The use of focal therapy for the treatment of prostate cancer in Canada: Where are we, how did we get here, and where are we going?

INTRODUCTION

Focal therapy is an emerging treatment for localized prostate cancer. The objectives of this review were to: 1) review how focal therapies are regulated and approved; 2) summarize the scope and quality of the literature regarding safety, efficacy, and side-effects; and 3) outline ongoing clinical trials of focal therapy in Canada.

METHODS

Using the PRISMA framework for scoping reviews, we searched PubMed, Embase, and Cochrane from 2021-2024, complementing Hopstaken et al's search up functional and oncologic outcomes. Additionally, we examined the FDA database for regulatory details and ongoing trials in Canada via ClinicalTrial.gov.

RESULTS

FDA approval for prostate tissue ablation was granted to high-intensity focused ultrasound (HIFU) in 2015 via the de novo pathway; other therapies followed the 510(k) route, citing equivalence to predicate devices. Most studies are in early stages, primarily single-arm, prospective cohort designs. Oncologic outcomes like cancer detection and survival rates, alongside functional data, such as adverse events and erectile function, were assessed. Recurrence-free survival at 48 months ranged from 58-92%, pad-free rates were greater than 95%, and rates of new-onset erectile dysfunction were variable, ranging from no change to 50%. Rates of serious adverse events (SAEs) were low, ranging from 0-14%. Three Canadian clinical trials are actively enrolling participants, and five private clinics were found offering private HIFU, irreversible electroporation (IRE), or transurethral ultrasound ablation (TULSA).

CONCLUSIONS

Focal therapy technologies have gained regulatory approval for prostate tissue ablation, and, aside from provincial support for cryoablation in Alberta, are available to Canadians through private payment or clinical trials. Many studies demonstrate promising cancer control and impressive functional outcomes but are limited by their short followup and lack of comparator group. Clinical trial or registry participation should be prioritized to ensure an evidence-based integration into current prostate cancer treatment approaches.

Magnetic Resonance Imaging-Targeted Versus Systematic Prostate Biopsies: 2-year Follow-up of a Prospective Randomized Trial (PRECISE)

BACKGROUND

The prospective randomized PRECISE trial demonstrated that magnetic resonance imaging (MRI) with only targeted biopsy (TBx) was noninferior to systematic transrectal ultrasound biopsy (SBx) in the detection of International Society of Urological Pathology grade group (GG) ≥2 prostate cancer (PC). An unanswered question is the outcome for patients who avoided a biopsy because of negative MRI findings.

OBJECTIVE

To explore the rate of PC diagnosis based on 2-yr MRI for PRECISE participants who had no biopsy and for patients who had a negative result or GG 1 on TBx in comparison to those with a negative result or GG 1 on SBx.

DESIGN, SETTING, AND PARTICIPANTS

The PRECISE prospective trial was conducted at five Canadian academic centers. The present analysis was for trial participants who were not diagnosed with clinically significant PC (csPC) at baseline. Of 453 randomized patients, 146 were diagnosed with GG ≥2 at baseline and were excluded. Eligible patients for this study included 83 men from the MRI arm who had negative MRI findings and no biopsy, 120 from the overall cohort who had a negative SBx or TBx, and 72 from the overall cohort who were diagnosed with GG 1 disease.

INTERVENTION

MRI at 2 yr in all men in the MRI and SBx arms and TBx for lesions with a Prostate Imaging-Reporting and Data System score of ≥3 or on the basis of clinical suspicion.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was the proportion of men diagnosed with GG ≥2 cancer. Secondary outcomes included the MRI outcome and the proportion of men diagnosed with GG 1 PC.

RESULTS AND LIMITATIONS

Evaluable 2-yr MRI scans were available for 75 (56%) eligible patients in the MRI arm and 69 (49%) in the SBx arm. Of these patients, 55 (73%) in the MRI arm and 51 (67%) SBx arm had negative 2-yr MRI. Of the 76 patients in the SBx arm with 2-yr MRI, 16 (21%) had a biopsy, for which the result was negative in eight (10%), GG1 in two (2.6%), and GG ≥2 in six (7.9%) cases. Of the 75 men in the MRI arm with 2-yr MRI, eight (11%) were biopsied, for which the result was negative in four cases (5%) and GG ≥2 in the other four (5%). At 2 yr, including baseline biopsy results, 116/221 (52.5%) in the MRI arm and 113/204 (55%) in the SBx arm were free of GG ≥2 disease, treatment, death from any cause, or progression (OR 1.08; p = 0.66).

CONCLUSIONS

After 2-yr follow-up including MRI for patients in both arms of PRECISE, there was no difference in the rate of csPC diagnosis between the MRI and SBx groups, even though 38% of men in the MRI group avoided an initial biopsy.

PATIENT SUMMARY

The PRECISE trial compared systematic biopsy of the prostate to a strategy of magnetic resonance imaging (MRI) with targeted biopsy of any lesions suspicious for cancer on the scan. After 2 years of follow-up that included 2-year MRI with or without biopsy in both groups, there was no difference in the rate of diagnosis of significant cancer, even though 38% of men in the initial MRI arm avoided an initial biopsy, and 30% avoided biopsy altogether. The PRECISE trial is registered on ClinicalTrials.gov as NCT02936258.

Patient Reported Outcomes Following Palliative Whole Brain Radiation Therapy in Patients with Brain Metastasis

PURPOSE/OBJECTIVE(S)

Brain metastases (BM) are a common occurrence in patients with advanced cancers, and extremely challenging to treat, resulting in short survival periods. Consequently, whole brain radiation therapy (WBRT) remains the standard palliative intervention for patients with BM. The present study set to evaluate the efficacy of WBRT by assessing the quality of life (QoL) and survival outcomes in WBRT-treated patients with BM. It was hypothesized that the WBRT would enhance the QoL through alleviation of symptoms and functionality, and prolong patient survival.

MATERIALS/METHODS

This was a prospective, longitudinal, hospital-based single-center study. Consecutive sampling methodology was used to recruit 52 patients with BM undergoing WBRT. Patients were followed up on days 7, 30, 90 and 180 after WBRT. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 15-Palliative care (EORTC QLQ-C15-PAL) was employed to report patient responses in a Likert scale. A descriptive analysis and multi-trait scaling correlation was computed using IBM SPSS Statistics 29.0, 95% confidence interval. The overall survival analysis (Kaplan-Meier) was also performed.

RESULTS

The study cohort was predominantly females (82.7%), and accordingly, 65.4% of the respondents had a breast primary tumor. A Shapiro-Wilk test of normality revealed that the data was not normally distributed (sig. < 0.05), however, statistic values (W) closer to 1 suggested a good fit. A goodness-of-fit test ascertained the assumption, yielding non-significant Chi square Pearson (p = 0.325) and Deviance (p = 1.000) residuals. There was a significant correlation (p < 0.001) between physical functioning and emotional functioning. Median overall survival was 180 days (∼6 months). A total of 20 patients (38%) that survived up to 180 days reported alleviated symptoms and better functioning. A significant improvement in physical functioning (p < 0.001) and emotional functioning (p = 0.031) was reported at 180 days post WBRT, compared to baseline. Similarly, a significant improvement in visual disorders (p = 0.002), motor dysfunction (p = 0.031), and communication deficit (p = 0.001) was also reported. A significant alleviation of pain was reported at day 90 (p = 0.042) by 53% of the patients that survived.

CONCLUSION

WBRT is an effective palliative intervention in patients with BM, resulting in improved QoL and prolonged survival. More than 50% of patients that survived 3 months reported a significant alleviation of pain, and 38% of patients that survived for 6 months reported a significantly improved functioning. This demonstrated the effectiveness of WBRT in palliative care and will add to the body of data on the efficacy of radiotherapy.

Multimodal Biomarkers That Predict the Presence of Gleason Pattern 4: Potential Impact for Active Surveillance

PURPOSE

Latent grade group ≥2 prostate cancer can impact the performance of active surveillance protocols. To date, molecular biomarkers for active surveillance have relied solely on RNA or protein. We trained and independently validated multimodal (mRNA abundance, DNA methylation, and/or DNA copy number) biomarkers that more accurately separate grade group 1 from grade group ≥2 cancers.

MATERIALS AND METHODS

Low- and intermediate-risk prostate cancer patients were assigned to training (n=333) and validation (n=202) cohorts. We profiled the abundance of 342 mRNAs, 100 DNA copy number alteration loci, and 14 hypermethylation sites at 2 locations per tumor. Using the training cohort with cross-validation, we evaluated methods for training classifiers of pathological grade group ≥2 in centrally reviewed radical prostatectomies. We trained 2 distinct classifiers, PRONTO-e and PRONTO-m, and validated them in an independent radical prostatectomy cohort.

RESULTS

PRONTO-e comprises 353 mRNA and copy number alteration features. PRONTO-m includes 94 clinical, mRNAs, copy number alterations, and methylation features at 14 and 12 loci, respectively. In independent validation, PRONTO-e and PRONTO-m predicted grade group ≥2 with respective true-positive rates of 0.81 and 0.76, and false-positive rates of 0.43 and 0.26. Both classifiers were resistant to sampling error and identified more upgrading cases than a well-validated presurgical risk calculator, CAPRA (Cancer of the Prostate Risk Assessment; P < .001).

CONCLUSIONS

Two grade group classifiers with superior accuracy were developed by incorporating RNA and DNA features and validated in an independent cohort. Upon further validation in biopsy samples, classifiers with these performance characteristics could refine selection of men for active surveillance, extending their treatment-free survival and intervals between surveillance.

Resilience in adolescence during the COVID-19 crisis in Canada

BACKGROUND

The COVID-19 pandemic constitutes a social crisis that will have long-term health consequences for much of the global population, especially for adolescents. Adolescents are triply affected as they: 1) are experiencing its immediate, direct effects, 2) will carry forward health habits they develop now into adulthood, and 3) as future parents, will shape the early life health of the next generation. It is therefore imperative to assess how the pandemic is influencing adolescent wellbeing, identify sources of resilience, and outline strategies for attenuating its negative impacts.

METHODS

We report the results of longitudinal analyses of qualitative data from 28 focus group discussions (FGDs) with 39 Canadian adolescents and of cross-sectional analyses of survey data from 482 Canadian adolescents gathered between September 2020 and August 2021. FGD participants and survey respondents reported on their: socio-demographic characteristics; mental health and wellbeing before and during the pandemic; pre- and during-pandemic health behaviours; experiences living through a crisis; current perceptions of their school, work, social, media, and governmental environments; and ideas about pandemic coping and mutual aid. We plotted themes emerging from FGDs along a pandemic timeline, noting socio-demographic variations. Following assessment for internal reliability and dimension reduction, quantitative health/wellbeing indicators were analyzed as functions of composite socio-demographic, health-behavioural, and health-environmental indicators.

RESULTS

Our mixed methods analyses indicate that adolescents faced considerable mental and physical health challenges due to the pandemic, and were generally in poorer health than expected in non-crisis times. Nevertheless, some participants showed significantly better outcomes than others, specifically those who: got more exercise; slept better; were food secure; had clearer routines; spent more time in nature, deep in-person social relationships, and leisure; and spent less time on social media.

CONCLUSIONS

Support for youth during times of crisis is essential to future population health because adolescence is a period in the life course which shapes the health behaviours, socio-economic capacities, and neurophysiology of these future parents/carers and leaders. Efforts to promote resilience in adolescents should leverage the factors identified above: helping them find structure and senses of purpose through strong social connections, well-supported work and leisure environments, and opportunities to engage with nature.

The use of Lutetium-177 PSMA radioligand therapy with high dose rate brachytherapy for locally recurrent prostate cancer after previous definitive radiation therapy: a randomized, single-institution, phase I/II study (ROADSTER)

BACKGROUND

Isolated local failure (ILF) can occur in patients who initially receive definitive radiation therapy for prostate cancer. Salvage therapy for ILF includes high dose rate (HDR) brachytherapy. Prostate Specific Membrane Antigen (PSMA) Positron Emission Tomography (PET) can accurately detect ILF and can exclude extraprostatic disease. Lutetium-177 PSMA Radioligand Therapy (RLT) is a novel treatment for prostate cancer that can target prostate cancer accurately, while sparing radiation dose to normal tissues.

METHODS

ROADSTER is a phase I/II randomized, single-institution study. Patients with an ILF of prostate cancer after definitive initial radiation therapy are eligible. The ILF will be confirmed with biopsy, magnetic resonance imaging (MRI) and PSMA PET. Patients will be randomized between HDR brachytherapy in two fractions (a standard of care salvage treatment at our institution) (cohort 1) or one treatment of intravenous Lutetium-177 PSMA RLT, followed by one fraction of HDR brachytherapy (cohort 2). The primary endpoints for the phase I portion of the study (n = 12) will be feasibility, defined as 10 or more patients completing the study protocol within 24 months of study activation; and safety, defined as zero or one patients in cohort 2 experiencing grade 3 or higher toxicity in the first 6 months post-treatment. If feasibility and safety are achieved, the study will expand to a phase II study (n = 30 total) where preliminary efficacy data will be evaluated. Secondary endpoints include changes in prostate specific antigen levels, acute toxicity, changes in quality of life, and changes in translational biomarkers. Translational endpoints will include interrogation of blood, urine, and tissue for markers of DNA damage and immune activation with each treatment.

DISCUSSION

ROADSTER explores a novel salvage therapy for ILF after primary radiotherapy with combined Lutetium-177 PSMA RLT and HDR brachytherapy. The randomized phase I/II design will provide a contemporaneous patient population treated with HDR alone to facilitate assessment of feasibility, tolerability, and biologic effects of this novel therapy.

TRIAL REGISTRATION

NCT05230251 (ClinicalTrials.gov).

Testosterone suppression plus enzalutamide versus testosterone suppression plus standard antiandrogen therapy for metastatic hormone-sensitive prostate cancer (ENZAMET): an international, open-label, randomised, phase 3 trial

BACKGROUND

The interim analysis of the ENZAMET trial of testosterone suppression plus either enzalutamide or standard nonsteroidal antiandrogen therapy showed an early overall survival benefit with enzalutamide. Here, we report the planned primary overall survival analysis, with the aim of defining the benefit of enzalutamide treatment in different prognostic subgroups (synchronous and metachronous high-volume or low-volume disease) and in those who received concurrent docetaxel.

METHODS

ENZAMET is an international, open-label, randomised, phase 3 trial conducted at 83 sites (including clinics, hospitals, and university centres) in Australia, Canada, Ireland, New Zealand, the UK, and the USA. Eligible participants were males aged 18 years or older with metastatic, hormone-sensitive prostate adenocarcinoma evident on CT or bone scanning with ^99mTc and an Eastern Cooperative Oncology Group performance status score of 0-2. Participants were randomly assigned (1:1), using a centralised web-based system and stratified by volume of disease, planned use of concurrent docetaxel and bone antiresorptive therapy, comorbidities, and study site, to receive testosterone suppression plus oral enzalutamide (160 mg once per day) or a weaker standard oral non-steroidal antiandrogen (bicalutamide, nilutamide, or flutamide; control group) until clinical disease progression or prohibitive toxicity. Testosterone suppression was allowed up to 12 weeks before randomisation and for up to 24 months as adjuvant therapy. Concurrent docetaxel (75 mg/m² intravenously) was allowed for up to six cycles once every 3 weeks, at the discretion of participants and physicians. The primary endpoint was overall survival in the intention-to-treat population. This planned analysis was triggered by reaching 470 deaths. This study is registered with ClinicalTrials.gov, NCT02446405, ANZCTR, ACTRN12614000110684, and EudraCT, 2014-003190-42.

FINDINGS

Between March 31, 2014, and March 24, 2017, 1125 participants were randomly assigned to receive non-steroidal antiandrogen (n=562; control group) or enzalutamide (n=563). The median age was 69 years (IQR 63-74). This analysis was triggered on Jan 19, 2022, and an updated survival status identified a total of 476 (42%) deaths. After a median follow-up of 68 months (IQR 67-69), the median overall survival was not reached (hazard ratio 0·70 [95% CI 0·58-0·84]; p<0·0001), with 5-year overall survival of 57% (0·53-0·61) in the control group and 67% (0·63-0·70) in the enzalutamide group. Overall survival benefits with enzalutamide were consistent across predefined prognostic subgroups and planned use of concurrent docetaxel. The most common grade 3-4 adverse events were febrile neutropenia associated with docetaxel use (33 [6%] of 558 in the control group vs 37 [6%] of 563 in the enzalutamide group), fatigue (four [1%] vs 33 [6%]), and hypertension (31 [6%] vs 59 [10%]). The incidence of grade 1-3 memory impairment was 25 (4%) versus 75 (13%). No deaths were attributed to study treatment.

INTERPRETATION

The addition of enzalutamide to standard of care showed sustained improvement in overall survival for patients with metastatic hormone-sensitive prostate cancer and should be considered as a treatment option for eligible patients.

FUNDING

Astellas Pharma.

A phase II clinical study of intravesical photo dynamic therapy in patients with BCG-unresponsive NMIBC (interim analysis)

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Background: Novel therapies are required for BCG-unresponsive, high risk non-muscle invasive bladder cancer. We report the interim results of a Phase II Clinical Study of Intravesical Photo Dynamic Therapy (PDT) in patients with BCG-Unresponsive Carcinoma In-Situ (CIS) with or without papillary disease. Methods: Out of a planned 125 patients, 42 patients have been enrolled and treated with two Study Treatments (Day 0 and Day 180) consisting of an intravesical instillation of the photosensitizer TLD-1433 (0.70 mg/cm2) followed by activation with a 520 nm intravesical laser under general anesthesia (Study Device TLC-3200) to a total of 90 J/cm2 of laser light. The primary outcome assessed was efficacy, evaluated by Complete Response (CR), at any point in time. The secondary outcome was duration of CR at 12 months, post initial CR. A tertiary objective is safety, evaluated by the incidence and severity of Adverse Events, Grade 4 or higher that do not resolve within 450 days post treatment. Patients with a negative cystoscopy and positive cytology have been defined as indeterminate response (IR), as these patients remain under investigation for lower and upper tract urothelial carcinoma. Results: Interim analyses included the first 42 patients, along with 3 patients treated in a preceding Phase Ib NMIBC clinical study assessing the safety of TLD-1433 PDT who weretreated at the same parameters, for a total of 45 patients. Data for the primary and secondary outcomes are listed in the table.The interim clinical data demonstrates a 90 day CR of 50% and a duration of response at 360 and 450 days of 35% and 21%, respectively.There have been eight Serious Adverse Events (SAE) identified (2 Grade II (tachycardia, hematuria), 3 Grade III (acute kidney injury, cellulitis), 2 Grade IV (urosepsis, depression/anxiety) and 1 Grade V). None of the SAEs were deemed to be directly related to the PDT. Conclusions: The interim data support that treatment with Photo Dynamic Therapy provides a viable treatment option for patients with BCG unresponsive CIS (+/- papillary disease) with an acceptable ongoing safety profile. Clinical trial information: NCT03945162 . [Table: see text]

Spontaneous Remission of Metastatic Castration-Resistant Prostate Cancer: Coley's Toxin Revisited?

Metastatic castration-resistant prostate cancer (mCRPC) is an incurable disease associated with poor survival outcomes. Immunotherapy was first pioneered by William Coley in the early 20th century with the injection of live and heat-killed bacteria. Despite the recent emergence of cancer immunotherapy, mCRPC remains an elusive immune target. Spontaneous remission of mCRPC following microbial infection has not been described in the literature to date. We present evidence of spontaneous biochemical and radiologic regression in a patient with mCRPC following multiple episodes of sepsis.

Registered reports in forensic science

Research assessing the validity and reliability of many forensic science disciplines has been published; however, the quality of this research varies depending on the methodologies employed. This was a major point of contention with the United States' President's Council of Advisors on Science and Technology, who recognized the existing literature but found the majority lacking because of methodological issues. Questionable scientific methodologies have undermined the forensic science community's ability to defend the scientific foundations and examination protocols used to examine evidence in criminal cases. Such scientific failures have significant legal implications. Registered reports, which strengthen the quality of scientific research and reliability of laboratory protocols, can provide transparency, validity and a stronger scientific foundation for forensic science.

Prostate cancer classification using radiomics and machine learning on mp-MRI validated using co-registered histology

BACKGROUND

Multi-parametric magnetic resonance imaging (mp-MRI) is emerging as a useful tool for prostate cancer (PCa) detection but currently has unaddressed limitations. Computer aided diagnosis (CAD) systems have been developed to address these needs, but many approaches used to generate and validate the models have inherent biases.

METHOD

All clinically significant PCa on histology was mapped to mp-MRI using a previously validated registration algorithm. Shape and size matched non-PCa regions were selected using a proposed sampling algorithm to eliminate biases towards shape and size. Further analysis was performed to assess biases regarding inter-zonal variability.

RESULTS

A 5-feature Naïve-Bayes classifier produced an area under the receiver operating characteristic curve (AUC) of 0.80 validated using leave-one-patient-out cross-validation. As mean inter-class area mismatch increased, median AUC trended towards positively biasing classifiers to producing higher AUCs. Classifiers were invariant to differences in shape between PCa and non-PCa lesions (AUC: 0.82 vs 0.82). Performance for models trained and tested only in the peripheral zone was found to be lower than in the central gland (AUC: 0.75 vs 0.95).

CONCLUSION

We developed a radiomics based machine learning system to classify PCa vs non-PCa tissue on mp-MRI validated on accurately co-registered mid-gland histology with a measured target registration error. Potential biases involved in model development were interrogated to provide considerations for future work in this area.

Randomized phase II trial of neoadjuvant abiraterone plus or minus cabazitaxel in high-risk prostate cancer: ACDC-RP

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Background: High-risk prostate cancer has a significant risk of recurrence when treated with unimodal therapy. The utility of neoadjuvant therapy prior to radical prostatectomy (RP) has yet to be defined. The ACDC-RP study investigated the use of abiraterone acetate (AA) + prednisone (P) + leuprolide (LHRH) with or without cabazitaxel prior to RP in high-risk patients. Methods: This phase II trial randomized patients to Arm A (AA/P + LHRH + cabazitaxel 20 mg/m2 with peg-filgrastim 6 cycles) or Arm B (AA/P + LHRH) for 6 months prior to RP. The primary objective was to compare the rate of pathological complete response (CR) or minimal residual disease (MRD) between treatment arms. MRD was defined as ≤5% of prostate volume involved by tumor. We present RP pathological outcomes, safety signals, and early biochemical response data. Results: Out of 78 randomized participants, 70 completed the full course of study treatment and underwent RP. Across both treatment arms, 31 (44%) men achieved either CR or MRD; 5 men had CR (2 in Arm A) and an additional 26 men exhibited MRD (15 in Arm A), p = 1 between Arm A and B. Kaplan-Meier analysis demonstrated no difference in biochemical-free survival (BFS) rate between the two treatment groups. Patients who achieved a CR/MRD experienced significantly longer BFS. Conclusions: Study findings indicate significant tumor response with 44% of patients exhibiting CR/MRD, with no significant difference observed between the two treatment arms. Patients who exhibit CR/MRD experienced better BFS rates. Genomic efforts are underway to determine predictors of response. Clinical trial information: NCT02543255. [Table: see text]

Effect of 18F-DCFPyL PET/CT on the Management of Patients with Recurrent Prostate Cancer: Results of a Prospective Multicenter Registry Trial

Background The high positivity rate of prostate-specific membrane antigen (PSMA) PET in the setting of biochemical failure (BCF), even when conventional imaging is negative, is promising. Purpose To assess the disease detection rate of PSMA-based PET/CT with fluorine 18-DCFPyL as a radiotracer and the PET-directed management change in men with suspected limited recurrent prostate cancer. Materials and Methods This prospective multicenter registry (Ontario PSMA-PET Registry for Recurrent Prostate Cancer, or PREP) enrolled men with BCF after primary therapy (radical prostatectomy plus or minus salvage radiation therapy or primary radiation therapy) and zero to four disease sites at conventional imaging (CT and bone scintigraphy). The positivity rate of PSMA PET according to serum prostate-specific antigen (PSA) level; frequency of local-egional, oligometastatic, and extensive metastatic recurrence; and rate of change in management after PET findings were recorded. The nonparametric Mood median test was used to assess the association between serum PSA level and change in management. Results A total of 1289 men (median age, 71 years [interquartile range, 65-75 years]) were evaluated. PSMA PET helped detect disease in 841 of 1289 men (65%) and in 615 of 999 men (62%) with negative conventional imaging. The recurrence detection rates according to serum PSA level at enrollment were 38% (160 of 424 men), 63% (107 of 171 men), and 83% (573 of 692 men) for PSA under 0.5 ng/mL, 0.5-1.0 ng/mL, and above 1.0 ng/mL, respectively. At PSMA PET, 399 of 1289 men (31%) had local-regional recurrence, 314 (24%) had oligometastatic disease, and 128 (10%) had extensive metastases. Following PET examination, a change in planned management was recorded in 748 of 1289 men (58%), and in 371 of 1250 men (30%), there was a change in management intent, more commonly from palliative to potentially curative intent (255 of 1289 men [20%]). Conclusion Prostate-specific membrane antigen PET helped detect additional sites of disease compared with conventional imaging in approximately 60% of men with biochemical failure and suspected low-volume metastatic disease, resulting in frequent change in management, including a change from palliative to curative or radical intent therapy in 20% of men. Long-term follow-up is needed to determine whether this impacts disease control. Clinical trial registration no. NCT03718260 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Civelek in this issue.

Association of Race and Ethnicity With Prostate Cancer-Specific Mortality in Canada

This cohort study uses data from the Canadian Census Health and Environment Cohorts to assess the association of race and ethnicity with prostate cancer–specific mortality among men in Canada.

Metastatic progression following multimodal therapy for unfavorable-risk prostate cancer

INTRODUCTION

Identifying the optimal management of unfavorable-risk (ProCaRS high intermediate-, high-, and very high-risk categories) non-metastatic prostate cancer is an important public health concern given the large burden of this disease. We compared the rate of metastatic progression-free survival among men diagnosed with unfavorable-risk non-metastatic prostate cancer who were initially treated with radiation therapy or radical prostatectomy.

METHODS

Information was obtained from medical records at two academic centers in Canada from 333 men diagnosed with unfavorable-risk non-metastatic prostate cancer between 2007 and 2012. Median followup was 90.4 months. Men were eligible for study if they received either primary radiation therapy (n=164) or radical prostatectomy (n=169), in addition to various adjuvant and salvage therapies when deemed clinically appropriate. Patients were matched on prognostic covariates using two matching techniques. Multivariable Cox proportional hazards models were used to estimate the hazard ratios (HR) and confidence intervals (CI) for metastatic progression-free survival between groups.

RESULTS

After matching, treatment groups were balanced on prognostic variables except for percent core positivity. Hazard ratios from all Cox proportional hazards models (i.e., before and after matching, and with and without multivariable adjustment) showed no difference in the rate of metastatic progression-free survival between groups (adjusted unmatched HR 1.16, 95% CI 0.63, 2.13, p=0.64).

CONCLUSIONS

Metastatic progression-free survival did not differ between men diagnosed with unfavorable risk non-metastatic prostate cancer who were treated with either radiation therapy or radical prostatectomy.

Short-duration dynamic [18F]DCFPyL PET and CT perfusion imaging to localize dominant intraprostatic lesions in prostate cancer: validation against digital histopathology and comparison to [18F]DCFPyL PET/MR at 120 minutes

Purpose

Localized prostate cancer (PCa) in patients is characterized by a dominant focus in the gland (dominant intraprostatic lesion, DIL). Accurate DIL identification may enable more accurate diagnosis and therapy through more precise targeting of biopsy, radiotherapy and focal ablative therapies. The goal of this study is to validate the performance of [¹⁸F]DCFPyL PET and CT perfusion (CTP) for detecting and localizing DIL against digital histopathological images.

Methods

Multi-modality image sets: in vivo T2-weighted (T2w)-MRI, 22-min dynamic [¹⁸F]DCFPyL PET/CT, CTP, and 2-h post-injection PET/MR were acquired in patients prior to radical prostatectomy. The explanted gland with implanted fiducial markers was imaged with T2w-MRI. All images were co-registered to the pathologist-annotated digital images of whole-mount mid-gland histology sections using fiducial markers and anatomical landmarks. Regions of interest encompassing DIL and non-DIL tissue were drawn on the digital histopathological images and superimposed on PET and CTP parametric maps. Logistic regression with backward elimination of parameters was used to select the most sensitive parameter set to distinguish DIL from non-DIL voxels. Leave-one-patient-out cross-validation was performed to determine diagnostic performance.

Results

[¹⁸F]DCFPyL PET and CTP parametric maps of 15 patients were analyzed. SUV_Late and a model combining K_i and k₄ of [¹⁸F]DCFPyL achieved the most accurate performance distinguishing DIL from non-DIL voxels. Both detection models achieved an AUC of 0.90 and an error rate of < 10%. Compared to digital histopathology, the detected DILs had a mean dice similarity coefficient of 0.8 for the K_i and k₄ model and 0.7 for SUV_Late.

Conclusions

We have validated using co-registered digital histopathological images that parameters from kinetic analysis of 22-min dynamic [¹⁸F]DCFPyL PET can accurately localize DILs in PCa for targeting of biopsy, radiotherapy, and focal ablative therapies. Short-duration dynamic [¹⁸F]DCFPyL PET was not inferior to SUV_Late in this diagnostic task.

Clinical trial registration number: NCT04009174 (ClinicalTrials.gov).

Antithrombotic strategy in patients with atrial fibrillation and acute coronary syndrome

Background

Atrial fibrillation (AF) is frequent in patients admitted with acute coronary syndromes (ACS). The development of this arrhythmia occurs in 2–21% of patients with non ST-elevation ACS and 21% of ST-elevation ACS. According with the most recent European guidelines, a short period up to 1 week of triple antithrombotic therapy (TAT) is recommended, followed by dual antithrombotic therapy (DAT) using a NOAC and a single antiplatelet agent, preferably clopidogrel.

Objective

To compare the antithrombotic strategy (DAT vs TAT) used and its prognostic value in patients with AF and ACS.

Methods

Retrospective analysis of patients' data admitted with ACS in a multicentric registry between 10/2010–09/2019. TAT was defined as the prescription of dual antiplatelet therapy and one anticoagulant and DAT as one antiplatelet and one anticoagulant. Survival and rehospitalization were evaluated through Kaplan-Meier curve.

Results

1067 patients were included, mean age 67±14 years, 72.3% male. Patients who developed de novo AF during hospitalization due to ACS were older (75±12 vs 66±14 years, p&lt;0.001) and with higher prevalence of cardiovascular risk factors and cardiovascular disease. AF was more often in patients with ST elevation ACS (53.4%). During hospitalization, AF patients were more often medicated with aspirin, glycoprotein inhibitor, heparin, fondaparinux and vitamin K antagonists. No difference was found regarding P2Y12 inhibitors. AF patients presented more often obstructive coronary disease (normal coronaries 5.4 vs 8.5%, p&lt;0.001) so they were more often submitted to PCI (79.5 vs 70.9%, p&lt;0.001). AF patients presented with higher rates of adverse in-hospital events as re-infarction, heart failure, shock, ventricular arrhythmias, cardiac arrest, stroke, major bleeding and death (p&lt;0.001). At discharge, AF patients were less prescribed with aspirin or ticagrelor, but the rate of clopidogrel prescription was higher, such as vitamin K antagonists or any of the new anticoagulants. In the AF group, 21.5% patients were discharged with TAT and 30.3% with DAT. Concerning patients discharged with TAT, 1-year follow-up revealed no significant differences in mortality (p=0.578), re-admission for cardiovascular causes (p=0.301) and total re-admission rates (p=0.291). Patients discharged with DAT had similar mortality (p=0.623) and re-admission for cardiovascular causes rates (p=0.138), but significant differences were identified regarding total re-admissions (p=0.024).

Conclusions

In patients with ACS and de novo AF, a low percentage of patients was discharged with oral anticoagulation (51.8%). In those whose anticoagulation was initiated, DAT was the preferred strategy. 1-year outcomes were not different between the antithrombotic strategy, except for all cause re-admission.

Funding Acknowledgement

Type of funding sources: None.