PSA, an outdated biomarker for prostate cancer: In search of a more specific biomarker, citrate takes the spotlight.

The prevailing biomarker employed for prostate cancer (PCa) screening and diagnosis is the prostate-specific antigen (PSA). Despite excellent sensitivity, PSA lacks specificity, leading to false positives, unnecessary biopsies and overdiagnosis. Consequently, PSA is increasingly less used by clinicians, thus underscoring the imperative for the identification of new biomarkers. An emerging biomarker in this context is citrate, a molecule secreted by the normal prostate, which has been shown to be inversely correlated with PCa. Here, we discuss about PSA and its usage for PCa diagnosis, its lack of specificity, and the various conditions that can affect its levels. We then provide our vision about what we think would be a valuable addition to our PCa diagnosis toolkit, citrate. We describe the unique citrate metabolic program in the prostate and how this profile is reprogrammed during carcinogenesis. Finally, we summarize the evidence that supports the usage of citrate as a biomarker for PCa diagnosis, as it can be measured in various patient samples and be analyzed by several methods. The unique relationship between citrate and PCa, combined with the stability of citrate levels in other prostate-related conditions and the simplicity of its detection, further accentuates its potential as a biomarker.

Protocol for transducing human primary epithelial prostate cells and patient-derived organoids with high efficiency.

Patient-derived organoids (PDOs) are now used to study many diseases, including prostate cancer. Here, we present a protocol for the transduction of human epithelial prostate cells and PDOs. We describe the steps for producing lentiviruses and transducing PDOs with high efficiency to obtain either overexpression or knockdown of specific genes. More generally, this protocol represents an efficient lentiviral transduction technique to study cell biology using various organoid models.

External validation of the Memorial Sloan Kettering Cancer Center preoperative nomogram predicting lymph node invasion in a cohort of high-grade prostate cancer patients.

BACKGROUND: Commonly used preoperative nomograms predicting clinical and pathological outcomes in prostate cancer (PCa) patients have not been yet validated in high-grade only PCa patients. Our objective is to perform an external validation of the Memorial Sloan Kettering Cancer Center (MSKCC) preoperative nomogram as a predictor of lymph node invasion (LNI) in a cohort of high-grade PCa patients. METHODS: We included patients with high-grade PCa (Gleason ≥8) treated at our institution between 2011 and 2020 with radical prostatectomy and pelvic lymph node dissection without receiving neoadjuvant or adjuvant therapy. The area under the curve (AUC) of the receiver operator characteristic (ROC) was used to quantify the accuracy of the model to predict LNI. A calibration plot was used to evaluate the model's precision, and a decision curve analysis was computed to evaluate the net benefit associated with its use. This study was approved by our institution's ethics board. RESULTS: A total of 242 patients with a median age of 66 (60-71) years were included. LNI was observed in 70 (29%) patients with a mean of 16 (median = 15; range = 2-42) resected nodes. The MSKCC nomogram discriminative accuracy, as evaluated by the AUC-ROC was 79.0% (CI: [0.727-0.853]). CONCLUSION: The MSKCC preoperative nomogram is a good predictor of LNI and a useful tool associated with net clinical benefit in this patient population.

An Extracellular Matrix Overlay Model for Bioluminescence Microscopy to Measure Single-Cell Heterogeneous Responses to Antiandrogens in Prostate Cancer Cells.

Prostate cancer (PCa) displays diverse intra-tumoral traits, impacting its progression and treatment outcomes. This study aimed to refine PCa cell culture conditions for dynamic monitoring of androgen receptor (AR) activity at the single-cell level. We introduced an extracellular matrix-Matrigel (ECM-M) culture model, enhancing cellular tracking during bioluminescence single-cell imaging while improving cell viability. ECM-M notably tripled the traceability of poorly adherent PCa cells, facilitating robust single-cell tracking, without impeding substrate permeability or AR response. This model effectively monitored AR modulation by antiandrogens across various PCa cell lines. Single-cell imaging unveiled heterogeneous antiandrogen responses within populations, correlating non-responsive cell proportions with drug IC50 values. Integrating ECM-M culture with the PSEBC-TSTA biosensor enabled precise characterization of ARi responsiveness within diverse cell populations. Our ECM-M model stands as a promising tool to assess heterogeneous single-cell treatment responses in cancer, offering insights to link drug responses to intracellular signaling dynamics. This approach enhances our comprehension of the nuanced and dynamic nature of PCa treatment responses.

The estrogen signaling pathway reprograms prostate cancer cell metabolism and supports proliferation and disease progression.

Just like the androgen receptor (AR), the estrogen receptor α (ERα) is expressed in the prostate and is thought to influence prostate cancer (PCa) biology. Yet the incomplete understanding of ERα functions in PCa hinders our ability to fully comprehend its clinical relevance and restricts the repurposing of estrogen-targeted therapies for the treatment of this disease. Using 2 human PCa tissue microarray cohorts, we first demonstrate that nuclear ERα expression was heterogeneous among patients, being detected in only half of the tumors. Positive nuclear ERα levels were correlated with disease recurrence, progression to metastatic PCa, and patient survival. Using in vitro and in vivo models of the normal prostate and PCa, bulk and single-cell RNA-Seq analyses revealed that estrogens partially mimicked the androgen transcriptional response and activated specific biological pathways linked to proliferation and metabolism. Bioenergetic flux assays and metabolomics confirmed the regulation of cancer metabolism by estrogens, supporting proliferation. Using cancer cell lines and patient-derived organoids, selective estrogen receptor modulators, a pure anti-estrogen, and genetic approaches impaired cancer cell proliferation and growth in an ERα-dependent manner. Overall, our study revealed that, when expressed, ERα functionally reprogrammed PCa metabolism, was associated with disease progression, and could be targeted for therapeutic purposes.

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.

Association of Cabozantinib Dose Reductions for Toxicity With Clinical Effectiveness in Metastatic Renal Cell Carcinoma (mRCC): Results From the Canadian Kidney Cancer Information System (CKCis).

BACKGROUND: Cabozantinib, an oral multi-targeted tyrosine kinase inhibitor (TKI), has demonstrated efficacy in metastatic renal cell carcinoma (mRCC). The association between toxicity and therapeutic effectiveness has been established with other TKIs. We investigated whether cabozantinib dose reductions, a surrogate for toxicity and adequate drug exposure, were associated with improved clinical outcomes in mRCC. METHODS: Employing the CKCis database, we analyzed patients treated with cabozantinib in the second line or later between 2011 to 2021. The cohort was stratified into those needing dose reductions (DR) during treatment and those not (no-DR). Outcomes, including objective response rate (ORR), time to treatment failure (TTF), and overall survival (OS), were compared based on dose reduction status. The influence of the initial dose on outcomes was also explored. RESULTS: Among 319 cabozantinib-treated patients, 48.3% underwent dose reductions. Response rates exhibited no significant difference between the DR and no-DR groups (15.1% vs. 18.2%, P = .55). Patients with DR had superior median OS (26.15 vs. 15.47 months, P = .019) and TTF (12.74 vs. 6.44 months, P = .022) compared to no-DR patients. These differences retained significance following adjustment for IMDC risk group (OS HR = 0.67, P = .032; TTF HR = 0.65, P = .008). There was no association between the initial dose and ORR, OS, or TTF. CONCLUSION: This study highlights the link between cabozantinib dose reductions due to toxicity and improved survival and time to treatment failure in mRCC patients. These findings underscore the potential of using on-treatment toxicity as an indicator of adequate drug exposure to individualize dosing and optimize treatment effectiveness. Larger studies are warranted to validate these results and develop individualized strategies for cabozantinib when given alone or in combination with immunotherapy.

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.

Salvage therapy for BCG failure with intravesical sequential gemcitabine and docetaxel in patients with recurrent NMIBC.

INTRODUCTION: Bacillus Calmette-Guérin (BCG) failure occurs in approximately 40% of patients with non-muscle-invasive bladder cancer (NMIBC) within two years. We describe our institutional experience with sequential intravesical gemcitabine and docetaxel (gem/doce) as salvage therapy post-BCG failure in patients who were not candidates for or declined radical cystectomy (RC). METHODS: We retrospectively reviewed NMIBC patients with BCG failure who received gem/doce from April 2019 through October 2022 at the CHU de Québec-Université Laval. Patients received at least five weekly intravesical instillations according to published protocols. Patients who responded to gem/doce had maintenance instillations monthly for up to two years. Primary outcome was progression-free survival (PFS). Secondary outcomes included recurrence-free survival (RFS), cystectomy-free survival (CFS), cancer-specific survival (CSS), overall survival (OS), and treatment adverse events. Survival probabilities were estimated using the Kaplan-Meier method from the first gem/doce instillation. RESULTS: Thirty-five patients with a median age of 78 years old were included in the study. The median followup time was 21 months (interquartile range 10-29). More than 25% of patients received two or more prior BCG induction treatments. Overall and MIBC PFS estimates at one year were 85% and 88%, and at two years, 60% and 70%, respectively. Adverse events occurred in 37% of the patients, but only two patients didn't complete the treatment due to intolerance. Three patients underwent RC due to cancer progression. OS was 94% at two years. CONCLUSIONS: With 60% of PFS at two years, gem/doce appears to be a safe and well-tolerated option for BCG failure patients. Further studies are needed to justify widespread use.

The impact of robotic surgery access on the management of patients with clinical stage I kidney tumors.

INTRODUCTION: Robotic surgery is used in the treatment of kidney tumors. We aimed to determine if robotic access was associated with initial choice of management for patients with a clinical stage I kidney mass. METHODS: Patients with a clinical stage I kidney mass were identified from the Canadian Kidney Cancer information system (CKCis) cohort. Sites were classified by year and access to robotic surgery. Associations between robotic access and initial management were determined using logistic regression. Univariable and multivariable analyses were performed, adjusting for tumor size and stage, and presented as relative risks (RR ) or adjusted RR (aRR) and 95% confidence intervals (CI). RESULTS: Overall, 4160 patients were included. Among patients treated with surgery, the proportion of partial nephrectomy compared to radical nephrectomy was significantly higher in robotic sites (77.3% for robotic sites vs. 65.9% for non-robotic sites; RR 1.17, 95% CI 1.12-1.23, p<0.0001; aRR 1.12, 95% CI 1.08-1.17, p<0.0001). Patients receiving partial nephrectomy at sites with robotic access were more likely to receive a minimally invasive approach compared to patients at non-robotic sites (61.4% vs. 50.9%, RR 1.21, 95% CI 1.12-1.30; aRR 1.16, 95% CI 1.08-1.25, p<0.0001). The proportion of patients managed by active surveillance was not significantly different between robotic (405, 16.9%) and non-robotic (258, 14.7%) sites (RR 1.15, 95% CI 0.99-1.32; aRR 0.97, 95% CI 0.84-1.12). CONCLUSIONS: Access to robotic kidney surgery was associated with increased use of partial nephrectomy and minimally invasive partial nephrectomy. Use of active surveillance was similar at robotic and non-robotic institutions. Limitations of this study include lack of data on perioperative complications and cancer recurrence.

Real-world Assessment of Clinical Outcomes in Patients with Metastatic Renal Cell Carcinoma with or Without Sarcomatoid Features Treated with First-line Systemic Therapies.

BACKGROUND AND OBJECTIVE: Metastatic renal cell carcinoma (mRCC) patients have been reported to have better outcomes when treated with immunotherapies (IO) compared to targeted therapies (TT). This study aims to evaluate the impact of first-line systemic therapies on survival of mRCC patients with or without sarcomatoid features using real-world data. METHODS: Metastatic RCC patients of International mRCC Database Consortium (IMDC) intermediate or high risk, diagnosed from January 2011 to December 2022, treated with first-line systemic therapies, and with histological documentation of the presence or absence of sarcomatoid features in nephrectomy specimens were identified using the Canadian Kidney Cancer information system. Patients were classified by initial treatment: (1) targeted therapy (TT) used alone or (2) immunotherapy (IO)-based systemic therapies used in combination of either IO-IO or IO-TT. The inverse probability of treatment weighting using propensity scores was used to balance for covariates. Cox proportional hazard models were used to assess the impact of initial treatment received on overall survival (OS). KEY FINDINGS AND LIMITATIONS: Of the 1202 eligible patients, 791 were treated with TT and 411 with IO combinations. Of the patients, 76% were male, and the majority (91%) had a nephrectomy before systemic therapy. In nonsarcomatoid patients (639 TT and 320 IO patients), treatment with IO was associated with improved OS compared with patients treated with TT (median of 72 vs 48 mo, hazard ratio [HR] 0.63, 95% confidence interval [CI] 0.50-0.80, objective response rate [ORR] of 38.5% for IO and 23.5% for TT). In sarcomatoid patients (152 TT and 91 IO patients), treatment with IO was associated with improved OS (median of 48 vs 18 mo, HR 0.41, 95% CI 0.26-0.64, ORR of 49.5% for IO and 13.8% for TT). Similar results were observed in patients with synchronous metastatic disease only. CONCLUSIONS AND CLINICAL IMPLICATIONS: IO treatment was associated with improved survival in mRCC patients. The magnitude of benefit is increased in patients with sarcomatoid mRCC, consequently, identifying the sarcomatoid status early on could help healthcare providers make a better treatment decision. PATIENT SUMMARY: Metastatic renal cell carcinoma (mRCC) patients of International mRCC Database Consortium intermediate and high risk, diagnosed from January 2011 to December 2022, treated with first-line systemic therapies, and with histological documentation of the presence or absence of sarcomatoid features in nephrectomy specimens were identified using the Canadian Kidney Cancer information system (CKCis). In this study, treatment with immunotherapy was associated to an improved survival and response rates for mRCC patients with and without sarcomatoid features. The magnitude of benefit is increased in patients with sarcomatoid mRCC.

Trends of Utilization of Systemic Therapies for Metastatic Renal Cell Carcinoma in the Canadian Health Care System.

PURPOSE: Standard-of-care therapies for metastatic renal cell carcinoma (mRCC) have greatly evolved. However, the availability of emerging options in global health care systems can vary. We sought to describe the integration and usage of systemic therapies for mRCC in Canada since 2011. METHODS: We included patients with mRCC enrolled in the Canadian Kidney Cancer Information System, a prospective cohort of patients from 14 Canadian academic centers, who received systemic therapy from January 1, 2011, to December 31, 2021. Patients were stratified by treatment era (cohort 1: 2011-2015, cohort 2: 2016-2021). Stacked bar charts were used to present treatment proportions; Sankey diagrams were used to show the evolution of treatment sequencing between the two cohorts. RESULTS: Four thousand one hundred seven patients were diagnosed with mRCC, of whom 2,752 (67%) received systemic therapy. Among these patients, mean age was 64 years, 74% were male, 75% had clear cell histology, and International Metastatic RCC Database Consortium risk classification was favorable, intermediate, and poor in 16%, 56%, and 28%, respectively. Utilization of immune checkpoint inhibition (ICI)-based treatments has increased in Canada and reflects global and local patterns of approval and adoption. The use of therapies after doublet ICI has mostly shifted toward vascular endothelial growth factor-tyrosine kinase inhibitors (VEGF-TKIs) that were previously used in first line with subsequent treatments reflecting approved and available agents after previous VEGF-TKI. Clinical trial participation among patients who received systemic therapy was 18% in first, 21% in second, and 24% in third line. CONCLUSION: In Canada's publicly funded health care system, availability of standard mRCC therapies broadly reflects access from government-funded clinical trials and compassionate access program sources. In an evolving therapeutic landscape, ongoing advocacy is required to continue to facilitate patient access to efficacious therapies.

Effects of omega-3 supplementation on psychological symptoms in men with prostate cancer: Secondary analysis of a double-blind placebo-controlled randomized trial.

BACKGROUND: In the general population, a higher omega-3 polyunsaturated fatty acids intake is associated with lower levels of several psychological symptoms, especially depression. However, the existing evidence in cancer is equivocal. METHODS: This phase IIB double-blind, placebo-controlled trial was aimed at comparing the effects of eicosapentaenoic acid monoacylglyceride (MAG-EPA) supplementation and high oleic acid sunflower oil (HOSO; placebo) on depression levels (primary outcome) and other symptoms (anxiety, fear of cancer recurrence, fatigue, insomnia, perceived cognitive impairments; secondary outcomes). Participants, recruited in a prostate cancer clinic, were randomized to MAG-EPA (3.75 g daily; n = 65) or HOSO (3.75 g daily; n = 65) for 1 year post-radical prostatectomy (RP), starting 4-10 weeks before surgery. Patients completed self-report scales at baseline (before RP) and 3, 6, 9, and 12 months after: Hospital Anxiety and Depression Scale (HADS), Fear of Cancer Recurrence Inventory (FCRI), Insomnia Severity Index (ISI), Fatigue Symptom Inventory (FSI), and Functional Assessment of Cancer Therapy-Cognitive Function (FACT-Cog). RESULTS: Analyses showed significant reductions in HADS-depression, HADS-anxiety, FCRI, ISI, FSI-number of days, and FACT-Cog-impact scores over time. A significant group-by-time interaction was obtained on FACT-Cog-Impact scores only; yet, the temporal change was significant in HOSO patients only. CONCLUSIONS: Several symptoms significantly decreased over time, mainly within the first months of the study. However, MAG-EPA did not produce greater reductions than HOSO. Omega-3 supplementation does not seem to improve psychological symptoms of men treated with RP.

Estimated glomerular filtration rate from the renal hypothermia trial: clinical implications.

OBJECTIVE: To assess if estimated glomerular filtration rate (eGFR) can replace measured GFR (mGFR) in partial nephrectomy (PN) trials, using data from a randomised clinical trial. PATIENTS AND METHODS: We conducted a post hoc analysis of the renal hypothermia trial. Patients underwent mGFR with diethylenetriaminepentaacetic acid (DTPA) plasma clearance preoperatively and 1 year after PN. The eGFR was calculated using the 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine equations incorporating age and sex, with and without race: 2009 eGFRcr(ASR) and 2009 eGFRcr(AS), and the 2021 equation that only incorporates age and sex: 2021 eGFRcr(AS). Performance was evaluated by determining the median bias, precision (interquartile range [IQR] of median bias), and accuracy (percentage of eGFR within 30% of mGFR). RESULTS: Overall, 183 patients were included. Pre- and postoperative median bias and precision were similar between the 2009 eGFRcr(ASR) (-0.2 mL/min/1.73 m2 , 95% confidence interval [CI] -2.2 to 1.7, IQR 18.8; and -2.9, 95% CI -5.1 to -1.5, IQR 15, respectively) and 2009 eGFRcr(AS) (-0.3 mL/min/1.73 m2 , 95% CI -2.4 to 1.5, IQR 18.8; and -3.0, 95% CI -5.7 to -1.7, IQR 15.0, respectively). Bias and precision were worse for the 2021 eGFRcr(AS) (-8.8 mL/min/1.73 m2 , 95% CI -10.9 to -6.3, IQR 24.7; and -12.0, 95% CI -15.8 to -8.9, IQR 23.5, respectively). Similarly, pre- and postoperative accuracy was >90% for the 2009 eGFRcr(ASR) and 2009 eGFRcr(AS) equations. Accuracy was 78.6% preoperatively and 66.5% postoperatively for 2021 eGFRcr(AS). CONCLUSION: The 2009 eGFRcr(AS) can accurately estimate GFR in PN trials and could be used instead of mGFR to reduce cost and patient burden.

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.