Antti Rannikko

MRI-Targeted or Standard Biopsy for Prostate-Cancer Diagnosis

Background Multiparametric magnetic resonance imaging (MRI), with or without targeted biopsy, is an alternative to standard transrectal ultrasonography–guided biopsy for prostate‐cancer detection in men with a raised prostate‐specific antigen level who have not undergone biopsy. However, comparative evidence is limited. Methods In a multicenter, randomized, noninferiority trial, we assigned men with a clinical suspicion of prostate cancer who had not undergone biopsy previously to undergo MRI, with or without targeted biopsy, or standard transrectal ultrasonography–guided biopsy. Men in the MRI‐targeted biopsy group underwent a targeted biopsy (without standard biopsy cores) if the MRI was suggestive of prostate cancer; men whose MRI results were not suggestive of prostate cancer were not offered biopsy. Standard biopsy was a 10‐to‐12–core, transrectal ultrasonography–guided biopsy. The primary outcome was the proportion of men who received a diagnosis of clinically significant cancer. Secondary outcomes included the proportion of men who received a diagnosis of clinically insignificant cancer. Results A total of 500 men underwent randomization. In the MRI‐targeted biopsy group, 71 of 252 men (28%) had MRI results that were not suggestive of prostate cancer, so they did not undergo biopsy. Clinically significant cancer was detected in 95 men (38%) in the MRI‐targeted biopsy group, as compared with 64 of 248 (26%) in the standard‐biopsy group (adjusted difference, 12 percentage points; 95% confidence interval [CI], 4 to 20; P=0.005). MRI, with or without targeted biopsy, was noninferior to standard biopsy, and the 95% confidence interval indicated the superiority of this strategy over standard biopsy. Fewer men in the MRI‐targeted biopsy group than in the standard‐biopsy group received a diagnosis of clinically insignificant cancer (adjusted difference, ‐13 percentage points; 95% CI, ‐19 to ‐7; P<0.001). Conclusions The use of risk assessment with MRI before biopsy and MRI‐targeted biopsy was superior to standard transrectal ultrasonography–guided biopsy in men at clinical risk for prostate cancer who had not undergone biopsy previously. (Funded by the National Institute for Health Research and the European Association of Urology Research Foundation; PRECISION ClinicalTrials.gov number, NCT02380027.)

Diffusion-weighted magnetic resonance imaging in prostate cancer patients on active surveillance one year after diagnosis and before repeat biopsy

Abstract Objective. The aim of this study was to evaluate prospectively whether diffusion-weighted magnetic resonance imaging (DW-MRI), interpreted in a routine clinical setting, can serve as a diagnostic and prognostic tool for prostate carcinoma patients on active surveillance (AS). Material and methods. Eighty men enrolled in the Finnish arm of the PRIAS (Prostate Cancer Research International: Active Surveillance) study were followed for at least 1 year and had DW-MRI scans taken in addition to repeat biopsy. Spearmans correlations were analysed between tumour appearance on DW-MRI and clinical variables [age, prostate-specific antigen (PSA), free PSA, PSA doubling time, prostate volume, percentage of cancer at diagnostic biopsy]. The Pearson chi-squared test clarified associations between outcome factors (number of positive cores and Gleason score on repeat biopsy, treatment change) and DW-MRI results. Assumed predictors of deferred radical treatment were examined with logistic regression analysis. Accuracy of tumour localization by DW-MRI compared to repeat biopsy findings was analysed by the chi-squared test. Results. DW-MRI revealed an anatomical lesion suggestive of cancer in 40 patients (50%). MRI positivity showed no significant correlation with clinical variables. No associations existed between tumour appearance on DW-MRI and biopsy findings or discontinuation of AS. The only variable predicting treatment change was higher PSA at discontinuation (p = 0.002). Appearance of tumour, either on T2-weighted MRI (p = 0.273) or on apparent diffusion coefficient maps (p = 0.691), was not a significant predictor of treatment change. Conclusions. Localized low-grade prostate cancer is challenging to visualize in DW-MRI, and this imaging technique provides no additional prognostic benefit compared to PSA and repeat biopsies.

Loss of PTEN expression in ERG-negative prostate cancer predicts secondary therapies and leads to shorter disease-specific survival time after radical prostatectomy

The clinical course of prostate cancer is highly variable. Current prognostic variables, stage, and Gleason score have limitations in assessing treatment regimens for individual patients, especially in the intermediate-risk group of Gleason score 7. ERG:TMPRSS2 fusion and loss of PTEN are some of the most common genetic alterations in prostate cancer. Immunohistochemistry of PTEN and ERG has generated interest as a promising method for more precise outcome prediction but requires further validation in population-based cohorts. We studied the predictive value of ERG and PTEN expression by immunohistochemistry in two large radical prostatectomy cohorts comprising 815 patients with extensive follow-up information. Clinical end points were initiation of secondary therapy, overall survival, and disease-specific survival. Predictions of clinical outcomes were also assessed according to androgen receptor (AR) activity. PTEN loss, especially in ERG-negative cancers, predicted initiation of secondary treatments and shortened disease-specific survival time, as well as stratifying Gleason score 7 patients into different prognostic groups with regard to secondary treatments and disease-specific survival. High AR immunoreactivity in ERG-negative cancers with PTEN loss predicted worse disease-specific survival. We also observed that in Gleason score 7 ERG-negative cases with PTEN loss and high AR expression have significantly shorter disease-specific survival time compared with ERG-positive cases. Our conclusion is that loss of PTEN is a strong determining factor for shorter disease-specific survival time and initiation of secondary therapies after radical prostatectomy. The predictive value of PTEN immunoreactivity is further accentuated in ERG-negative cancers with high AR expression. Negative PTEN expression, accompanied by ERG status, can be used to stratify patients with Gleason score 7 into different survival groups. Assessment of PTEN and ERG status could provide an additional tool for initial diagnostics when determining the prognosis and subsequent follow-up regimen for patients treated by radical prostatectomy.

Metabolomic Profiling of Extracellular Vesicles and Alternative Normalization Methods Reveal Enriched Metabolites and Strategies to Study Prostate Cancer-Related Changes

Body fluids are a rich source of extracellular vesicles (EVs), which carry cargo derived from the secreting cells. So far, biomarkers for pathological conditions have been mainly searched from their protein, (mi)RNA, DNA and lipid cargo. Here, we explored the small molecule metabolites from urinary and platelet EVs relative to their matched source samples. As a proof-of-concept study of intra-EV metabolites, we compared alternative normalization methods to profile urinary EVs from prostate cancer patients before and after prostatectomy and from healthy controls. Methods: We employed targeted ultra-performance liquid chromatography-tandem mass spectrometry to profile over 100 metabolites in the isolated EVs, original urine samples and platelets. We determined the enrichment of the metabolites in the EVs and analyzed their subcellular origin, pathways and relevant enzymes or transporters through data base searches. EV- and urine-derived factors and ratios between metabolites were tested for normalization of the metabolomics data. Results: Approximately 1 x 1010 EVs were sufficient for detection of metabolite profiles from EVs. The profiles of the urinary and platelet EVs overlapped with each other and with those of the source materials, but they also contained unique metabolites. The EVs enriched a selection of cytosolic metabolites including members from the nucleotide and spermidine pathways, which linked to a number of EV-resident enzymes or transporters. Analysis of the urinary EVs from the patients indicated that the levels of glucuronate, D-ribose 5-phosphate and isobutyryl-L-carnitine were 2-26-fold lower in all pre-prostatectomy samples compared to the healthy control and post-prostatectomy samples (p < 0.05). These changes were only detected from EVs by normalization to EV-derived factors or with metabolite ratios, and not from the original urine samples. Conclusions: Our results suggest that metabolite analysis of EVs from different samples is feasible using a high-throughput platform and relatively small amount of sample material. With the knowledge about the specific enrichment of metabolites and normalization methods, EV metabolomics could be used to gain novel biomarker data not revealed by the analysis of the original EV source materials.

Comprehensive Drug Testing of Patient-derived Conditionally Reprogrammed Cells from Castration-resistant Prostate Cancer

BACKGROUND Technology development to enable the culture of human prostate cancer (PCa) progenitor cells is required for the identification of new, potentially curative therapies for PCa. OBJECTIVE We established and characterized patient-derived conditionally reprogrammed cells (CRCs) to assess their biological properties and to apply these to test the efficacies of drugs. DESIGN, SETTING, AND PARTICIPANTS CRCs were established from seven patient samples with disease ranging from primary PCa to advanced castration-resistant PCa (CRPC). The CRCs were characterized by genomic, transcriptomic, protein expression, and drug profiling. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS The phenotypic quantification of the CRCs was done based on immunostaining followed by image analysis with Advanced Cell Classifier using Random Forest supervised machine learning. Copy number aberrations (CNAs) were called from whole-exome sequencing and transcriptomics using in-house pipelines. Dose-response measurements were used to generate multiparameter drug sensitivity scores using R-statistical language. RESULTS AND LIMITATIONS We generated six benign CRC cultures which all had an androgen receptor-negative, basal/transit-amplifying phenotype with few CNAs. In three-dimensional cell culture, these cells could re-express the androgen receptor. The CRCs from a CRPC patient (HUB.5) displayed multiple CNAs, many of which were shared with the parental tumor. We carried out high-throughput drug-response studies with 306 emerging and clinical cancer drugs. Using the benign CRCs as controls, we identified the Bcl-2 family inhibitor navitoclax as the most potent cancer-specific drug for the CRCs from a CRPC patient. Other drug efficacies included taxanes, mepacrine, and retinoids. CONCLUSIONS Comprehensive cancer pharmacopeia-wide drug testing of CRCs from a CRPC patient highlighted both known and novel drug sensitivities in PCa, including navitoclax, which is currently being tested in clinical trials of CRPC. PATIENT SUMMARY We describe an approach to generate patient-derived cancer cells from advanced prostate cancer and apply such cells to discover drugs that could be applied in clinical trials for castration-resistant prostate cancer.

KeepEX, a simple dilution protocol for improving extracellular vesicle yields from urine

&NA; Urinary extracellular vesicles (EVs) are a promising source of biomarkers, which can be obtained in a non‐invasive manner. However, the yield of EVs from urine samples may be insufficient for various analyses due to the entrapment of EVs by the Tamm‐Horsfall protein (THP) meshwork. Here, we developed a simple dilution protocol to increase the urinary EV yield by disrupting the interaction between THP filaments and EVs with the help of alkaline pH and lowered ionic concentration. The integrity of the EVs and THP was assessed by electron microscopy. The effect of the protocol on the EV yield was quantified against an undiluted control by western blotting of four EV markers, nanoparticle tracking analysis and measuring of the RNA/miRNA concentration of the EV samples. The average EV yield from the dilution protocol was 2–7 fold the yield from the undiluted control i.e. increased by 130–624% as measured by western blotting and NTA. The yield increased most from samples with a high THP to EV ratio. The morphology and size range of the EVs were unaltered by the protocol. However, RNA/miRNA yields were the same as from the undiluted control and THP filaments could still be detected in EV samples. The dilution protocol, that we named KeepEX, provides a simple and efficient way to prevent loss of EVs thus increasing their yield from urine. Since KeepEX does not require individual adjustment of sample pH nor extra centrifugation steps, it could be used on its own or in combination with other EV purification protocols to improve EV isolation particularly from small urine volumes. Graphical Abstract Figure. No caption available.

Expert consensus document: Semantics in active surveillance for men with localized prostate cancer — results of a modified Delphi consensus procedure

Active surveillance (AS) is broadly described as a management option for men with low-risk prostate cancer, but semantic heterogeneity exists in both the literature and in guidelines. To address this issue, a panel of leading prostate cancer specialists in the field of AS participated in a consensus-forming project using a modified Delphi method to reach international consensus on definitions of terms related to this management option. An iterative three-round sequence of online questionnaires designed to address 61 individual items was completed by each panel member. Consensus was considered to be reached if ≥70% of the experts agreed on a definition. To facilitate a common understanding among all experts involved and resolve potential ambiguities, a face-to-face consensus meeting was held between Delphi survey rounds two and three. Convenience sampling was used to construct the panel of experts. In total, 12 experts from Australia, France, Finland, Italy, the Netherlands, Japan, the UK, Canada and the USA participated. By the end of the Delphi process, formal consensus was achieved for 100% (n = 61) of the terms and a glossary was then developed. Agreement between international experts has been reached on relevant terms and subsequent definitions regarding AS for patients with localized prostate cancer. This standard terminology could support multidisciplinary communication, reduce the extent of variations in clinical practice and optimize clinical decision making.

Increase of prostate biopsy-related bacteremic complications in southern Finland, 2005-2013: a population-based analysis.

BACKGROUND:The most severe manifestations of prostate biopsy complications are bacteremic infections. These complications are increasing alarmingly.METHODS:A retrospective cohort study of 17 183 transrectal prostate biopsies performed at the Helsinki and Uusimaa hospital district in southern Finland during 2005–2013. Biopsies were linked to a database of positive blood cultures, yielding 111 bacteremic cases, and yearly bacteremia rates were determined. By multiple regression analysis, demographic risk factors of the whole biopsy cohort for developing bacteremia or fluoroquinolone (FQ)-resistant bacteremia were studied. Clinical risk factors for bacteremia caused by an FQ-resistant organism and for serious bacteremic outcomes were studied by univariate and multivariate analyzes.RESULTS:The average bacteremia rate was 0.7% (111 of 17 183 biopsies) and an increase was observed from 0.5% in 2005 (95% confidence interval (CI): 0.3–0.9) to 1.2% in 2012 (95% CI 0.8–1.8); 53.2% were caused by an FQ-resistant organism. In univariate regression analysis, previous biopsy sessions and increasing calendar year of biopsy associated with the risk of developing bacteremia (odds ratio (OR) 1.232, 95% CI: 1.020–1.488, P=0.030 and OR 1.164, 95% CI: 1.079–1.255, P<0.001, respectively), but only increasing calendar year of biopsy remained statistically significant (OR 1.155, 95% CI: 1.070–1.247, P<0.001) in multivariate analysis. Foreign travel within 3 months was associated with FQ resistance in multivariate analysis (OR 7.158, 95% CI: 1.042 to infinite, P=0.045). The study failed to show any significant clinical risk factors for serious bacteremic outcomes (requiring intensive care, developing deep infection foci or death).CONCLUSIONS:The postbiopsy bacteremia rate doubled during the study period and half of the cases were caused by FQ-resistant organisms. Recent foreign travel increased the risk for FQ resistance. Future research efforts should be aimed at better identifying risk factors, targeted prophylaxis and reducing the need for biopsies.

PTEN Loss but Not ERG Expression in Diagnostic Biopsies Is Associated with Increased Risk of Progression and Adverse Surgical Findings in Men with Prostate Cancer on Active Surveillance

BACKGROUND Active surveillance (AS) is an option for men with low-risk prostate cancer (PCa). PTEN and ERG have been considered as potential biomarkers of PCa progression and survival. OBJECTIVE To study the role of ERG and PTEN status in the Prostate Cancer Research International: Active Surveillance (PRIAS) trial diagnostic biopsies (DBxs) in predicting surveillance discontinuation and adverse surgical findings in subsequent radical prostatectomy (RP). DESIGN, SETTING, AND PARTICIPANTS A total of 231 patients were recruited to the PRIAS between 2007 and 2013 in Helsinki. DBx tissue for immunohistochemistry (IHC) was available from 190 patients. Tissue microarrays (TMAs) were constructed from 57 specimens of subsequent RPs. DBxs containing grade group (GG) 1 PCa and RP TMA sections were stained with ERG and PTEN antibodies, and scored as either negative or positive. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES Outcomes were followed up by biopsy GG upgrade (GG ≥ 2) and protocol-based treatment change, as well as adverse findings in RP (GG ≥ 3 or pathological stage≥3). Clinical variables and biomarker status in DBx were correlated in Cox regression analysis and cumulative survival in Kaplan-Meier analysis, and finally, Grays competing risk analysis was performed and nonprotocol-based discontinuation was considered as a competing event. RESULTS AND LIMITATIONS In both uni- and multivariate Cox regression analyses, only the number of positive cores in the DBx, the number of rebiopsy sessions, and PTEN status at diagnosis were significantly associated with rebiopsy GG upgrade, treatment change, and adverse histopathology in RP. In Kaplan-Meier analysis, PTEN loss was associated with a shorter time to GG upgrade and treatment change. Patients with PTEN loss had a higher probability for protocol-based discontinuation but not for competing risk factors compared with patients with intact PTEN. Biopsy ERG status was concordant with RP TMA ERG status, while PTEN was not. Limitations include a retrospective analysis of prospective cohort data. CONCLUSIONS PTEN status at diagnosis is a potential biomarker for identifying patients with PCa on AS with a high risk for progression or adverse findings on subsequent RP. PATIENT SUMMARY A simple diagnostic biopsy-based analysis of PTEN status may help identify patients with high risk for prostate cancer progression.

Reduction of quality of life in prostate cancer patients: experience among 6200 men in the Nordic countries

Abstract Objective: Although many studies have dealt with adverse effects (AEs) and quality of life (QoL) in prostate cancer (PCa) patients, the quantification of the patients’ perspective on AE-related reduction in QoL has been less studied. This study describes the impact of self-reported local (erectile, bowel, urinary dysfunction) or systemic (mental distress, fatigue, virility loss) AEs on QoL reduction. Materials and methods: Nordic PCa patients completed a questionnaire containing 84 multiple-choice questions. The main outcome variable of the survey was patient-reported PCa-induced QoL reduction, assessed by descriptive and regression analyses. The level of significance was p < 0.05. Results: Among 6200 patients, 39% described their QoL as reduced owing to the PCa trajectory: radical prostatectomy group (RPGroup): 42%, radiotherapy without hormones (RADGroup): 27%, hormones (HormGroup): 47% and no treatment (NoTrtGroup): 19%. Except for the NoTrtGroup, urinary leakage and fatigue doubled the risk of QoL reduction, while virility loss and erectile dysfunction tripled the risk. Significant intergroup differences emerged for the age-adjusted odds of QoL reduction: RPGroup (0.66), RADGroup (0.40), HormGroup (0.95) and NoTrtGroup (0.22). Conclusions: After RP, RAD or hormone treatment of PCa, systemic AEs, in particular loss of virility, significantly reduce PCa patients’ QoL similarly to or more than local AEs. The probability of reduced QoL is highest during hormone treatment and lowest in patients without anticancer therapy, and seems lower in patients treated with RAD without hormones than after RP. The treatment-related risk of reduced QoL due to systemic AEs should become a part of the pretreatment counselling of patients.