Stereotactic body radiation therapy after radical prostatectomy: current status and future directions.

PURPOSE: Around 40% of men with intermediate-risk or high-risk prostate cancer will experience a biochemical recurrence after radical prostatectomy (RP). The aim of this review is to describe both toxicity and oncological outcomes following stereotactic body radiation therapy (SBRT) delivered to the prostate bed (PB). METHOD: In april 2023, we performed a systematic review of studies published in MEDLINE or ClinicalTrials.gov according to Preferred Reporting Items for Systematic Reviews, using the keywords "stereotactic radiotherapy" AND "postoperative" AND "prostate cancer". RESULTS: A total of 14 studies assessing either adjuvant or salvage SBRT to the whole PB or macroscopic local recurrence (MLR) within the PB, and SBRT on radiorecurrent MLR within the PB were included. Doses delivered to either whole PB or MLR between 30 to 40 Gy are associated with a low rate of late grade ≥ 2 genitourinary (GU) toxicity, ranging from 2.2 to 15.1%. Doses above 40 Gy are associated with increased rate of late GU toxicity, raising up to 38%. Oncological outcomes should be interpreted with caution, due to both short follow-up, heterogeneous populations and androgen deprivation therapy (ADT) use. CONCLUSION: PB or MLR SBRT delivered at doses up to 40 Gy appears safe with relatively low late severe GU toxicity rates. Caution is needed with dose-escalated RT schedules above 40 Gy. Further prospective trials are eagerly awaited in this disease setting.

Low Serum Testosterone in Men with Newly Diagnosed Androgen-Deprivation Therapy-Naïve Prostate Cancer and Its Relationship to Cardiovascular Risk Factors: A RADICAL-PC Substudy.

PURPOSE: Cardiovascular disease is a common cause of death in prostate cancer patients. Low testosterone is associated with increased cardiovascular risk in the general male population. We investigated the relationship between serum testosterone, cardiovascular disease and risk factors in androgen-deprivation therapy-naïve prostate cancer patients. MATERIALS AND METHODS: We performed a cross-sectional analysis of a subgroup of 1,326 androgen-deprivation therapy-naïve men from RADICAL-PC (Role of Androgen-Deprivation Therapy In CArdiovascular Disease-A Longitudinal Prostate Cancer study) in whom serum testosterone was measured at baseline. RADICAL-PC is a prospective multicenter cohort study of men (2,565) enrolled within 1 year of prostate cancer diagnosis, or within 6 months of commencing androgen-deprivation therapy for the first time. Cardiovascular risk factors, cancer characteristics and total serum testosterone were collected at baseline. Low testosterone was defined as total serum testosterone <11 nmol/L (<320 ng/dL). A Framingham cardiovascular risk score ≥15 was considered high risk for future cardiovascular events. We performed logistic regression to calculate odds ratios for the association between testosterone and cardiovascular risk. RESULTS: Among 1,326 participants (median age 67 years, range 45-93), 553 (42%) had low testosterone. Low testosterone was associated with existing cardiovascular disease, diabetes, elevated hemoglobin A1c, obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol, hypertension and Framingham score >15. Among patients with low testosterone, the odds ratio for high cardiovascular risk was 1.33 (1.02-1.73) after adjusting for ethnicity, education, alcohol use, cancer characteristics, physical activity and body mass index. CONCLUSIONS: Among androgen-deprivation therapy-naïve prostate cancer patients, low testosterone is common and associated with increased cardiovascular risk factors.

The Clinical Significance of Bone Mineral Density Changes Following Long-Term Androgen Deprivation Therapy in Localized Prostate Cancer Patients.

PURPOSE: Long-term androgen deprivation therapy has been associated with decreased bone mineral density in men with prostate cancer. Some evidence suggests that there is no impact on fracture risk despite this bone mineral density loss. Our study aimed to quantify changes in bone mineral density in men with high risk prostate cancer on long-term androgen deprivation therapy and calcium and vitamin D supplementation. MATERIALS AND METHODS: Bone mineral density analysis was conducted for localized high risk prostate cancer patients enrolled in the phase III randomized trial PCS-V (Prostate Cancer Study 5), comparing conventional and hypofractionated radiation therapy. Patients received 28 months of luteinizing hormone-releasing hormone agonist and calcium and vitamin D supplementation (500 mg calcium BID+400 IU vitamin D3 BID). The areal density and T-scores (spine, femoral neck and total femur) at baseline and 30 months of followup were extracted, and the absolute change was calculated. Clinical bone density status (normal, osteopenia, osteoporosis) was monitored. RESULTS: The lumbar spine, femoral neck and total femoral bone mineral density were measured for 226, 231, and 173 patients, respectively. The mean percent change in bone mineral density was -2.65%, -2.76% and -4.27% for these respective sites (p <0.001 for all). The average decrease in bone mineral density across all sites was -3.2%, with no decline in bone mineral density category in most patients (83%). Eight patients (4%) became osteoporotic. CONCLUSIONS: Despite a mild decline in bone mineral density, the change in clinical bone mineral density category remained low with long-term androgen deprivation therapy. Consequently, calcium and vitamin D supplementation alone may suffice for most localized prostate cancer patients on long-term androgen deprivation therapy.

Combined radiotherapy and immunotherapy in urothelial bladder cancer: harnessing the full potential of the anti-tumor immune response.

PURPOSE: Radiotherapy (RT), as part of trimodal therapy, is an attractive alternative treatment in patients with urothelial muscle-invasive bladder cancer (MIBC). There is accumulating evidence suggesting the immunomodulatory effects of RT and its potential synergy when combined with immunotherapy. The aim of this review was to report on the most recent advances on this combination, including the mechanisms of RT immunomodulation, practical approach to combining RT and immunotherapy, and ongoing clinical trials in bladder cancer. METHODS: Using the PubMed database, we identified articles published between March 2004 and April 2020 on the combination of RT with immunotherapy in localized or metastatic MIBC. A search of the Clinicaltrials.gov and Clinicaltrialsregister.eu/ retrieved ongoing clinical trials on the topic as well. RESULTS: Combination of RT with immunotherapy leads to immunogenic cell death and an increase in immune markers thus leading to improved tumor control. For localized MIBC, there are safety concerns related to the use of concurrent immunotherapy with hypofractionated RT, thus neoadjuvant or adjuvant immunotherapy is preferred. In the metastatic setting, the combination of multi-site RT with SBRT-like doses (≥ 6 Gy per fraction) and concurrent immunotherapy seems most efficacious at harnessing the abscopal effect. At least 25 clinical trials combining immunotherapy and RT in MIBC are currently ongoing and will answer pending questions on safety, efficacy, and practical considerations on RT scheduling, fractionation, and targets volumes. CONCLUSION: RT has the potential to synergize with immunotherapy to improve oncological outcomes in patient with localized or metastatic MIBC. Clinical trials results are eagerly awaited.

Testosterone Breakthrough Rates during Androgen Deprivation Therapy for Castration Sensitive Prostate Cancer.

PURPOSE: Androgen deprivation therapy is an established therapy for castration sensitive prostate cancer and recent studies have observed that patients whose testosterone levels are suppressed below 0.7 nmol/l have improved outcomes. Testosterone breakthrough, or a rise in testosterone above a target threshold after the first month of androgen deprivation therapy, is generally associated with treatment deficiency. The purpose of this review is to summarize breakthrough rate data and explore the relationship to clinical outcomes in patients with castration sensitive prostate cancer receiving androgen deprivation therapy. MATERIALS AND METHODS: Our systematic search identified 45 studies with a total of 52 cohorts representing 6,047 total patients reporting testosterone breakthrough rates or derivative measures above the thresholds of 1.7 nmol/l (51 cohorts, 6,015 patients) or 0.7 nmol/l (15 cohorts, 2,495 patients). RESULTS: Significantly higher weighted mean breakthrough rates were seen for the 0.7 nmol/l threshold compared to 1.7 nmol/l (41.3% vs 6.9%, p <0.0001). A significant association between breakthrough rates and worse clinical outcomes overall was not found, although when larger trials (sample size greater than 100) and higher event rates (greater than 50%) were considered for the lowest threshold, significant associations between breakthrough rates and clinical outcomes were observed. Clinical factors such as administration and monitoring frequency, type of testosterone assay and type of androgen deprivation therapy did not significantly affect breakthrough rates, although nonvalidated assays were associated with a large degree of variability. CONCLUSIONS: Results from our analysis indicate that testosterone breakthroughs likely result in worse clinical outcomes and should be avoided. Moreover, there is a need to standardize assessment of testosterone levels both clinically and in the research context to better inform treatment decisions and improve the reliability and comparability of results across studies.

Cardiovascular Risk in Men with Prostate Cancer: Insights from the RADICAL PC Study.

PURPOSE: We describe the cardiovascular risk profile in a representative cohort of patients with prostate cancer treated with or without androgen deprivation therapy. MATERIALS AND METHODS: We prospectively characterized in detail 2,492 consecutive men (mean age 68 years) with prostate cancer (newly diagnosed or with a plan to prescribe androgen deprivation therapy for the first time) from 16 Canadian sites. Cardiovascular risk was estimated by calculating Framingham risk scores. RESULTS: Most men (92%) had new prostate cancer (intermediate risk 41%, high risk 50%). The highest level of education achieved was primary school in 12%. Most (58%) were current or former smokers, 22% had known cardiovascular disease, 16% diabetes, 45% hypertension, 31% body mass index 30 kg/m2 or greater, 24% low levels of physical activity, mean handgrip strength was 37.3 kg and 69% had a Framingham risk score consistent with high cardiovascular risk. Participants in whom androgen deprivation therapy was planned had higher Framingham risk scores than those not intending to receive androgen deprivation therapy, and this risk was abolished after adjustment for confounders. CONCLUSIONS: Two-thirds of men with prostate cancer are at high cardiovascular risk. There is a positive association between a plan to use androgen deprivation therapy and baseline cardiovascular risk factors. However, this association is explained by confounding factors.

Enhanced radiosensitization of enzalutamide via schedule dependent administration to androgen-sensitive prostate cancer cells.

BACKGROUND: Prostate cancer (PCa) is a progressive disease and the most diagnosed cancer in men. The current standard of care for high-risk localized PCa is a combination of androgen deprivation therapy (ADT) and radiation (XRT). The majority of these patients however become resistant due to incomplete responses to ADT as a result of selective cells maintaining androgen receptor (AR) activity. Improvement can be made if increasing radiosensitivity is realized. Therefore, the aim of this study is to investigate the efficacy of the next-generation PCa drug Enzalutamide (ENZA), as a radiosensitizer in XRT therapy. METHODS: Using a number of androgen-dependent (LNCaP, PC3-T877A) and androgen-independent (C4-2, 22RV1, PC3, PC3-AR V7) cell lines, the effect of ENZA as a radiosensitizer was studied alone or in combination with ADT and/or XRT. Cell viability and cell survival were assessed, along with determination of cell cycle arrest, DNA damage response and repair, apoptosis and senescence. RESULTS: Our results indicated that either ENZA alone (in AR positive, androgen-dependent PCa cells) or in combination with ADT (in AR positive, hormone-insensitive PCa cells) potentiates radiation response [Dose enhancement factor (DEF) of 1.75 in LNCAP and 1.35 in C4-2] stronger than ADT + XRT conditions. Additionally, ENZA sensitized androgen dependent PCa cells to XRT in a schedule-dependent manner, where concurrent administration of ENZA and radiation lead to a maximal radiosensitization when compared to either drug administration prior or after XRT. In LNCaP cells, ENZA treatment significantly prolonged the presence of XRT-induced phospho-γH2AX up to 24 h after treatment; suggesting enhanced DNA damage. It also significantly increased XRT-induced apoptosis and senescence. CONCLUSIONS: Our data indicates that ENZA acts as a much stronger radiosensitizer compared to ADT. We have also observed that its efficacy is schedule dependent and related to increased levels of DNA damage and a delay of DNA repair processes. Finally, the initial abrogation of DNA-PKcs activity by AR inhibition and its subsequent recovery might represent an important mechanism by which PCa cells acquire resistance to combined anti-androgen and XRT treatment. This work suggests a new use of ENZA in combination with XRT that could be applicable in clinical trial settings for patients with early and intermediate hormone responsive disease.

177Lu-PSMA-617 in Metastatic Castration-Resistant Prostate Cancer: A Review of the Evidence and Implications for Canadian Clinical Practice.

Prostate-specific membrane antigen (PSMA) is highly expressed in prostate cancer and a therapeutic target. Lutetium-177 (177Lu)-PSMA-617 is the first radioligand therapy to be approved in Canada for use in patients with metastatic castration-resistant prostate cancer (mCRPC). As this treatment represents a new therapeutic class, guidance regarding how to integrate it into clinical practice is needed. This article aims to review the evidence from prospective phase 2 and 3 clinical trials and meta-analyses of observational studies on the use of 177Lu-PSMA-617 in prostate cancer and discuss how Canadian clinicians might best apply these data in practice. The selection of appropriate patients, the practicalities of treatment administration, including necessary facilities for treatment procedures, the assessment of treatment response, and the management of adverse events are considered. Survival benefits were observed in clinical trials of 177Lu-PSMA-617 in patients with progressive, PSMA-positive mCRPC who were pretreated with androgen receptor pathway inhibitors and taxanes, as well as in taxane-naïve patients. However, the results of ongoing trials are awaited to clarify questions regarding the optimal sequencing of 177Lu-PSMA-617 with other therapies, as well as the implications of predictive biomarkers, personalized dosimetry, and combinations with other therapies.

Addressing controversial areas in the management of advanced prostate cancer in Canada Areas of consensus and controversy from the third Canadian consensus forum.

INTRODUCTION: The management of prostate cancer (PCa) is rapidly evolving. Treatment and diagnostic options grow annually, however, high-level evidence for the use of new therapeutics and diagnostics is lacking. In November 2022, the Genitourinary Research Consortium held its 3rd Canadian Consensus Forum (CCF3) to provide guidance on key controversial areas for management of PCa. METHODS: A steering committee of eight multidisciplinary physicians identified topics for discussion and adapted questions from the Advanced Prostate Cancer Consensus Conference 2022 for CCF3. Questions focused on management of metastatic castration-sensitive prostate cancer (mCSPC); use of novel imaging, germline testing, and genomic profiling; and areas of non-consensus from CCF2. Fifty-eight questions were voted on during a live forum, with threshold for "consensus agreement" set at 75%. RESULTS: The voting panel consisted of 26 physicians: 13 urologists/uro-oncologists, nine medical oncologists, and four radiation oncologists. Consensus was reached for 32 of 58 questions (one ad-hoc). Consensus was seen in the use of local treatment, to not use metastasis-directed therapy for low-volume mCSPC, and to use triplet therapy for synchronous high-volume mCSPC (low prostate-specific antigen). Consensus was also reached on sufficiency of conventional imaging to manage disease, use of germline testing and genomic profiling for metastatic disease, and poly (ADP-ribose) polymerase (PARP) inhibitors for BRCA-positive prostate cancer. CONCLUSIONS: CCF3 identified consensus agreement and provides guidance on >30 practice scenarios related to management of PCa and nine areas of controversy, which represent opportunities for research and education to improve patient care. Consensus initiatives provide valuable guidance on areas of controversy as clinicians await high-level evidence.

Port-Site Metastasis Identified on Prostate-Specific Membrane Antigen-Targeted 18 F-DCFPyL PET/CT After Robot-Assisted Laparoscopic Radical Prostatectomy.

ABSTRACT: Port-site metastasis is an extremely rare complication following minimally invasive oncologic surgery for prostate cancer. We present the case of a 74-year-old man who underwent robot-assisted laparoscopic radical prostatectomy followed by salvage radiotherapy. Despite treatment, he developed biochemical recurrence. However, there was no evidence of disease on CT and bone scan at a prostate-specific antigen of 4.6 ng/mL. Subsequently, 18 F-DCFPyL PET/CT revealed a solitary focus of intense uptake in the right rectus abdominis muscle that was felt to represent a port-site metastasis. Histopathologic evaluation with immunostaining following ultrasound-guided needle biopsy confirmed the presence of metastatic adenocarcinoma of the prostate.

Advances in PARP Inhibitors for Prostate Cancer.

Poly-adenosine diphosphate-ribose polymerase plays an essential role in cell function by regulating apoptosis, genomic stability and DNA repair. PARPi is a promising drug class that has gained significant traction in the last decade with good outcomes in different cancers. Several trials have sought to test its effectiveness in metastatic castration resistant prostate cancer (mCRPC). We conducted a comprehensive literature review to evaluate the current role of PARPi in this setting. To this effect, we conducted queries in the PubMed, Embase and Cochrane databases. We reviewed and compared all major contemporary publications on the topic. In particular, recent phase II and III studies have also demonstrated the benefits of olaparib, rucaparib, niraparib, talazoparib in CRPC. Drug effectiveness has been assessed through radiological progression or overall response. Given the notion of synthetic lethality and potential synergy with other oncological therapies, several trials are looking to integrate PARPi in combined therapies. There remains ongoing controversy on the need for genetic screening prior to treatment initiation as well as the optimal patient population, which would benefit most from PARPi. PARPi is an important asset in the oncological arsenal for mCRPC. New combinations with PARPi may improve outcomes in earlier phases of prostate cancer.

Salvage Whole-Pelvic Radiation and Long-Term Androgen-Deprivation Therapy in the Management of High-Risk Prostate Cancer: Long-Term Update of the McGill 0913 Study.

PURPOSE: To report the long-term outcomes of the McGill 0913 study and the potential benefits of combining prostate-bed radiotherapy (PBRT), pelvic-lymph-node radiotherapy (PLNRT), and long term ADT (LT-ADT). MATERIALS AND METHODS: From 2010 to 2016, 46 high-risk prostate cancer patients who experienced biochemical recurrence (BCR) after radical prostatectomy (RP) were enrolled in this single-arm phase II clinical trial. The patients were eligible if they had a Gleason score > 8, locally advanced disease (≥pT3), a preoperative PSA of >20 ng/mL, or positive lymph nodes (LN). The patients were treated with a combination of 24 months of ADT, PBRT, and PLNRT. The primary outcome was biochemical progression-free survival (bPFS) and the predefined secondary endpoints included distant-metastasis-free survival (DMFS), overall survival (OS), and toxicity. In this update, we also report the median follow-up of 8.8 years and 10 years OS. RESULTS: At a median follow-up of 8.8 years, 43 patients were eligible for analysis. The median pre-salvage PSA was 0.30 µg/L. Half (51%) of the patients (n = 22) had positive margins, 40% (n = 17) had Gleason scores > 8, 63% (n = 27) had extracapsular extension, 42% (n = 18) had seminal vesicle invasion, and 19% (n = 8) had LN involvement. The 10-year bPFS was 68.3 %. The 10-year DMFS was 72.9%. The 10-year OS was 97%. There were two non-cancer-related deaths. The first patient died of congestive heart failure while the other died of an unknown cause. No new toxicity was observed after the initial report. CONCLUSIONS: Our study demonstrates that treatment escalation with PBRT, PLNRT, and LT-ADT improves long term outcomes. In view of the recently published SPPORT study, we conclude that this novel approach of treatment intensification in high-risk post-prostatectomy patients is safe and effective, and that it should be offered as the standard of care.

Advancements in MRI-Based Radiomics and Artificial Intelligence for Prostate Cancer: A Comprehensive Review and Future Prospects.

The use of multiparametric magnetic resonance imaging (mpMRI) has become a common technique used in guiding biopsy and developing treatment plans for prostate lesions. While this technique is effective, non-invasive methods such as radiomics have gained popularity for extracting imaging features to develop predictive models for clinical tasks. The aim is to minimize invasive processes for improved management of prostate cancer (PCa). This study reviews recent research progress in MRI-based radiomics for PCa, including the radiomics pipeline and potential factors affecting personalized diagnosis. The integration of artificial intelligence (AI) with medical imaging is also discussed, in line with the development trend of radiogenomics and multi-omics. The survey highlights the need for more data from multiple institutions to avoid bias and generalize the predictive model. The AI-based radiomics model is considered a promising clinical tool with good prospects for application.

Neoadjuvant versus Concurrent Androgen Deprivation Therapy in Localized Prostate Cancer Treated with Radiotherapy: A Systematic Review of the Literature.

BACKGROUND: There is an ongoing debate on the optimal sequencing of androgen deprivation therapy (ADT) and radiotherapy (RT) in patients with localized prostate cancer (PCa). Recent data favors concurrent ADT and RT over the neoadjuvant approach. METHODS: We conducted a systematic review in PubMed, EMBASE, and Cochrane Databases assessing the combination and optimal sequencing of ADT and RT for Intermediate-Risk (IR) and High-Risk (HR) PCa. FINDINGS: Twenty randomized control trials, one abstract, one individual patient data meta-analysis, and two retrospective studies were selected. HR PCa patients had improved survival outcomes with RT and ADT, particularly when a long-course Neoadjuvant-Concurrent-Adjuvant ADT was used. This benefit was seen in IR PCa when adding short-course ADT, although less consistently. The best available evidence indicates that concurrent over neoadjuvant sequencing is associated with better metastases-free survival at 15 years. Although most patients had IR PCa, HR participants may have been undertreated with short-course ADT and the absence of pelvic RT. Conversely, retrospective data suggests a survival benefit when using the neoadjuvant approach in HR PCa patients. INTERPRETATION: The available literature supports concurrent ADT and RT initiation for IR PCa. Neoadjuvant-concurrent-adjuvant sequencing should remain the standard approach for HR PCa and is an option for IR PCa.

Prophylactic A-Blockers for Radiotherapy-Induced Lower Urinary Tract Symptoms in Men with Prostate Cancer: A Phase III Randomized Trial.

PURPOSE: The present phase III randomized trial assessed the efficacy of prophylactic versus therapeutic α-blockers at improving RI-LUTSs in prostate cancer patients receiving external beam radiotherapy (EBRT). METHODS: A total of 148 prostate cancer patients were randomized 1:1 to receive either prophylactic silodosin on day one of EBRT or the occurrence of RI-LUTSs. LUTSs were quantified using the international prostate symptom score (IPSS) at regular intervals during the study. The primary endpoint was the change in the IPSS from baseline to the last day of radiotherapy (RT). Secondary endpoints included changes in IPSS from baseline to 4 weeks and 12 weeks after the start of RT. RESULTS: Patient demographics, baseline IPSS, and prescribed radiation doses were balanced between arms. On the last day of RT, the mean IPSS was 14.8 (SD 7.6) in the experimental arm and 15.7 (SD 8.5) in the control arm (p = 0.40). There were no significant differences in IPSSs between the study arms in the intention-to-treat (ITT) analysis at baseline, the last day of RT, and 4 and 12 weeks post-RT. CONCLUSION: Prophylactic α-blockers were not effective at significantly reducing RI-LUTSs in prostate cancer patients treated with EBRT. Treating patients with α-blockers at the onset of RI-LUTSs will avoid unnecessary drug exposure and toxicity.

Comparing digital to analog prostate-specific membrane antigen-targeted piflufolastat 18 F PET/CT in prostate cancer patients in early biochemical failure.

PURPOSE: Prostate-specific membrane antigen (PSMA) positron emission tomography/computer tomography (PET/CT) in prostate cancer patients with biochemical failure(BCF) showslimited sensitivity when the prostate-specific antigen(PSA) <0.5 ng/mL. The development of digital PET/CT has greatly improved smaller lesion detection. This study's goal was to compare the performance and clinical value of PSMA-targeted piflufolastat PET/CT for prostate cancer BCF with digital versus analog PET/CT. METHODS: In this retrospective study, all piflufolastat PET/CT scans in subjects with PSA ≤ 3.0 ng/mL who were referred for prostate cancer BCF were included. The performance characteristics of 171 analog PET/CT studies in 155 subjects from May 2017 to January 2020 and 106 digital PET/CT studies in 103 subjects from February 2020 to December 2020 were compared. Lesions were considered malignant if they did not match the known physiological distribution of piflufolastat and did not represent uptake in benign lesions. PSMA PET/CT studies were considered positive if at least one malignant lesion was detected and negative if none were detected. RESULTS: Digital piflufolastat PET/CT outperformed analog piflufolastat PET/CT in subjects with PSA < 0.5 ng/mL with a positivity rate of 69% versus 37%, respectively. In patients with PSA ≥ 0.5 ng/mL, both technologies performed similarly. There was no statistically significant difference between the number or size of piflufolastat-avid lesions detected per PET/CT study. CONCLUSION: In prostate cancer patients with BCF and PSA < 0.5 ng/mL, digital piflufolastat PET/CT has a higher detection rate of malignant lesions than analog piflufolastat PET/CT.

Real-world utilization and outcomes of docetaxel among older men with metastatic prostate cancer: a retrospective population-based cohort study in Canada.

BACKGROUND: The adoption of docetaxel for systemic treatment of metastatic prostate cancer (PCa), in both castration-sensitive (mCSPC) and castration-resistant (mCRPC) settings, is poorly understood. This study examined the real-world utilization of docetaxel in these patients and their outcomes. METHODS: A retrospective population-based study used administrative data from Ontario, Canada, to identify men aged ≥66 years who were diagnosed with de novo mCSPC or mCRPC between 2014 and 2019 and received docetaxel. The study assessed treatment tolerability and toxicity, and survival in both cohorts. Descriptive and comparative statistical analysis were conducted. RESULTS: The study identified 11.2% (399/3556) and 13.2% (203/1534) patients diagnosed with de novo mCSPC and with mCRPC who received docetaxel respectively. The median age in both cohorts was 72 years (IQR: 68-76). Overall, 43.9% (n = 175) patients with de novo mCSPC and 52.1% (n = 85) with mCRPC completed ≥6 cycles of docetaxel. Over two-fifth also needed dose adjustments in both cohorts. Hospitalization or emergency department visit for febrile neutropenia were noted in 15.8% (n = 63) of de novo mCSPC patients and similarly in 19% (n = 31) of mCRPC cohort. The median survival of PCa patients who completed ≥6 cycles of docetaxel was significantly longer relative to those who completed <4 cycles: 32.7 vs. 23.5 months (p < 0.001) for mCSPC and 20.5 vs. 10.7 (p = 0.012) for mCRPC respectively. CONCLUSIONS: In this population-based study of elderly patients with metastatic PCa, treatment with docetaxel was associated with poor tolerability and higher toxicity compared with clinical trials. Receipt of limited cycles and reduced overall dose of docetaxel were associated with inferior overall survival.

The Burden of Uncontrolled Cardiovascular Risk Factors in Men With Prostate Cancer: A RADICAL-PC Analysis.

Background: Cardiovascular disease (CVD) incidence is higher in men with prostate cancer (PC) than without. Objectives: We describe the rate and correlates of poor cardiovascular risk factor control among men with PC. Methods: We prospectively characterized 2,811 consecutive men (mean age 68 ± 8 years) with PC from 24 sites in Canada, Israel, Brazil, and Australia. We defined poor overall risk factor control as ≥3 of the following: suboptimal low-density lipoprotein cholesterol (>2 mmol/L if Framingham Risk Score [FRS] ≥15 and ≥3.5 mmol/L if FRS <15), current smoker, physical inactivity (<600 MET min/wk), suboptimal blood pressure (BP) (≥140/90 mm Hg if no other risk factors, systolic BP ≥120 mm Hg if known CVD or FRS ≥15, and ≥130/80 mm Hg if diabetic), and waist:hip ratio >0.9. Results: Among participants (9% with metastatic PC and 23% with pre-existing CVD), 99% had ≥1 uncontrolled cardiovascular risk factor, and 51% had poor overall risk factor control. Not taking a statin (odds ratio [OR]: 2.55; 95% CI: 2.00-3.26), physical frailty (OR: 2.37; 95% CI: 1.51-3.71), need for BP drugs (OR: 2.36; 95% CI: 1.84-3.03), and age (OR per 10-year increase: 1.34; 95% CI: 1.14-1.59) were associated with poor overall risk factor control after adjustment for education, PC characteristics, androgen deprivation therapy, depression, and Eastern Cooperative Oncology Group functional status. Conclusions: Poor control of modifiable cardiovascular risk factors is common in men with PC, highlighting the large gap in care and the need for improved interventions to optimize cardiovascular risk management in this population.

Genetic testing practices among specialist physicians who treat prostate cancer A Canadian, cross-sectional survey.

INTRODUCTION: In patients with prostate cancer (PCa), the identification of an alteration in genes associated with homologous recombination repair (HRR) has implications for prognostication, optimization of therapy, and familial risk mitigation. The aim of this study was to assess the genomic testing landscape of PCa in Canada and to recommend an approach to offering germline and tumor testing for HRR-associated genes. METHODS: The Canadian Genitourinary Research Consortium (GURC) administered a cross-sectional survey to a largely academic, multidisciplinary group of investigators across 22 GURC sites between January and June 2022. RESULTS: Thirty-eight investigators from all 22 sites responded to the survey. Germline genetic testing was initiated by 34%, while 45% required a referral to a genetic specialist. Most investigators (82%) reported that both germline and tumor testing were needed, with 92% currently offering germline and 72% offering tissue testing to patients with advanced PCa. The most cited reasons for not offering testing were an access gap (50%), uncertainties around who to test and which genes to test, (33%) and interpreting results (17%). A majority reported that patients with advanced PCa (74-80%) should be tested, with few investigators testing patients with localized disease except when there is a family history of PCa (45-55%). CONCLUSIONS: Canadian physicians with academic subspecialist backgrounds in genitourinary malignancies recognize the benefits of both germline and somatic testing in PCa; however, there are challenges in accessing testing across practices and specialties. An algorithm to reduce uncertainty for providers when ordering genetic testing for patients with PCa is proposed.

Quality and Quantity: Evaluating Tumor Biology Alongside Novel Imaging on Diagnosis of Metastatic Hormone-sensitive Prostate Cancer.

Tumor biology may play an important role as an effective predictive biomarker that is complementary to functional imaging for metastatic hormone-sensitive prostate cancer.