Burden of illness of bone metastases in prostate cancer patients in Québec, Canada: A population-based analysis

Unveiling novel insights in prostate cancer through single-cell RNA sequencing

Single-cell RNA sequencing (scRNA-seq) is a cutting-edge technology that provides insights at the individual cell level. In contrast to traditional bulk RNA-seq, which captures gene expression at an average level and may overlook important details, scRNA-seq examines each individual cell as a fundamental unit and is particularly well-suited for identifying rare cell populations. Analogous to a microscope that distinguishes various cell types within a tissue sample, scRNA-seq unravels the heterogeneity and diversity within a single cell species, offering great potential as a leading sequencing method in the future. In the context of prostate cancer (PCa), a disease characterized by significant heterogeneity and multiple stages of progression, scRNA-seq emerges as a powerful tool for uncovering its intricate secrets.

Validation of Algorithms to Identify Bone Metastases Using Administrative Claims Data in a Japanese Hospital

BACKGROUND

Validated coding algorithms are essential to generate high-quality, real-world evidence from claims data studies.

OBJECTIVE

We aimed to evaluate the validity of the algorithms to identify patients with bone metastases using claims data from a Japanese hospital.

PATIENTS AND METHODS

This study used administrative claims data and electronic medical records at Juntendo University Hospital from April 2017 to March 2019. We developed two candidate claims-based algorithms to detect bone metastases, one based on diagnosis codes alone (Algorithm 1) and the other based on the combination of diagnosis and imaging test codes (Algorithm 2). Of the patients identified by Algorithm 1, 100 patients were randomly sampled. Among these 100 patients, 88 patients met the conditions of Algorithm 2; further, 12 additional patients were randomly sampled from those identified by Algorithm 2, thus obtaining a total of 100 patients for Algorithm 2. They were evaluated for their true diagnosis using the patient chart review as the gold standard. The positive predictive value (PPV) was calculated to assess the accuracy of each algorithm.

RESULTS

For Algorithm 1, 82 patients were analyzed after excluding 18 patients without diagnostic imaging reports. Of these, 69 patients were true positive by chart review, resulting in a PPV of 84.1% (95% confidence interval (CI) 74.5-90.6). For Algorithm 2, 92 patients were analyzed after excluding eight patients whose diagnoses were not judged by chart review. Of these, 76 patients were confirmed positive by chart review, yielding a PPV of 82.6% (95% CI 73.4-89.1).

CONCLUSION

Both claims-based algorithms yielded high PPVs of approximately 85%, with no improvement in PPV by adding imaging test conditions. The diagnosis code-based algorithm is sufficient and valid for identifying bone metastases in this Japanese hospital.

Epidemiology of spinal metastases, metastatic epidural spinal cord compression and pathologic vertebral compression fractures in patients with solid tumors: A systematic review

Introduction

Spinal metastases (SM) are a frequent complication of cancer and may lead to pathologic vertebral compression fractures (pVCF) and/or metastatic epidural spinal cord compression (MESCC). Based on autopsy studies, it is estimated that about one third of all cancer patients will develop SM. These data may not provide a correct estimation of the incidence in clinical practice.

Objective

This systematic review (SR) aims to provide a more accurate estimation of the incidence of SM, MESCC and pVCF in a clinical setting.

Methods

We performed a SR of papers regarding epidemiology of SM, pVCF, and MESCC in patients with solid tumors conform PRISMA guidelines. A search was conducted in the PubMed and Web of Science database using the terms epidemiology, prevalence, incidence, global burden of disease, cost of disease, spinal metastas*, metastatic epidural spinal cord compression, pathologic fracture, vertebral compression fracture, vertebral metastas* and spinal neoplasms. Papers published between 1975 and august 2021 were included. Quality was evaluated by the STROBE criteria.

Results

While 56 studies were included, none of them reports the actual definition used for MESCC and pVCF, inevitably introducing heterogenity. The overall cumulative incidence of SM and MESCC is 15.67% and 2.84% respectively in patients with a solid tumor. We calculated a mean cumulative incidence in patients with SM of 9.56% (95% CI 5.70%-13.42%) for MESCC and 12.63% (95% CI 7.00%-18.25%) for pVCF. Studies show an important delay between onset of symptoms and diagnosis.

Conclusions

While the overall cumulative incidence for clinically diagnosed SM in patients with a solid tumor is 15.67%, autopsy studies reveal that SM are present in 30% by the time they die, suggesting underdiagnosing of SM. Approximately 1 out of 10 patients with SM will develop MESCC and another 12.6% will develop a pVCF. Understanding these epidemiologic data, should increase awareness for first symptoms, allowing early diagnosis and subsequent treatment, thus improving overall outcome.

State-of-the-art imaging for diagnosis of metastatic bone disease

Metastatic bone disease (MBD) is common—it is detected in up to 65–75% of patients with breast or prostate cancer, in over 35% of patients with lung cancer; and almost all patients with symptomatic multiple myeloma have focal lesions or a diffuse bone marrow infiltration. Metastatic bone disease can cause a variety of symptoms and is often associated with a poorer prognosis, with high social and health-care costs. Population-based cohort studies confirm significantly increased health-care utilization costs in patients presenting with cancer with MBD compared with those without MBD. The prolonged survival of patients with bone metastasis thanks to advances in therapy presents an opportunity for better treatments for this patient cohort. Early and accurate diagnosis of bone metastases is therefore crucial. The patterns and presentation of MBD are quite heterogeneous and necessitate good knowledge of the possibilities and limitations of each imaging modality. Here, we review the state-of-the-art imaging techniques, assess the need for evidence-based and cost-effective patient care pathways, and advocate multidisciplinary management based on collaborations between orthopedic surgeons, pathologists, oncologists, radiotherapists, and radiologists aimed at improving patient outcomes. Radiologists play a key role in this multidisciplinary approach to decision-making through correlating the tumor entity, the tumor biology, the impact on the surrounding tissues and progression, as well as the overall condition of the patient. This approach helps to choose the best patient-tailored imaging plan advocating a “choose wisely” strategy throughout the initial diagnosis, minimally invasive treatment procedures, as well as follow-up care plans.

Prostate cancer cell-intrinsic interferon signaling regulates dormancy and metastatic outgrowth in bone

The latency associated with bone metastasis emergence in castrate-resistant prostate cancer is attributed to dormancy, a state in which cancer cells persist prior to overt lesion formation. Using single-cell transcriptomics and ex vivo profiling, we have uncovered the critical role of tumor-intrinsic immune signaling in the retention of cancer cell dormancy. We demonstrate that loss of tumor-intrinsic type I IFN occurs in proliferating prostate cancer cells in bone. This loss suppresses tumor immunogenicity and therapeutic response and promotes bone cell activation to drive cancer progression. Restoration of tumor-intrinsic IFN signaling by HDAC inhibition increased tumor cell visibility, promoted long-term antitumor immunity, and blocked cancer growth in bone. Key findings were validated in patients, including loss of tumor-intrinsic IFN signaling and immunogenicity in bone metastases compared to primary tumors. Data herein provide a rationale as to why current immunotherapeutics fail in bone-metastatic prostate cancer, and provide a new therapeutic strategy to overcome the inefficacy of immune-based therapies in solid cancers.

Symptoms Related to Moderate Skeletal-Related Events as Clues for the Diagnosis of Bone Metastasis

BACKGROUND

Early diagnosis of bone metastasis is difficult. The aim of the present study was to determine whether symptoms related to skeletal-related events (SREs) can be used for the diagnosis of bone metastasis in the absence of screening tests.

METHODS

We reviewed 81 patients with bone metastasis to evaluate their SREs at diagnosis. SREs were arbitrarily classified as moderate or severe. Moderate SREs included radiation to the bone before pathological fracture or paralysis, bone surgery before pathological fracture or paralysis, and hypercalcemia without dialysis. Severe SREs included pathological fracture, spinal cord compression, and hypercalcemia necessitating dialysis.

RESULTS

The complication rates of SREs at the time the bone metastasis was diagnosed were 59.3% and 24.7% for severe and moderate SREs, respectively, and only 16.0% of cases were uncomplicated. The clinical factors that showed a significant relationship with the severity of SREs were age and history of malignancy. However, there was no significant relationship between the complication rate of total SREs and the presence or absence of a malignancy history (83.3% vs. 85.2%, respectively, p=0.83).

CONCLUSION

The results of the present study suggest that symptoms related to SREs can be used to diagnose bone metastasis in the absence of a screening test. Bone metastasis should be diagnosed as often as possible based on symptoms related to moderate SREs and should be treated as soon as possible before patients develop severe SREs.

Challenges in the Diagnosis of bone Metastasis in Patients without a History of Malignancy at Their First Clinic Visit

BACKGROUND

Many patients with bone metastases whose diagnoses came only after they had suffered aggravated conditions are still frequently encountered. However, there have been few studies regarding the early diagnosis of such metastases. We retrospectively reviewed the clinical courses of cases we experienced between 2004 and 2014 to clarify the practical situation of diagnosis of such bone metastases.

METHODS

We undertook a retrospective review of 56 of our patients with bone metastasis who had no history of malignancy at their first visit, who visited our departments between 2004 and 2014. The initial diagnoses at the first visit to any clinic, the period from the first visit to any clinic to diagnosis of bone metastasis, the process to make the diagnosis, the frequency of severe skeletal-related events at diagnosis, and the examination serving as the basis for diagnosis were evaluated.

RESULTS

The diagnosis of bone metastasis was made at the first visit in only 6 of the 56 patients. Pathological fractures, paralysis and/or calcemia were seen in 62.5% of the patients at diagnosis of bone metastasis. The median period from the first visit to any clinic to diagnosis was 7.0 weeks. Typically, the diagnosis of bone metastasis was made only after aggravation. The most frequent examination to serve as the basis of diagnosis was magnetic resonance imaging.

CONCLUSIONS

Diagnosis of bone metastasis is challenging in patients without a history of malignancy at their first visit. For early diagnosis, it is important to recognize this challenge and to keep it in mind together with ongoing observation.

The burden of symptomatic skeletal events in castrate-resistant prostate cancer patients with bone metastases at three Canadian uro-oncology centres

INTRODUCTION

Metastatic bone disease in castrate-resistant prostate cancer risks significant morbidity, including symptomatic skeletal events. We estimated the healthcare resource costs of managing skeletal events.

METHODS

A retrospective chart review was conducted for patients who died from or were treated palliatively for metastatic castrate-resistant prostate cancer from 2006-2013 at Centre Hospitalier de l'Université de Montréal (Montreal), Princess Margaret Cancer Centre (Toronto), or Vancouver General Hospital (Vancouver).

RESULTS

Of 393 patients, 275 (70%) experienced 833 events (85 per 100 patient-years), with a median (95% confidence interval) time (months) to first event of 17.6 (15.3, 21.7). The mean metastatic bone disease-related healthcare resource use cost (2014 Canadian dollars) estimate for patients without symptomatic skeletal events was $9550 and between $22 101 (observed) and $34 615 (adjusted) for patients with at least one event. Fewer patients in Montreal (55%) experienced events compared to Toronto (79%) or Vancouver (76%). Median time (months) to first event was longer in Montreal (25.0 [18.5, 32.6]) than in Toronto (14.6 [9.7, 16.8] or Vancouver (17.3 [14.8, 24.0]). More patients received bone-targeted therapy in Montreal (64%) and Toronto (60%) than in Vancouver (24%). Bone-targeted therapy was mostly administered every 3-4 weeks in Montréal and every 3-4 months in Toronto.

CONCLUSIONS

Metastatic bone disease-related healthcare resource use costs for Canadian castrate-resistant prostate cancer patients are high. Symptomatic skeletal events occurred frequently, with the incremental cost of one or more events estimated between $12 641 and $25 120. Symptomatic skeletal event incidence and bone-targeted therapy use varied considerably between three Canadian uro-oncology centres. An important limitation is that only patients who died from prostate cancer were included, potentially overestimating costs.

Treatments for Metastatic Prostate Cancer (mPC): A Review of Costing Evidence

BACKGROUND

Prostate cancer (PC) is the most common cancer in Western countries. More than one third of PC patients develop metastatic disease, and the 5-year expected survival in distant disease is about 35%. During the last few years, new treatments have been launched for metastatic castrate-resistant prostate cancer (mCRPC).

OBJECTIVES

We aimed to review the current literature on health economic analysis on the treatment of metastatic prostate cancer (mPC), compare the studies, summarize the findings and make the results available to administrators and decision makers.

METHODS

A systematic literature search was done for economic evaluations (cost-minimization, cost-effectiveness, cost-utility, cost-of-illness, cost-of-drug, and cost-benefit analyses). We employed the PubMed^® search engine and searched for publications published between 2012 and 2016. The terms used were "prostate cancer", "metastatic" and "cost". An initial screening of all headlines was performed, selected abstracts were analysed, and finally the full papers investigated. Study characteristics, treatment and comparator, country, type of evaluation, perspective, year of value, time horizon, efficacy data, discount rate, total costs and sensitivity analysis were analysed. The quality was assessed using the Quality of Health Economic Studies (QHES) instrument.

RESULTS

A total of 227 publications were detected and screened, 58 selected for full-text assessment and 31 included in the final analyses. Despite the significant international literature on the treatment of mCRPC, there were only 15 studies focusing on cost-effectiveness analysis (CEA). Medical treatment constituted two thirds of the selected studies. Significant costs in the treatment of mCRPC were disclosed. In the pre-docetaxel setting, both abiraterone acetate (AA) and enzalutamide were concluded beyond accepted cost/quality-adjusted life year limits. In the docetaxel refractory setting, most studies concluded that enzalutamide was cost-effective and superior to AA. In most studies, cabazitaxel was not recommended, because of high cost. Looking at bone-targeting drugs, generic zoledronic acid (ZA) was recommended. External beam radiotherapy (EBRT) was analysed in three studies, and single fraction radiotherapy was concluded to be cost saving. Radium-223 was documented as beneficial, but costly. The quality of the studies was generally good, but sensitivity analyses, discounting and the measurement of health outcomes were present in less than two thirds of the selected studies.

CONCLUSIONS

The treatment of mCRPC was associated with significant cost. In the post-docetaxel setting, single fraction radiotherapy and enzalutamide were considered cost-effective in most studies. Generic ZA was the recommended bone-targeting therapy.

Oncolytic adenovirus-mediated therapy for prostate cancer

Prostate cancer is a leading cause of cancer-related death and morbidity in men in the Western world. Tumor progression is dependent on functioning androgen receptor signaling, and initial administration of antiandrogens and hormone therapy (androgen-deprivation therapy) prevent growth and spread. Tumors frequently develop escape mechanisms to androgen-deprivation therapy and progress to castration-resistant late-stage metastatic disease that, in turn, inevitably leads to resistance to all current therapeutics, including chemotherapy. In spite of the recent development of more effective inhibitors of androgen–androgen receptor signaling such as enzalutamide and abiraterone, patient survival benefits are still limited. Oncolytic adenoviruses have proven efficacy in prostate cancer cells and cause regression of tumors in preclinical models of numerous drug-resistant cancers. Data from clinical trials demonstrate that adenoviral mutants have limited toxicity to normal tissues and are safe when administered to patients with various solid cancers, including prostate cancer. While efficacy in response to adenovirus administration alone is marginal, findings from early-phase trials targeting local-ized and metastatic prostate cancer suggest improved efficacy in combination with cytotoxic drugs and radiation therapy. Here, we review recent progress in the development of multimodal oncolytic adenoviruses as biological therapeutics to improve on tumor elimination in prostate cancer patients. These optimized mutants target cancer cells by several mechanisms including viral lysis and by expression of cytotoxic transgenes and immune-stimulatory factors that activate the host immune system to destroy both infected and noninfected prostate cancer cells. Additional modifications of the viral capsid proteins may support future systemic delivery of oncolytic adenoviruses.

Management of localized and advanced prostate cancer in Canada: A lifetime cost and quality-adjusted life-year analysis

BACKGROUND

To the authors' knowledge, the literature to date lacks studies examining lifetime costs and quality-adjusted life-years (QALYs) of prostate cancer (PCa) management strategies that integrate localized and advanced disease. The objective of the current study was to assess lifetime costs and QALYs associated with contemporary PCa management strategies across risk groups by integrating localized and advanced disease.

METHODS

The authors' validated Markov chain Monte Carlo model was used to predict lifetime direct costs and QALYs. The health states modeled were active surveillance, initial treatments (radical prostatectomy or radiotherapy), PCa recurrence, PCa recurrence free, metastatic castration-resistant prostate cancer, and death (cause specific/other causes). Data regarding treatment distribution, state transition probabilities, adverse effects of management options, costs, utilities, and disutilities were derived from the published literature.

RESULTS

The total cost per patient for the overall cohort increased from $18,503 at 5 years to $28,032 and $39,143, respectively, at 10 years and 15 years. Furthermore, the results indicated the influence of risk group on total cost, with the high-risk group accruing the maximum per patient cost followed by the intermediate-risk and low-risk groups. Active surveillance was found to confer the most QALYs (12.5 years) and was the least costly strategy ($18,452) for individuals at low risk. For all risk groups, radical prostatectomy was less costly and conferred modestly more QALYs compared with intensity-modulated radiotherapy modalities.

CONCLUSIONS

Public health care systems in Canada and elsewhere are operating under budget constraints to allocate finite resources. The findings of the current study might inform discussions concerning budget planning to provide health care services.