Direct transposition of native DNA for sensitive multimodal single-molecule sequencing.

Concurrent readout of sequence and base modifications from long unamplified DNA templates by Pacific Biosciences of California (PacBio) single-molecule sequencing requires large amounts of input material. Here we adapt Tn5 transposition to introduce hairpin oligonucleotides and fragment (tagment) limiting quantities of DNA for generating PacBio-compatible circular molecules. We developed two methods that implement tagmentation and use 90-99% less input than current protocols: (1) single-molecule real-time sequencing by tagmentation (SMRT-Tag), which allows detection of genetic variation and CpG methylation; and (2) single-molecule adenine-methylated oligonucleosome sequencing assay by tagmentation (SAMOSA-Tag), which uses exogenous adenine methylation to add a third channel for probing chromatin accessibility. SMRT-Tag of 40 ng or more human DNA (approximately 7,000 cell equivalents) yielded data comparable to gold standard whole-genome and bisulfite sequencing. SAMOSA-Tag of 30,000-50,000 nuclei resolved single-fiber chromatin structure, CTCF binding and DNA methylation in patient-derived prostate cancer xenografts and uncovered metastasis-associated global epigenome disorganization. Tagmentation thus promises to enable sensitive, scalable and multimodal single-molecule genomics for diverse basic and clinical applications.

First-in-human Evaluation of a Prostate-specific Membrane Antigen-targeted Near-infrared Fluorescent Small Molecule for Fluorescence-based Identification of Prostate Cancer in Patients with High-risk Prostate Cancer Undergoing Robotic-assisted Prostatectomy.

BACKGROUND: Men with high-risk prostate cancer undergoing surgery likely recur due to failure to completely excise regional and/or local disease. OBJECTIVE: The first-in-human evaluation of safety, pharmacokinetics, and exploratory efficacy of IS-002, a novel near-infrared prostate-specific membrane antigen (PSMA)-targeted fluorescence imaging agent, designed for intraoperative prostate cancer visualization. DESIGN, SETTING, AND PARTICIPANTS: A phase 1, single-center, dose-escalation study was conducted in 24 men with high-risk prostate cancer scheduled for robotic-assisted radical prostatectomy with (extended) pelvic lymph node dissection using the da Vinci surgical system. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Adverse events (AEs), vital signs, complete blood count, complete metabolic panel, urinalysis, and electrocardiogram were assessed over a 14-d period and compared with baseline. The pharmacokinetic profile of IS-002 was determined. Diagnostic accuracy was assessed for exploratory efficacy. RESULTS AND LIMITATIONS: AEs predominantly included discoloration of urine (n = 22/24; expected, related, grade 1). There were no grade ≥2 AEs. IS-002 Cmax and area under the curve increased with increasing dose. Plasma concentrations declined rapidly in a biphasic manner, with the median terminal half-lives ranging from 5.0 to 7.6 h, independent of dose and renal function. At 25 µg/kg, the exploratory efficacy readouts for the negative and positive predictive values were, 97% and 45% for lymph nodes, and 100% and 80% for residual/locoregional disease detection, respectively. CONCLUSIONS: IS-002 is safe and well tolerated, and has the potential to enable intraoperative tumor detection that could not be identified using standard imaging. PATIENT SUMMARY: IS-002 is a new imaging agent that specifically targets the prostate-specific membrane antigen receptor. In this study, we tested IS-002 for the first time in men with high-risk prostate cancer undergoing surgery and found that IS-002 is safe, is cleared from the body quickly, and potentially allows identification of prostate cancer in areas that would not be identified by conventional white light imaging.

Transcriptomic Heterogeneity of Expansile Cribriform and Other Gleason Pattern 4 Prostate Cancer Subtypes.

BACKGROUND: Prostate cancers featuring an expansile cribriform (EC) pattern are associated with worse clinical outcomes following radical prostatectomy (RP). However, studies of the genomic characteristics of Gleason pattern 4 subtypes are limited. OBJECTIVE: To explore transcriptomic characteristics and heterogeneity within Gleason pattern 4 subtypes (fused/poorly formed, glomeruloid, small cribriform, EC/intraductal carcinoma [IDC]) and the association with biochemical recurrence (BCR)-free survival. DESIGN, SETTING, AND PARTICIPANTS: This was a retrospective cohort study including 165 men with grade group 2-4 prostate cancer who underwent RP at a single academic institution (2016-2020) and Decipher testing of the RP specimen. Patients with Gleason pattern 5 were excluded. IDC and EC patterns were grouped. Median follow-up was 2.5 yr after RP for patients without BCR. OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS: Prompted by heterogeneity within pattern 4 subtypes identified via exploratory analyses, we investigated transcriptomic consensus clusters using partitioning around medoids and hallmark gene set scores. The primary clinical outcome was BCR, defined as two consecutive prostate-specific antigen measurements >0.2 ng/ml at least 8 wk after RP, or any additional treatment. Multivariable Cox proportional-hazards models were used to determine factors associated with BCR-free survival. RESULTS AND LIMITATIONS: In this cohort, 99/165 patients (60%) had EC and 67 experienced BCR. Exploratory analyses and clustering demonstrated transcriptomic heterogeneity within each Gleason pattern 4 subtype. In the multivariable model controlled for pattern 4 subtype, margin status, Cancer of the Prostate Risk Assessment Post-Surgical score, and Decipher score, a newly identified steroid hormone-driven cluster (hazard ratio 2.35 95% confidence interval 1.01-5.47) was associated with worse BCR-free survival. The study is limited by intermediate follow-up, no validation cohort, and lack of accounting for intratumoral and intraprostatic heterogeneity. CONCLUSIONS: Transcriptomic heterogeneity was present within and across each Gleason pattern 4 subtype, demonstrating there is additional biologic diversity not captured by histologic subtypes. This heterogeneity can be used to develop novel signatures and to classify transcriptomic subtypes, which may help in refining risk stratification following RP to further guide decision-making on adjuvant and salvage treatments. PATIENT SUMMARY: We studied prostatectomy specimens and found that tumors with similar microscopic appearance can have genetic differences that may help to predict outcomes after prostatectomy for prostate cancer. Our results demonstrate that further gene expression analysis of prostate cancer subtypes may improve risk stratification after prostatectomy. Future studies are needed to develop novel gene expression signatures and validate these findings in independent sets of patients.

The Impact of Delayed Radical Prostatectomy on Recurrence Outcomes After Initial Active Surveillance: Results from a Large Institutional Cohort.

BACKGROUND AND OBJECTIVE: Active surveillance (AS) of prostate cancer (PCa) involves regular monitoring for disease progression. The aim is to avoid unnecessary treatment while ensuring appropriate and timely treatment for those whose disease progresses. AS has emerged as the standard of care for low-grade (Gleason grade 1, GG 1) PCa. Opponents are concerned that initial undersampling and delay of definitive management for patients with GG 2 disease may lead to adverse outcomes. We sought to determine whether the timing for definitive management of GG 2 PCa, either upfront or after initial AS, affects recurrence outcomes after radical prostatectomy (RP). METHODS: Participants were diagnosed with cT1-2N0/xM0/x, prostate-specific antigen (PSA) <20 ng/ml, and GG 1-2 PCa between 2000 and 2020 and underwent immediate RP for GG 2 or AS followed by delayed RP on upgrading to GG 2. The outcome was recurrence-free survival (RFS) after surgery, with recurrence defined as either biochemical failure (2 PSA measurements ≥0.2 ng/ml) or a second treatment. Multivariable Cox proportional-hazards regression models were used to calculate associations between the timing for definitive RP and the risk of recurrence, adjusted for age at diagnosis, percentage of positive biopsy cores (PPC), PSA density, PSA before RP, year of diagnosis, surgical margins, genomic risk score, and prostate MRI findings. KEY FINDINGS: Of the 1259 men who met the inclusion criteria, 979 underwent immediate RP after diagnosis of GG 2, 190 underwent RP within 12 mo of upgrading to GG 2 on AS, and 90 men underwent RP >12 mo after upgrading to GG 2. The 5-yr RFS rates were 81% for the immediate RP group, 80% for the delayed RP ≤12 mo, and 70% for the delayed RP >12 mo group (univariate log-rank p = 0.03). Cox multivariable regression demonstrated no difference in RFS outcomes between immediate RP for GG 2 disease and delayed RP after upgrading on AS. PPC (hazard ratio [HR] per 10% increment 1.08, 95% confidence interval [CI] 1.02-1.15; p = 0.01) and PSA before RP (HR 1.06, 95% CI 1.03-1.09; p < 0.01) were significantly associated with the risk of recurrence. CONCLUSIONS AND CLINICAL IMPLICATIONS: PPC and PSA before RP, but not the timing of definitive surgery after upgrade to GG 2, were associated with the risk of PCa recurrence after RP on multivariable analysis. These findings support the safety of AS and delayed definitive therapy for a subset of patients with GG 2 disease. PATIENT SUMMARY: In a large group of 1259 patients with low-grade prostate cancer, we found that delaying surgical treatment after an initial period of active surveillance resulted in no differences in prostate cancer recurrence. Our results support the safety of active surveillance for low-grade prostate cancer.

The Long-term Incidence and Quality of Life Outcomes Associated With Treatment-Related Toxicities of External Beam Radiotherapy for Prostate Cancer.

OBJECTIVE: To assess the long-term incidence of treatment-related toxicities and quality of life (QOL) outcomes associated with toxicity after external beam radiotherapy (EBRT) for prostate cancer. METHODS: We identified all men who had EBRT between 1994 and 2017 from Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE), a longitudinal, nationwide prostate cancer registry. CaPSURE was queried for patient-reported and International Classification of Diseases-9/10 and Current Procedural Terminology codes. The Medical Outcomes Studies Short Form 36 and the University of California, Los Angeles Prostate Cancer Index were used to provide measures of general health, sexual, urinary, and bowel function. Repeated measures mixed models were used to determine QOL change after onset of toxicity. RESULTS: From a total of 15,332, 1744 (11.4%) men had EBRT. The median follow-up was 7.9years (interquartile range [IQR] 4.3-12.7). The median time to onset of any toxicity including urinary pad usage in 265 (15.4% at 8years) men was 4.3years (IQR 1.8-8.0). The most frequent toxicity was hemorrhagic cystitis (104, 5.9% at 8years) after a median of 3.7years (1.3-7.8), gastrointestinal (48, 2.7% at 8years) after a median of 4.2years (IQR 1.3-7.8), followed by urethral stricture (47, 2.4% at 8years) after a median of 3.7years (IQR 1.9-9.1). Repeated measures mixed models found that onset of hemorrhagic cystitis was associated with change in general health over time. CONCLUSION: EBRT for prostate cancer is associated with distinct treatment-related toxicities which can occur many years after treatment and can affect QOL. These results may help men understand the long-term implications of treatment decisions.

Stability of Prognostic Estimation Using the CAPRA Score Incorporating Imaging-based vs Physical Exam-based Staging.

PURPOSE: Although official T-staging criteria for prostate cancer are based on digital rectal examination findings, providers increasingly rely on transrectal US and MRI to define pragmatic clinical stage to guide management. We assessed the impact of incorporating imaging findings into T-staging on performance of a well-validated prognostic instrument. MATERIALS AND METHODS: Patients who underwent radical prostatectomy for prostate cancer diagnosed between 2000 and 2019 with stage ≤cT3a on both digital rectal examination and imaging (transrectal US/MRI) were included. The University of California, San Francisco CAPRA (Cancer of the Prostate Risk Assessment) score was computed 2 ways: (1) incorporating digital rectal examination-based T stage and (2) incorporating imaging-based T stage. We assessed for risk changes across the 2 methods and associations of CAPRA (by both methods) with biochemical recurrence, using unadjusted and adjusted Cox proportional hazards models. Model discrimination and net benefit were assessed with time-dependent area under the curve and decision curve analysis, respectively. RESULTS: Of 2,222 men included, 377 (17%) increased in CAPRA score with imaging-based staging (P < .01). Digital rectal examination-based (HR 1.54; 95% CI 1.48-1.61) and imaging-based (HR 1.52; 95% CI 1.46-1.58) CAPRA scores were comparably accurate for predicting recurrence with similar discrimination and decision curve analyses. On multivariable Cox regression, positive digital rectal examination at diagnosis (HR 1.29; 95% CI 1.09-1.53) and imaging-based clinical T3/4 disease (HR 1.72; 95% CI 1.43-2.07) were independently associated with biochemical recurrence. CONCLUSIONS: The CAPRA score remains accurate whether determined using imaging-based staging or digital rectal examination-based staging, with relatively minor discrepancies and similar associations with biochemical recurrence. Staging information from either modality can be used in the CAPRA score calculation and still reliably predict risk of biochemical recurrence.

Limited Relevance of the Very Low Risk Prostate Cancer Classification in the Modern Era: Results from a Large Institutional Active Surveillance Cohort.

Although the American Urological Association recently dropped the very low-risk (VLR) subcategory for low-risk prostate cancer (PCa) and the European Association of Urology does not substratify low-risk PCa, the National Comprehensive Cancer Network (NCCN) guidelines still maintain this stratum, which is based on the number of positive biopsy cores, tumor extent in each core, and prostate-specific antigen density. This subdivision may be less applicable in the modern era in which imaging-targeted prostate biopsies are common practice. In our large institutional active surveillance cohort of patients diagnosed from 2000 to 2020 (n = 1276), the number of patients meeting NCCN VLR criteria decreased significantly in recent years, with no patient meeting VLR criteria after 2018. By contrast, the multivariable Cancer of the Prostate Risk Assessment (CAPRA) score effectively substratified patients over the same period and was predictive of upgrading on repeat biopsy to Gleason grade group ≥2 on multivariable Cox proportional-hazards regression modeling (hazard ratio 1.21, 95% confidence interval 1.05-1.39; p < 0.01), independent of age, genomic test results, and magnetic resonance imaging findings. These findings suggest that the NCCN VLR criteria are less applicable in the targeted biopsy era, and that the CAPRA score or similar instruments are better contemporary risk stratification tools for men on active surveillance. PATIENT SUMMARY: We investigated whether the National Comprehensive Cancer Network classification of very low risk (VLR) for prostate cancer is relevant in the modern era. We found that in a large group of patients on active surveillance, no man diagnosed after 2018 satisfied the VLR criteria. However, the Cancer of the Prostate Risk Assessment (CAPRA) score discriminated patients by cancer risk at diagnosis and was predictive of outcomes on active surveillance, and thus may be a more relevant classification scheme in the modern era.

The natural history of a delayed detectable PSA after radical prostatectomy.

INTRODUCTION: Men with a detectable PSA after radical prostatectomy (RP) are often offered salvage therapy while those with an undetectable PSA are monitored. We aim to better characterize the natural history of men with an initially undetectable PSA who subsequently developed a detectable PSA > 6 months after RP. METHODS: Retrospective analysis of men who underwent RP for clinically localized prostate cancer at the University of California, San Francisco from 2000 to 2022. The primary outcome was biochemical recurrence, defined as 2 consecutive PSA > = 0.03 ng/mL starting 6 months after surgery. Secondary outcomes were salvage treatment, post-salvage treatment, metastasis free survival (MFS), prostate cancer specific mortality (PCSM), and all-cause mortality (ACM). This cohort was compared to a previously described cohort who had an immediately detectable post-operative PSA. RESULTS: From our cohort of 3348 patients, we identified 2868 men who had an undetectable post-op PSA. Subsequently, 642 men had a delayed detectable PSA at a median of 25 months (IQR 15, 43) with median follow-up of 72 months after RP. PSA at time of failure was <0.10 ng/mL for 65.7% of men. Of those with a delayed detectable PSA, 46% underwent salvage treatment within 10 years after RP at a median PSA of 0.08 ng/mL (IQR 0.05, 0.14). High CAPRA-S score (HR 1.09, CI 1.02-1.17, p = 0.02) and PSA doubling time (PSA-DT) of <6 months (HR 7.58, CI 5.42-10.6, p < 0.01) were associated with receiving salvage treatment. After salvage treatment, 62% of men had recurrent PSA failure within 10 years. Overall, MFS was 92%, PCSM 3%, and ACM 6% at 10 years. For those who received tertiary treatment for recurrent PSA failure, MFS was 54%, PCSM 23% and ACM 23% at 10 years' time. CONCLUSIONS: Men who develop a detectable PSA > 6 months post-operatively may have excellent long-term outcomes, even in the absence of salvage therapy.

Gleason Grade 1 Prostate Cancer Volume at Biopsy Is Associated With Upgrading but Not Adverse Pathology or Recurrence After Radical Prostatectomy: Results From a Large Institutional Cohort.

PURPOSE: Clinical guidelines suggest that for low-grade, clinically localized prostate cancer, patients with higher volume of disease at diagnosis may benefit from definitive therapy, although the data remain unclear. Our objective was to determine associations between low-grade prostate cancer volume and outcomes in men managed with primary radical prostatectomy. MATERIALS AND METHODS: Men with cT1-2N0/xM0/x prostate cancer, prostate specific antigen at diagnosis <10 ng/mL, and Gleason grade group 1 pathology on diagnostic biopsy managed with primary radical prostatectomy were included. Outcomes were pathological upgrade at radical prostatectomy (≥Gleason grade group 2), University of California, San Francisco adverse pathology at radical prostatectomy (≥Gleason grade group 3, pT3/4, or pN1), alternate adverse pathology at radical prostatectomy (≥Gleason grade group 3, ≥pT3b, or pN1), and recurrence (biochemical failure with 2 prostate specific antigen ≥0.2 ng/mL or salvage treatment). Multivariable logistic regression models were used to estimate associations between percentage of positive cores and risk of upgrade and adverse pathology at radical prostatectomy. Multivariable Cox proportional hazards regression models were used to estimate associations between percentage of positive cores and hazard of recurrence after radical prostatectomy. RESULTS: A total of 1,029 men met inclusion criteria. Multivariable logistic regression models demonstrated significant associations between percentage of positive cores and pathological upgrade (OR 1.31, 95% CI 1.1-1.57, P < .01), but not University of California, San Francisco adverse pathology at radical prostatectomy (P = .84); percentage of positive cores was negatively associated with alternate adverse pathology (OR 0.67, 95% CI 0.48-0.93, P = .02). Multivariable Cox regression models demonstrated no association between percentage of positive cores and hazard of recurrence after radical prostatectomy (P = .11). CONCLUSIONS: In men with Gleason grade group 1 prostate cancer, tumor volume may be associated with upgrading at radical prostatectomy, but not more clinically significant outcomes of adverse pathology or recurrence.

The endoplasmic reticulum stress response in prostate cancer.

In order to proliferate in unfavourable conditions, cancer cells can take advantage of the naturally occurring endoplasmic reticulum-associated unfolded protein response (UPR) via three highly conserved signalling arms: IRE1α, PERK and ATF6. All three arms of the UPR have key roles in every step of tumour progression: from cancer initiation to tumour growth, invasion, metastasis and resistance to therapy. At present, no cure for metastatic prostate cancer exists, as targeting the androgen receptor eventually results in treatment resistance. New research has uncovered an important role for the UPR in prostate cancer tumorigenesis and crosstalk between the UPR and androgen receptor signalling pathways. With an improved understanding of the mechanisms by which cancer cells exploit the endoplasmic reticulum stress response, targetable points of vulnerability can be uncovered.

Improving multiparametric MR-transrectal ultrasound guided fusion prostate biopsies with hyperpolarized 13 C pyruvate metabolic imaging: A technical development study.

PURPOSE: To develop techniques and establish a workflow using hyperpolarized carbon-13 (13 C) MRI and the pyruvate-to-lactate conversion rate (kPL ) biomarker to guide MR-transrectal ultrasound fusion prostate biopsies. METHODS: The integrated multiparametric MRI (mpMRI) exam consisted of a 1-min hyperpolarized 13 C-pyruvate EPI acquisition added to a conventional prostate mpMRI exam. Maps of kPL values were calculated, uploaded to a picture archiving and communication system and targeting platform, and displayed as color overlays on T2 -weighted anatomic images. Abdominal radiologists identified 13 C research biopsy targets based on the general recommendation of focal lesions with kPL >0.02(s-1 ), and created a targeting report for each study. Urologists conducted transrectal ultrasound-guided MR fusion biopsies, including the standard 1 H-mpMRI targets as well as 12-14 core systematic biopsies informed by the research 13 C-kPL targets. All biopsy results were included in the final pathology report and calculated toward clinical risk. RESULTS: This study demonstrated the safety and technical feasibility of integrating hyperpolarized 13 C metabolic targeting into routine 1 H-mpMRI and transrectal ultrasound fusion biopsy workflows, evaluated via 5 men (median age 71 years, prostate-specific antigen 8.4 ng/mL, Cancer of the Prostate Risk Assessment score 2) on active surveillance undergoing integrated scan and subsequent biopsies. No adverse event was reported. Median turnaround time was less than 3 days from scan to 13 C-kPL targeting, and scan-to-biopsy time was 2 weeks. Median number of 13 C targets was 1 (range: 1-2) per patient, measuring 1.0 cm (range: 0.6-1.9) in diameter, with a median kPL of 0.0319 s-1 (range: 0.0198-0.0410). CONCLUSIONS: This proof-of-concept work demonstrated the safety and feasibility of integrating hyperpolarized 13 C MR biomarkers to the standard mpMRI workflow to guide MR-transrectal ultrasound fusion biopsies.

Addition of Enzalutamide to Leuprolide and Definitive Radiation Therapy Is Tolerable and Effective in High-Risk Localized or Regional Nonmetastatic Prostate Cancer: Results From a Phase 2 Trial.

Background: Enzalutamide is an antiandrogen used to treat both metastatic and nonmetastatic prostate cancer. Here we present results from a phase 2 trial designed to determine the safety, tolerability, and efficacy of adding enzalutamide to standard androgen deprivation therapy with radiation therapy in high-risk localized or regional, nonmetastatic patients with prostate cancer. Methods and Materials: Enrollment criteria included at least 2 of the following: stage cT3a/b, prostate specific antigen (PSA) ≥20 ng/mL, Gleason grade 8 to 10, ≥33% core involvement on biopsy, or pelvic lymph node involvement on computed tomography or magnetic resonance imaging. Patients with metastatic disease were excluded. All patients received 24 months of leuprolide and enzalutamide, and 5 weeks of intensity modulated radiation therapy followed by a brachytherapy boost. Adverse events (AE), PSA, testosterone, and basic laboratory tests were then followed for up to 36 months. Primary outcomes were safety and tolerability and PSA complete response rate (PSA-CR, defined as PSA ≤0.3). Secondary outcomes included time to biochemical recurrence (BCR; nadir + 2 ng/mL). Results: Sixteen patients were enrolled; 2 were ineligible and 3 withdrew before starting treatment. Median age at enrollment was 69.0 years (interquartile range [IQR] 11.5). Median treatment duration was 24.0 months (IQR 11.9). Median follow-up time was 35.5 months (IQR 11.2), and 9 of 11 (81.8%) patients completed the 36 months of follow-up. One of 11 (9%) patients had grade 4 AE (seizure), and no grade 5 AE were reported. Four of 11 (36.4%) patients had grade 3 AE, such as erectile dysfunction and hot flashes. All patients achieved PSA-CR, and median time to PSA-CR was 4.2 months (IQR 1.4). At 24 months follow-up, 0 of 11 (0%) patients had a biochemical recurrence. At 36 months, 1 of 9 (11.1%) patient had a biochemical recurrence. Of note, this patient did not complete the full 24 months of enzalutamide and leuprolide due to AEs. Conclusions: Enzalutamide in combination with standard androgen deprivation therapy and radiation therapy was well-tolerated and effective warranting further study in a randomized controlled trial.

Patient engagement in a mobile health intervention to improve preparedness for prostate biopsy.

OBJECTIVE: We designed and implemented a peri-procedural text message (SMS) program for patients undergoing transrectal prostate biopsy and aimed to evaluate predictors of patient enrollment and engagement with the SMS program. METHODS: We designed an SMS-based program with 8 messages containing web-based modules with educational content and reminders confirming MRI for fusion biopsy, antibiotic adherence, enema use, and anticoagulation cessation. Data on patient demographics, enrollment, and engagement with modules were collected from June 1, 2018 to February 28, 2021. Engagement was defined as a patient clicking a link delivered via SMS to access modules. We made multivariable models to identify predictors of patient enrollment and engagement. RESULTS: Of the 1,760 prostate biopsies between June 2018 and March 2021, 1,383 (78.6%) were enrolled in SMS, 182 (10.3%) in email, 106 (6.0%) in both, and 240 (13.6%) were not enrolled. Of 1418 patients enrolled, 1,270 (89.6%) engaged with at least one module. African American patients had 50% lower odds of being enrolled (OR = 0.50, 95% CI 0.28-0.96; P = 0.03), but once enrolled there were no differences in engagement. Patients for whom English was not listed as their primary language had 60% lower odds of engagement (OR = 0.40, 95% CI 0.17-1.00, P = .04) and patients who were single or divorced had a 40% lower odds of engagement (OR = 0.60, 95% CI 0.41-0.91, P = 0.01). CONCLUSIONS: A cohort of older men undergoing prostate biopsy were able to engage with a text message-based education and reminder program. Future efforts must address barriers to enrollment for Black or African American men and improve accessibility to non-English speaking patients.

The effect of preoperative membranous urethral length on likelihood of postoperative urinary incontinence after robot-assisted radical prostatectomy.

BACKGROUND: Urinary incontinence after radical prostatectomy affects many men. In addition to surgical and patient factors, longer preoperative membranous urethral length (MUL) has been suggested to be associated with improved postoperative urinary continence outcomes. Here, we assess the association of preoperative MUL and the risk of persistent postoperative urinary incontinence after robot-assisted radical prostatectomy (RARP) for prostate cancer on extended follow-up. METHODS: All participants underwent RARP at the University of California, San Francisco between 2000-2018. Patients were excluded if preoperative MRI-measured MUL was not performed by a radiologist. A single, blinded urologist remeasured MUL retrospectively. Logistic regression models examined associations between radiologist- and urologist-measured MUL and likelihood of persistent incontinence post-RARP by two definitions: strict incontinence (>0 pad/day) and social incontinence (>1 pad/day). RESULTS: In 251 men with a median follow-up of 42 months (IQR 29-76), the median MUL measurements were 14 mm ([IQR 12-17], radiologist) and 15 mm ([IQR 12-18], urologist) with poor agreement (interclass correlation coefficient 0.34). On logistic regression, urologist-measured longer MUL was associated with lower likelihood of strict incontinence within 6 months (odds ratio [OR] 0.87; 95% confidence interval [CI] 0.81-0.94) and 12 months (OR 0.90; 95% CI 0.82-0.98) and social incontinence within 6 months (OR 0.93; 95% CI 0.86-1.00) and 12 months (OR 0.84; 95% CI 0.74-0.95). Radiologist-measured longer MUL was associated with lower likelihood of strict incontinence within 6 months (OR 0.93; 95% CI 0.87-1.00) and social within 12 months (OR 0.87; 95% CI 0.77-1.00). MUL was not associated with likelihood of strict or social incontinence within 24 months. CONCLUSION: Preoperative MRI-measured MUL was not associated with urinary incontinence after 12 months post-RARP. Poor agreement between radiologists' and urologist's measurements supports standardizing MUL measurements to establish the likelihood of early incontinence.

US lesion visibility predicts clinically significant upgrade of prostate cancer by systematic biopsy.

PURPOSE: To identify predictors of when systematic biopsy leads to a higher overall prostate cancer grade compared to targeted biopsy. METHODS AND MATERIALS: 918 consecutive patients who underwent prostate MRI followed by MRI/US fusion biopsy and systematic biopsies from January 2015 to November 2019 at a single academic medical center were retrospectively identified. The outcome was upgrade of PCa by systematic biopsy, defined as cases when systematic biopsy led to a Gleason Grade (GG) ≥ 2 and greater than the maximum GG detected by targeted biopsy. Generalized linear regression and conditional logistic regression were used to analyze predictors of upgrade. RESULTS: At the gland level, the presence of an US-visible lesion was associated with decreased upgrade (OR 0.64, 95% CI 0.44-0.93, p = 0.02). At the sextant level, upgrade was more likely to occur through the biopsy of sextants with MRI-visible lesions (OR 2.58, 95% CI 1.87-3.63, p < 0.001), US-visible lesions (OR 1.83, 95% CI 1.14-2.93, p = 0.01), and ipsilateral lesions (OR 3.89, 95% CI 2.36-6.42, p < 0.001). CONCLUSION: Systematic biopsy is less valuable in patients with an US-visible lesion, and more likely to detect upgrades in sextants with imaging abnormalities. An approach that takes additional samples from regions with imaging abnormalities may provide analogous information to systematic biopsy.

The Natural History of Untreated Biopsy Grade Group Progression and Delayed Definitive Treatment for Men on Active Surveillance for Early-Stage Prostate Cancer.

PURPOSE: For men with clinically localized prostate cancer outcomes of continuing active surveillance (AS) after biopsy progression are not well understood. We aim to determine the impact of continuing AS and delayed definitive treatment after biopsy progression on oncologic outcomes. MATERIALS AND METHODS: Participants in our prospective AS cohort (1990-2018) diagnosed with grade group (GG) 1, localized prostate cancer, with prostate specific antigen <20 who were subsequently upgraded to ≥GG2, and underwent further surveillance (biopsy/imaging/prostate specific antigen) were identified. Patients were stratified by post-progression followup into 3 groups: continue AS untreated, pursue early radical prostatectomy (RP) ≤6 months, or undergo late RP within 6 months to 5 years of progression. Patients receiving other treatments were excluded. We compared characteristics between groups and examined the associations of early vs late RP with risk of adverse pathology (AP) at RP and recurrence-free survival (RFS) after RP. RESULTS: Of 531 patients with biopsy progression and further surveillance 214 (40%) remained untreated, 192 (36%) pursued early RP and 125 (24%) underwent late RP. Among patients who underwent early vs late RP, there was no difference in GG (p=0.15) or AP (55% vs 53%, p=0.74) rate at RP, or 3-year RFS (80% vs 87%, log-rank p=0.64) after RP. In multivariable models, only Cancer of Prostate Risk Assessment post-surgical score was associated with risk of RFS (HR=1.42 per point, 95% CI 1.24-1.64). CONCLUSIONS: Among patients continuing AS after biopsy progression, 60% underwent surgery within 5 years. Delayed surgery after progression was not associated with higher risk of AP or RFS. This suggests select patients may be able to safely delay treatment after progression.

Targeting a splicing-mediated drug resistance mechanism in prostate cancer by inhibiting transcriptional regulation by PKCß1.

The androgen receptor (AR) is a central driver of aggressive prostate cancer. After initial treatment with androgen receptor signaling inhibitors (ARSi), reactivation of AR signaling leads to resistance. Alternative splicing of AR mRNA yields the AR-V7 splice variant, which is currently an undruggable mechanism of ARSi resistance: AR-V7 lacks a ligand binding domain, where hormones and anti-androgen antagonists act, but still activates AR signaling. We reveal PKCß as a druggable regulator of transcription and splicing at the AR genomic locus. We identify a clinical PKCß inhibitor in combination with an FDA-approved anti-androgen as an approach for repressing AR genomic locus expression, including expression of AR-V7, while antagonizing full-length AR. PKCß inhibition reduces total AR gene expression, thus reducing AR-V7 protein levels and sensitizing prostate cancer cells to current anti-androgen therapies. We demonstrate that this combination may be a viable therapeutic strategy for AR-V7-positive prostate cancer.

Characteristics of Cancer Progression on Serial Biopsy in Men on Active Surveillance for Early-stage Prostate Cancer: Implications for Focal Therapy.

BACKGROUND: Active surveillance (AS) is a safe and accepted option for managing men with low-risk prostate cancer. Nevertheless, some patients lack confidence in or access to AS. Focal therapy (FT) is a possible alternative to radical treatment for such patients. OBJECTIVE: We evaluated dominant tumor (DT) progression across serial biopsies to determine whether men on AS could be reasonable candidates for FT. DESIGN, SETTING, AND PARTICIPANTS: Men enrolled in AS at University of California, San Francisco between 1996 and 2017 with low/intermediate risk were included. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Changes in biopsy grade, volume, and focality of the DT over time were assessed. Focality (good or poor for FT) was defined by the number of cores, laterality, and contiguity of prostate sites containing tumor (based on pathology reports). Candidates (either for targeted/quadrant ablation or for hemigland ablation) were defined based on good focality, grade group (GG) ≤2, and low-volume disease. Patients were classified as favorable (GG ≤ 2 with good focality and concordant multiparametric magnetic resonance imaging [mpMRI]) or unfavorable (poor focality or high-volume disease or discordant mpMRI) for FT at surveillance biopsies. RESULTS AND LIMITATIONS: A total of 1057 men met the inclusion criteria. The median number of biopsies per patient was three (interquartile range 2-4), and 196 patients (18.5%) underwent five or more biopsies. At confirmatory biopsy, 43% remained candidates for FT (67% for targeted/quadrant ablation and 33% for hemigland ablation) and 20% had a negative biopsy. Of the candidates for FT at initial biopsy, 11% had less favorable characteristics at confirmatory biopsy. Among candidates for FT based on both initial and confirmatory biopsies, 70% remained favorable for hemigland ablation at subsequent biopsies. Limitations include retrospective design and mpMRI information only at surveillance biopsy. CONCLUSIONS: Serial biopsy findings in men with early-stage cancer on AS show that tumor location remains relatively stable and significant changes in grade and/or volume occur largely in the DT. Combined diagnostic and confirmatory biopsy findings help better select patients for FT than the use of the diagnostic biopsy alone. PATIENT SUMMARY: In a large cohort of patients on active surveillance for prostate cancer, we evaluated changes across serial biopsies to identify potential candidates for focal therapy (FT). Our findings showed that the dominant tumor remained stable over time and the majority of men were favorable candidates for FT.

ERα is an RNA-binding protein sustaining tumor cell survival and drug resistance.

Estrogen receptor α (ERα) is a hormone receptor and key driver for over 70% of breast cancers that has been studied for decades as a transcription factor. Unexpectedly, we discover that ERα is a potent non-canonical RNA-binding protein. We show that ERα RNA binding function is uncoupled from its activity to bind DNA and critical for breast cancer progression. Employing genome-wide cross-linking immunoprecipitation (CLIP) sequencing and a functional CRISPRi screen, we find that ERα-associated mRNAs sustain cancer cell fitness and elicit cellular responses to stress. Mechanistically, ERα controls different steps of RNA metabolism. In particular, we demonstrate that ERα RNA binding mediates alternative splicing of XBP1 and translation of the eIF4G2 and MCL1 mRNAs, which facilitates survival upon stress conditions and sustains tamoxifen resistance of cancer cells. ERα is therefore a multifaceted RNA-binding protein, and this activity transforms our knowledge of post-transcriptional regulation underlying cancer development and drug response.

Diagnostic Accuracy of 68Ga-PSMA-11 PET for Pelvic Nodal Metastasis Detection Prior to Radical Prostatectomy and Pelvic Lymph Node Dissection: A Multicenter Prospective Phase 3 Imaging Trial.

IMPORTANCE: The presence of pelvic nodal metastases at radical prostatectomy is associated with biochemical recurrence after prostatectomy. OBJECTIVE: To assess the accuracy of prostate-specific membrane antigen (PSMA) 68Ga-PSMA-11 positron emission tomographic (PET) imaging for the detection of pelvic nodal metastases compared with histopathology at time of radical prostatectomy and pelvic lymph node dissection. DESIGN, SETTING, AND PARTICIPANTS: This investigator-initiated prospective multicenter single-arm open-label phase 3 imaging trial of diagnostic efficacy enrolled 764 patients with intermediate- to high-risk prostate cancer considered for prostatectomy at University of California, San Francisco and University of California, Los Angeles from December 2015 to December 2019. Data analysis took place from October 2018 to July 2021. INTERVENTIONS: Imaging scan with 3 to 7 mCi of 68Ga-PSMA-11 PET. MAIN OUTCOMES AND MEASURES: The primary end point was the sensitivity and specificity for the detection pelvic lymph nodes compared with histopathology on a per-patient basis using nodal region correlation. Each scan was read centrally by 3 blinded independent central readers, and a majority rule was used for analysis. RESULTS: A total of 764 men (median [interquartile range] age, 69 [63-73] years) underwent 1 68Ga-PSMA-11 PET imaging scan for primary staging, and 277 of 764 (36%) subsequently underwent prostatectomy with lymph node dissection (efficacy analysis cohort). Based on pathology reports, 75 of 277 patients (27%) had pelvic nodal metastasis. Results of 68Ga-PSMA-11 PET were positive in 40 of 277 (14%), 2 of 277 (1%), and 7 of 277 (3%) of patients for pelvic nodal, extrapelvic nodal, and bone metastatic disease. Sensitivity, specificity, positive predictive value, and negative predictive value for pelvic nodal metastases were 0.40 (95% CI, 0.34-0.46), 0.95 (95% CI, 0.92-0.97), 0.75 (95% CI, 0.70-0.80), and 0.81 (95% CI, 0.76-0.85), respectively. Of the 764 patients, 487 (64%) did not undergo prostatectomy, of which 108 were lost to follow-up. Patients with follow-up instead underwent radiotherapy (262 of 379 [69%]), systemic therapy (82 of 379 [22%]), surveillance (16 of 379 [4%]), or other treatments (19 of 379 [5%]). CONCLUSIONS AND RELEVANCE: This phase 3 diagnostic efficacy trial found that in men with intermediate- to high-risk prostate cancer who underwent radical prostatectomy and lymph node dissection, the sensitivity and specificity of 68Ga-PSMA-11 PET were 0.40 and 0.95, respectively. This academic collaboration is the largest known to date and formed the foundation of a New Drug Application for 68Ga-PSMA-11. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT03368547, NCT02611882, and NCT02919111.