Overdiagnosis and overtreatment of prostate cancer

Confirmatory biopsy for the assessment of prostate cancer in men considering active surveillance: reference centre experience

OBJECTIVES

To evaluate how accurate a 12-core transrectal biopsy derived low-risk prostate cancer diagnosis is for an active surveillance programme by comparing the histological outcome with that from confirmatory transperineal sector biopsy.

SUBJECTS AND METHODS

The cohort included 166 men diagnosed with low volume Gleason score 3+3 prostate cancer on initial transrectal biopsy who also underwent a confirmatory biopsy. Both biopsy techniques were performed according to standard protocols and samples were taken for histopathology analysis. Subgroup analysis was performed according to disease severity at baseline to determine possible disease parameters of upgrading at confirmatory biopsy.

RESULTS

After confirmatory biopsy, 34% demonstrated Gleason score upgrade, out of which 25% were Gleason score 3+4 and 8.5% primary Gleason pattern 4. Results remained consistent for the subgroup analysis and a weak positive association, but not statistically significant, between prostate specific antigen (PSA), age, and percentage of positive cores, and PCa upgrading at confirmatory biopsy was found.

CONCLUSION

In our single centre study, we found that one-third of patients had higher Gleason score at confirmatory biopsy. Furthermore 8.5% of these upgraders had a primary Gleason pattern 4. Our results together with previously published evidence highlight the need for the revision of current guidelines in prostate cancer diagnosis for the selection of men for active surveillance.

Predictors of pathological upgrading in low-risk prostate cancer patients without hypointense lesions on an apparent diffusion coefficient map of multiparametric magnetic resonance imaging

PURPOSE

To examine the clinicopathological features and identify the predictors of pathological upgrading in low-risk prostate cancer (PCa) patients without hypointense lesions on the apparent diffusion coefficient (ADC) map calculated from multiparametric magnetic resonance imaging.

METHODS

We reviewed the medical records of 1905 PCa patients who underwent radical prostatectomy between 2007 and 2015. All ADC images were graded using the five-grade Likert scale; the positive hypointense lesions were graded 4-5. We analyzed 256 patients with low-risk classifications according to D'Amico criteria. Patients were classified into two groups according to the pathologic upgrading in the surgical specimens. The predictive factors for pathologic upgrading were evaluated using a multivariate logistic regression analysis.

RESULTS

In 256 patients with low-risk PCa, the percentage of positive cores [odds ratio (OR) 1.09; 95 % confidence interval (CI) 1.02-1.16], the percentage of cancer in the positive cores (OR 1.07, 95 % CI 1.03-1.12), and the presence of hypointensity on an ADC map (OR 2.28; 95 % CI 1.23-4.22) were independent predictors of pathologic upgrading. Notably, 138 of low-risk patients (53.9 %) had no hypointense lesions on an ADC map. Of these 138 patients, the percentage of positive cores (OR 1.09; 95 % CI 1.01-1.18) and the percentage of cancer in the positive cores (OR 1.06; 95 % CI 1.01-1.12) remained independent predictors of pathologic upgrading.

CONCLUSIONS

In low-risk PCa patients without hypointense lesions on an ADC map, biopsy-related parameters such as the percentage of positive cores and the percentage of cancer in the positive cores were independent predictors of pathological upgrading following radical prostatectomy.

Predicting Low-Risk Prostate Cancer from Transperineal Saturation Biopsies

Introduction. To assess the performance of five previously described clinicopathological definitions of low-risk prostate cancer (PC). Materials and Methods. Men who underwent radical prostatectomy (RP) for clinical stage ≤T2, PSA <10 ng/mL, Gleason score <8 PC, diagnosed by transperineal template-guided saturation biopsy were included. The performance of five previously described criteria (i.e., criteria 1-5, criterion 1 stringent (Gleason score 6 + ≤5 mm total max core length PC + ≤3 mm max per core length PC) up to criterion 5 less stringent (Gleason score 6-7 with ≤5% Gleason grade 4) was analysed to assess ability of each to predict insignificant disease in RP specimens (defined as Gleason score ≤6 and total tumour volume <2.5 mL, or Gleason score 7 with ≤5% grade 4 and total tumour volume <0.7 mL). Results. 994 men who underwent RP were included. Criterion 4 (Gleason score 6) performed best with area under the curve of receiver operating characteristics 0.792. At decision curve analysis, criterion 4 was deemed clinically the best performing transperineal saturation biopsy-based definition for low-risk PC. Conclusions. Gleason score 6 disease demonstrated a superior trade-off between sensitivity and specificity for clarifying low-risk PC that can guide treatment and be used as reference test in diagnostic studies.

Oncological and functional outcomes 1 year after radical prostatectomy for very-low-risk prostate cancer: results from the prospective LAPPRO trial

OBJECTIVES

To analyse oncological and functional outcomes 12 months after treatment of very-low-risk prostate cancer with radical prostatectomy in men who could have been candidates for active surveillance.

PATIENTS AND METHODS

We conducted a prospective study of all men with very-low-risk prostate cancer who underwent radical prostatectomy at one of 14 participating centres. Validated patient questionnaires were collected at baseline and after 12 months by independent healthcare researchers. Biochemical recurrence (BCR) was defined as prostate-specific antigen (PSA) ≥0.25 ng/mL or treatment with salvage radiotherapy or with hormones. Urinary continence was defined as <1 pad changed per 24 h. Erectile function was defined as ability to achieve erection hard enough for penetration more than half of the time after sexual stimulation. Changes in tumour grade and stage were obtained from pathology reports. We report descriptive frequencies and proportions of men who had each outcome in various subgroups. Fisher's exact test was used to assess differences between the age groups.

RESULTS

Of the 4003 men in the LAPPRO cohort, 338 men fulfilled the preoperative national criteria for very-low-risk prostate cancer. Adverse pathology outcomes included upgrading, defined as pT3 or postoperative Gleason sum ≥7, which was present in 35% of the men (115/333) and positive surgical margins, which were present in 16% of the men (54/329). Only 2.1% of the men (7/329) had a PSA concentration >0.1 ng/mL 6-12 weeks postoperatively. Erectile function and urinary continence were observed in 44% (98/222) and 84% of the men (264/315), respectively, 12 months postoperatively. The proportion of men achieving the trifecta, defined as preoperative potent and continent men who remained potent and continent with no BCR, was 38% (84/221 men) at 12 months.

CONCLUSIONS

Our prospective study of men with very-low-risk prostate cancer undergoing open or robot-assisted radical prostatectomy showed that there were favourable oncological outcomes in approximately two-thirds. Approximately 40% did not have surgically induced urinary incontinence or erectile dysfunction 12 months postoperatively. These results provide additional support for the use of active surveillance in men with very-low-risk prostate cancer; however, the number of men with risk of upgrading and upstaging is not negligible. Improved stratification is still urgently needed.

Active surveillance for prostate cancer: current evidence and contemporary state of practice

Prostate cancer remains one of the most commonly diagnosed malignancies worldwide. Early diagnosis and curative treatment seem to improve survival in men with unfavourable-risk cancers, but significant concerns exist regarding the overdiagnosis and overtreatment of men with lower-risk cancers. To this end, active surveillance (AS) has emerged as a primary management strategy in men with favourable-risk disease, and contemporary data suggest that use of AS has increased worldwide. Although published surveillance cohorts differ by protocol, reported rates of metastatic disease and prostate-cancer-specific mortality are exceedingly low in the intermediate term (5-10 years). Such outcomes seem to be closely associated with programme-specific criteria for selection, monitoring, and intervention, suggesting that AS--like other management strategies--could be individualized based on the level of risk acceptable to patients in light of their personal preferences. Additional data are needed to better establish the risks associated with AS and to identify patient-specific characteristics that could modify prognosis.

Urinary miR-183 and miR-205 do not surpass PCA3 in urine as predictive markers for prostate biopsy outcome despite their highly dysregulated expression in prostate cancer tissue

BACKGROUND

MicroRNAs (miRNAs) have shown to be promising novel biomarkers in various cancers. We aimed to translate the results of an own previous tissue-based miRNA profile of prostate carcinoma (PCa) with upregulated miR-183 and downregulated miR-205 into a urine-based testing procedure for diagnosis of PCa.

METHODS

Urine sediments were prepared from urine samples collected after a standardized digital-rectal examination (DRE) of patients undergoing prostate biopsy with PSA (prostate-specific antigen) values <20 μg/L in consecutive order. According to the sample-size calculation (α=0.05, power=0.95), 38 patients each with PCa and without PCa were randomly enrolled in this study. PCA3 (prostate cancer associated 3) in urine as Food and Drug Administration-approved assay was determined as reference standard for comparison. The miRNAs were measured by RT-qPCR using TaqMan assays and normalized using different approaches.

RESULTS

Both miRNAs were correlated to the mRNA PSA concentrations in the sediments indicating a relationship to the released prostate cells after DRE. However, they had no discriminating capacity between patients with and without PCa. In contrast, PCA3 clearly differentiated between these two patients groups. There was also no significant correlation between miRNAs and standard clinicopathologic variables like Gleason score and serum PSA.

CONCLUSIONS

The data of our study show that miR-183 and miR-205 failed to detect early and aggressive PCa despite their highly dysregulated expression in cancer tissue. Our results and the critical evaluation of the few data of other studies raise serious doubts concerning the capability of urinary miRNAs to replace or improve PCA3 as predictive marker for prostate biopsy outcome.

Role of multiparametric magnetic resonance imaging in early detection of prostate cancer

Abstract

Most prostate cancers (PC) are currently found on the basis of an elevated PSA, although this biomarker has only moderate accuracy. Histological confirmation is traditionally obtained by random transrectal ultrasound guided biopsy, but this approach may underestimate PC. It is generally accepted that a clinically significant PC requires treatment, but in case of an non-significant PC, deferment of treatment and inclusion in an active surveillance program is a valid option. The implementation of multiparametric magnetic resonance imaging (mpMRI) into a screening program may reduce the risk of overdetection of non-significant PC and improve the early detection of clinically significant PC. A mpMRI consists of T2-weighted images supplemented with diffusion-weighted imaging, dynamic contrast enhanced imaging, and/or magnetic resonance spectroscopic imaging and is preferably performed and reported according to the uniform quality standards of the Prostate Imaging Reporting and Data System (PIRADS). International guidelines currently recommend mpMRI in patients with persistently rising PSA and previous negative biopsies, but mpMRI may also be used before first biopsy to improve the biopsy yield by targeting suspicious lesions or to assist in the selection of low-risk patients in whom consideration could be given for surveillance.

Teaching Points

• MpMRI may be used to detect or exclude significant prostate cancer.

• MpMRI can guide targeted rebiopsy in patients with previous negative biopsies.

• In patients with negative mpMRI consideration could be given for surveillance.

• MpMRI may add valuable information for the optimal treatment selection.

Male Pattern Baldness in Relation to Prostate Cancer-Specific Mortality: A Prospective Analysis in the NHANES I Epidemiologic Follow-up Study

We used male pattern baldness as a proxy for long-term androgen exposure and investigated the association of dermatologist-assessed hair loss with prostate cancer-specific mortality in the first National Health and Nutrition Examination Survey Epidemiologic Follow-up Study. From the baseline survey (1971-1974), we included 4,316 men who were 25-74 years of age and had no prior cancer diagnosis. We estimated hazard ratios and used Cox proportional hazards regressions with age as the time metric and baseline hazard stratified by baseline age. A hybrid framework was used to account for stratification and clustering of the sample design, with adjustment for the variables used to calculate sample weights. During follow-up (median, 21 years), 3,284 deaths occurred; prostate cancer was the underlying cause of 107. In multivariable models, compared with no balding, any baldness was associated with a 56% higher risk of fatal prostate cancer (hazard ratio = 1.56; 95% confidence interval: 1.02, 2.37), and moderate balding specifically was associated with an 83% higher risk (hazard ratio = 1.83; 95% confidence interval: 1.15, 2.92). Conversely, patterned hair loss was not statistically significantly associated with all-cause mortality. Our analysis suggests that patterned hair loss is associated with a higher risk of fatal prostate cancer and supports the hypothesis of overlapping pathophysiological mechanisms.

The Prostate Health Index: Its Utility in Prostate Cancer Detection

The Prostate Health Index is a Food and Drug Administration-approved blood test combining total, free, and [-2]pro prostate-specific antigen with greater specificity than free and total prostate-specific antigen for clinically significant prostate cancer. This article reviews the evidence on the performance of the Prostate Health Index to predict prostate biopsy outcome, its incorporation into multivariable risk-assessment tools, and its ability to predict prognosis after conservative management or prostate cancer treatment.

The current and future role of magnetic resonance imaging in prostate cancer detection and management

Purpose

Accurate detection of clinically significant prostate cancer (PC) and correct risk attribution are essential to individually counsel men with PC. Multiparametric MRI (mpMRI) facilitates correct localization of index lesions within the prostate and MRI-targeted prostate biopsy (TPB) helps to avoid the shortcomings of conventional biopsy such as false-negative results or underdiagnosis of aggressive PC. In this review we summarize the different sequences of mpMRI, characterize the possibilities of incorporating MRI in the biopsy workflow and outline the performance of targeted and systematic cores in significant cancer detection. Furthermore, we outline the potential of MRI in patients undergoing active surveillance (AS) and in the pre-operative setting.

Materials and methods

An electronic MEDLINE/PubMed search up to February 2015 was performed. English language articles were reviewed for inclusion ability and data were extracted, analyzed and summarized.

Results

Targeted biopsies significantly outperform conventional systematic biopsies in the detection of significant PC and are not inferior when compared to transperineal saturation biopsies. MpMRI can detect index lesions in app. 90% of cases as compared to prostatectomy specimen. The diagnostic performance of biparametric MRI (T2w + DWI) is not inferior to mpMRI, offering options to diminish cost- and time-consumption. Since app 10% of significant lesions are still MRI-invisible, systematic cores seem to be necessary. In-bore biopsy and MRI/TRUS-fusion-guided biopsy tend to be superior techniques compared to cognitive fusion. In AS, mpMRI avoids underdetection of significant PC and confirms low-risk disease accurately. In higher-risk disease, pre-surgical MRI can change the clinically-based surgical plan in up to a third of cases.

Conclusions

mpMRI and targeted biopsies are able to detect significant PC accurately and mitigate insignificant PC detection. As long as the negative predictive value (NPV) is still imperfect, systematic cores should not be omitted for optimal staging of disease. The potential to correctly classify aggressiveness of disease in AS patients and to guide and plan prostatectomy is evolving.

Index lesion characterization by (11)C-Choline PET/CT and Apparent Diffusion Coefficient parameters at 3 Tesla MRI in primary prostate carcinoma

BACKGROUND

Index lesion characterization is important in the evaluation of primary prostate carcinoma (PPC). The aim of this study was to analyze the contribution of (11) C-Choline PET/CT and the Apparent Diffusion Coefficient maps (ADC) in detecting the Index Lesion and clinically significant tumors in PPC.

METHODS

Twenty-one untreated patients with biopsy-proven PPC and candidates for radical prostatectomy (RP) were prospectively evaluated by means of Ultra-High Definition PET/CT and 3T MRI, which included T2-weighted imaging (T2WI) and ADC maps obtained from diffusion weighted imaging (DWI). Independent experts analyzed all the images separately and were unaware of the pathological data. In each case, the Index lesion was defined as the largest tumor measured on histopathology (Index H). In addition, the largest lesion observed on MRI (Index MRI) and the highest avid (11) C-Choline uptake lesion (Index PET) were obtained. The Gleason scores (GS) of the tumors were determined. PET/CT and ADC map quantitative parameters were also calculated. Measures of correlation among imaging parameters as well as the sensitivity (S), specificity (Sp), negative and positive predictive values (NPV and PPV) for tumor detection were analyzed. All data was validated with the pathological study.

RESULTS

In the morphological study, 139 foci of carcinoma were identified, 47 of which corresponded to clinically significant tumors (>0.5 cm(3)). The remaining foci presented a maximum diameter (dmax ) of 0.1 cm ± SD 0.75 and were not classified as clinically significant. Thirty-two tumors presented a GS (3 + 3), nine GS (3 + 4), and six GS (4 + 3). A total of 21 Index H (dmax = 1.37 cm SD ± 0.61) were identified. The S, Sp, NPV, and PPV for tumor detection with PET were 100%, 70%, 83%, 100%, and for MRI were 46%, 100%, 100%, 54%, respectively. Both Index PET and Index MRI were complementary and identified 95% of the Index H when quantitative criteria were used.

CONCLUSION

In spite of the fact that PET imaging has higher tumor sensitivity than MRI, (11) C-Choline PET and ADC maps have complementary roles in the evaluation of Index Lesion in PPC. Index PET and Index MRI could be complementary targets in the therapeutic planning of PPC.

Outcomes of Active Surveillance for Ductal Carcinoma in Situ: A Computational Risk Analysis

BACKGROUND

Ductal carcinoma in situ (DCIS) is a noninvasive breast lesion with uncertain risk for invasive progression. Usual care (UC) for DCIS consists of treatment upon diagnosis, thus potentially overtreating patients with low propensity for progression. One strategy to reduce overtreatment is active surveillance (AS), whereby DCIS is treated only upon detection of invasive disease. Our goal was to perform a quantitative evaluation of outcomes following an AS strategy for DCIS.

METHODS

Age-stratified, 10-year disease-specific cumulative mortality (DSCM) for AS was calculated using a computational risk projection model based upon published estimates for natural history parameters, and Surveillance, Epidemiology, and End Results data for outcomes. AS projections were compared with the DSCM for patients who received UC. To quantify the propagation of parameter uncertainty, a 95% projection range (PR) was computed, and sensitivity analyses were performed.

RESULTS

Under the assumption that AS cannot outperform UC, the projected median differences in 10-year DSCM between AS and UC when diagnosed at ages 40, 55, and 70 years were 2.6% (PR = 1.4%-5.1%), 1.5% (PR = 0.5%-3.5%), and 0.6% (PR = 0.0%-2.4), respectively. Corresponding median numbers of patients needed to treat to avert one breast cancer death were 38.3 (PR = 19.7-69.9), 67.3 (PR = 28.7-211.4), and 157.2 (PR = 41.1-3872.8), respectively. Sensitivity analyses showed that the parameter with greatest impact on DSCM was the probability of understaging invasive cancer at diagnosis.

CONCLUSION

AS could be a viable management strategy for carefully selected DCIS patients, particularly among older age groups and those with substantial competing mortality risks. The effectiveness of AS could be markedly improved by reducing the rate of understaging.

The high prevalence of undiagnosed prostate cancer at autopsy: implications for epidemiology and treatment of prostate cancer in the Prostate-specific Antigen-era

Widespread prostate-specific antigen (PSA) screening detects many cancers that would have otherwise gone undiagnosed. To estimate the prevalence of unsuspected prostate cancer, we reviewed 19 studies of prostate cancer discovered at autopsy among 6,024 men. Among men aged 70-79, tumor was found in 36% of Caucasians and 51% of African-Americans. This enormous prevalence, coupled with the high sensitivity of PSA screening, has led to the marked increase in the apparent incidence of prostate cancer. The impact of PSA screening on clinical practice is well-recognized, but its effect on epidemiologic research is less appreciated. Before screening, a larger proportion of incident prostate cancers had lethal potential and were diagnosed at advanced stage. However, in the PSA era, overall incident prostate cancer mainly is indolent disease, and often reflects the propensity to be screened and biopsied. Studies must therefore focus on cancers with lethal potential, and include long follow-up to accommodate the lead time induced by screening. Moreover, risk factor patterns differ markedly for potentially lethal and indolent disease, suggesting separate etiologies and distinct disease entities. Studies of total incident or indolent prostate cancer are of limited clinical utility, and the main focus of research should be on prostate cancers of lethal potential.

The challenging landscape of medical device approval in localized prostate cancer

Findings of research using modern multiparametric MRI have provided clinicians with reliable targets for guiding prostate biopsy sampling and directing targeted therapy, often termed focal therapy, to specific areas of the prostate. This emerging shift in treatment strategy from a whole-gland approach to a lesion-specific or region-specific approach requires novel medical devices. The rules regulating the approval and clinical use of such new devices often differ between the USA and Europe, and these differences can affect the treatments that patients receive. Current regulatory pathways for approval of various image-guided biopsy and focal therapy devices intended to be used in patients with prostate cancer are discussed in detail. Finally, we offer some perspective on the current status of research in the field, and propose a potential roadmap towards the establishment of timely, safe and standardized criteria for optimal evaluation of novel image-guided devices for treatment of patients with localized prostate cancer.

Prostate Health Index (PHI) Predicts High-stage Pathology in African American Men

OBJECTIVE

To evaluate the association between the Prostate Health Index (PHI) and adverse pathology in a cohort of African American (AA) men undergoing radical prostatectomy.

MATERIALS AND METHODS

Eighty AA men with prostate-specific antigen (PSA) of 2-10 ng/mL underwent measurement of PSA, free PSA (fPSA), and p2PSA prior to radical prostatectomy. PHI was calculated as [(p2PSA/fPSA) × (PSA)(½)]. Biomarker association with pT3 disease was assessed using logistic regression, and covariates were added to a baseline multivariable model including digital rectal examination. Biomarker ability to predict pT3 disease was measured using the area under the receiver operator characteristic curve.

RESULTS

Sixteen men (20%) demonstrated pT3 disease on final pathology. Mean age, PSA, and %fPSA were similar in men with and without pT3 disease (all P  >  .05), whereas PHI was significantly greater in men with pT3 disease (mean 57.2 vs 46.6, P  =  .04). Addition of PHI to the baseline multivariable model improved discriminative ability by 12.9% (P  =. .04) and yielded greater diagnostic accuracy than models, including other individual biomarkers.

CONCLUSION

In AA men with PSA of 2-10 ng/mL, PHI was predictive of pT3 prostate cancer and may help to identify men at increased risk of adverse pathology. Additional studies are needed to substantiate these findings and identify appropriate thresholds for clinical use.

The Effect of Start and Stop Age at Screening on the Risk of Being Diagnosed with Prostate Cancer

PURPOSE

We investigated the effect of age and number of screens on the risk of prostate cancer diagnosis.

MATERIALS AND METHODS

Since 1995 the Göteborg randomized population based prostate cancer screening trial has invited men biennially for prostate specific antigen testing, until the upper age limit of 70 years. Men with a prostate specific antigen above the threshold of 2.5 ng/ml were recommended further evaluation including 10-core biopsy (sextant before 2009). The present study comprises 9,065 men born between 1930 and 1943 (1944 excluded due to different screening algorithm). Complete attendees were defined as men who accepted all screening invitations (maximum 3 to 9 invitations). The cumulative incidence of prostate cancer was calculated using standard methods.

RESULTS

Of the 3,488 (38%) complete attendees 667 were diagnosed with prostate cancer (followup 1995 to June 30, 2014). At age 70 years there was no significant difference in prostate cancer risk among those who started screening at the age of 52 (9 screens), 55 (7 screens) or 60 (5 screens) years. However, the cumulative risk of prostate cancer diagnosis increased dramatically with age, and was 7.9% at age 60, 15% at age 65 and 21% at age 70 for men who had been screened 4 or more times.

CONCLUSIONS

There was no clear association between risk of prostate cancer and the number of screens. Starting screening at an early age appears to advance the time of prostate cancer diagnosis but does not seem to increase the risk of being diagnosed with the disease. Age at termination of screening is strongly associated with the risk of being diagnosed with prostate cancer.

Active surveillance for prostate cancer

It is worth distinguishing between the two strategies of expectant management for prostate cancer. Watchful waiting entails administering non-curative androgen deprivation therapy to patients on development of symptomatic progression, whereas active surveillance entails delivering curative treatment on signs of disease progression. The objectives of the two management strategies and the patients enrolled in either are different: (i) to review the role of active surveillance as a management strategy for patients with low-risk prostate cancer; and (ii) review the benefits and pitfalls of active surveillance. We carried out a systematic review of active surveillance for prostate cancer in the literature using the National Center for Biotechnology Information's electronic database, PubMed. We carried out a search in English using the terms: active surveillance, prostate cancer, watchful waiting and conservative management. Selected studies were required to have a comprehensive description of the demographic and disease characteristics of the patients at the time of diagnosis, inclusion criteria for surveillance, and a protocol for the patients' follow up. Review articles were included, but not multiple papers from the same datasets. Active surveillance appears to reduce overtreatment in patients with low-risk prostate cancer without compromising cancer-specific survival at 10 years. Therefore, active surveillance is an option for select patients who want to avoid the side-effects inherent to the different types of immediate treatment. However, inclusion criteria for active surveillance and the most appropriate method of monitoring patients on active surveillance have not yet been standardized.

The Prevalence of Clinically Significant Prostate Cancer According to Commonly Used Histological Thresholds in Men Undergoing Template Prostate Mapping Biopsies

PURPOSE

Transrectal prostate biopsies are inaccurate and, thus, the prevalence of clinically significant prostate cancer in men undergoing biopsy is unknown. We determined the ability of different histological thresholds to denote clinically significant cancer in men undergoing a more accurate biopsy, that of transperineal template prostate mapping.

MATERIALS AND METHODS

In this multicenter, cross-sectional cohort of men who underwent template prostate mapping biopsies between May 2006 and January 2012, 4 different thresholds of significance combining tumor grade and burden were used to measure the consequent variation with respect to the prevalence of clinically significant disease.

RESULTS

Of 1,203 men 17% (199) had no previous biopsy, 38% (455) had a prior negative transrectal ultrasound biopsy, 24% (289) were on active surveillance and 21% (260) were seeking risk stratification. Mean patient age was 63.5 years (SD 7.6) and median prostate specific antigen was 7.4 ng/ml (IQR 5.3-10.5). Overall 35% of the patients (424) had no cancer detected. The prevalence of clinically significant cancer varied between 14% and 83% according to the histological threshold used, in particular between 30% and 51% among men who had no previous biopsy, between 14% and 27% among men who had a prior negative biopsy, between 36% and 74% among men on active surveillance, and between 47% and 83% among men seeking risk stratification.

CONCLUSIONS

According to template prostate mapping biopsy between 1 in 2 and 1 in 3 men have prostate cancer that is histologically defined as clinically significant. This suggests that the commonly used thresholds may be set too low.

Clinical Relevance of Incidental Prostatic Lesions on FDG-Positron Emission Tomography/Computerized Tomography-Should Patients Receive Further Evaluation?

PURPOSE

FDG ((18)F-fluoro-2-deoxy-D-glucose)-PET/CT (positron emission tomography)/(computerized tomography) is a widely used diagnostic tool for whole body imaging. Incidental prostatic uptake is often found on FDG-PET/CT. The objective of this study was to determine the clinical relevance of incidental prostatic uptake on FDG-PET/CT.

MATERIALS AND METHODS

We analyzed 108 consecutive male patients with bladder cancer who underwent FDG-PET/CT and subsequently radical cystoprostatectomy between May 2009 and November 2014. PET/CT scans were blindly reviewed by a dedicated nuclear medicine physician for incidental prostatic FDG uptake. If present, the maximum standardized uptake value was determined. Subsequently incidental prostatic uptake was categorized as suspect, indeterminate or nonsuspect for prostate cancer.

RESULTS

Incidental prostatic uptake was present in 43 of 108 patients (40%). Of these 43 patients 13 (30%) had occult prostate cancer in cystoprostatectomy specimens. Overall prostate cancer was found in 25 of 108 specimens (23%). If all incidental prostatic uptake was regarded as prostate cancer, the sensitivity and specificity of FDG-PET/CT for prostate cancer detection were 52% and 64%, respectively. Positive and negative predictive values were 30% and 82%, respectively. If only lesions labeled suspect or indeterminate were regarded as prostate cancer, sensitivity, specificity, and positive and negative predictive values were 32%, 76%, 29% and 79%, respectively. Categorizing indeterminate lesions as nonprostate cancer did not improve diagnostic accuracy. Gleason score did not correlate with maximum standardized uptake value or serum prostate specific antigen.

CONCLUSIONS

Incidental prostatic uptake on FDG-PET/CT has a low positive predictive value for prostate cancer. An attempt to classify lesions as suspect or nonsuspect did not increase diagnostic accuracy. Based on these results physicians should be cautious about applying invasive diagnostic methods to detect prostate cancer in case of incidental prostatic uptake on FDG-PET/CT.

[The HAROW study: an example of outcomes research: a prospective, non-interventional study comparing treatment options in localized prostate cancer]

BACKGROUND

The HAROW study was initiated to investigate the provision of ongoing medical care for patients with localized prostate cancer in a prospective, noninterventional setting and to investigate treatment options (Hormonal treatment, Active surveillance, Radiotherapy, Operation, Watchful waiting) under real-life conditions.

MATERIALS AND METHODS

A total of 3169 patients were enrolled by 259 participating physicians in private practice in Germany. The median follow-up was 28.4 months. At 6-month intervals, the treating physicians reported data on clinical parameters, clinical course of disease, and quality of patient-physician interaction.

RESULTS

The highest proportion of patients with low risk tumor was found in the defensive treatment groups (AS and WW). As expected, the AS group showed the highest progression rate. In all, 112 AS patients (23.9%) changed therapeutic strategy, 21 of them upon medical advice in the absence of any signs of progression. Metastases were seen most frequently in the WW group (1.5%). No metastases occurred in AS patients. Medical support in managing the disease reached high scores in all groups, the highest in AS.

CONCLUSION

The data enable a differentiated comparative analysis of patient and tumor characteristics of each treatment group. Indication of AS was predominantly consistent with the guideline. The high rate of AS termination based on the physician's recommendation rather than on clinical progression is remarkable, and may be interpreted as a kind of insecurity in dealing with AS. Results regarding communication indicate that patients appreciated being involved in treatment decisions.

Tumor volume in insignificant prostate cancer: Increasing the threshold is a safe approach to reduce over-treatment

BACKGROUND

There are conflicting results in the literature regarding the tumor volume (TV) threshold that defines insignificant prostate cancer (PCa). In this study, we retrospectively evaluate the association of an increasing TV with biochemical recurrence (BCR) following radical prostatectomy (RP) in order to provide further clarification surrounding the TV threshold definition for insignificant PCa.

METHODS

RP patients were recruited from January 2004 to December 2009. Inclusion criteria were localized (stage ≤pT2c, negative surgical margins) Gleason 6 PCa with a total TV of ≤2.50 cm(3) . BCR was the primary outcome and defined as a PSA of ≥0.1. All cases with BCR were re-evaluated by the pathologist with reassessment of tumor grade, pathological stage and surgical margin status.

RESULTS

From 1,636 patients, 178 men (10.9%) met all inclusion criteria. Ninety-six patients (53.9%) had a TV <0.5 cm(3) and 82 patients (46.1%) had a TV 0.5-2.5 cm(3) . Three out of 178 patients (1.7%) presented with BCR during follow-up. One of these had TV <0.5 cm(3) and two had TV 0.5-2.5 cm(3) . These three cases of BCR underwent re-review of pathology; one patient was found to have a positive surgical margin and one patient was upgraded to Gleason 3 + 4 = 7. The third patient was re-reported as having positive margins for a benign hyperplastic nodule (incomplete RP specimen). Subsequently, these three cases were excluded from final analysis as they did not fit inclusion criteria. Median follow-up duration was 84 months (IQR 70-102 months). On final analysis, there were no patients with BCR, corresponding with a final BCR rate of 0% for both patients with a TV of <0.5 cm(3) and 0.5-2.5 cm(3) .

CONCLUSIONS

Our results have shown that, with a median follow-up of 84 (IQR 70-102) months, patients in our cohort with localized Gleason 6 PCa with a total TV 0.5-2.5 cm(3) have a BCR rate of 0%. We would support a more liberal total TV threshold of 2.5 cm(3) for the further development of algorithms to identify patients suitable for active surveillance.

Cost-effectiveness of multiparametric magnetic resonance imaging and targeted biopsy in diagnosing prostate cancer

INTRODUCTION

Transrectal ultrasound-guided biopsy (TRUSGB) is the recommended approach to diagnose prostate cancer (PCa). Overdiagnosis and sampling errors represent major limitations. Magnetic resonance imaging (MRI)-targeted biopsy (MRTB) detects higher proportion of significant PCa and reduces diagnosis of insignificant PCa. Costs prevent MRTB from becoming the new standard in PCa diagnosis. The present study aimed at assessing whether added costs of MRI outweigh benefits of MRTB in a cost-utility model.

MATERIALS AND METHODS

A Markov model was developed to estimate quality-adjusted life-year gained (QALY) and costs for 2 strategies (the standard 12-core TRUSGB strategy and the MRTB strategy) over 5, 10, 15, and 20 years. MRI was used as triage test in biopsy-naive men with clinical suspicion of PCa. The model takes into account probability of men harboring PCa, diagnostic accuracy of both procedures, and probability of being assigned to various treatment options. Direct medical costs based on health care system perspective were included.

RESULTS

Following standard TRUSGB pathway, calculated cumulative effects at 5, 10, 15, and 20 years were 4.25, 7.17, 9.03, and 10.09 QALY, respectively. Cumulative effects in MRTB pathway were 4.29, 7.26, 9.17, and 10.26 QALY, correspondingly. Costs related to TRUSGB strategy were $8,027, $11,406, $14,883, and $17,587 at 5, 10, 15, and 20 years, respectively, as compared with $7,231, $10,450, $13,267, and $15,400 for the MRTB strategy. At 5, 10, 15, and 20 years, MRTB was the established dominant strategy.

CONCLUSIONS

Incorporation of MRI and MRTB in PCa diagnosis and management represents a cost-effective measure at 5, 10, 15, and 20 years after initial diagnosis.

Systematic Identification of MicroRNAs That Impact on Proliferation of Prostate Cancer Cells and Display Changed Expression in Tumor Tissue

BACKGROUND

Systematic approaches to functionally identify key players in microRNA (miRNA)-target networks regulating prostate cancer (PCa) proliferation are still missing.

OBJECTIVE

To comprehensively map miRNA regulation of genes relevant for PCa proliferation through phenotypic screening and tumor expression data.

DESIGN, SETTING, AND PARTICIPANTS

Gain-of-function screening with 1129 miRNA molecules was performed in five PCa cell lines, measuring proliferation, viability, and apoptosis. These results were integrated with changes in miRNA expression from two cohorts of human PCa (188 tumors in total). For resulting miRNAs, the predicted targets were collected and analyzed for patterns with gene set enrichment analysis, and for their association with biochemical recurrence free survival.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Rank product statistical analysis was used to evaluate miRNA effects in phenotypic screening and for expression differences in the prostate tumor cohorts. Expression data were analyzed using the significance analysis of microarrays (SAM) method and the patient material was subjected to Kaplan-Meier statistics.

RESULTS AND LIMITATIONS

Functional screening identified 25 miRNAs increasing and 48 miRNAs decreasing cell viability. Data integration resulted in 14 miRNAs, with aberrant expression and effect on proliferation. These miRNAs are predicted to regulate >3700 genes, of which 28 were found up-regulated and 127 down-regulated in PCa compared with benign tissue. Seven genes, FLNC, MSRB3, PARVA, PCDH7, PRNP, RAB34, and SORBS1, showed an inverse association to their predicted miRNA, and were identified to significantly correlate with biochemical recurrence free survival in PCa patients.

CONCLUSIONS

A systematic in vitro screening approach combined with in vivo expression and gene set enrichment analysis provide unbiased means for revealing novel miRNA-target links, possibly driving the oncogenic processes in PCa.

PATIENT SUMMARY

This study identified novel regulatory molecules, which impact on PCa proliferation and are aberrantly expressed in clinical tumors. Thus, our study reveals regulatory nodes with potential for therapy.

Differential Predictive Roles of A- and B-Type Nuclear Lamins in Prostate Cancer Progression

BACKGROUND

Prostate cancer (PCa) is the most common cancer among men in western countries. While active surveillance is increasingly utilized, the majority of patients are currently treated with radical prostatectomy. In order to avoid over-treatment, there is an indisputable need for reliable biomarkers to identify the potentially aggressive and lethal cases. Nuclear intermediate filament proteins called lamins play a role in chromatin organization, gene expression and cell stiffness. The expression of lamin A is associated with poor outcome in colorectal cancer but to date the prognostic value of the lamins has not been tested in other solid tumors.

METHODS

We studied the expression of different lamins with immunohistochemistry in a tissue microarray material of 501 PCa patients undergoing radical prostatectomy and lymph node dissection. Patients were divided into two staining categories (low and high expression). The correlation of lamin expression with clinicopathological variables was tested and the association of lamin status with biochemical recurrence (BCR) and disease specific survival (DSS) was further analyzed.

RESULTS

Low expression of lamin A associated with lymph node positivity (p<0.01) but not with other clinicopathological variables and low expression had a borderline independent significant association with DSS (HR = 0.4; 95% CI 0.2-1.0; p = 0.052). Similarly, low lamin C expression associated with poorer survival (HR = 0.2; 95% CI 0.1-0.6; p = 0.004). Lamin B1 expression did not associate with clinicopathological variables but high expression independently predicted BCR in multivariable Cox regression analysis (HR = 1.8; 95% CI 1.1-2.9; p = 0.023). Low expression of lamin B2 correlated with lymph node positivity (p<0.01) and predicted unfavorable DSS (HR = 0.4; 95% CI 0.2-1.0; p = 0.047).

CONCLUSIONS

These results suggest differential roles for lamins in PCa progression. Reduced amounts of lamin A/C and B2 increase risk for lymph node metastasis and disease specific death possibly through increased nuclear deformability while high expression of lamin B1 predicts disease recurrence.

Focal irreversible electroporation for prostate cancer: functional outcomes and short-term oncological control

BACKGROUND

Current data on the use of irreversible electroporation (IRE) in the treatment of prostate cancer (PCa) is limited. We aim to evaluate the safety, short-term functional and oncological outcomes of focal IRE in low-intermediate risk PCa.

METHODS

Between February 2013 and May 2014, 32 consecutive men underwent IRE at a single centre. Patients with low-intermediate risk PCa who had not received previous PCa treatment were included for analysis. The tumour was ablated using 3-6 electrodes, ensuring a minimum 5-mm safety margin around the visible magnetic resonance imaging (MRI) lesion. Follow-up included recording Clavien complications, Expanded Prostate Cancer Index Composite (EPIC) questionnaires (baseline, 1.5, 3, 6 months), 6-month multi-parametric MRI (mp-MRI) and 7-month biopsy. Findings on mp-MRI and biopsy were sub-divided into infield, adjacent or outfield of the treatment zone.

RESULTS

Twenty-five men were included for final analysis. Safety follow-up revealed one Clavien Grade 3 complication and five Grade 1 complications. Functional follow-up confirmed no significant change in American Urological Association urinary symptom score, sexual or bowel function. Infield, there were no suspicious findings on mp-MRI (n=24) or biopsy (n=21) in all patients. Adjacent to the treatment zone, five (21%) had suspicious findings on mp-MRI with four (19%) proving to be significant on biopsy. Outfield, there were two (8%) with suspicious findings on mp-MRI and one (5%) significant finding on biopsy. For the five patients with significant findings on follow-up biopsy, one is awaiting repeat IRE, one had radical prostatectomy and three remained on active surveillance.

CONCLUSIONS

In selected patients with low-intermediate risk PCa, focal IRE appears to be safe with minimal morbidity. There were no infield recurrences and 76% of patients were histologically free of significant cancer at 8 months. Almost all recurrences were adjacent to the treatment zone, and this was addressed by widening the treatment margins.

Incorporating Known Genetic Variants Does Not Improve the Accuracy of PSA Testing to Identify High Risk Prostate Cancer on Biopsy

INTRODUCTION

Prostate-specific antigen (PSA) testing is a widely accepted screening method for prostate cancer, but with low specificity at thresholds giving good sensitivity. Previous research identified four single nucleotide polymorphisms (SNPs) principally associated with circulating PSA levels rather than with prostate cancer risk (TERT rs2736098, FGFR2 rs10788160, TBX3 rs11067228, KLK3 rs17632542). Removing the genetic contribution to PSA levels may improve the ability of the remaining biologically-determined variation in PSA to discriminate between high and low risk of progression within men with identified prostate cancer. We investigate whether incorporating information on the PSA-SNPs improves the discrimination achieved by a single PSA threshold in men with raised PSA levels.

MATERIALS AND METHODS

Men with PSA between 3-10 ng/mL and histologically-confirmed prostate cancer were categorised as high or low risk of progression (Low risk: Gleason score≤6 and stage T1-T2a; High risk: Gleason score 7-10 or stage T2C). We used the combined genetic effect of the four PSA-SNPs to calculate a genetically corrected PSA risk score. We calculated the Area under the Curve (AUC) to determine how well genetically corrected PSA risk scores distinguished men at high risk of progression from low risk men.

RESULTS

The analysis includes 868 men with prostate cancer (Low risk: 684 (78.8%); High risk: 184 (21.2%)). Receiver operating characteristic (ROC) curves indicate that including the 4 PSA-SNPs does not improve the performance of measured PSA as a screening tool for high/low risk prostate cancer (measured PSA level AUC = 59.5% (95% CI: 54.7,64.2) vs additionally including information from the 4 PSA-SNPs AUC = 59.8% (95% CI: 55.2,64.5) (p-value = 0.40)).

CONCLUSION

We demonstrate that genetically correcting PSA for the combined genetic effect of four PSA-SNPs, did not improve discrimination between high and low risk prostate cancer in men with raised PSA levels (3-10 ng/mL). Replication and gaining more accurate estimates of the effects of the 4 PSA-SNPs and additional variants associated with PSA levels and not prostate cancer could be obtained from subsequent GWAS from larger prospective studies.

Comparison of pathological data between prostate biopsy and radical prostatectomy specimen in patients with low to very low risk prostate cancer

OBJECTIVE

To analyze the correlation between pathological data found in radical prostatectomy and previously performed biopsy in patients at low risk prostate cancer.

MATERIAL AND METHODS

A descriptive, cross-sectional study was conducted to assess the characteristics of radical prostatectomies performed in our center from January 2012 to November 2014. The inclusion criteria were patients with low-risk disease (cT1c-T2a, PSA≤10ng/mL and Gleason score≤6). We excluded patients who had fewer than 8 cores in the biopsy, an unspecified number of affected cores, rectal examinations not reported in the medical history or biopsies performed in another center.

RESULTS

Of the 184 patients who underwent prostatectomy during this period, 87 met the inclusion criteria, and 26 of these had<3 affected cores and PSA density≤.15 (very low risk). In the entire sample, the percentage of undergrading (Gleason score≥7) and extracapsular invasion (pT3) was 18.4% (95% CI 10.3-27.6) and 10.35% (95% CI 4.6-17.2), respectively. The percentage of positive margins was 21.8% (95% CI 12.6-29.9). In the very low-risk group, we found no cases of extracapsular invasion and only 1 case of undergrading (Gleason 7 [3+4]), representing 3.8% of the total (95% CI 0-12.5). Predictors of no correlation (stage≥pT3a or undergrading) were the initial risk group, volume, PSA density and affected cores.

CONCLUSIONS

Prostate volume, PSA density, the number of affected cores and the patient's initial risk group influence the poor pathological prognosis in the radical prostatectomy specimen (extracapsular invasion and Gleason score≥7).

Reducing overdiagnosis by polygenic risk-stratified screening: findings from the Finnish section of the ERSPC

BACKGROUND

We derived estimates of overdiagnosis by polygenic risk groups and examined whether polygenic risk-stratified screening for prostate cancer reduces overdiagnosis.

METHODS

We calculated the polygenic risk score based on genotypes of 66 known prostate cancer loci for 4967 men from the Finnish section of the European Randomised Study of Screening for Prostate Cancer. We stratified the 72 072 men in the trial into those with polygenic risk below and above the median. Using a maximum likelihood method based on interval cancers, we estimated the mean sojourn time (MST) and episode sensitivity. For each polygenic risk group, we estimated the proportion of screen-detected cancers that are likely to be overdiagnosed from the difference between the observed and expected number of screen-detected cancers.

RESULTS

Of the prostate cancers, 74% occurred among men with polygenic risk above population median. The sensitivity was 0.55 (95% confidence interval (CI) 0.45-0.65) and MST 6.3 (95% CI 4.2-8.3) years. The overall overdiagnosis was 42% (95% CI 37-52) of the screen-detected cancers, with 58% (95% CI 54-65) in men with the lower and 37% (95% CI 31-47) in those with higher polygenic risk.

CONCLUSION

Targeting screening to men at higher polygenic risk could reduce the proportion of cancers overdiagnosed.

Updated prostate imaging reporting and data system (PIRADS v2) recommendations for the detection of clinically significant prostate cancer using multiparametric MRI: critical evaluation using whole-mount pathology as standard of reference

OBJECTIVES

To evaluate the recommendations for multiparametric prostate MRI (mp-MRI) interpretation introduced in the recently updated Prostate Imaging Reporting and Data System version 2 (PI-RADSv2), and investigate the impact of pathologic tumour volume on prostate cancer (PCa) detectability on mpMRI.

METHODS

This was an institutional review board (IRB)-approved, retrospective study of 150 PCa patients who underwent mp-MRI before prostatectomy; 169 tumours ≥0.5-mL (any Gleason Score [GS]) and 37 tumours <0.5-mL (GS ≥4+3) identified on whole-mount pathology maps were located on mp-MRI consisting of T2-weighted imaging (T2WI), diffusion-weighted (DW)-MRI, and dynamic contrast-enhanced (DCE)-MRI. Corresponding PI-RADSv2 scores were assigned on each sequence and combined as recommended by PI-RADSv2. We calculated the proportion of PCa foci on whole-mount pathology correctly identified with PI-RADSv2 (dichotomized scores 1-3 vs. 4-5), stratified by pathologic tumour volume.

RESULTS

PI-RADSv2 allowed correct identification of 118/125 (94 %; 95 %CI: 90-99 %) peripheral zone (PZ) and 42/44 (95 %; 95 %CI: 89-100 %) transition zone (TZ) tumours ≥0.5 mL, but only 7/27 (26 %; 95 %CI: 10-42 %) PZ and 2/10 (20 %; 95 %CI: 0-52 %) TZ tumours with a GS ≥4+3, but <0.5 mL. DCE-MRI aided detection of 4/125 PZ tumours ≥0.5 mL and 0/27 PZ tumours <0.5 mL.

CONCLUSIONS

PI-RADSv2 correctly identified 94-95 % of PCa foci ≥0.5 mL, but was limited for the assessment of GS ≥4+3 tumours ≤0.5 mL. DCE-MRI offered limited added value to T2WI+DW-MRI.

KEY POINTS

• PI-RADSv2 correctly identified 95 % of PCa foci ≥0.5 mL • PI-RADSv2 was limited for the assessment of GS ≥4+3 tumours ≤0.5 mL • DCE-MRI offered limited added value to T2WI+DW-MRI.

First-in-human uPAR PET: Imaging of Cancer Aggressiveness

A first-in-human clinical trial with Positron Emission Tomography (PET) imaging of the urokinase-type plasminogen activator receptor (uPAR) in patients with breast, prostate and bladder cancer, is described. uPAR is expressed in many types of human cancers and the expression is predictive of invasion, metastasis and indicates poor prognosis. uPAR PET imaging therefore holds promise to be a new and innovative method for improved cancer diagnosis, staging and individual risk stratification. The uPAR specific peptide AE105 was conjugated to the macrocyclic chelator DOTA and labeled with ⁶⁴Cu for targeted molecular imaging with PET. The safety, pharmacokinetic, biodistribution profile and radiation dosimetry after a single intravenous dose of ⁶⁴Cu-DOTA-AE105 were assessed by serial PET and computed tomography (CT) in 4 prostate, 3 breast and 3 bladder cancer patients. Safety assessment with laboratory blood screening tests was performed before and after PET ligand injection. In a subgroup of the patients, the in vivo stability of our targeted PET ligand was determined in collected blood and urine. No adverse or clinically detectable side effects in any of the 10 patients were found. The ligand exhibited good in vivo stability and fast clearance from plasma and tissue compartments by renal excretion. In addition, high uptake in both primary tumor lesions and lymph node metastases was seen and paralleled high uPAR expression in excised tumor tissue. Overall, this first-in-human study therefore provides promising evidence for safe use of ⁶⁴Cu-DOTA-AE105 for uPAR PET imaging in cancer patients.

A fully automatic computer aided diagnosis system for peripheral zone prostate cancer detection using multi-parametric magnetic resonance imaging

Multiparametric (mp)-Magnetic Resonance Imaging (MRI) is emerging as a powerful test to diagnose and stage prostate cancer (PCa). However, its interpretation is a time consuming and complex feat requiring dedicated radiologists. Computer-aided diagnosis (CAD) tools could allow better integration of data deriving from the different MRI sequences in order to obtain accurate, reproducible, non-operator dependent information useful to identify and stage PCa. In this paper, we present a fully automatic CAD system conceived as a 2-stage process. First, a malignancy probability map for all voxels within the prostate is created. Then, a candidate segmentation step is performed to highlight suspected areas, thus evaluating both the sensitivity and the number of false positive (FP) regions detected by the system. Training and testing of the CAD scheme is performed using whole-mount histological sections as the reference standard. On a cohort of 56 patients (i.e. 65 lesions) the area under the ROC curve obtained during the voxel-wise step was 0.91, while, in the second step, a per-patient sensitivity of 97% was reached, with a median number of FP equal to 3 in the whole prostate. The system here proposed could be potentially used as first or second reader to manage patients suspected to have PCa, thus reducing both the radiologist's reporting time and the inter-reader variability. As an innovative setup, it could also be used to help the radiologist in setting the MRI-guided biopsy target.

[Liquid biopsies, a revolution in oncology?]

The detection and analysis of circulating tumour DNA and/or circulating tumour cells in the blood of cancer patients open new possibilities for cancer characterisation and management. The approach has generated much commercial interest, but still requires more proof of clinical utility; it is however likely to play an important role in monitoring the evolution of cancer cells during therapy.

Gleason 6 Prostate Cancer: Translating Biology into Population Health

PURPOSE

Gleason 6 (3+3) is the most commonly diagnosed prostate cancer among men with prostate specific antigen screening, the most histologically well differentiated and is associated with the most favorable prognosis. Despite its prevalence, considerable debate exists regarding the genetic features, clinical significance, natural history, metastatic potential and optimal management.

MATERIALS AND METHODS

Members of the Young Urologic Oncologists in the Society of Urologic Oncology cooperated in a comprehensive search of the peer reviewed English medical literature on Gleason 6 prostate cancer, specifically focusing on the history of the Gleason scoring system, histological features, clinical characteristics, practice patterns and outcomes.

RESULTS

The Gleason scoring system was devised in the early 1960s, widely adopted by 1987 and revised in 2005 with a more restrictive definition of Gleason 6 disease. There is near consensus that Gleason 6 meets pathological definitions of cancer, but controversy about whether it meets commonly accepted molecular and genetic criteria of cancer. Multiple clinical series suggest that the metastatic potential of contemporary Gleason 6 disease is negligible but not zero. Population based studies in the U.S. suggest that more than 90% of men newly diagnosed with prostate cancer undergo treatment and are exposed to the risk of morbidity for a cancer unlikely to cause symptoms or decrease life expectancy. Efforts have been proposed to minimize the number of men diagnosed with or treated for Gleason 6 prostate cancer. These include modifications to prostate specific antigen based screening strategies such as targeting high risk populations, decreasing the frequency of screening, recommending screening cessation, incorporating remaining life expectancy estimates, using shared decision making and novel biomarkers, and eliminating prostate specific antigen screening entirely. Large nonrandomized and randomized studies have shown that active surveillance is an effective management strategy for men with Gleason 6 disease. Active surveillance dramatically reduces the number of men undergoing treatment without apparent compromise of cancer related outcomes.

CONCLUSIONS

The definition and clinical relevance of Gleason 6 prostate cancer have changed substantially since its introduction nearly 50 years ago. A high proportion of screen detected cancers are Gleason 6 and the metastatic potential is negligible. Dramatically reducing the diagnosis and treatment of Gleason 6 disease is likely to have a favorable impact on the net benefit of prostate cancer screening.

Ethnicity and prostate cancer: the way to solve the screening problem?

In their analysis in BMC Medicine, Lloyd et al. provide individual patient lifetime risks of prostate cancer diagnosis and prostate cancer death stratified by ethnicity. This easy to understand information is helpful for men to decide whether to start prostate-specific antigen testing (i.e. screening). A higher lifetime risk of prostate cancer death in some ethnic groups is not automatically a license to start screening. The potential benefit in the form of reducing metastases and death should still be weighed against the potential risk of over diagnosis. In case of ethnicity, this harm-to-benefit ratio does not differ between groups. Stratifying men for screening based on ethnicity is therefore not optimal and will not solve the current screening problem. Other methods for risk-stratifying men have been proven to produce a more optimal harm-to-benefit ratio. Please see related article: http://www.biomedcentral.com/1741-7015/13/171.

Gene interference strategies as a new tool for the treatment of prostate cancer

Prostate cancer (PCa) is one of the most common cancer in men. It affects older men and the incidence increases with age; the median age at diagnosis is 67 years. The diagnosis of PCa is essentially based on three tools: digital rectal exam, serum concentration of prostate specific antigen, and transrectal ultrasound-guided biopsy. Currently, the therapeutic treatments of this cancer are different and range from the prostatectomy to hormonal therapy, to radiation therapy, to immunotherapy, and to chemotherapy. However, additional efforts are required in order to find new weapons for the treatment of metastatic setting of disease. The purpose of this review is to highlight new therapeutic strategies based on gene interference; in fact, numerous siRNA and miRNA in the therapeutic treatment of PCa are reported below.