Exploring the tumor genomic landscape of aggressive prostate cancer by whole-genome sequencing of tissue or liquid biopsies

Treatment resistance remains a major issue in aggressive prostate cancer (PC), and novel genomic biomarkers may guide better treatment selection. Circulating tumor DNA (ctDNA) can provide minimally invasive information about tumor genomes, but the genomic landscape of aggressive PC based on whole-genome sequencing (WGS) of ctDNA remains incompletely characterized. Thus, we here performed WGS of tumor tissue (n = 31) or plasma ctDNA (n = 10) from a total of 41 aggressive PC patients, including 11 hormone-naïve, 15 hormone-sensitive, and 15 castration-resistant patients. Across all variant types, we found progressively more altered tumor genomic profiles in later stages of aggressive PC. The potential driver genes most frequently affected by single-nucleotide variants or insertions/deletions included the known PC-related genes TP53, CDK12, and PTEN and the novel genes COL13A1, KCNH3, and SENP3. Etiologically, aggressive PC was associated with age-related and DNA repair-related mutational signatures. Copy number variants most frequently affected 14q11.2 and 8p21.2, where no well-recognized PC-related genes are located, and also frequently affected regions near the known PC-related genes MYC, AR, TP53, PTEN, and BRCA1. Structural variants most frequently involved not only the known PC-related genes TMPRSS2 and ERG but also the less extensively studied gene in this context, PTPRD. Finally, clinically actionable variants were detected throughout all stages of aggressive PC and in both plasma and tissue samples, emphasizing the potential clinical applicability of WGS of minimally invasive plasma samples. Overall, our study highlights the feasibility of using liquid biopsies for comprehensive genomic characterization as an alternative to tissue biopsies in advanced/aggressive PC.

Exergaming Improves Cardiac Risk Factors in Prostate Cancer Patients: A Single-Blinded Randomized Controlled Trial

Purpose: Androgen deprivation therapy (ADT) may induce unfavorable changes in metabolic outcomes, insulin sensitivity, insulin-like growth factors (IGFs), and in serum levels of adipocyte-derived hormones. In this preplanned randomized ancillary study, we aimed to investigate the ability of exercise to counteract alterations in triglyceride, cholesterol, waist circumference, and insulin caused by ADT in men with locally advanced and metastatic prostate cancer (PCa). Materials and Methods: Forty-six PCa patients undergoing treatment were randomized to 12 weeks of 180 minutes of weekly unsupervised home-based exergaming or usual care. Blood glucose, lipids, cholesterol, adiponectin, leptin, insulin sensitivity, and the insulin growth factor axis were measured at baseline, and after 12 and 24 weeks. Biomarkers were analyzed using a linear mixed-effect model of the difference between the groups from baseline to week 24. In addition, blood pressure, body mass index, body weight, and waist circumference were measured at baseline and after 12 weeks/end of intervention and analyzed using adjusted linear regression analysis. Results: After 24 weeks, a significant difference was seen between the intervention and usual care groups in plasma triglyceride (diff: 0.5 mmol/L, P = 0.02) and high-density lipoprotein (HDL; diff: 0.2 mmol/L, P = 0.01) favoring the intervention group, whereas IGF-binding protein-3 (diff: 148 μg/L, P = 0.01) favored the usual care group. The remaining outcomes were unaffected. Conclusion: Improvement in HDL cholesterol could be used as a primary biomarker in future randomized controlled trials investigating the cardiovascular protecting properties of exergaming.

Stroma-specific gene expression signature identifies prostate cancer subtype with high recurrence risk

Current prognostic tools cannot clearly distinguish indolent and aggressive prostate cancer (PC). We hypothesized that analyzing individual contributions of epithelial and stromal components in localized PC (LPC) could improve risk stratification, as stromal subtypes may have been overlooked due to the emphasis on malignant epithelial cells. Hence, we derived molecular subtypes of PC using gene expression analysis of LPC samples from prostatectomy patients (cohort 1, n = 127) and validated these subtypes in two independent prostatectomy cohorts (cohort 2, n = 406, cohort 3, n = 126). Stroma and epithelium-specific signatures were established from laser-capture microdissection data and non-negative matrix factorization was used to identify subtypes based on these signatures. Subtypes were functionally characterized by gene set and cell type enrichment analyses, and survival analysis was conducted. Three epithelial (E1-E3) and three stromal (S1-S3) PC subtypes were identified. While subtyping based on epithelial signatures showed inconsistent associations to biochemical recurrence (BCR), subtyping by stromal signatures was significantly associated with BCR in all three cohorts, with subtype S3 indicating high BCR risk. Subtype S3 exhibited distinct features, including significantly decreased cell-polarity and myogenesis, significantly increased infiltration of M2-polarized macrophages and CD8 + T-cells compared to subtype S1. For patients clinically classified as CAPRA-S intermediate risk, S3 improved prediction of BCR. This study demonstrates the potential of stromal signatures in identification of clinically relevant PC subtypes, and further indicated that stromal characterization may enhance risk stratification in LPC and may be particularly promising in cases with high prognostic ambiguity based on clinical parameters.

Cumulative incidence of second primary cancers in a large nationwide cohort of Danish cancer survivors: a population-based retrospective cohort study

BACKGROUND

A new primary cancer is a serious late effect of a pre-existing cancer diagnosis, and can be attributed to hereditary cancer syndromes, immune or hormonal factors, cancer treatment, or modifiable lifestyle or environmental factors. We investigated the absolute and relative incidence of second primary cancers in a large cohort of Danish cancer survivors. Furthermore, we examined the association between alcohol-related, smoking-related, virus-related, and hormone-related first and second primary cancers.

METHODS

In this retrospective cohort study, we identified a cohort of Danish adults (aged ≥40 years) diagnosed with cancer from Jan 1, 1997, to Dec 31, 2014 and alive 1 year after diagnosis. Follow-up was from date of first cancer diagnosis and lasted up to 24 years, ending on Dec 31, 2020. Cohort identification and information on second primary cancers was obtained from the Danish Cancer Registry, and comorbidity and sociodemographic information was obtained from Danish population-based registries. Overall, and for 27 cancer types, cumulative incidence functions and Cox proportional hazard regression models were used to estimate the incidence of second primary cancer and death, and hazard ratios (HRs) and 95% CIs of second primary cancer adjusted for sex, age and year of diagnosis, cohabitation status, income, and comorbidity.

FINDINGS

457 334 Danish adults were included in our study (230 150 [50·3%] male individuals and 227 184 [49·7%] female individuals; median age at diagnosis 68·3 years, IQR 59·7-76·6; median follow-up 3·6 years, IQR 0·6-9·3). The cumulative incidence of second primary cancer increased over time from 6·3% (95% CI 6·2-6·4) 5 years after diagnosis to 10·5% (10·4-10·6) 10 years after diagnosis and to 13·5% (13·4-13·7) 15 years after diagnosis. The highest cumulative incidence of second primary cancer 10 years after diagnosis was observed in survivors of cancers in the larynx (21·8%, 20·5-23·1), oropharynx and oral cavity (19·5%, 18·7-20·3), and bladder and urinary tract (18·5%, 18·0-19·0). Survivors of cancers related to alcohol (HR 1·09, 95% CI 1·06-1·13), smoking (1·73, 1·68-1·78), diet high in red or processed meat (1·32, 1·24-1·39), or virus (1·23, 1·13-1·35) were at increased risk of developing a second cancer with the same aetiology, whereas having had a hormone-related first cancer was associated with lower risk of a second hormone-related cancer (0·77, 0·73-0·81).

INTERPRETATION

Our results could help optimise prevention efforts targeting modifiable risk factors to reduce risk of developing a second primary cancer.

FUNDING

Nordic Cancer Union and The Health Foundation (Helsefonden).

Association between copy number alterations estimated using low-pass whole genome sequencing of formalin-fixed paraffin-embedded prostate tumor tissue and cancer-specific clinical parameters

Copy number alterations (CNAs) are frequently observed in early-stage prostate cancer and are associated with disease recurrence and tumor aggressiveness. Cost-effective assessment of CNAs could enhance clinical utility of CNAs. Here, we combined the cost-effectiveness of low-pass (low coverage) whole genome sequencing (LPWGS) and the routine availability of formalin-fixed paraffin-embedded (FFPE) tumor tissue for assessing CNAs in a cohort of 187 men with early-stage localised prostate cancer. We detected well known CNAs in 8p, 8q, 13q and 16q and recurrent gains of the oncogene MYC and losses of the tumor suppressor genes NKX3-1, PTEN and RB1, indicating assay reliability. The estimated burden of CNAs was significantly associated with Gleason score, pathological T stage, surgical margin status and biochemical recurrence. Further, genomic losses or gains in specific chromosomal arms were significantly associated with worse BCR-free survival. Copy number signatures extracted from the LPWGS data showed potential for risk stratifying patients, where signatures S1 and S2 showed significant association to worse BCR-free survival compared to S3. Our study provides clinical validation of the associations between CNAs and tumor aggressiveness in an independent and representative RP cohort, while demonstrating the feasibility of performing LPWGS of FFPE tumor tissue for cost-effective assessment of CNAs.

Spatial whole transcriptome profiling of primary tumor from patients with metastatic prostate cancer

Prostate cancer (PCa) is a highly heterogeneous disease in terms of its molecular makeup and clinical prognosis. The prostate tumor microenvironment (TME) is hypothesized to play an important role in driving disease aggressiveness, but precise mechanisms remain elusive. In our study, we used spatial transcriptomics to explore for the first time the spatial gene expression heterogeneity within primary prostate tumors from patients with metastatic disease. In total, we analyzed 5459 tissue spots from three PCa patients comprising castration-resistant (CRPC) and neuroendocrine (NEPC) disease stages. Within CRPC, we identified a T cell cluster whose activity might be impaired by nearby regulatory T cells, potentially mediating the aggressive disease phenotype. Moreover, we identified Hallmark signatures of epithelial-mesenchymal transition in a cancer-associated fibroblast (CAF) cluster, indicating the aggressive characteristic of the primary TME leading to metastatic dissemination. Within NEPC, we identified active immune-stroma cross-talk exemplified by significant ligand-receptor interactions between CAFs and M2 macrophages. Further, we identified a malignant cell population that was associated with the down-regulation of an immune-related gene signature. Lower expression of this signature was associated with higher levels of genomic instability in advanced PCa patients (SU2C cohort, n = 99) and poor recurrence free survival in early-stage PCa patients (TCGA cohort, n = 395), suggesting prognostic biomarker potential. Taken together, our study reveals the importance of whole transcriptome profiling at spatial resolution for biomarker discovery and for advancing our understanding of tumor biology.

Characterizing prostate cancer risk through multi-ancestry genome-wide discovery of 187 novel risk variants

The transferability and clinical value of genetic risk scores (GRSs) across populations remain limited due to an imbalance in genetic studies across ancestrally diverse populations. Here we conducted a multi-ancestry genome-wide association study of 156,319 prostate cancer cases and 788,443 controls of European, African, Asian and Hispanic men, reflecting a 57% increase in the number of non-European cases over previous prostate cancer genome-wide association studies. We identified 187 novel risk variants for prostate cancer, increasing the total number of risk variants to 451. An externally replicated multi-ancestry GRS was associated with risk that ranged from 1.8 (per standard deviation) in African ancestry men to 2.2 in European ancestry men. The GRS was associated with a greater risk of aggressive versus non-aggressive disease in men of African ancestry (P = 0.03). Our study presents novel prostate cancer susceptibility loci and a GRS with effective risk stratification across ancestry groups.

Danish Prostate Cancer Consortium Study 1 (DPCC-1) protocol: Multicentre prospective validation of the urine-based three-microRNA biomarker model uCaP

INTRODUCTION

The primary objective of the Danish Prostate Cancer Consortium Study 1 (DPCC-1) is to provide validation for a novel urine-based microRNA biomarker, called uCaP, for a diagnosis of prostate cancer.

METHODS AND ANALYSIS

Eligible participants are biopsy naïve men aged ≥18 years with prostate-specific antigen (PSA) levels ≥3 ng/mL, who are referred to prostate MRI due to suspicion of PC at one of the following three major urology/uroradiology centers: Aarhus University Hospital, Herlev & Gentofte University Hospital, or Odense University Hospital, where MRI and targeted biopsy are implemented in clinical use. Exclusion criteria include previous diagnosis of urogenital cancer, contraindication to MRI, gender reassignment treatment or PSA level >20 ng/mL. The participants will be asked to donate a urine sample in connection with their MRI. The study is observational, uses a diagnostic accuracy testing setup and will integrate into the current diagnostic pathway.We will measure the levels of the three microRNAs in the uCaP model (miR-222-3 p, miR-24-3 p and miR-30c-5p) in extracellular vesicle-enriched cell-free urine samples, to assess if uCaP can improve specificity and retain sensitivity for International Society of Urological Pathology Grade Group ≥2 PC, when used as a reflex test to PSA ≥3 ng/mL. We hypothesise that uCaP can improve selection for prostate MRI and reduce the number of unnecessary scans and biopsies.

ETHICS AND DISSEMINATION

This study is approved by the Central Denmark Region Committee on Health Research Ethics (reference number: 1-10-72-85-22). All participants will provide written informed consent. Study results will be published in peer-reviewed journals and presented in scientific meetings.

TRIAL REGISTRATION NUMBER

NCT05767307 at clinicaltrials.gov.

Impact of germline DNA repair gene variants on prognosis and treatment of men with advanced prostate cancer

The clinical importance of germline variants in DNA repair genes (DRGs) is becoming increasingly recognized, but their impact on advanced prostate cancer prognosis remains unclear. A cohort of 221 newly diagnosed metastatic castration-resistant prostate cancer (mCRPC) patients were screened for pathogenic germline variants in 114 DRGs. The primary endpoint was progression-free survival (PFS) on first-line androgen signaling inhibitor (ARSI) treatment for mCRPC. Secondary endpoints were time to mCRPC progression on initial androgen deprivation therapy (ADT) and overall survival (OS). Twenty-seven patients (12.2%) carried a germline DRG variant. DRG carrier status was independently associated with shorter PFS on first-line ARSI [HR 1.72 (1.06-2.81), P = 0.029]. At initiation of ADT, DRG carrier status was independently associated with shorter progression time to mCRPC [HR 1.56, (1.02-2.39), P = 0.04] and shorter OS [HR 1.99, (1.12-3.52), P = 0.02]. Investigating the contributions of individual germline DRG variants on PFS and OS revealed CHEK2 variants to have little effect. Furthermore, prior taxane treatment was associated with worse PFS on first-line ARSI for DRG carriers excluding CHEK2 (P = 0.0001), but not for noncarriers. In conclusion, germline DRG carrier status holds independent prognostic value for predicting advanced prostate cancer patient outcomes and may potentially inform on optimal treatment sequencing already at the hormone-sensitive stage.

Results from the PRIMA Trial: Comparison of the STHLM3 Test and Prostate-specific Antigen in General Practice for Detection of Prostate Cancer in a Biopsy-naïve Population

BACKGROUND

Current management of prostate cancer (PC) lacks biomarker tests and diagnostic procedures that can accurately distinguish clinically significant and clinically insignificant PCs at an early stage of the disease.

OBJECTIVE

To compare the Stockholm 3 (STHLM3) test and prostate-specific antigen (PSA) as entry tests for magnetic resonance imaging (MRI) in a prospective study of PC diagnosis in general practice.

DESIGN, SETTING, AND PARTICIPANTS

Participants were biopsy-naïve men aged 50-69 yr who had a PSA test in general practice. Participants with PSA 1-10 ng/ml also had an STHLM3 test and were referred for MRI if the STHLM311 test was positive (risk ≥11%) and/or PSA ≥3 ng/ml, and to targeted MRI-guided biopsy (MRGB) if their Prostate Imaging-Reporting and Data System (PI-RADS) score was ≥3.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was the number of International Society of Urological Pathology grade group ≥2 (GG ≥2) cases detected with a positive STHLM311 test versus PSA ≥3 ng/ml. Post hoc analysis was performed using a higher STHLM3 test cutoff (risk ≥15%; positive STHLM315 test).

RESULTS AND LIMITATIONS

Between January 2018 and December 2021, we recruited 1905 men. The STHLM3 test was performed in 1134 participants. Of these, 437 underwent MRI and 117 underwent MRGB, which detected 38 (32.5%) GG ≥2 and 52 (44.4%) with GG 1 cases. In comparison to PSA ≥3 ng/ml, a positive STHLM311 test increased detection of GG ≥2 from 30 to 37 cases (23.3%, 95% confidence interval [CI] 5.6-52.2%) and detection of GG 1 from 37 to 50 cases (35.1%, 95%CI 11.6-66.7%). STHLM315 positivity did not differ from PSA ≥3 ng/ml regarding detection of GG ≥2 PC (30 vs 32; 6.6%, 95% CI -8.1% to 25.9%), GG 1 PC (37 vs 37; 0.0%, 95% CI -19.6% to 25.0%), or MRGB use (88 vs 83; -5.7%, 95% CI -17.9% to 7.4%), but reduced MRI scans from 320 to 236 (-26.2%, 95% CI -33.1% to -18.9%).

CONCLUSIONS

The STHLM311 test improved sensitivity but not specificity for detection of GG ≥2 PC in the clinical setting of nonsystematic PC testing in general practice. Further studies are needed to validate a possible benefit of using a higher cutoff for STHLM3 positivity as an entry test for MRI.

PATIENT SUMMARY

We used a test called STHLM3 for detection of prostate cancer in general practice and compared its performance to the conventional PSA (prostate-specific antigen) test. We found that STHLM3 test results of 11% or above were not better at selecting men for MRI (magnetic resonance imaging) scans than the PSA test with a cutoff of 3 ng/ml or above. Analysis suggested that a higher cutoff for a positive STHLM3 test may improve selection of men for MRI scans, but further validation is needed.

Social inequality in cancer survivorship: Educational differences in health-related quality of life among 27,857 cancer survivors in Denmark

BACKGROUND

With a growing population of cancer survivors in Denmark, the evaluation of health-related quality of life (HRQoL) has become increasingly important. We describe variations in HRQoL between educational groups in a national population of cancer survivors.

METHODS

We conducted a cross-sectional questionnaire study among breast, prostate, lung, and colon cancer survivors diagnosed in 2010-2019 in Denmark. We used the EORTC QLQ-C30 to assess HRQoL including physical, role, emotional, cognitive, social functioning, and symptoms (fatigue, nausea and vomiting, pain, dyspnea, insomnia, appetite loss, constipation, diarrhea, and financial difficulties). Information on educational level and clinical data were extracted from national registers and clinical databases. Levels of impaired functioning and severe symptoms were identified using newly established thresholds for clinical importance. Multivariate logistic regression was used to examine associations between education and HRQoL. All statistical tests were 2-sided.

RESULTS

In total, 27,857 (42%) participated in the study. Up to 72% and 75% of cancer survivors with short education (≤9 years) reported impaired functioning and severe symptoms, respectively. Cancer survivors with short compared to long education (>12 years) were more likely to report impaired functioning and severe symptoms, with for example significantly higher odds ratios (ORs) for impaired physical function (breast OR = 2.41, 99% CI = 2.01-2.89; prostate OR = 1.81, 99% CI = 1.48-2.21; lung OR = 2.97, 99% CI = 1.95-4.57; and colon cancer OR = 1.69, 99% CI = 1.28-2.24).

CONCLUSIONS

Cancer survivors with short education are at greater risk of impaired HRQoL than survivors with long education 2-12 years after diagnosis. This underscores the need for systematic screening and symptom management in cancer aftercare, in order to reach all cancer survivors, also cancer survivors with short education.

Educational differences in healthcare use among survivors after breast, prostate, lung, and colon cancer - a SEQUEL cohort study

BACKGROUND

Many cancer survivors experience late effects after cancer. Comorbidity, health literacy, late effects, and help-seeking behavior may affect healthcare use and may differ among socioeconomic groups. We examined healthcare use among cancer survivors, compared with cancer-free individuals, and investigated educational differences in healthcare use among cancer survivors.

METHODS

A Danish cohort of 127,472 breast, prostate, lung, and colon cancer survivors from the national cancer databases, and 637,258 age- and sex-matched cancer-free individuals was established. Date of entry was 12 months after diagnosis/index date (for cancer-free individuals). Follow-up ended at death, emigration, new primary cancer, December 31st, 2018, or up to 10 years. Information about education and healthcare use, defined as the number of consultations with general practitioner (GP), private practicing specialists (PPS), hospital, and acute healthcare contacts 1-9 years after diagnosis/index date, was extracted from national registers. We used Poisson regression models to compare healthcare use between cancer survivors and cancer-free individuals, and to investigate the association between education and healthcare use among cancer survivors.

RESULTS

Cancer survivors had more GP, hospital, and acute healthcare contacts than cancer-free individuals, while the use of PPS were alike. One-to-four-year survivors with short compared to long education had more GP consultations (breast, rate ratios (RR) = 1.28, 95% CI = 1.25-1.30; prostate, RR = 1.14, 95% CI = 1.10-1.18; lung, RR = 1.18, 95% CI = 1.13-1.23; and colon cancer, RR = 1.17, 95% CI = 1.13-1.22) and acute contacts (breast, RR = 1.35, 95% CI = 1.26-1.45; prostate, RR = 1.26, 95% CI = 1.15-1.38; lung, RR = 1.24, 95% CI = 1.16-1.33; and colon cancer, RR = 1.35, 95% CI = 1.14-1.60), even after adjusting for comorbidity. One-to-four-year survivors with short compared to long education had less consultations with PPS, while no association was observed for hospital contacts.

CONCLUSION

Cancer survivors used more healthcare than cancer-free individuals. Cancer survivors with short education had more GP and acute healthcare contacts than survivors with long education. To optimize healthcare use after cancer, we need to better understand survivors' healthcare-seeking behaviors and their specific needs, especially among survivors with short education.

Long-term risk of benign prostatic hyperplasia-related surgery and acute urinary retention in men treated with 5-alpha reductase inhibitor versus alpha-blocker monotherapy in routine clinical care

OBJECTIVES

To assess the risk of benign prostatic hyperplasia (BPH)-related surgery and acute urinary retention (AUR) in men treated with 5-alpha-reductase inhibitor (5-ARI) versus alpha-blocker monotherapy in routine clinical care over 15 years of follow-up.

METHODS

Using population-based Danish Health registries, we identified all new-users of 5-ARI or alpha-blocker monotherapy in Denmark, 1997-2017. We defined an index date 180 days after the date of first prescription and included men who redeemed at least one additional prescription before the index date. We used multiple imputation to replace missing prostate-specific antigen values. We performed propensity score-weighted Cox regression to estimate weighted hazard ratios (wHRs) and cumulative incidence function to estimate weighted cumulative risks of BPH-related surgery and AUR in intention to treat (ITT) and per protocol (PP) analyses.

RESULTS

We included 18,421 and 95,984 men treated with 5-ARI and alpha-blocker monotherapy, respectively. Overall, treatment with 5-ARI monotherapy was associated with a reduced risk of BPH-related surgery (ITT wHR = 0.73 (95% confidence interval [CI]: 0.68-0.78), PP wHR = 0.77 (95% CI: 0.70-0.84) and AUR (ITT wHR = 0.73 (95% CI: 0.67-0.78), PP wHR = 0.75 (95% CI: 0.66-0.84). The 15-year risk of BPH-related surgery in men treated with 5-ARI versus alpha-blocker monotherapy was 14.8% (95% CI: 14.1%-15.5%) versus 19.1% (95% CI: 18.7%-19.5%) in the ITT analysis and 13.8% (95% CI: 12.6%-14.9%) versus 17.5% (95% CI: 16.9%-18.0%) in the PP analysis. The 15-year risk of AUR in men treated with 5-ARI versus alpha-blocker was 13.0% (95% CI: 12.3%-13.6%) versus 16.6% (95% CI: 16.3%-17.0%) in the ITT analysis and 12.6% (95%: 11.3%-14.0%) versus 16.9% (95% CI: 16.3%-17.6%) in the PP analysis.

CONCLUSION

Treatment with 5-ARI versus alpha-blocker monotherapy in routine clinical care was associated with a reduced risk of BPH-related surgery and AUR for up to 15 years of follow-up. After 15 years of follow-up, the relative risk reduction was 21%-25% and the absolute risk reduction was 4%.

Abstract 5839: Novel stroma-derived prostate cancer subtypes are associated with risk of clinical progression

The tumor microenvironment influences prostate cancer aggressiveness, and by focusing on how different changes to the microenvironment can affect the cancer, we aimed to identify novel stromal subtypes in localized prostate cancer (LPC), characterize these subtypes, and utilize subtypes to increase accuracy in prostate cancer risk stratification. Subtype identification was conducted using non-negative matrix factorization with consensus clustering on a stroma-specific expression signature in RNA sequencing data. A discovery cohort (127 LPC patients) and two independent validation cohorts (406 LPC & 126 LPC patients) were used for subtype identification. All three cohorts were subsequently used for subtype characterization and prognostic evaluation. Identified subtypes were characterized by evaluation of clinical characteristics, by gene set enrichment analysis, and by cell-type deconvolution analysis. Survival differences between subtypes were assessed using Kaplan-Meier and univariate Cox regression analyses with biochemical recurrence (BCR) as endpoint. Lastly, a high-risk stromal subtype was investigated for its ability to improve risk stratification for intermediate risk prostate cancer using hazard ratio changes from univariate Cox regression analysis. We identified three stromal subtypes (S1-S3) in prostate cancer. Of these, subtype S3 showed characteristics of a highly reactive stromal environment with significantly (adj. p < 0.05) decreased cell polarity and stroma related functions, significantly (adj. p < 0.05) reduced fibroblast infiltration, and a significantly (adj. p < 0.05) increased immune cells infiltration compared to the other subtypes. Survival analysis also revealed significant (p < 0.05) association of S3 with BCR in all three cohorts (HR = 3.2, 2.1, and 3.4 in cohorts 1, 2 and 3 respectively). Lastly, S3 significantly (p < 0.05) improved the risk prediction for patients with intermediate recurrence risk according to the clinical nomogram CAPRA-S (cohort 1, delta HR = 1.4; cohort 2, delta HR = 2.3; cohort 3, delta HR = 4.2). In conclusion, by focusing on the stromal alteration in prostate cancer, this study sheds new light on the influence of tumor microenvironment on LPC aggressiveness. A stromal subtype characterized by dysregulated stromal functions and changes in stroma and immune cells infiltration predicted adverse outcome in patients with a high prognostic ambiguity. This utilization of stromal information to improve risk assessment for clinically intermediate risk PC indicates a potential use in future evaluation of PC aggressiveness.

Citation Format: Martin Rasmussen, Jacob Fredsøe, Paul V. Salachan, Marcus P. Blanke, Benedicte P. Ulhøi, Michael Borre, Karina D. Sørensen. Novel stroma-derived prostate cancer subtypes are associated with risk of clinical progression. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5839.

Abstract 3778: Genome-Scale CRISPRa and CRISPRi screening for lncRNA drivers of prostate cancer progression

Background: Overtreatment of indolent prostate cancer (PC) and delayed treatment of aggressive PC is common due to suboptimal risk stratification tools, thus warranting identification of novel prognostic biomarkers. Although a few long non-coding RNAs (lncRNAs) with biomarker potential in PC are known, the majority of lncRNAs remain uncharacterized. Here, we aimed to identify novel lncRNA biomarker candidates. We hypothesized that strong candidates would have a functional role in driving PC progression in addition to their expression being linked to PC prognosis, and we therefore combined functional CRISPR screening with lncRNA expression profiling of PC patients.

Methods: Total RNA sequencing (RNAseq) data was generated from 31 adjacent normal (AN) and 125 tumor samples from 141 clinically localized PC patients, along with 17 primary tumor samples from metastatic PC patients. Raw reads were mapped to the hg38 reference genome and kallisto was used for quantification. CRISPR activating (CRISPRa) and CRISPR interference (CRISPRi) screens were performed in the LNCaP PC cell line stably expressing either dCas9-VP64 or dCas9-KRAB, respectively. Cells were transduced in duplicate with custom single guide RNA (sgRNA) libraries targeting 20,306 and 20,474 lncRNA transcripts of interest using 72,281 and 72,360 sgRNAs (CRISPRa and CRISPRi, respectively). Cells were harvested and DNA extracted from an early (day 4 post-transduction) and a late (day 17-21) timepoint and next-generation sequenced. MAGeCK was used for data analysis.

Results: To identify lncRNAs with biomarker potential in PC, we analyzed lncRNA expression in total RNAseq data from 158 PC patients. Using differential expression analysis and cox regression analysis with biochemical recurrence as endpoint, we identified 6,928 lncRNAs with biomarker potential. To investigate if any of these had a functional role in driving PC progression, we performed CRISPRa and CRISPRi screens to assess how lncRNA activation/inhibition affected PC cell proliferation. Based on the screens, lncRNA candidates with the most prominent phenotypes (normalized read count difference >200 and log-fold change >33% between the early and late timepoint for ≥3 sgRNAs in both replicates) were selected for individual validation. This identified 7 (CRISPRa) and 8 (CRISPRi) negative hits (decreased cell proliferation) along with 5 (CRISPRa) and 2 (CRISPRi) positive hits (increased cell proliferation). Individually activated/inhibited LNCaP cell lines have been established for the 22 candidate lncRNAs and proliferation assays are performed to validate their functional role in PC progression.

Conclusion: We identified numerous lncRNAs with biomarker potential and a possible driver role in PC progression.

Citation Format: Simone Weiss, Allegra Lord, Bernhard Schmierer, Anne B. Rovsing, Emil A. Thomsen, Jacob G. Mikkelsen, Benedicte Ulhøi, Jakob S. Pedersen, Michael Borre, Karina D. Sørensen. Genome-Scale CRISPRa and CRISPRi screening for lncRNA drivers of prostate cancer progression. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3778.

[Not Available]

This review investigates prostate cancer which with approx. 4,500 new cases annually is the most frequent male cancer, and the incidence is expected to increase due to demographic developments. Prostate cancer can have a natural history without progression to symptomatic or fatal disease, which is why overdiagnosis is one of the disease's biggest challenges. In contrast to potential curable localized clinically significant disease, this is not the case after metastasis. Fortunately, new treatments, and not least combinations thereof, have increased both lifespan and quality of life in these patients significantly.

Prognostic Value of Low-Pass Whole Genome Sequencing of Circulating Tumor DNA in Metastatic Castration-Resistant Prostate Cancer

BACKGROUND

Multiple treatments are available for metastatic castration-resistant prostate cancer (mCRPC), including androgen receptor signaling inhibitors (ARSI) enzalutamide and abiraterone, but therapy resistance remains a major clinical obstacle. We examined the clinical utility of low-pass whole-genome sequencing (LPWGS) of circulating tumor DNA (ctDNA) for prognostication in mCRPC.

METHODS

A total of 200 plasma samples from 143 mCRPC patients collected at the start of first-line ARSI treatment (baseline) and at treatment termination (n = 57, matched) were analyzed by LPWGS (median: 0.50X) to access ctDNA% and copy number alteration (CNA) patterns. The best confirmed prostate specific antigen (PSA) response (≥50% decline [PSA50]), PSA progression-free survival (PFS), and overall survival (OS) were used as endpoints. For external validation, we used plasma LPWGS data from an independent cohort of 70 mCRPC patients receiving first-line ARSI.

RESULTS

Baseline ctDNA% ranged from ≤3.0% to 73% (median: 6.6%) and CNA burden from 0% to 82% (median: 13.1%) in the discovery cohort. High ctDNA% and high CNA burden at baseline was associated with poor PSA50 response (P = 0.0123/0.0081), poor PFS (P < 0.0001), and poor OS (P < 0.0001). ctDNA% and CNA burden was higher at PSA progression than at baseline in 32.7% and 42.3% of the patients. High ctDNA% and high CNA burden at baseline was also associated with poor PFS and OS (P ≤ 0.0272) in the validation cohort.

CONCLUSIONS

LPWGS of ctDNA provides clinically relevant information about the tumor genome in mCRPC patients. Using LPWGS data, we show that high ctDNA% and CNA burden at baseline is associated with short PFS and OS in 2 independent cohorts.

Acute urinary retention in men: 21-year trends in incidence, subsequent benign prostatic hyperplasia-related treatment and mortality: A Danish population-based cohort study

OBJECTIVE

To examine trends in incidence of acute urinary retention, subsequent benign prostatic hyperplasia-related treatment and mortality in the era of medical therapy for benign prostatic hyperplasia. Additionally, to compare mortality with the general population.

MATERIALS AND METHODS

We conducted a Danish nationwide registry-based study including 70,775 men aged 45 years or older with a first hospitalization for acute urinary retention during 1997-2017. We computed annual standardized incidence rates, subsequent 1-year cumulative incidence of benign prostatic hyperplasia-related surgical and medical treatment, and standardized 3-month and 1-year mortality rates. Finally, we compared standardized all-cause and cause-specific mortality ratios with the general population.

RESULTS

The standardized incidence rate of acute urinary retention per 1000 person-years increased transiently from 2.34 to 3.42 during 1997-2004, but gradually declined to 2.95 in 2017. The 1-year cumulative incidence of benign prostatic hyperplasia-related surgery declined from 31.2% to 19.8% and 20.5% to 7.7% after spontaneous and precipitated acute urinary retention, respectively. During 1997-2017, the standardized 1-year mortality declined from 22.2% to 17.2%. Compared with the general population, mortality was 4-5 times higher after 3 months and 2-3 times higher after 1 year of acute urinary retention. The cause-specific standardized mortality ratios were particularly high for deaths attributable to malignancies, urogenital disease, certain infections, chronic pulmonary disease, and diabetes.

CONCLUSION

During 1997-2017, we observed a transient increase in the incidence of acute urinary retention. The subsequent use of benign prostatic hyperplasia-related surgery declined considerably and mortality continued to be high, mainly because of deaths from malignancies, urogenital disease, infections, and preexisting comorbidity.

Identification of a high-risk immunogenic prostate cancer patient subset as candidates for T-cell engager immunotherapy and the introduction of a novel albumin-fused anti-CD3 × anti-PSMA bispecific design

BACKGROUND

Cancer immunotherapies such as bispecific T-cell engagers have seen limited adoption in prostate cancer (PC), possibly due to differing levels of cancer receptor expression and effector T-cell infiltration between patients and inherent defects in T-cell engager design.

METHODS

CD8⁺ T-cell infiltration and PSMA expression were determined by RNA sequencing of primary PC tissue samples from 126 patients with localised PC and 17 patients with metastatic PC. Prognostic value was assessed through clinical parameters, including CAPRA-S risk score. A panel of albumin-fused anti-CD3 ×  anti-PSMA T-cell engagers with different neonatal Fc receptor (FcRn) affinity were characterised by flow cytometry, Bio-Layer Interferometry and functional cellular assays.

RESULTS

A subset of patients with localised (30/126 = 24%) and metastatic (10/17 = 59%) PC showed both high PSMA expression and high CD8⁺ T-cell enrichment. The High/High phenotype in localised PC associated with a clinically high-risk cancer subtype, confirmed in an external patient cohort (n = 550, PRAD/TCGA). The T-cell engagers exhibited tunable FcRn-driven cellular recycling, CD3 and PSMA cellular engagement, T-cell activation and PSMA level-dependent cellular cytotoxicity.

CONCLUSION

This work presents an albumin-fused bispecific T-cell engager with programmable FcRn engagement and identifies a high-risk PC patient subset as candidates for treatment with the T-cell engager class of immuno-oncology biologics.

Recurrence rate after radical prostatectomy following primary staging of high-risk prostate cancer with 68Ga-PSMA PET/CT

BACKGROUND

Accurate primary staging is one of the most important issues for initial management of prostate cancer (PCa) patients to perform an optimal selection of patients for curative intended treatment. ⁶⁸Ga-Prostate-Specific-Membrane-Antigen (PSMA) PET/CT was found superior to conventional imaging both for detection of recurrence after curative intended treatment and for primary staging. We studied the recurrence rate after radical prostatectomy in high-risk PCa patients primary staged with ⁶⁸Ga-PSMA PET/CT compared with conventional imaging.

MATERIAL AND METHODS

The study included 247 D'Amico high-risk PCa patients treated with radical prostatectomy (RP) after primary staging with ⁶⁸Ga-PSMA PET/CT and a reference group of 137 high-risk patients with RP after conventional imaging (^99mTc bone scintigraphy and CT). Recurrence rates were assessed by Cox regression and Kaplan-Meier analysis.

RESULTS

The 5-year recurrence-free survival rate was 71.1% in the ⁶⁸Ga-PSMA PET/CT cohort compared with 56.4% in the conventional imaging cohort. Primary staging by ⁶⁸Ga-PSMA PET/CT reduced biochemical recurrence (BCR) risk by 42% (HR = 0.58 (0.41-0.83), p = .004).

CONCLUSION

The present data could indicate a lower recurrence rate after RP following primary staging with ⁶⁸Ga-PSMA PET/CT compared to conventional imaging, likely due to improved selection of patients for surgery.

Predicting Grade group 2 or higher cancer at prostate biopsy by 4Kscore in blood and uCaP microRNA model in urine

Elevated prostate-specific antigen (PSA) levels often lead to unnecessary and possibly harmful transrectal ultrasound guided biopsy, e.g. when the biopsy is negative or contains only low-grade insignificant cancer, unlikely to become symptomatic in the man's normal lifespan. A model based on four-kallikrein markers in blood (commercialized as 4Kscore) predicts risk of Grade group 2 or higher prostate cancer at biopsy, reducing unnecessary biopsies. We assessed whether these results extend to a single institution prostate biopsy cohort of Danish men and are enhanced by three microRNAs from urine (referred to as uCaP). The 4Kscore measured in cryopreserved blood from 234 men referred for 10+ core biopsy to Aarhus University Hospital, 29 with PSA > 25 ng/ml. We explored uCaP in urine from 157 of these men. Combined with age and DRE findings, both 4Kscore and uCaP could accurately predict Grade group 2 or higher prostate cancer (all patients: AUC = 0.802 and 0.797; PSA ≤ 25: AUC = 0.763 and 0.759). There was no additive effect when combining the 4Kscore and uCaP. Limitations include a study cohort with higher risk than commonly reported for biopsy cohorts. Our findings further support the clinical use of the 4Kscore to predict Grade group 2 or higher cancers in men being considered for biopsy.

A genome-wide CRISPR-Cas9 knockout screen identifies novel PARP inhibitor resistance genes in prostate cancer

DNA repair gene mutations are frequent in castration-resistant prostate cancer (CRPC), suggesting eligibility for poly(ADP-ribose) polymerase inhibitor (PARPi) treatment. However, therapy resistance is a major clinical challenge and genes contributing to PARPi resistance are poorly understood. Using a genome-wide CRISPR-Cas9 knockout screen, this study aimed at identifying genes involved in PARPi resistance in CRPC. Based on the screen, we identified PARP1, and six novel candidates associated with olaparib resistance upon knockout. For validation, we generated multiple knockout populations/clones per gene in C4 and/or LNCaP CRPC cells, which confirmed that loss of PARP1, ARH3, YWHAE, or UBR5 caused olaparib resistance. PARP1 or ARH3 knockout caused cross-resistance to other PARPis (veliparib and niraparib). Furthermore, PARP1 or ARH3 knockout led to reduced autophagy, while pharmacological induction of autophagy partially reverted their PARPi resistant phenotype. Tumor RNA sequencing of 126 prostate cancer patients identified low ARH3 expression as an independent predictor of recurrence. Our results advance the understanding of PARPi response by identifying four novel genes that contribute to PARPi sensitivity in CRPC and suggest a new model of PARPi resistance through decreased autophagy.

Unsupervised detection of fragment length signatures of circulating tumor DNA using non-negative matrix factorization

Sequencing of cell-free DNA (cfDNA) is currently being used to detect cancer by searching both for mutational and non-mutational alterations. Recent work has shown that the length distribution of cfDNA fragments from a cancer patient can inform tumor load and type. Here, we propose non-negative matrix factorization (NMF) of fragment length distributions as a novel and completely unsupervised method for studying fragment length patterns in cfDNA. Using shallow whole-genome sequencing (sWGS) of cfDNA from a cohort of patients with metastatic castration-resistant prostate cancer (mCRPC), we demonstrate how NMF accurately infers the true tumor fragment length distribution as an NMF component - and that the sample weights of this component correlate with ctDNA levels (r=0.75). We further demonstrate how using several NMF components enables accurate cancer detection on data from various early stage cancers (AUC=0.96). Finally, we show that NMF, when applied across genomic regions, can be used to discover fragment length signatures associated with open chromatin.

Abstract 3409: Whole genome sequencing of liquid tumor biopsies (ctDNA) from men with metastatic castration resistant prostate cancer

Background: Prostate cancer (PC) is the fifth most lethal male malignancy worldwide, as advanced metastatic castration resistant PC (mCRPC) remains incurable. Genomic biomarkers that can predict treatment response are urgently needed to facilitate personalized mCRPC treatment. Such biomarkers can be identified by whole genome sequencing (WGS) of tumor biopsies. Blood plasma can serve as a non-invasive liquid tumor biopsy as it contains cell free DNA (cfDNA), a subset of which in cancer patients is tumor-derived (circulating tumor DNA; ctDNA). The biomarker discovery potential of WGS of cfDNA in mCRPC remains largely undescribed, as most WGS studies to date have focused on tissue biopsies. Thus, we here aimed to characterize the genomic tumor landscape of mCRPC using WGS of cfDNA.

Methods: We previously performed low-pass WGS (mean coverage: 0.5X) of cfDNA sampled prior to initiation of first-line mCRPC treatment from 143 mCRPC patients (mean ctDNA fraction: 0.15). From these, 10 patients with high (&gt;0.35) ctDNA fractions who received enzalutamide as first-line mCRPC treatment were selected for deeper WGS here. Matched germline DNA from buffy coat (peripheral blood mononuclear cells) was also sequenced. Single-nucleotide variants (SNVs) were called with Mutect2 and CaVEMan, indels with Mutect2 and Pindel, copy-number variants (CNVs) with ASCAT, and structural variants (SVs) with BRASS. For the final analysis, we considered only SNVs and indels called by both tools.

Results: We sequenced germline samples to a mean coverage of 25X (range: 19-28X) and cfDNA samples to a mean coverage of 32X (range: 23-43X). We identified a median of 5,241 SNVs/indels (range: 3,422-48,314) per patient and the mean tumor mutation burden was 1.7 mutations/Mb. One sample had &gt;9 times more SNVs/indels than the median, suggesting microsatellite instability. Among the most recurrently mutated genes were LRP1B (7/10 patients), ARSB (5/10 patients), and TP53 (4/10 patients). COSMIC mutational signature analysis revealed that the clock-like signatures 1, 5, and 40 were most frequent. In contrast, the hypermutated sample was driven primarily by the defective DNA mismatch repair signatures 15, 26, and 44. CNVs affected a mean of 40.9% of the genome. Common PC CNVs were observed, including gains at chromosome 8 (MYC) in 8/10 patients and losses at chromosome 10 (PTEN) in 5/10 patients. Recurrent focal amplifications (defined as &gt;8 copies in regions &lt;3 Mb) affected chromosome 15q11.2 in 3/10 patients, chromosome 22q11.21 in 3/10 patients, and chromosome Xq12, where AR is located, in 3/10 patients. Finally, we identified a median of 241 SVs (range: 92-525) per patient. SVs affecting TMPRSS2 were observed in 3/10 patients.

Conclusion: This study highlights that WGS of cfDNA contributes to the identification of genomic aberrations that may serve as potential biomarkers to guide personalized treatment of mCRPC in the future.

Citation Format: Simone Weiss, Philippe Lamy, Maibritt Nørgaard, Michael Knudsen, Jørgen B. Jensen, Jakob S. Pedersen, Michael Borre, Karina D. Sørensen. Whole genome sequencing of liquid tumor biopsies (ctDNA) from men with metastatic castration resistant prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3409.

Randomised double-blind phase 3 clinical study testing impact of atorvastatin on prostate cancer progression after initiation of androgen deprivation therapy: study protocol

INTRODUCTION

Blood cholesterol is likely a risk factor for prostate cancer prognosis and use of statins is associated with lowered risk of prostate cancer recurrence and progression. Furthermore, use of statins has been associated with prolonged time before development of castration resistance (CR) during androgen deprivation therapy (ADT) for prostate cancer. However, the efficacy of statins on delaying castration-resistance has not been tested in a randomised placebo-controlled setting.This study aims to test statins' efficacy compared to placebo in delaying development of CR during ADT treatment for primary metastatic or recurrent prostate cancer. Secondary aim is to explore effect of statin intervention on prostate cancer mortality and lipid metabolism during ADT.

METHODS AND ANALYSIS

In this randomised placebo-controlled trial, a total of 400 men with de novo metastatic prostate cancer or recurrent disease after primary treatment and starting ADT will be recruited and randomised 1:1 to use daily 80 mg of atorvastatin or placebo. All researchers, study nurses and patients will be blinded throughout the trial. Patients are followed until disease recurrence or death. Primary outcome is time to formation of CR after initiation of ADT. Serum lipid levels (total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and trigyserides) are analysed to test whether changes in serum cholesterol parameters during ADT predict length of treatment response. Furthermore, the trial will compare quality of life, cardiovascular morbidity, changes in blood glucose and circulating cell-free DNA, and urine lipidome during trial.

ETHICS AND DISSEMINATION

This study is approved by the Regional ethics committees of the Pirkanmaa Hospital District, Science centre, Tampere, Finland (R18065M) and Tarto University Hospital, Tarto, Estonia (319/T-6). All participants read and sign informed consent form before study entry. After publication of results for the primary endpoints, anonymised summary metadata and statistical code will be made openly available. The data will not include any information that could make it possible to identify a given participant.

TRIAL REGISTRATION NUMBER

Clinicaltrial.gov: NCT04026230, Eudra-CT: 2016-004774-17, protocol code: ESTO2, protocol date 10 September 2020 and version 6.

Independent validation of a pre-specified four-kallikrein marker model for prediction of adverse pathology and biochemical recurrence

BACKGROUND

Accurate markers for prostate cancer (PC) risk stratification could aid decision-making for initial management strategies. The 4Kscore has an undefined role in predicting outcomes after radical prostatectomy (RP).

METHODS

We included 1476 patients with 4Kscore measured prior to RP at two institutions. The 4Kscore was assessed for prediction of adverse pathology at RP and biochemical recurrence (BCR) relative to a clinical model. We pre-specified that all analyses would be assessed in biopsy Grade Group 1 (GG1) or 2 (GG2) PC patients, separately.

RESULTS

The 4Kscore increased discrimination for adverse pathology in all patients (delta area under the receiver operative curve (AUC) 0.009, 95% confidence interval (CI) 0.002, 0.016; clinical model AUC 0.767), driven by GG1 (delta AUC 0.040, 95% CI 0.006, 0.073) rather than GG2 patients (delta AUC 0.005, 95% CI -0.012, 0.021). Adding 4Kscore improved prediction of BCR in all patients (delta C-index 0.014, 95% CI 0.007, 0.021; preop-BCR nomogram C-index 0.738), again with larger changes in GG1 than in GG2.

CONCLUSIONS

This study validates prior investigations on the use of 4Kscore in men with biopsy-confirmed PC. Men with GG1 PC and a high 4Kscore may benefit from additional testing to guide treatment selection. Further research is warranted regarding the value of the 4Kscore in men with biopsy GG2 PC.

An inverse association between plasma benzoxazinoid metabolites and PSA after rye intake in men with prostate cancer revealed with a new method

Prostate cancer (PC) is a common cancer among men, and preventive strategies are warranted. Benzoxazinoids (BXs) in rye have shown potential against PC in vitro but human studies are lacking. The aim was to establish a quantitative method for analysis of BXs and investigate their plasma levels after a whole grain/bran rye vs refined wheat intervention, as well as exploring their association with PSA, in men with PC. A quantitative method for analysis of 22 BXs, including novel metabolites identified by mass spectrometry and NMR, was established, and applied to plasma samples from a randomized crossover study where patients with indolent PC (n = 17) consumed 485 g whole grain rye/rye bran or fiber supplemented refined wheat daily for 6 wk. Most BXs were significantly higher in plasma after rye (0.3–19.4 nmol/L in plasma) vs. refined wheat (0.05–2.9 nmol/L) intake. HBOA-glc, 2-HHPAA, HBOA-glcA, 2-HPAA-glcA were inversely correlated to PSA in plasma (p < 0.04). To conclude, BXs in plasma, including metabolites not previously analyzed, were quantified. BX metabolites were significantly higher after rye vs refined wheat consumption. Four BX-related metabolites were inversely associated with PSA, which merits further investigation.

The transcriptional landscape and biomarker potential of circular RNAs in prostate cancer

Background

Circular RNAs (circRNAs) constitute a largely unexplored source for biomarker discovery in prostate cancer (PC). Here, we characterize the biomarker potential of circRNAs in PC, where the need for novel diagnostic and prognostic tools to facilitate more personalized management is pressing.

Methods

We profiled the transcriptomic landscape of circRNAs in PC by total RNA sequencing of 31 adjacent-normal and 143 tumor samples from localized (radical prostatectomy (RP)) and metastatic PC patients (cohort 1, training). Diagnostic and prognostic potential was evaluated in cohort 1, and 39 top circRNA candidates were selected for validation in two additional PC cohorts (cohort 2, n = 111; RP cohort 3, n = 191) by NanoString-based expression analysis. Biochemical recurrence (BCR)-free survival was assessed using Kaplan-Meier, univariate, and multivariate Cox regression analyses. The circRNA candidates were further detected in extracellular vesicle (EV)-enriched plasma samples from PC patients and controls (cohort 4, n = 54).

Results

Expression of circABCC4, circFAT3, circATRNL1, and circITGA7 was highly cancer-specific (area under the curve 0.71–0.86), while low circITGA7 expression was significantly (P < 0.05) associated with BCR in univariate analysis in two RP cohorts. Moreover, we successfully trained and validated a novel 5-circRNA prognostic signature (circKMD1A/circTULP4/circZNF532/circSUMF1/circMKLN1) significantly associated with BCR beyond routine clinicopathological variables (RP cohort 1: P = 0.02, hazard ratio = 2.1; RP cohort 3: P < 0.001, hazard ratio = 2.1). Lastly, we provide proof-of-principle for detection of candidate circRNAs in EV-enriched plasma samples from PC patients.

Conclusions

circRNAs hold great biomarker potential in PC and display both high cancer specificity and association to disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-021-01009-3.

Microbiota of the prostate tumor environment investigated by whole-transcriptome profiling

Background

With over 350,000 estimated deaths worldwide in 2018, prostate cancer (PCa) continues to be a major health concern and a significant cause of cancer-associated mortality among men. While cancer in general is considered a disease of the human genome, there is a growing body of evidence suggesting that changes to the healthy microbiota could play a vital role in cancer development, progression, and/or treatment outcome.

Methods

Using a metatranscriptomic approach, we annotated the microbial reads obtained from total RNA sequencing of 106 prostate tissue samples from 94 PCa patients (discovery cohort). We investigated microbial dysbiosis associated with PCa by systematically comparing the microbiomes between benign and malignant tissue samples, between less vs. more-aggressive PCa, and between patients who had biochemical recurrence as opposed to those who did not. We further performed differential gene expression and cell type enrichment analysis to explore the host transcriptomic and cellular responses to selected microbial genera. A public dataset (GSE115414) of total RNA sequencing reads from 24 prostate tissue samples (8 benign and 16 malignant) served as the validation cohort.

Results

We observed decreased species diversity and significant under-representation of Staphylococcus saprophyticus and Vibrio parahaemolyticus, as well as significant over-abundance of Shewanella in malignant as compared to benign prostate tissue samples in both the discovery (p < 0.01) and validation (p < 0.05) cohorts. In addition, we identified Microbacterium species (p < 0.01) to be significantly over-abundant in pathologically advanced T3 tumors compared to T2 in the discovery cohort. Malignant samples having high vs. low Shewanella counts were associated with downregulated Toll-like receptor signaling pathways and decreased enrichment of dendritic cells. Malignant samples having low vs. high V. parahaemolyticus counts were enriched for olfactory transduction and drug metabolism pathways. Finally, malignant samples were enriched for M1 and M2 macrophages as compared to benign tissue samples.

Conclusions

The results from this exploratory study support the existence of an important biological link between the prostate microbiota and PCa development/progression. Our results highlight Shewanella, V. parahaemolyticus, and Microbacterium sp. as interesting candidates for further investigation of their association with PCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13073-022-01011-3.

Acute urinary retention and risk of cancer: population based Danish cohort study

OBJECTIVE

To examine the risk of urogenital, colorectal, and neurological cancers after a first diagnosis of acute urinary retention.

DESIGN

Nationwide population based cohort study.

SETTING

All hospitals in Denmark.

PARTICIPANTS

75 983 patients aged 50 years or older with a first hospital admission for acute urinary retention during 1995-2017.

MAIN OUTCOME MEASURES

Absolute risk of urogenital, colorectal, and neurological cancer and excess risk of these cancers among patients with acute urinary retention compared with the general population.

RESULTS

The absolute risk of prostate cancer after a first diagnosis of acute urinary retention was 5.1% (n=3198) at three months, 6.7% (n=4233) at one year, and 8.5% (n=5217) at five years. Within three months of follow-up, 218 excess cases of prostate cancer per 1000 person years were detected. An additional 21 excess cases per 1000 person years were detected during three to less than 12 months of follow-up, but beyond 12 months the excess risk was negligible. Within three months of follow-up the excess risk for urinary tract cancer was 56 per 1000 person years, for genital cancer in women was 24 per 1000 person years, for colorectal cancer was 12 per 1000 person years, and for neurological cancer was 2 per 1000 person years. For most of the studied cancers, the excess risk was confined to within three months of follow-up, but the risk of prostate and urinary tract cancer remained increased during three to less than 12 months of follow-up. In women, an excess risk of invasive bladder cancer persisted for several years.

CONCLUSIONS

Acute urinary retention might be a clinical marker for occult urogenital, colorectal, and neurological cancers. Occult cancer should possibly be considered in patients aged 50 years or older presenting with acute urinary retention and no obvious underlying cause.

Immune cell analyses of the tumor microenvironment in prostate cancer highlight infiltrating regulatory T cells and macrophages as adverse prognostic factors

Improved risk stratification is needed for patients with localized prostate cancer. This study characterized and assessed the prognostic potential of distinct immune cell infiltration patterns in the prostate tumor microenvironment. Using tissue microarrays, multiplex immunohistochemistry/immunofluorescence, and automated digital pathology, we analyzed radical prostatectomy specimens from two large patient cohorts (training: n = 470; validation: n = 333) to determine infiltration levels of seven immune cell types in malignant versus benign prostate tissue: CD3⁺ CD8^- FoxP3^- T helper cells, CD3⁺ CD8⁺ FoxP3^- cytotoxic T cells (CTLs), CD3⁺ CD8^- FoxP3⁺ regulatory T cells (T_regs ), CD20⁺ B cells, CD68⁺ CD163^- M1 macrophages, CD68⁺ CD163⁺ M2 macrophages, and tryptase⁺ mast cells. Results were further validated by cell type enrichment analyses of bulk tumor RNAseq data from a third independent patient cohort (n = 99). Prognostic potential was assessed by Kaplan-Meier and uni-/multi-variate Cox regression analyses. Clinical endpoint was biochemical recurrence. All seven immune cell types were enriched in prostate cancer versus benign stroma, while there was selective enrichment for B cells, T_regs , M1 and M2 macrophages, and depletion of mast cells and CTLs in prostate cancer epithelium. In all three cohorts, high levels of infiltrating T_regs , M1, and M2 macrophages in stroma and/or epithelium were associated with biochemical recurrence (p < 0.05; log-rank test). After adjustment for routine clinical variables, T_regs and M2 macrophages remained significant adverse predictors of biochemical recurrence (p < 0.05; multivariate Cox regression). Our comprehensive analyses of immune cell infiltration patterns in the prostate tumor microenvironment highlight infiltrating T_regs , M1, and M2 macrophages as adverse predictors of prostate cancer outcome. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Ipatasertib plus abiraterone and prednisolone in metastatic castration-resistant prostate cancer (IPATential150): a multicentre, randomised, double-blind, phase 3 trial

BACKGROUND

The PI3K/AKT and androgen-receptor pathways are dysregulated in metastatic castration-resistant prostate cancers (mCRPCs); tumours with functional PTEN-loss status have hyperactivated AKT signalling. Dual pathway inhibition with AKT inhibitor ipatasertib plus abiraterone might have greater benefit than abiraterone alone. We aimed to compare ipatasertib plus abiraterone with placebo plus abiraterone in patients with previously untreated mCRPC with or without tumour PTEN loss.

METHODS

We did a randomised, double-blind, phase 3 trial at 200 sites across 26 countries or regions. Patients aged 18 years or older with previously untreated asymptomatic or mildly symptomatic mCRPC who had progressive disease and Eastern Collaborative Oncology Group performance status of 0 or 1 were randomly assigned (1:1; permuted block method) to receive ipatasertib (400 mg once daily orally) plus abiraterone (1000 mg once daily orally) and prednisolone (5 mg twice a day orally) or placebo plus abiraterone and prednisolone (with the same dosing schedule). Patients received study treatment until disease progression, intolerable toxicity, withdrawal from the study, or study completion. Stratification factors were previous taxane-based therapy for hormone-sensitive prostate cancer, type of progression, presence of visceral metastasis, and tumour PTEN-loss status by immunohistochemistry. Patients, investigators, and the study sponsor were masked to the treatment allocation. The coprimary endpoints were investigator-assessed radiographical progression-free survival in the PTEN-loss-by-immunohistochemistry population and in the intention-to-treat population. This study is ongoing and is registered with ClinicalTrials.gov, NCT03072238.

FINDINGS

Between June 30, 2017, and Jan 17, 2019, 1611 patients were screened for eligibility and 1101 (68%) were enrolled; 554 (50%) were assigned to the placebo-abiraterone group and 547 (50%) to the ipatasertib-abiraterone group. At data cutoff (March 16, 2020), median follow-up duration was 19 months (range 0-33). In the 521 (47%) patients who had tumours with PTEN loss by immunohistochemistry (261 in the placebo-abiraterone group and 260 in the ipatasertib-abiraterone group), median radiographical progression-free survival was 16·5 months (95% CI 13·9-17·0) in the placebo-abiraterone group and 18·5 months (16·3-22·1) in the ipatasertib-abiraterone group (hazard ratio [HR] 0·77 [95% CI 0·61-0·98]; p=0·034; significant at α=0·04). In the intention-to-treat population, median progression-free survival was 16·6 months (95% CI 15·6-19·1) in the placebo-abiraterone group and 19·2 months (16·5-22·3) in the ipatasertib-abiraterone group (HR 0·84 [95% CI 0·71-0·99]; p=0·043; not significant at α=0·01). Grade 3 or higher adverse events occurred in 213 (39%) of 546 patients in the placebo-abiraterone group and in 386 (70%) of 551 patients in the ipatasertib-abiraterone group; adverse events leading to discontinuation of placebo or ipatasertib occurred in 28 (5%) in the placebo-abiraterone group and 116 (21%) in the ipatasertib-abiraterone group. Deaths due to adverse events deemed related to treatment occurred in two patients (<1%; acute myocardial infarction [n=1] and lower respiratory tract infection [n=1]) in the placebo-abiraterone group and in two patients (<1%; hyperglycaemia [n=1] and chemical pneumonitis [n=1]) in the ipastasertb-abiraterone group.

INTERPRETATION

Ipatasertib plus abiraterone significantly improved radiographical progression-free survival compared with placebo plus abiraterone among patients with mCRPC with PTEN-loss tumours, but there was no significant difference between the groups in the intention-to-treat population. Adverse events were consistent with the known safety profiles of each agent. These data suggest that combined AKT and androgen-receptor signalling pathway inhibition with ipatasertib and abiraterone is a potential treatment for men with PTEN-loss mCRPC, a population with a poor prognosis.

FUNDING

F Hoffmann-La Roche and Genentech.

Risk stratification in men with a negative prostate biopsy: an interim analysis of a prospective cohort study

OBJECTIVE

To investigate whether a risk score for prostate cancer (PCa) lifetime risk can be used to optimise triaging of patients with a negative prostate biopsy, but under sustained suspicion of PCa.

PATIENTS AND METHODS

In this prospective clinical study, we included, and risk scored patients who had a PCa-negative transrectal ultrasonography (TRUS)-guided prostate biopsy, but elevated prostate-specific antigen (PSA), a suspicious prostate digital rectal examination and/or a positive family history (FH) of PCa. The risk score estimated individual lifetime risk of PCa, based on a polygenic risk score (33 single nucleotide polymorphisms), age, and FH of PCa. Patients were followed, under urological supervision, for up to 4 years with annual controls, always including PSA measurements. Multiparametric magnetic resonance imaging (mpMRI) and/or prostate biopsy was performed at selected annual controls depending on risk score and at the urologist's/patient's discretion, which means that the follow-up differed based on the risk score.

RESULTS

We included 429 patients. After risk scoring, 376/429 (88%) patients were allocated to a normal-risk group (<30% PCa lifetime risk) and 53/429 (12%) to a high-risk group (≥30% PCa lifetime risk). The high-risk group had significantly different follow-up, with more biopsy and mpMRI sessions compared to the normal-risk group. PCa was detected in 89/429 (21%) patients, with 67/376 (18%) patients diagnosed in the normal-risk group and 22/53 (42%) in the high-risk group. There was no statistically significant difference in the cumulative incidence of PCa between the normal-risk group and the high-risk group after 4 years of follow-up. Currently, 67/429 (16%) patients are still being followed in this ongoing study.

CONCLUSION

In a 4-year perspective, our PCa lifetime risk score did not demonstrate significant prognostic value for triaging patients, with a negative TRUS-guided biopsy and sustained suspicion of PCa.

Safety and Effects of Football in Skeletal Metastatic Prostate Cancer: a Subgroup Analysis of the FC Prostate Community Randomised Controlled Trial

Background

Skeletal metastatic disease excludes many cancer patients from participating in exercise and physical activity due to safety concerns. Empirical evidence from high-quality trials is warranted to guide clinicians and patients.

Objective

To evaluate the safety and potential benefits of high-impact aerobic exercise in patients with prostate cancer with skeletal metastases.

Design

Exploratory subgroup analysis of a pragmatic, multicentre, parallel randomised controlled trial.

Setting

The trial recruited 214 patients from five hospital urological departments in Denmark.

Participants

Patients with prostate cancer with skeletal metastases (n = 41).

Intervention

Six months of football training twice weekly at a local club or usual care. Both groups received brief information on physical activity recommendations at the time of randomisation.

Main Outcome(s) and Measure(s)

Safety, defined as falls, fractures and hospital admissions. Effects were evaluated on the primary outcome (prostate cancer-specific quality of life) and secondary outcomes (lean body mass, fat mass, hip and spine bone mineral density, and general physical and mental health).

Results

The original trial comprised 214 participants, 41 of whom had skeletal metastases at enrolment. Of these, 22 were allocated to football and 19 to usual care. The trial retention rate was 95% at 12 weeks and 88% at 6 months. Football participants attended 13 sessions on average at 12 weeks and 23 at 6 months. There were two falls, one in each group after 6 months, and no fractures. There were four unplanned hospital admissions in the study period, all four in the usual care group. Statistically significant between-group difference was observed in the primary outcome change in prostate cancer-specific quality of life at 12 weeks (7.6 points [95% CI 0.5 to 15.0]; P = 0.038). No statistical changes were found in the secondary outcomes.

Conclusion

The analysis showed that football training was safe in patients with skeletal metastatic prostate cancer and significantly improved quality of life. Larger analyses and/or trials are warranted to confirm the safety of exercise more broadly in cancer patients with skeletal metastatic disease.

Trial Registration

ClinicalTrials.gov, NCT02430792. Date of registration 30 April 2015

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-021-00318-6.

High-Throughput and Automated Acoustic Trapping of Extracellular Vesicles to Identify microRNAs With Diagnostic Potential for Prostate Cancer

Molecular profiling of extracellular vesicles (EVs) offers novel opportunities for diagnostic applications, but the current major obstacle for clinical translation is the lack of efficient, robust, and reproducible isolation methods. To bridge that gap, we developed a microfluidic, non-contact, and low-input volume compatible acoustic trapping technology for EV isolation that enabled downstream small RNA sequencing. In the current study, we have further automated the acoustic microfluidics-based EV enrichment technique that enables us to serially process 32 clinical samples per run. We utilized the system to enrich EVs from urine collected as the first morning void from 207 men referred to 10-core prostate biopsy performed the same day. Using automated acoustic trapping, we successfully enriched EVs from 199/207 samples (96%). After RNA extraction, size selection, and library preparation, a total of 173/199 samples (87%) provided sufficient materials for next-generation sequencing that generated an average of 2 × 10⁶ reads per sample mapping to the human reference genome. The predominant RNA species identified were fragments of long RNAs such as protein coding and retained introns, whereas small RNAs such as microRNAs (miRNA) accounted for less than 1% of the reads suggesting that partially degraded long RNAs out-competed miRNAs during sequencing. We found that the expression of six miRNAs was significantly different (P_adj < 0.05) in EVs isolated from patients found to have high grade prostate cancer [ISUP 2005 Grade Group (GG) 4 or higher] compared to those with GG3 or lower, including those with no evidence of prostate cancer at biopsy. These included miR-23b-3p, miR-27a-3p, and miR-27b-3p showing higher expression in patients with GG4 or high grade prostate cancer, whereas miR-1-3p, miR-10a-5p, and miR-423-3p had lower expression in the GG4 PCa cases. Cross referencing our differentially expressed miRNAs to two large prostate cancer datasets revealed that the putative tumor suppressors miR-1, miR-23b, and miR-27a are consistently deregulated in prostate cancer. Taken together, this is the first time that our automated microfluidic EV enrichment technique has been found to be capable of enriching EVs on a large scale from 900 μl of urine for small RNA sequencing in a robust and disease discriminatory manner.

Potential synergy between PSMA uptake and tumour blood flow for prediction of human prostate cancer aggressiveness

Background

Both prostate-specific membrane antigen (PSMA) uptake and tumour blood flow (TBF) correlate with International Society of Urological Pathology (ISUP) Grade Group (GG) and hence prostate cancer (PCa) aggressiveness. The aim of the present study was to evaluate the potential synergistic benefit of combining the two physiologic parameters for separating significant PCa from insignificant findings.

Methods

From previous studies of [⁸²Rb]Rb positron emission tomography (PET) TBF in PCa, the 43 patients that underwent clinical [⁶⁸Ga]Ga-PSMA-11 PET were selected for this retrospective study. Tumours were delineated on [⁶⁸Ga]Ga-PSMA-11 PET or magnetic resonance imaging. ISUP GG was recorded from 52 lesions.

Results

[⁶⁸Ga]Ga-PSMA-11 maximum standardized uptake value (SUVmax) and [⁸²Rb]Rb SUVmax correlated moderately with ISUP GG (rho = 0.59 and rho = 0.56, both p < 0.001) and with each other (r = 0.65, p < 0.001). A combined model of [⁶⁸Ga]Ga-PSMA-11 and [⁸²Rb]Rb SUVmax separated ISUP GG > 2 from ISUP GG 1–2 and benign with an area-under-the-curve of 0.85, 96% sensitivity, 74% specificity, and 95% negative predictive value. The combined model performed significantly better than either tracer alone did (p < 0.001), primarily by reducing false negatives from five or six to one (p ≤ 0.025).

Conclusion

PSMA uptake and TBF provide complementary information about tumour aggressiveness. We suggest that a combined analysis of PSMA uptake and TBF could significantly improve the negative predictive value and allow non-invasive separation of significant from insignificant PCa.

Internet-delivered Mindfulness-Based Cognitive Therapy for anxiety and depression in cancer survivors: Predictors of treatment response

BACKGROUND

The present study investigates possible predictors of treatment response in an Internet-delivered Mindfulness-Based Cognitive Therapy (iMBCT) intervention with therapist support. This iMBCT program, a fully online delivered intervention with asynchronous therapist support, has previously been shown to be efficacious in reducing symptoms of anxiety and depression in women treated for breast cancer and men treated for prostate cancer.

METHODS

Eighty-two breast- and prostate cancer survivors experiencing psychological distress received 8 weeks of therapist-guided iMBCT. Primary outcomes were improvement in anxiety and depression scores from baseline to post-treatment and from baseline to six-months follow-up. Clinical predictors included levels of depression and anxiety at the time of screening and at baseline, as well as time since diagnosis. Demographic predictors included age and educational level. Therapy-related predictors included working alliance, self-compassion, and five facets of mindfulness. Mixed Linear Models were employed to test the prediction effects over time.

RESULTS

Higher levels of baseline depression were associated with increased treatment response in anxiety at post-treatment, and lower levels of self-compassion were associated with increased treatment response in depression at post-treatment. None of the proposed predictors significantly predicted treatment response at six-months follow-up.

CONCLUSION

The findings suggest that iMBCT can be provided for cancer survivors regardless of their age, educational level, and time since diagnosis (up to five years) and that therapeutic alliance is not crucial for treatment response. We did not identify characteristics predicting treatment response, although many factors were tested. Still, other characteristics may be predictors, and given the relatively small sample size and a large number of statistical tests, the results should be interpreted with caution.

Trans-ancestry genome-wide association meta-analysis of prostate cancer identifies new susceptibility loci and informs genetic risk prediction

Prostate cancer is a highly heritable disease with large disparities in incidence rates across ancestry populations. We conducted a multiancestry meta-analysis of prostate cancer genome-wide association studies (107,247 cases and 127,006 controls) and identified 86 new genetic risk variants independently associated with prostate cancer risk, bringing the total to 269 known risk variants. The top genetic risk score (GRS) decile was associated with odds ratios that ranged from 5.06 (95% confidence interval (CI), 4.84-5.29) for men of European ancestry to 3.74 (95% CI, 3.36-4.17) for men of African ancestry. Men of African ancestry were estimated to have a mean GRS that was 2.18-times higher (95% CI, 2.14-2.22), and men of East Asian ancestry 0.73-times lower (95% CI, 0.71-0.76), than men of European ancestry. These findings support the role of germline variation contributing to population differences in prostate cancer risk, with the GRS offering an approach for personalized risk prediction.

FRMD6 has tumor suppressor functions in prostate cancer

Available tools for prostate cancer (PC) prognosis are suboptimal but may be improved by better knowledge about genes driving tumor aggressiveness. Here, we identified FRMD6 (FERM domain-containing protein 6) as an aberrantly hypermethylated and significantly downregulated gene in PC. Low FRMD6 expression was associated with postoperative biochemical recurrence in two large PC patient cohorts. In overexpression and CRISPR/Cas9 knockout experiments in PC cell lines, FRMD6 inhibited viability, proliferation, cell cycle progression, colony formation, 3D spheroid growth, and tumor xenograft growth in mice. Transcriptomic, proteomic, and phospho-proteomic profiling revealed enrichment of Hippo/YAP and c-MYC signaling upon FRMD6 knockout. Connectivity Map analysis and drug repurposing experiments identified pyroxamide as a new potential therapy for FRMD6 deficient PC cells. Finally, we established orthotropic Frmd6 and Pten, or Pten only (control) knockout in the ROSA26 mouse prostate. After 12 weeks, Frmd6/Pten double knockouts presented high-grade prostatic intraepithelial neoplasia (HG-PIN) and hyperproliferation, while Pten single-knockouts developed only regular PIN lesions and displayed lower proliferation. In conclusion, FRMD6 was identified as a novel tumor suppressor gene and prognostic biomarker candidate in PC.

Positive Predictive Value of Benign Prostatic Hyperplasia and Acute Urinary Retention in the Danish National Patient Registry: A Validation Study

Background and Aim

Benign prostatic hyperplasia comprises a significant burden to ageing men due to frequently associated lower urinary tract symptoms and the risk of developing serious complications, such as acute urinary retention. Healthcare databases are a valuable source of epidemiological research; however, continuous validation of definitions is imperative. We examined the positive predictive values of International Classification of Diseases, 10th Revision (ICD-10), diagnostic coding for benign prostatic hyperplasia and acute urinary retention in men in the Danish National Patient Registry.

Methods

We investigated a random sample of 100 men diagnosed with benign prostatic hyperplasia and 100 men diagnosed with acute urinary retention between 2011 and 2017 in the Central Denmark Region. Using medical record review as reference standard, we estimated the positive predictive value with corresponding 95% confidence intervals (CI) overall and stratified by age, type of hospital (university hospital vs regional hospital), type of hospital contact (inpatient, outpatient or emergency room), calendar year group (2011–2013, 2014–2017), and department (department of urology, geriatrics, endocrinology or emergency room).

Results

Medical records were available for all 200 sampled patients. We found an overall positive predictive value (PPV) of 95% (95% CI: 89–98%) for benign prostatic hyperplasia and 98% (95% CI: 93–99%) for acute urinary retention. The PPVs were consistent across age, type of hospital, type of hospital contact, calendar year group, and department.

Conclusion

The PPVs of ICD-10 codes for benign prostatic hyperplasia and acute urinary retention recorded in the Danish National Patient Registry are high.

The power of empirical data; lessons from the clinical registry initiatives in Scandinavian cancer care

BACKGROUND

In Scandinavia, there is a strong tradition for research and quality monitoring based on registry data. In Denmark, Norway and Sweden, 63 clinical registries collect data on disease characteristics, treatment and outcome of various cancer diagnoses and groups based on process-related and outcome-related variables.

AIM

We describe the cancer-related clinical registries, compare organizational structures and quality indicators and provide examples of how these registries have been used to monitor clinical performance, develop prediction models, assess outcome and provide quality benchmarks. Further, we define unmet needs such as inclusion of patient-reported outcome variables, harmonization of variables and barriers for data sharing.

RESULTS AND CONCLUSIONS

The clinical registry framework provides an empirical basis for evidence-based development of high-quality and equitable cancer care. The registries can be used to follow implementation of new treatment principles and monitor patterns of care across geographical areas and patient groups. At the same time, the lessons learnt suggest that further developments and coordination are needed to utilize the full potential of the registry initiative in cancer care.

Renal cryoablation: five- and 10-year survival outcomes in patients with biopsy-proven renal cell carcinoma

OBJECTIVE

To investigate the long-term oncological efficacy of renal cryoablation (CA) of small renal tumors.

MATERIALS AND METHODS

A review of patients treated with CA for a biopsy confirmed renal cell carcinoma less than 4 cm in diameter. All patients were identified from a prospectively maintained clinical database. Treatment efficacy was computed using the Kaplan-Meier method to estimate disease-free survival (DFS) and overall survival rates (OS).

RESULTS

A total of 179 patients (116 men and 63 women) with a mean age of 64 years (95% CI = 63 - 66) were included in the analysis. Mean tumor size was 27 mm (95% CI = 25.5-28.0) with a low, moderate and high PADUA complexity score in 30.2%, 44.7% and 16.2% of the cases, respectively. A total of 19 patients (11%) were diagnosed with residual unablated tumor, six patients (3%) were diagnosed with late local recurrence and six patients (3%) were diagnosed with metastatic disease. The estimated 5 years image confirmed the DFS rate was 79% (95% CI = 70-85). The estimated 5- and 10-year OS rates were 82% (95% CI = 75-87) and 61% (95% CI = 48-71), respectively. During the 10-year follow-up period a total of five patients (3%) died due to renal cancer, while 46 patients (26%) died from other causes.

CONCLUSIONS

CA appears to be an effective treatment modality for patients with small renal tumors. The present study demonstrated low rates of local recurrence and disease progression with excellent long-term cancer-specific survival.

Validation of the four-miRNA biomarker panel MiCaP for prediction of long-term prostate cancer outcome

Improved prostate cancer prognostic biomarkers are urgently needed. We previously identified the four-miRNA prognostic biomarker panel MiCaP ((miR-23a-3p × miR-10b-5p)/(miR-133a-3p × miR-374b-5p)) for prediction of biochemical recurrence (BCR) after radical prostatectomy (RP). Here, we identified an optimal numerical cut-off for MiCaP dichotomisation using a training cohort of 475 RP patients and tested this in an independent cohort of 281 RP patients (PCA281). Kaplan–Meier, uni- and multivariate Cox regression analyses were conducted for multiple endpoints: BCR, metastatic-(mPC) and castration-resistant prostate cancer (CRPC), prostate cancer-specific (PCSS) and overall survival (OS). Functional effects of the four MiCaP miRNAs were assessed by overexpression and inhibition experiments in prostate cancer cell lines. We found the numerical value 5.709 optimal for MiCaP dichotomisation. This was independently validated in PCA281, where a high MiCaP score significantly [and independent of the Cancer of the Prostate Risk Assessment Postsurgical (CAPRA-S) score] predicted BCR, progression to mPC and CRPC, and PCSS, but not OS. Harrell’s C-index increased upon addition of MiCaP to CAPRA-S for all endpoints. Inhibition of miR-23a-3p and miR-10b-5p, and overexpression of miR-133a-3p and miR-374b-5p significantly reduced cell survival. Our results may promote future implementation of a MiCaP-based test for improved prostate cancer risk stratification.

68Ga-PSMA PET/CT for Primary Lymph Node and Distant Metastasis NM Staging of High-Risk Prostate Cancer

With the largest high-risk prostate cancer (PCa) cohort to date undergoing ⁶⁸Ga-prostate-specific membrane antigen (PSMA) PET/CT primary staging, we aimed to, first, characterize the metastatic spread of PCa in relation to tumor ⁶⁸Ga-PSMA uptake and the D'Amico classification and, second, compare ⁶⁸Ga-PSMA PET/CT findings with radical prostatectomy and pelvic lymph node dissection (PLND) histopathology findings. Methods: The study included 691 consecutive newly diagnosed, biopsy-proven, treatment-naïve, D'Amico high-risk PCa patients primary-staged by ⁶⁸Ga-PSMA PET/CT. PSMA SUV_max and metastatic findings were compared with prostate-specific antigen level, International Society of Urological Pathology (ISUP) grade, and clinical stage as traditional risk stratification parameters. Moreover, ⁶⁸Ga-PSMA PET/CT findings were compared with histology findings in radical prostatectomy patients undergoing PLND. Undetected lymph node metastases (LNMs) underwent immunohistochemical PSMA staining. Results: Advanced disease (N1/M1) was observed in 35.3% of patients (244/691) and was associated with increasing prostate-specific antigen level, ISUP grade, and clinical stage. LNMs (N1/M1a) were detected in 31.4% (217/691) and bone metastases (M1b) in 16.8% (116/691). Advanced disease frequencies in patients with ISUP grades 2 and 3 were 10.8% (11/102) and 37.1% (33/89), respectively. Risk of advanced disease for cT2a, cT2b, and cT2c tumors was almost equal (24.2%, 27.9%, and 22.4%, respectively). We observed a weak correlation between SUV_max and biopsy ISUP grade (ρ = 0.21; P < 0.001) and a modest correlation between SUV_max and postprostatectomy ISUP grade (ρ = 0.38; P < 0.001). Sensitivity, specificity, positive and negative predictive value, and accuracy for LNM detection on ⁶⁸Ga-PSMA PET/CT in the PLND cohort were 30.6%, 96.5%, 68.8%, 84.5%, and 83.1%, respectively. Undetected LNMs either were micrometastases located in the lymph node border or were without PSMA expression. Conclusion: In this high-risk PCa cohort, we identified advanced disease in about one third at diagnosis. ISUP grade was the superior predictor for advanced disease at diagnosis. We found a significant difference in frequency of advanced disease between ISUP grades 2 and 3, as supports the Gleason score 7 subdivision. Interestingly, we observed no significant differences in risk of advanced disease when comparing the different cT2 stages. The undetected LNMs were either PSMA-negative or micrometastases.

Renal Potassium Excretion Visualized on 82Rubidium PET/CT

The positron emission tomography (PET) flow tracer ⁸²Rubidium is a known potassium analogue. During our studies of tumor blood flow in prostate cancer, we found that approximately 10% of the patients had high urinary ⁸²Rubidium activity. In roughly half of these patients, the increased renal rubidium/potassium excretion was either causing hypokalemia or explained by Thiazide treatment. In the other half, there was no obvious explanation or clinical consequence of the renal rubidium/potassium excretion. This is the first time enhanced renal potassium excretion is visualized on ⁸²Rubidium PET/CT.

Profiling of Circulating microRNAs in Prostate Cancer Reveals Diagnostic Biomarker Potential

Early detection of prostate cancer (PC) is paramount as localized disease is generally curable, while metastatic PC is generally incurable. There is a need for improved, minimally invasive biomarkers as current diagnostic tools are inaccurate, leading to extensive overtreatment while still missing some clinically significant cancers. Consequently, we profiled the expression levels of 92 selected microRNAs by RT-qPCR in plasma samples from 753 patients, representing multiple stages of PC and non-cancer controls. First, we compared plasma miRNA levels in patients with benign prostatic hyperplasia (BPH) or localized prostate cancer (LPC), versus advanced prostate cancer (APC). We identified several dysregulated microRNAs with a large overlap of 59 up/down-regulated microRNAs between BPH versus APC and LPC versus APC. Besides identifying several novel PC-associated dysregulated microRNAs in plasma, we confirmed the previously reported upregulation of miR-375 and downregulation of miR-146a-5p. Next, by randomly splitting our dataset into a training and test set, we identified and successfully validated a novel four microRNA diagnostic ratio model, termed bCaP (miR-375*miR-33a-5p/miR-16-5p*miR-409-3p). Combined in a model with prostate specific antigen (PSA), digital rectal examination status, and age, bCaP predicted the outcomes of transrectal ultrasound (TRUS)-guided biopsies (negative vs. positive) with greater accuracy than PSA alone (Training: area under the curve (AUC), model = 0.84; AUC, PSA = 0.63. Test set: AUC, model = 0.67; AUC, PSA = 0.56). It may be possible in the future to use this simple and minimally invasive bCaP test in combination with existing clinical parameters for a more accurate selection of patients for prostate biopsy.