Expression of the Androgen-Regulated Fusion Gene TMPRSS2-ERG Does Not Predict Response to Endocrine Treatment in Hormone-Naïve,Node-Positive Prostate Cancer

Background

Fusion of the androgen-regulated gene transmembrane protease, serine 2, TMPRSS2, to the v-ets erythroblastosis virus E26 oncogene homolog (avian), ERG, of the erythroblast transformation-specific (ETS) family is the most common genetic alteration in prostate cancer (PCa).

Objective

To determine whether expression of androgen-regulated TMPRSS2-ERG predicts response to endocrine treatment in hormone-naïve, node-positive PCa.

Design, setting, and participants

Eighty-five patients with histologically confirmed, node-positive PCa who were without treatment at the moment of lymph node dissection were analysed. RNA was isolated from the paraffin-embedded lymph node metastases and complementary DNA (cDNA) was made. The quality of cDNA was tested by polymerase chain reaction (PCR) analysis of the expression of the housekeeping gene hydroxymethylbilane synthase, HMBS (formerly PBGD). TMPRSS2-ERG expression was analysed by PCR using a forward primer in TMPRSS2 exon 1 and a reverse primer in ERG exon 4.

Measurements

The primary end point was time from start of endocrine therapy to the occurrence of three consecutive rises in prostate-specific antigen (PSA) that were at least 2 wk apart and resulted in two 50% increases over the PSA nadir. Secondary end points were time to PSA nadir after start of endocrine treatment and cancer-specific and overall survival.

Results and limitations

TMPRSS2-ERG was expressed in 59% of the 71 patients who could be analysed. Median duration of response to endocrine therapy was 20.9 mo versus 24.1 mo for gene fusion–positive versus gene fusion–negative patients (95% confidence intervals: 18.6–23.1 vs 18.9–29.4, p = 0.70). Furthermore, no significant differences were seen between the two groups for the secondary end points.

Conclusions

Expression of TMPRSS2-ERG is frequent in lymph node metastases of patients with untreated PCa; however, expression of this androgen-regulated fusion gene did not correspond with duration of response to endocrine therapy. Our results suggest that expression of TMPRSS2-ERG is not a candidate marker to select for metastatic PCa patients who will benefit more from endocrine treatment.     

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

Background

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

Objective

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

Design, setting, and participants

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

Outcome measurements and statistical analysis

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

Results and limitations

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

Conclusions

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

PSA doubling time versus PSA velocity to predict high-risk prostate cancer: data from the Baltimore Longitudinal Study of Aging

Background

Our group has previously shown that prostate-specific antigen (PSA) velocity (PSAV) is associated with the presence of life-threatening prostate cancer. Less is known about the relative utility of pretreatment PSA doubling time (PSA DT) to predict tumor aggressiveness.

Objective

To compare the utility of PSAV and PSA DT for the prediction of life-threatening prostate cancer.

Design, setting, and participants

From the Baltimore Longitudinal Study of Aging, we identified 681 men with serial PSA measurements.

Measurements

Receiver operating characteristic analysis was used to evaluate the relationship between PSAV, PSA DT, and the presence of high-risk disease.

Results and limitations

Within the period of 5 yr prior to diagnosis, PSAV was significantly higher among men with high-risk or fatal prostate cancer than men without it. By contrast, PSA DT was not significantly associated with high-risk or fatal disease. On multivariate analysis, including age, date of diagnosis, and PSA, the addition of PSAV significantly improved the concordance index from 0.85 to 0.88 (p < 0.001), whereas PSA DT did not.

Conclusions

These data suggest that PSAV is more useful than PSA DT in the pretreatment setting to help identify those men with life-threatening disease.     

Metformin and Prostate Cancer: Reduced Development of Castration-resistant Disease and Prostate Cancer Mortality

Background

In vitro data and early clinical results suggest that metformin has desirable antineoplastic effects and has a theoretical benefit on castration-resistant prostate cancer (CRPC).

Objective

To determine whether the use of metformin would be associated with improved clinical outcomes and a reduction in the development of CRPC.

Design, setting, and participants

Data from 2901 consecutive patients (157 metformin, 162 diabetic non-metformin, and 2582 nondiabetic) with localized prostate cancer treated with external-beam radiation therapy from 1992 to 2008 were collected from a single institution in the United States.

Intervention

Use of metformin in localized prostate cancer.

Outcome measurements and statistical analysis

Univariate and multivariate regression models utilizing k-sample, Fine and Gray, Cox regression, log-rank, and Kaplan-Meier methods to assess prostate-specific antigen-recurrence-free survival (PSA-RFS), distant metastases-free survival (DMFS), prostate cancer–specific mortality (PCSM), overall survival (OS), and development of CRPC.

Results and limitations

With a median follow-up of 8.7 yr, the 10-yr actuarial rates for metformin, diabetic non-metformin, and nondiabetic patients for PCSM were 2.7%, 21.9%, and 8.2% (log-rank p ≤ 0.001), respectively. Metformin use independently predicted (correcting for PSA, T stage, Gleason score, age, diabetic status, and androgen-deprivation therapy use) improvement in all outcomes compared with the diabetic non-metformin group; PSA-RFS (hazard ratio [HR]: 1.99 [1.24–3.18]; p = 0.004), DMFS (adjusted HR: 3.68 [1.78–7.62]; p < 0.001), and PCSM (HR: 5.15 [1.53–17.35]; p = 0.008). Metformin use was also independently associated with a decrease in the development of CRPC in patients experiencing biochemical failure compared with diabetic non-metformin patients (odds ratio: 14.81 [1.83–119.89]; p = 0.01). The retrospective study design was the primary limitation of the study.

Conclusions

To our knowledge, our results are the first clinical data to indicate that metformin use may improve PSA-RFS, DMFS, PCSM, OS, and reduce the development of CRPC in prostate cancer patients. Further validation of metformin's potential benefits is warranted.     

A panel of TMPRSS2:ERG fusion transcript markers for urine-based prostate cancer detection with high specificity and sensitivity

Background

The TMPRSS2:ERG fusion is both prevalent and unique to prostate cancer (PCa) and has great potential for noninvasive diagnosis of PCa in bodily fluids.

Objectives

To evaluate the specificity and sensitivity of the TMPRSS2:ERG fusion in urine from diverse clinical contexts and to explore potential clinical applications.

Design, setting, and participants

A total of 101 subjects were enrolled in 2008 from urologic oncology clinics to form three study groups: 44 PCa free, 46 confirmed PCa, and 11 negative prostate biopsies. The PCa-free group included females, healthy young men, and post–radical prostatectomy (RP) patients. The confirmed PCa group was composed of patients under active surveillance, scheduled for treatment, or with metastatic disease.

Measurements

Urine was collected after attentive digital rectal exam (DRE) and coded to blind group allocation for laboratory test. RNA from urine sediments was analyzed using a panel of four TMPRSS2:ERG fusion markers with quantitative polymerase chain reaction (qPCR).

Results and limitations

Our fusion markers demonstrated very high technical specificity and sensitivity for detecting a single fusion-positive cancer cell (VCaP) in the presence of at least 3000 cells in urine sediments. In clinical analysis, there were no fusion-positive samples in the PCa-free group (0 of 44 samples), while there were 16 of 46 (34.8%) fusion-positive samples in the confirmed PCa group. The fusion incidence varied significantly among the three PCa subgroups. The clinical sensitivity increased to 45.4% in cancer patients prior to treatments. The fusion markers were detected in 2 of 11 (18.2%) biopsy-negative patients, suggesting potentially false negative biopsies. This study is not prospective and is limited in sample sizes.

Conclusions

Our novel panel of TMPRSS2:ERG fusion markers provided a very specific and sensitive tool for urine-based detection of PCa. Theses markers can potentially be used to diagnose patients with PCa who have negative biopsies.     

A 36-gene Signature Predicts Clinical Progression in a Subgroup of ERG-positive Prostate Cancers

Background

The molecular basis of the clinical heterogeneity of prostate cancer (PCa) is not well understood.

Objective

The purpose of our study was to identify and characterize genes in a clinically relevant gene expression signature in a subgroup of primary PCa positive for transmembrane protease, serine 2 (TMPRSS2)–v-ets erythroblastosis virus E26 oncogene homolog (avian) (ERG).

Design, setting, and participants

We studied gene expression profiles by unsupervised hierarchical clustering in 48 primary PCas from patients with a long clinical follow-up. Results were correlated with clinical outcome and validated in an independent patient cohort. Selected genes from a defined classifier were tested in vitro for biologic properties.

Intervention

Initial treatment of primary tumors was radical prostatectomy.

Outcome measurements and statistical analysis

Associations between clinical and histopathologic variables were evaluated by the Pearson χ² test, Mann-Whitney U test, or Kruskal-Wallis test, where appropriate. The log-rank test or Breslow method was used for statistical analysis of Kaplan-Meier survival curves.

Results and limitations

Most tumors that overexpressed ERG clustered separately from other primary PCas. No differences in any clinical end points between ERG-positive and ERG-negative cancers were detected. Importantly, within the ERG-positive samples, two subgroups were identified, which differed significantly in prostate-specific antigen recurrence-free survival, and cancer-specific and overall survival. From our findings, we defined a gene expression classifier of 36 genes. In a second, completely independent tumor set, the classifier also distinguished ERG-positive subgroups with different clinical outcome. In both patient cohorts, the classifier was not predictive in ERG-negative tumors. Biologic processes regulated by genes in the classifier included cell adhesion and bone remodeling. Tumor growth factor-β signaling was indicated as the main differing signaling pathway between the two ERG subgroups. In vitro biologic assays of two selected genes from the classifier (inhibin, beta A [INHBA] and cadherin 11, type 2, OB-cadherin (osteoblast) [CDH11]) supported a functional role in PCa progression. Possible multifocality and limited number of PCa samples can be limitations of the study.

Conclusions

The classifier identified can contribute to prediction of tumor progression in ERG-positive primary prostate tumors and might be instrumental in therapy decisions.     

A Population-based Assessment of Germline HOXB13 G84E Mutation and Prostate Cancer Risk

Background

A rare but recurrent missense mutation (G84E, rs138213197) in the gene homeobox B13 (HOXB13) was recently reported to be associated with hereditary prostate cancer.

Objective

To explore the prevalence and penetrance of HOXB13 G84E in a general population.

Design, setting, and participants

G84E and 14 additional HOXB13 polymorphisms were genotyped in two population-based, Swedish, case-control samples (Cancer of the Prostate in Sweden [CAPS] and Stockholm-1) comprising 4693 controls and 5003 prostate cancer cases. CAPS collected data on patients and population controls nationally between 2001 and 2003. Stockholm-1 collected data on biopsy-positive patients and biopsy-negative controls in the Stockholm area between 2005 and 2007.

Outcome measurements and statistical analysis

The outcome was pathologically verified prostate cancer. Relative and absolute risks among HOXB13 G84E mutation carriers were explored, as was the combined impact on disease risk of G84E and a polygenic score based on 33 established, common, low-risk variants.

Results and limitations

HOXB13 G84E was observed in 1.3% of population controls and was strongly associated with prostate cancer risk (CAPS: odds ratio [OR]: 3.4; 95% confidence interval [CI], 2.2–5.4; Stockholm-1: OR: 3.5; 95% CI, 2.4–5.2). The strongest association was observed for young-onset (OR: 8.6; 95% CI, 5.1–14.0) and hereditary (OR: 6.6; 95% CI, 3.3–12.0) prostate cancer. Haplotype analyses supported that G84E is a founder mutation. G84E carriers have an estimated 33% (95% CI, 23–46) cumulative risk to age 80 yr of prostate cancer, compared to 12% (95% CI, 11–13) among noncarriers. For G84E carriers within the top quartile of a polygenic score of established susceptibility variants, the cumulative risk was estimated at 48% (95% CI, 36–64).

Conclusions

HOXB13 G84E is prevalent in >1% of the Swedish population and is associated with a 3.5-fold increased risk of prostate cancer. One-third of G84E carriers will be diagnosed with prostate cancer, which has implications for surveillance in mutation carriers.     

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

Background

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

Objective

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

Design, setting, and participants

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

Outcome measurements and statistical analysis

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

Results and limitations

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

Conclusions

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

Pharmacological Approaches to Reducing the Risk of Prostate Cancer

Context

It is now possible to reduce a man's risk of developing biopsy-detectable prostate cancer. This review addresses the evidence and issues surrounding prostate cancer risk reduction.

Objective

The scientific basis, therapeutic approach, and risks and benefits of prostate cancer prevention are reviewed. Special attention is given to data on 5α-reductase inhibitors (5-ARIs).

Evidence acquisition

Medline searches consisted of articles published since 2003 regarding prostate cancer chemoprevention, prevention, or risk reduction, as well as searches around specific topics within this review.

Evidence synthesis

Current data support the use of finasteride for prostate cancer risk reduction in appropriately selected men. The initial concern that finasteride increased the incidence of high-grade prostate cancer has not been confirmed by subsequent analyses. The efficacy of dutasteride, a dual 5-ARI, for prostate cancer risk reduction is currently being evaluated in men with elevated prostate-specific antigen (PSA). Other medical approaches to prostate cancer risk reduction, including statins, cyclooxygenase-2 (COX-2) inhibitors, selective estrogen receptor modulators, and dietary supplements, await validation in controlled clinical trials.

Conclusions

It is now possible to reduce an individual man's risk of developing biopsy-detectable prostate cancer. The greatest benefit arises from decreasing the amount of unnecessary treatment in men harboring low-risk cancers. Presently, there is no evidence that 5-ARIs or any other approach to prostate cancer risk reduction will reduce the risk of lethal prostate cancers. Finasteride, however, does enhance the utility of PSA for diagnosing high-grade cancers.     

The Evolving Role of Oestrogens and Their Receptors in the Development and Progression of Prostate Cancer

Context

Oestrogens were proven effective in the hormonal treatment of advanced prostate cancer (PCa) >60 yr ago and are still used as second-line hormonal therapy. Paradoxically, oestrogens might also be involved in the development and progression of PCa.

Objective

To examine mechanisms of how oestrogens may affect prostate carcinogenesis and tumour progression.

Evidence acquisition

Recent data obtained from animal, experimental, and clinical studies were reviewed.

Evidence synthesis

The human prostate is equipped with a dual system of oestrogen receptors (oestrogen receptor alpha [ERα], oestrogen receptor beta [ERβ]) that undergoes profound remodelling during PCa development and tumour progression. In high-grade prostatic intraepithelial neoplasia (HGPIN), the ERα is upregulated and most likely mediates carcinogenic effects of estradiol as demonstrated in animal models. Preliminary clinical studies with the ERα antagonist toremifene have identified the ERα as a promising target for PCa prevention. The partial loss of the ERβ in HGPIN indicates that the ERβ acts as a tumour suppressor. The ERβ is generally retained in hormone-naïve PCa but is partially lost in castration-resistant disease. The progressive emergence of the ERα and the oestrogen-regulated progesterone receptor (PR) during PCa progression and hormone-refractory disease suggests that these tumours can use oestrogens and progestins for their growth. The TMPRSS2-ERG gene fusion recently reported as a potentially aggressive molecular subtype of PCa is regulated by ER-dependent signalling. TMPRSS2-ERG expression has been found to be increased by ERα agonist (oestrogens) and decreased by ERβ agonists.

Conclusions

Oestrogens and their receptors are implicated in PCa development and tumour progression. There is significant potential for the use of ERα antagonists and ERβ agonists to prevent PCa and delay disease progression. Tumours equipped with the pertinent receptors are potential candidates for this new therapeutic approach.     

Concordance of tumor differentiation among brothers with prostate cancer

Background

Genetic factors seem to be of greater importance in prostate cancer than in other forms of cancer. Studies have suggested familial concordance in survival, but the extent to which that is due to tumor characteristics is not known.

Objective

We hypothesized that a brother of an index case with prostate cancer is at particularly increased risk of prostate cancer with the same tumor differentiation as the index case.

Design, setting and participants

We identified 21 930 brothers of index cases with prostate cancer in the Prostate Cancer Data Base Sweden and followed them up for incidence of prostate cancer.

Outcome measurements and statistical analysis

The relative risk of Gleason score–specific prostate cancer in the cohort of brothers was estimated by using the standardized incidence ratio (SIR) stratified by Gleason score of the index case. We estimated 95% confidence intervals (CIs) assuming a Poisson distribution.

Results and limitations

Among brothers of index cases with Gleason score 8–10 cancer, the SIR was 2.53 (95% CI, 1.97–3.21) for a Gleason score 2–6 cancer and 4.00 (95% CI, 2.63–5.82) for a Gleason score 8–10 cancer. SIR for Gleason score 2–6 cancer among brothers decreased with time since the date of the index cases’ diagnoses, whereas the risk of Gleason 8–10 cancer increased over time for brothers of index cases with Gleason 8–10 cancer (p for trend = 0.009).

Conclusions

Brothers of men with high-grade prostate cancer are at particularly increased risk of high-grade prostate cancer. Likewise, there is a concordance of less malignant prostate cancers within families. These findings may have direct clinical relevance for counseling men with a family history of prostate cancer.     

Multicenter European External Validation of a Prostate Health Index–based Nomogram for Predicting Prostate Cancer at Extended Biopsy

Background

External validation of a prediction tool is mandatory to assess the tool's accuracy and generalizability within different patient cohorts.

Objective

To externally validate a previously developed Prostate Health Index (PHI)–based nomogram for predicting the presence of prostate cancer (PCa) at biopsy.

Design, setting, and participants

The study population consisted of 883 patients who were scheduled for a prostate biopsy at one of five European tertiary care centers. Total prostate-specific antigen (tPSA), free prostate-specific antigen (fPSA), and [−2]pro–prostate-specific antigen (p2PSA) levels were determined. The fPSA-to-tPSA ratio (%fPSA), p2PSA, and PHI ([p2PSA / fPSA] × √tPSA) were calculated.

Intervention

Extended initial and repeat prostate biopsy.

Outcome measurements and statistical analysis

Logistic regression models were fitted to test the predictors of PCa and to determine their predictive accuracy. A calibration plot was used to evaluate the extent of overestimation or underestimation between nomogram predictions and observed PCa rate. Decision curve analysis (DCA) provided an estimate of the net benefit obtained by using the PHI-based nomogram.

Results and limitations

Of 833 patients, 365 (41.3%) were diagnosed with PCa at extended prostate biopsy. In accuracy analyses, PHI was the most informative predictor of PCa (0.68), outperforming tPSA (0.51) and %fPSA (0.64). The predictive accuracy of the previously developed nomogram was 75.2% (95% confidence interval, 71.4–78.1). Calibration of the nomogram was good in patients at a low to intermediate predicted probability of PCa, while calibration was suboptimal, with a tendency to overestimate the presence of PCa, in high-risk patients. Finally, DCA demonstrated that the use of the PHI-based nomogram resulted in the highest net benefit. The main limitation of the study is the fact that only Caucasian patients were included.

Conclusions

At external validation, the previously developed PHI-based nomogram confirmed its ability to determine the presence of PCa at biopsy. These findings provide further evidence supporting the potential role of the nomogram in the biopsy decision pathway for European men with suspected PCa.

Patient summary

In the current study, we externally validated a Prostate Health Index–based nomogram to predict the presence of prostate cancer (PCa) at biopsy. This tool may help clinicians determine the need for a prostate biopsy in European patients with suspected PCa.     

Observed correlation between the expression levels of catalytic subunit,Cβ2, of cyclic adenosine monophosphate–dependent protein kinase and prostate cancer aggressiveness

Background

Today overtreatment of indolent prostate cancers and undertreatment of aggressive prostate cancer are a major concern for patients, their families, and the health care system. New biomarkers distinguishing indolent and aggressive prostate cancer are needed to improve precision medicine. In prostate cancer, protein kinase A (PKA) is known to activate the androgen receptor and published data indicate that PKA subunits can act as predictive markers for response to radiation and chemotherapy. We have previously shown that the catalytic subunit, Cβ2, of PKA is up-regulated in prostate cancer and we would in this study investigate the potential of Cβ2 to become a prognostic biomarker in prostate cancer.

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

Background

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

Objective

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

Design, setting, and participants

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

Intervention

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

Measurements

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

Results and limitations

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

Conclusions

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

Oncologic Outcome after Laparoscopic Radical Prostatectomy: 10 Years of Experience

Background

While the published short-term oncologic outcomes after laparoscopic radical prostatectomy (LRP) are encouraging, intermediate and long-term data are lacking.

Objective

We analyzed the oncologic outcome after LRP based on 10 yr of experience.

Design, setting, and participants

This retrospective analysis of data prospectively collected from 1998 to 2007 studies 1564 consecutive patients with clinically localized prostate cancer (cT1c–cT3a) who underwent LRP.

Intervention

LRP was performed by two surgeons at either L’Institut Mutualiste Montsouris (IMM) in Paris, France, or Memorial Sloan-Kettering Cancer Center (MSKCC) in New York City, USA.

Measurements

Progression of disease was defined as a prostate-specific antigen (PSA) of ≥0.1 ng/ml with confirmatory rise or initiation of secondary therapy. Patients were stratified as low, intermediate, or high risk based on the pretreatment prostate cancer nomogram progression-free probability of >90%, 89–71%, and <70%, respectively.

Results and limitations

The overall 5-yr and 8-yr probability of freedom from progression (PFP) was 78% (95% confidence interval [CI], 74–82%) and 71% (95% CI, 63–78%), respectively. For low-, intermediate-, and high-risk cancer, the 5-yr PFP was 91% (95% CI, 85–95%), 77% (95% CI, 71–82%), and 53% (95% CI, 40–65%), respectively. Surgical margins (SMs) were positive in 13% of the cases. Nodal metastases were detected in 3% of the patients after limited pelvic lymph node dissection (PLND) and in 10% after a standard PLND (p < 0.001). The 3-yr PFP for node-positive patients was 49%. There were 22 overall deaths and 2 deaths from prostate cancer.

Conclusions

LRP provided 5- and 8-yr cancer control in 78% and 71% of patients, respectively, with clinically localized prostate cancer and in 53% of those with high-risk cancer at 5 yr. A PLND limited to the external iliac nodal group is inadequate for detecting nodal metastases.     

Hedgehog signalling in androgen independent prostate cancer

Objectives

Androgen-deprivation therapy effectively shrinks hormone-naïve prostate cancer, both in the prostate and at sites of distant metastasis. However prolonged androgen deprivation generally results in relapse and androgen-independent tumour growth, which is inevitably fatal. The molecular events that enable prostate cancer cells to proliferate in reduced androgen conditions are poorly understood. Here we investigate the role of Hedgehog signalling in androgen-independent prostate cancer (AIPC).

Methods

Activity of the Hedgehog signalling pathway was analysed in cultured prostate cancer cells, and circulating prostate tumour cells were isolated from blood samples of patients with AIPC.

Results

AIPC cells were derived through prolonged culture in reduced androgen conditions, modelling hormone therapy in patients, and expressed increased levels of Hedgehog signalling proteins. Exposure of cultured AIPC cells to cyclopamine, which inhibits Hedgehog signalling, resulted in inhibition of cancer cell growth. The expression of the Hedgehog receptor PTCH and the highly prostate cancer–specific gene DD3^PCA3 was significantly higher in circulating prostate cancer cells isolated from patients with AIPC compared with samples prepared from normal individuals. There was an association between PTCH and DD3^PCA3 expression and the length of androgen-ablation therapy.

Conclusions

Our data are consistent with reports implicating overactivity of Hedgehog signalling in prostate cancer and suggest that Hedgehog signalling contributes to the androgen-independent growth of prostate cancer cells. As systemic anti-Hedgehog medicines are developed, the Hedgehog pathway will become a potential new therapeutic target in advanced prostate cancer.     

A Negative Confirmatory Biopsy Among Men on Active Surveillance for Prostate Cancer Does Not Protect Them from Histologic Grade Progression

Background

Many men (21–52%) are reported to have no cancer on the second, also known as the confirmatory, biopsy (B2) for prostate cancer active surveillance (AS). If these men had a reduced risk of pathologic progression, particularly grade related, the intensity of their follow-up could be decreased.

Objective

To investigate if men with no cancer on B2 are less likely to undergo subsequent pathologic progression.

Design, setting, and participants

Men were identified from our tertiary care center AS prostate cancer database (1995–2012). Eligibility criteria were prostate-specific antigen (PSA) ≤10, cT2 or lower, no Gleason grade 4 or 5, three or fewer positive cores, and no core >50% involved. Only patients with three or more biopsies were selected and then dichotomized on cancer status (yes or no) at B2.

Intervention

AS.

Outcome measurements and statistical analysis

Pathologic progression was defined as grade (advancement in Gleason score) and/or volume (more than three positive cores, >50% core involved). Progression-free survival was compared. Predictors of progression were investigated using a Cox proportional hazards model.

Results and limitations

Of the 286 patients remaining on AS after B2, 149 (52%) had no cancer and 137 (48%) had cancer. The median follow-up after B2 was 41 mo (interquartile range [IQR]: 26.5–61.9). Progression-free survival at 5 yr was 85.2% versus 67.3% for negative B2 versus cancer on B2, respectively (p = 0.002). Men with no cancer at B2 had a 53% reduction in risk of subsequent progression (hazard ratio [HR]: 0.47; 95% confidence interval [CI], 0.29–0.77; p = 0.003). Subanalysis showed prognostic indicators of volume-related progression were absence of cancer (HR: 0.36; 95% CI, 0.20–0.62; p = 0.0006) and PSA density (HR: 1.79; 95% CI, 1.12–2.89; p = 0.01). The only predictor of grade-related progression was age (HR: 1.05; 95% CI, 1.00–1.10; p = 0.04). Retrospective analysis was the major limitation of the study.

Conclusions

Absence of cancer on B2 is associated with a significantly decreased risk of volume-related but not grade-related progression. This must be considered when counseling men on AS.     

Functional Magnetic Resonance Imaging in Prostate Cancer

Context

Magnetic resonance imaging (MRI) combined with magnetic resonance spectroscopy imaging (MRSI), dynamic contrast-enhanced MRI, and diffusion-weighted MRI emerged as promising tests in the diagnosis of prostate cancer, and they show encouraging results.

Objective

This review emphasizes different functional MRI techniques in the diagnosis of prostate cancer and includes information about their clinical value and usefulness.

Evidence acquisition

The authors searched the Medline, Embase, and Cochrane Library databases. There were no language restrictions. The last search was performed in October 2008.

Evidence synthesis

The combination of conventional MRI with functional MRI techniques is more reliable for differentiating benign and malignant prostate tissues than any other diagnostic procedure. At present, no guideline is available that outlines which technique is best in a specific clinical situation. It also remains uncertain whether improved spatial resolution and signal-to-noise ratio of 3-T MRI will improve diagnostic performance.

Conclusions

A limited number of small studies suggest that functional MRI may improve the diagnosis and staging of prostate cancer. This finding needs further confirmation in larger studies, and cost-effectiveness needs to be established.     

Lifestyle Changes for Improving Disease-specific Quality of Life in Sedentary Men on Long-term Androgen-Deprivation Therapy for Advanced Prostate Cancer: A Randomised Controlled Trial

Background

Prostate cancer is a key driver of cancer-related global disability-adjusted life-years. Androgen-deprivation therapy (ADT) for advanced disease is linked to fatigue, reduced physical function, and quality of life (QoL).

Objective

To evaluate the effect of a lifestyle intervention on disease-specific QoL, diastolic blood pressure, and cancer-related fatigue in sedentary men receiving long-term ADT for advanced prostate cancer.

Design, setting, and participants

A total of 100 hundred sedentary men with locally advanced or metastatic prostate cancer on long-term ADT were randomised to an intervention or usual care group.

Intervention

A 12-wk lifestyle intervention consisting of aerobic and resistance exercise with parallel dietary advice.

Outcome measurements and statistical analysis

Disease-specific QoL was measured using the Functional Assessment of Cancer Therapy-Prostate (FACT-P) and Functional Assessment of Cancer Therapy-Fatigue (FACT-F) questionnaires at 12 wk postintervention and at 6 mo following withdrawal of support. Analysis of covariance and mixed regression were conducted.

Results and limitations

Clinically relevant improvements in FACT-P were seen at 12 wk in the intervention group compared with controls (mean difference: 8.9 points; 95% confidence interval [CI], 3.7–14.2; adjusted p = 0.001). No difference was apparent at 6 mo (mean difference: 3.3 points; 95% CI, −2.6 to 9.3; adjusted p = 0.27). No difference in diastolic blood pressure was seen at either follow-up (all p > 0.05). Clinically relevant improvements in FACT-F were seen at 12 wk (mean difference: 5.3 points; 95% CI, 2.7–7.9; adjusted p < 0.001) and maintained following withdrawal of supervision (mean difference: 3.9 points; 95% CI, 1.1–6.8; adjusted p = 0.007). Improvements in exercise tolerance and behaviour were maintained at 6 mo (adjusted p < 0.001 and 0.038).

Conclusions

A lifestyle intervention resulted in a clinically meaningful improvement in disease-specific QoL that was not maintained postintervention. No effect on blood pressure occurred. Durability of response was seen in fatigue and exercise behaviour. Further evaluation of support structures is essential.

Trial registration

ISRCTN88605738.