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.

Real-world use of systemic therapies in men with metastatic castration resistant prostate cancer (mCRPC) in Canada.

BACKGROUND: Management of advanced prostate cancer has evolved rapidly with the availability of multiple systemic treatments such as androgen-receptor axis-targeted therapies (ARATs), taxane-based chemotherapy, radium-223, and other approaches. However, limited data exists on real-world treatment selection and clinical outcomes. This study examines the utilization and survival impact of these therapies in men with metastatic castration-resistant prostate cancer (mCRPC) in the real-world setting of Ontario, Canada. METHODS: This study was a retrospective, longitudinal, population-based study of administrative claims data between January 2016 and April 2020. Men ≥ 66 years with mCRPC receiving advanced treatment were included. Patients were indexed on the day they initiated mCRPC treatment and followed up until death or end of study period to assess treatment and survival. Multinomial regression was used to model the association between baseline covariates, treatment and survival. RESULTS: Median age was 75 years among the 944 mCRPC patients who received life-prolonging therapies during this time period. Over 90% of patients used an ARAT as a first-line therapy, and 71.5% received only first-line therapy before death or censoring. Of patients that received two or more lines, over 80% received subsequent therapy with a different mechanism of action. Median overall survival was 18.9 months. CONCLUSIONS: ARATs have become the predominant first-line systemic treatment option for mCRPC patients in recent years. Notably, the majority of patients received only a single line of life-prolonging therapy after developing mCRPC. In keeping with the recognized efficacy-effectiveness gap, real-world outcomes in this cohort appear poorer than in clinical trials.

Prognostic Association between Common Laboratory Tests and Overall Survival in Elderly Men with De Novo Metastatic Castration Sensitive Prostate Cancer: A Population-Based Study in Canada.

De novo cases of metastatic prostate cancer (mCSPC) are associated with poorer prognosis. To assist in clinical decision-making, we aimed to determine the prognostic utility of commonly available laboratory-based markers with overall survival (OS). In a retrospective population-based study, a cohort of 3556 men aged ≥66 years diagnosed with de novo mCSPC between 2014 and 2019 was identified in Ontario (Canada) administrative database. OS was assessed by using the Kaplan-Meier method. Multivariate Cox regression analysis was performed to evaluate the association between laboratory markers and OS adjusting for patient and disease characteristics. Laboratory markers that were assessed include neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), albumin, hemoglobin, serum testosterone and PSA kinetics. Among the 3556 older men with de novo mCSPC, their median age was 77 years (IQR: 71-83). The median survival was 18 months (IQR: 10-31). In multivariate analysis, a statistically significant association with OS was observed with all the markers (NLR, PLR, albumin, hemoglobin, PSA decrease, reaching PSA nadir and a 50% PSA decline), except for testosterone levels. Our findings support the use of markers of systemic inflammation (NLR, PLR and albumin), hemoglobin and PSA metrics as prognostic indicators for OS in de novo mCSPC.

Results from a Canadian consensus forum of key controversial areas in the management of advanced prostate cancer: Recommendations for Canadian healthcare providers.

INTRODUCTION: Rapid progress in diagnostics and therapeutics for the management of prostate cancer (PCa) has created areas where high-level evidence to guide practice is lacking. The Genitourinary Research Consortium (GURC) conducted its second Canadian consensus forum to address areas of controversy in the management of PCa and provide recommendations to guide treatment. METHODS: A panel of PCa specialists discussed topics related to the management of PCa. The core scientific committee finalized the design, questions, and analysis of the consensus results. Attendees then voted to indicate their management choice regarding each statement/topic. Questions for voting were adapted from the 2019 Advanced Prostate Cancer Consensus Conference. The thresholds for agreement were set at ≥75% for "consensus agreement," >50% for "near-consensus," and ≤50% for "no consensus." RESULTS: The panel was comprised of 29 PCa experts, including urologists (n=12), medical oncologists (n=12), and radiation oncologists (n=5). Voting took place for 65 predetermined questions and three ad hoc questions. Consensus was reached for 34 questions, spanning a variety of areas, including biochemical recurrence, treatment of metastatic castration-sensitive PCa, management of non-metastatic and metastatic castration-resistant PCa, bone health, and molecular profiling. CONCLUSIONS: The consensus forum identified areas of consensus or near-consensus in more than half of the questions discussed. Areas of consensus typically aligned with available evidence, and areas of variability may indicate a lack of high-quality evidence and point to future opportunities for further research and education.

Real-world management of advanced prostate cancer: A description of management practices of community-based physicians and prostate cancer specialists.

INTRODUCTION: The Canadian Genitourinary Research Consortium (GURC) conducted a consensus development conference leading to 31 recommendations. Using the GURC consensus development questionnaire, we conducted a survey to measure the corresponding community-based practices on the management of metastatic castration-sensitive prostate cancer (mCSPC), metastatic castration-resistant prostate cancer (mCRPC) and non-metastatic castration-resistant prostate cancer (nmCRPC). METHODS: An 87-item online questionnaire was sent to 600 community urologists and oncologists involved in the treatment of prostate cancer. RESULTS: Seventy-two community physicians responded to the survey. Of note, 50% community physicians indicated they would treat nmCRPC with agents approved for this indication if advanced imaging showed metastases. Radiation to the prostate for low-volume mCSPC was identified as a treatment practice by 27% of community physicians, and 35% indicated docetaxel as the next line of treatment after use of apalutamide. Use of genetic testing was reported in 36% of community physicians for newly diagnosed metastatic prostate cancer. CONCLUSIONS: There are several areas of community-based management of advanced prostate cancer that could represent potential areas for education, practice tools, and future research.

Optimizing management of advanced urothelial carcinoma: A review of emerging therapies and biomarker-driven patient selection.

INTRODUCTION: Advanced urothelial carcinoma has been challenging to treat due to limited treatment options, poor response rates, and poor long-term survival. New treatment options hold the promise of improved outcomes for these patients. METHODS: A multidisciplinary working group drafted a management algorithm for advanced urothelial carcinoma using "consensus development conference" methodology. A targeted literature search identified new and emerging treatments for inclusion in the management algorithm. Published clinical data were considered during the algorithm development process, as well as the risks and benefits of the treatment options. Biomarkers to guide patient selection in clinical trials for new treatments were incorporated into the algorithm. RESULTS: The advanced urothelial carcinoma management algorithm includes newly approved first-line anti-programmed death receptor-1 (PD1)/ programmed death-ligand 1 (PD-L1) therapies, a newly approved anti-fibroblast growth factor receptors (FGFR) therapy, and an emerging anti-Nectin 4 therapy, which have had encouraging results in phase 2 trials for second-line and third-line therapy, respectively. This algorithm also incorporates suggestions for biomarker testing of PD-L1 expression and FGFR gene alterations. CONCLUSIONS: Newly approved and emerging therapies are starting to cover an unmet need for more treatment options, better response rates, and improved overall survival in advanced urothelial carcinoma. The management algorithm provides guidance on how to incorporate these new options, and their associated biomarkers, into clinical practice.

Management algorithms for metastatic prostate cancer.

INTRODUCTION: Prostate cancer poses a significant lifetime risk to Canadian men. Treatment for metastatic prostatic cancer (mPCa) is an area of ongoing research with a lack of up-to-date clinical guidance. The multidisciplinary Canadian Genitourinary Research Consortium (GURC) determined that additional guidance focusing on management of mPCa was warranted. METHODS: The most up-to-date guidelines, consensus statements, and emerging phase 3 trials were identified and used to inform development of algorithms by a multidisciplinary genitourinary oncology panel outlining recommendations for the management of mPCa. RESULTS: A single pan-Canadian guideline and five national and international guidelines or consensus statements published since 2015 were identified, along with two new phase 3 trials and one additional randomized comparison. Iterative GURC discussions led to the development of two mPCa algorithms: the first addressing management of newly diagnosed metastatic castration-sensitive prostate cancer (mCSPC) patients and the second addressing treatment of patients with metastatic castration-resistant prostate cancer (mCRPC). For newly diagnosed mCSPC patients with high-volume/high-risk disease, either docetaxel or abiraterone acetate and prednisone (AAP) added to androgen-deprivation therapy (ADT) is recommended. The addition of radiotherapy to ADT is suggested for those with low-volume disease and/or AAP to ADT for low-volume or low-risk disease. For first-line mCRPC, androgen receptor-axis-targeted (ARAT) therapy is recommended for most patients, while sequencing with docetaxel, radium-223, ARAT therapy, and/or cabazitaxel is recommended for later lines of therapy. CONCLUSIONS: Two treatment algorithms were developed for the management of mPC and can be used by multidisciplinary specialist teams to guide treatment.

Controversial issues in the management of patients with advanced prostate cancer: Results from a Canadian consensus forum.

INTRODUCTION: The management of advanced prostate cancer (PCa) continues to evolve with the emergence of new diagnostic and therapeutic strategies. As a result, there are multiple areas in this landscape with a lack of high-level evidence to guide practice. Consensus initiatives are an approach to establishing practice guidance in areas where evidence is unclear. We conducted a Canadian-based consensus forum to address key controversial areas in the management of advanced PCa. METHODS: As part of a modified Delphi process, a core scientific group of PCa physicians (n=8) identified controversial areas for discussion and developed an initial set of questions, which were then reviewed and finalized with a larger group of 29 multidisciplinary PCa specialists. The main areas of focus were non-metastatic castration-resistant prostate cancer (nmCRPC), metastatic castration-sensitive prostate cancer (mCSPC), metastatic castration-resistant prostate cancer (mCRPC), oligometastatic prostate cancer, genetic testing in prostate cancer, and imaging in advanced prostate cancer. The predetermined threshold for consensus was set at 74% (agreement from 20 of 27 participating physicians). RESULTS: Consensus participants included uro-oncologists (n=13), medical oncologists (n=10), and radiation oncologists (n=4). Of the 64 questions, consensus was reached in 30 questions (n=5 unanimously). Consensus was more common for questions related to biochemical recurrence, sequencing of therapies, and mCRPC. CONCLUSIONS: A Canadian consensus forum in PCa identified areas of agreement in nearly 50% of questions discussed. Areas of variability may represent opportunities for further research, education, and sharing of best practices. These findings reinforce the value of multidisciplinary consensus initiatives to optimize patient care.

Management algorithms for prostate-specific antigen progression in prostate cancer: Biochemical recurrence after definitive therapy and progression to non-metastatic castrate-resistant prostate cancer.

INTRODUCTION: Current prostate cancer (PCa) guidelines primarily focus on localized or metastatic PCa. A multidisciplinary genitourinary oncology panel determined that additional guidance focusing on monitoring and management of biochemical recurrence (BCR) following radical therapy and non-metastatic castration-resistant prostate cancer (nmCRPC) was warranted. METHODS: The most up-to-date national and international guidelines, consensus statements, and emerging phase 3 trials were identified and used to inform development of algorithms by a multidisciplinary genitourinary oncology panel outlining optimal monitoring and treatment for patients with non-metastatic PCa. RESULTS: A total of eight major national and international guidelines/consensus statements published since 2015 and three phase 3 trials were identified. Working group discussions among the multidisciplinary genitourinary oncology panel led to the development of two algorithms: the first addressing management of patients with BCR following radical therapy (post-BCR), and the second addressing management of nmCRPC. The post-BCR algorithm suggests consideration of early salvage treatment in select patients and provides guidance regarding observation vs. intermittent or continuous androgen-deprivation therapy (ADT). The nmCRPC algorithm suggests continued ADT and monitoring for all patients, with consideration of treatment with apalutamide or enzalutamide for patients with high-risk disease (prostate-specific antigen [PSA] doubling time of ≤ 10 months). CONCLUSIONS: Two treatment algorithms have been developed to guide the management of non-metastatic PCa and should be considered in the context of local guidelines and practice patterns.

Disparity in public funding of therapies for metastatic castrate-resistant prostate cancer across Canadian provinces.

INTRODUCTION: Treatment using abiraterone acetate plus prednisone, enzalutamide, cabazitaxel, and radium-223 (Ra-223) improves overall survival (OS) and quality of life for patients with metastatic castrate-resistant prostate cancer (mCRPC). Despite their proven benefits, access to these therapies is not equal across Canada. METHODS: We describe provincial differences in access to approved mCRPC therapies. Data sources include the pan-Canadian Oncology Drug Review database, provincial cancer care resources, and correspondence with pharmaceutical companies. RESULTS: Both androgen receptor-axis-targeted therapies (ARATs), abiraterone acetate plus prednisone and enzalutamide, are funded by provinces in the pre-and post-chemotherapy setting, however, sequential ARAT use is not funded. "Sandwich" therapy, where one ARAT is used pre-chemotherapy and a second is used upon progression on chemotherapy, is funded in six provinces: Ontario (ON), Alberta, New Brunswick, Prince Edward Island (PEI), Nova Scotia (NS), and Newfoundland and Labrador. Ra-223 is funded in five provinces: ON, Quebec (QC), British Columbia (BC), Saskatchewan, and Manitoba to varying degrees; ON allows Ra-223 either pre- or post-chemo (not both); QC allows Ra-223 post-chemo unless chemo is not tolerated; BC allows Ra-223 if other life-prolonging mCRPC therapies have been received or ineligible. Cabazitaxel is funded in all provinces post-docetaxel, except QC and PEI. Cabazitaxel is not funded as fist-line treatment for mCPRC or in combination with other agents. In ON, BC, QC, and PEI, cabazitaxel is not funded after progression on an ARAT in the post-chemotherapy setting. CONCLUSIONS: While all provinces have access to docetaxel and ARATs, sandwiching sequential ARATs with docetaxel is funded only in select provinces. Ra-223 and cabazitaxel access is not ubiquitous across Canada. Such inequalities in access to life-prolonging therapies could lead to disparities in survival and quality of life among patients with mCRPC. Further research should quantify interprovincial variation in outcomes and cost that may result from variable access.

Physician perceptions and preferences in the treatment of acquired immunodeficiency syndrome (AIDS)-related lymphoma.

The optimal management of acquired immunodeficiency syndrome-related lymphoma (ARL) in the era of combination antiretroviral therapy (cART) is unclear. We administered a survey to determine physician preferences and perceptions in the management of ARL and to assess the variability in treatment in Canada. Of 196 lymphoma-treating physicians, 117 (63%) responded. The majority of respondents (98%) had a positive attitude towards the treatment of ARL. Most physicians (66%) recommended the concomitant use of cART in the care of their patients with ARL, and a majority (86%) recommended CHOP-like regimens (cyclophosphamide, doxorubicin, vincristine, and prednisone) to form the backbone of chemotherapy. The addition of rituximab was preferred by 43% of physicians, while 39% and 18% would either not use rituximab or were unsure of the agent's role, respectively. In logistic regression analysis, use of rituximab was predicted only by location of practice (province); physicians from the province of British Colombia were much more likely to administer rituximab than practitioners from Ontario (odds ratio 41.8; 95% confidence interval 7.44-235.1, p < 0.001). In the current cART era, physicians have a positive attitude towards the treatment of ARL. The majority prefer to use cART in combination with CHOP for ARL. The use and perceived benefit of rituximab may be influenced by interprovincial formulary differences and regional variation in guideline recommendations.

Tenofovir: a nucleotide analog for the management of human immunodeficiency virus infection.

Tenofovir disoproxil fumarate, an acyclic nucleotide analog of adenosine monophosphate, is the most recent addition to the antiretroviral arsenal. After conversion to tenofovir by diester hydrolysis, subsequent phosphorylation by cellular enzymes to form the active tenofovir diphosphate is necessary for antiretroviral activity. Preliminary data suggest that tenofovir is as safe and efficacious as stavudine when given in combination with lamivudine and efavirenz for the treatment of antiretroviral-naïve patients. In antiretroviral-experienced patients, the addition of tenofovir to stable background antiretroviral therapy resulted in approximately a 0.6 log10 copies/ml reduction in viral load relative to placebo. Extended follow-up suggests that such virologic gains may be durable. In vitro, recombinant human immunodeficiency virus (HIV) expressing the K65R mutation showed a 3-4-fold increase in the 50% inhibitory concentrations of tenofovir when compared with wild type. In vivo, this mutation thus far appears to occur infrequently and is associated with variable virologic responses. Response rates to tenofovir vary with the number and pattern of thymidine analog mutations present before starting treatment with this agent. Tenofovir appears to be a well-tolerated agent in patients who are heavily pretreated and who have advanced disease. The main adverse effects appear to be gastrointestinal in nature and include nausea, vomiting, and diarrhea. In animals, osteomalacia and nephrotoxicity have occurred with tenofovir at exposures much higher than those observed in humans. Although no patient had to discontinue therapy as a result of elevated creatinine levels or hypophosphatemia through 58 weeks of treatment, the toxicities associated with long-term tenofovir therapy in humans are unknown. Concomitant administration of tenofovir and didanosine increases the area under the concentration-time curve of the latter by 44-60%; monitoring for signs and symptoms of didanosine toxicity is recommended. The approved dosage of tenofovir is 300 mg (one tablet) once/day with meals. Given the ease of administration and relative safety from the perspectives of adverse effects and drug interactions, tenofovir has the potential to assume a large role in the treatment of patients with HIV infection.