unnecessary treatment, in those with no disease or insignificant cancer. In addition, avoidance of postbiopsy artifact caused by hemorrhage will lead to better local staging accuracy, while determining more accurately the disease burden. This approach could improve risk stratification by selecting those who require adjuvant therapy or dose escalation. Furthermore, MRI evaluation of cancer burden could be important in active surveillance regimens to select those needing intervention.

Cancer prevention research - then and now

Throughout history, humankind has won the battle against deadly diseases, including small pox and polio, by defeating them through prevention. Cancer prevention is a global priority, but studying history suggests that the journey towards achieving this goal is difficult and full of detours and roadblocks. Epidemiology and clinical evidence clearly indicate that specific genetic, environmental and behavioural factors are associated with an increased risk for cancer development. What can we learn from the past that is applicable to the reality of successful cancer prevention?

Gleason grading controversies: what the chemoprevention trials have taught us

The recent Prostate Chemoprevention Trial (PCPT), which assessed the efficacy of finasteride in reducing prostate cancer incidence, showed promising results. However, patients who developed cancer had higher Gleason scores than those on placebo. Moreover, recent evidence has shown that the biopsy Gleason scores in patients on finasteride were actually more accurate compared with patients on placebo when matched with the final, radical prostatectomy (RP) scores. This accuracy was due to a reduction in prostate volume induced by the drug, and better performance of prostate-specific antigen correlation for identifying men with high-grade cancer. Re-evaluation of the results based on the pathology of the RP specimens and longer follow-up showed a 30% reduction in cancer incidence with finasteride and no significant differences in Gleason scores compared with placebo.

A broader role for 5ARIs in prostate disease? Existing evidence and emerging benefits

5ARIs are recommended for men who have moderate-to-severe lower urinary tract symptoms (LUTS) and benign prostatic enlargement (BPE) secondary to benign prostatic hyperplasia. Studies have confirmed the utility of combining 5ARIs with alpha-blockers; the MTOPS study showed that risk of overall clinical progression was significantly reduced after 4.5 years with combination therapy (finasteride/doxazosin) in comparison with either monotherapy, while the ongoing CombAT trial (dutasteride/tamsulosin) has for the first time shown benefit in improving symptoms for combination therapy over monotherapies within 12 months of treatment. Data also suggest roles for 5ARIs in prostate cancer. Several studies indicate that treatment with a 5ARI improves the performance of PSA testing for identifying men with prostate cancer, while the PCPT showed a significant reduction in the risk of developing prostate cancer with finasteride. However, widespread use of finasteride in this setting has been tempered by an apparent increase in high-grade disease observed in the study. The ongoing REDUCE study will provide further insight into prostate cancer prevention with 5ARIs. 5ARI-containing regimens may have utility as less aggressive treatment options for patients who only have rising PSA after definitive local therapy, and in patients with disease resistant to androgen deprivation therapy who have PSA progression. Current evidence therefore shows that 5ARIs are effective in treating LUTS/BPE and preventing disease progression, and may also have a role in the prevention of prostate cancer. The overlap between BPE and prostate cancer may allow a more unified approach to managing these conditions, with 5ARIs having a central role.