Evaluating key characteristics of ideal colorectal cancer screening modalities: the microsimulation approach

Stress-Testing US Colorectal Cancer Screening Guidelines: Decennial Colonoscopy from Age 45 is Robust to Natural History Uncertainty and Colonoscopy Sensitivity Assumptions

PurposeThe 2023 American College of Physicians (ACP) guidelines for colorectal cancer (CRC) screening are at odds with the United States Preventive Task Force (USPSTF) guidelines, with the former recommending screening starting at age 50 y and the latter at age 45 y. This article "stress tests" CRC colonoscopy screening strategies to investigate their robustness to uncertainties stemming from the natural history of disease and sensitivity of colonoscopy.MethodsThis study uses the CRC-SPIN microsimulation model to project the life-years gained (LYG) under several colonoscopy CRC screening strategies. The model was extended to include birth cohort effects on adenoma risk. We estimated natural history parameters under 2 different assumptions about the youngest age of adenoma initiation. For each, we generated 500 parameter sets to reflect uncertainty in the natural history parameters. We simulated 26 colonoscopy screening strategies and examined 4 different colonoscopy sensitivity assumptions, encompassing the range of sensitivities consistent with prior tandem colonoscopy studies. Across this set of scenarios, we identify efficient screening strategies and report posterior credible intervals for benefits of screening (LYG), burden (number of colonoscopies), and incremental burden-effectiveness ratios.ResultsProjected absolute screening benefits varied widely based on assumptions, but strategies starting at age 45 y were consistently in the efficiency frontier. Strategies in which screening starts at age 50 y with 10-y intervals were never efficient, saving fewer life-years than starting screening at age 45 y and performing colonoscopies every 15 y while requiring more colonoscopies per person.ConclusionsDecennial colonoscopy screening initiation at age 45 y remained a robust recommendation. Colonoscopy screening with a 10-y interval starting at age 50 y did not result in an efficient use of colonoscopies in any of the scenarios evaluated.HighlightsColorectal cancer colonoscopy screening strategies initiated at age 45 y were projected to yield more life-years gained while requiring the least number of colonoscopies across different model assumptions about disease natural history and colonoscopy sensitivity.Colonoscopy screening starting at age 50 y with a 10-y interval consistently underperformed strategies that started at age 45 y.

Optimising colorectal cancer screening strategies and target populations in budget-constrained regions through cost-effectiveness analysis: a case from eastern China

OBJECTIVES

The primary aim of this study was to optimise colorectal cancer (CRC) screening strategies and target populations in resource-limited areas through cost-effectiveness analysis, evaluating the best screening methods and appropriate screening ages.

DESIGN

A prospective microsimulation model was used for cost-effectiveness analysis, calibrated with real-world data.

SETTING

The study was conducted in Huzhou City, Zhejiang Province, China, focusing on primary and secondary healthcare levels. Data were obtained from the Huzhou Center for Disease Control and Prevention.

PARTICIPANTS

The study included 418 805 local residents who participated in the Huzhou screening programme between 2020 and 2022. Inclusion criteria were individuals aged 45-100 years and residing in the local area.

INTERVENTIONS

Four initial screening methods were evaluated: single-sample immunochemical faecal occult blood test (iFOBT), double-sample iFOBT, single-sample iFOBT combined with a risk assessment questionnaire and double-sample iFOBT combined with a risk assessment questionnaire. Screening frequencies included annual and biennial intervals.

PRIMARY OUTCOME MEASURES

The primary outcome measure was the cost per incremental quality-adjusted life year (QALY) for different screening strategies. Also, the impact on CRC incidence, related deaths, life years saved (LYS) and QALYs was considered.

RESULTS

The primary data were sourced from the Huzhou screening programme, which included 418 805 individuals from 2020 to 2022. All screening strategies were found to be effective, with the cost per incremental QALY being less than $1036, which is below the minimum standard for middle-income countries. The most effective screening strategy was the annual combined two-sample iFOBT and risk evaluation questionnaires. This approach led to a reduction in CRC incidence and related deaths by 2435 and 1174 cases per 100 000 individuals, respectively, and an increase in LYS by 13 903 years and QALYs by 35 564 years. The recommended ages to begin and end screening were 48 and 72 years, respectively.

CONCLUSIONS

All CRC screening strategies demonstrated effectiveness compared with non-screening, with the annual combined two-sample iFOBT and risk evaluation questionnaires emerging as the optimal approach. For additional regions, the best screening strategy can be selected based on the health outcomes and costs we have provided.

Integrative genome-wide aberrant DNA methylation and transcriptome analysis identifies diagnostic markers for colorectal cancer

Colorectal cancer remains a major cause of cancer mortality, with limited sensitivity in current diagnostics. Aberrant DNA methylation in expression-regulating sites shows biomarker potential, though few studies explore such methylation-based diagnostic tools for colorectal cancer. We conducted genome-wide DNA methylation and RNA sequencing on matched colorectal cancer and normal tissues to identify expression-related differentially methylated CpG sites (DMCs). Diagnostic models were constructed with training and validation sets of 689 samples. Machine learning techniques (random forest, elastic net, support vector machine) were employed to identify optimal diagnostic markers. Methylation-specific PCR confirmed marker-host gene regulatory relationships, and targeted bisulfite sequencing validated these markers in an independent cohort of 200 samples. Host genes roles in colorectal cancer pathogenesis were further investigated through in vivo and in vitro assays and tissue microarray analysis. We identified 64,824 DMCs in colorectal cancer, with 442 associated with gene expression. These sites impact transcription factor binding, and their host genes are linked to chemotherapy resistance. Diagnostic panels showed high efficacy, with methylation changes significantly impacting RNA and protein expression of host genes. Markers cg16851417, cg19498960, and cg16302790 were validated in blood for noninvasive screening. Clustering expression-related DMCs with similar methylation patterns may facilitate diagnostic tools development. Host genes SIM2, PDX1, and TNS4 influence colorectal cancer progression and may impact therapy response. Expression-related DMCs hold strong potential as colorectal cancer biomarkers, with implications for prognosis and therapy. The specific expression patterns of these DMCs in host genes support development of non-invasive blood-based diagnostic tools.

Stool and blood biomarkers for colorectal cancer management: an update on screening and disease monitoring

BACKGROUND

Biomarkers have revolutionized the management of colorectal cancer (CRC), facilitating early detection, prevention, personalized treatment, and minimal residual disease (MRD) monitoring. This review explores current CRC screening strategies and emerging biomarker applications.

MAIN BODY

We summarize the landscape of non-invasive CRC screening and MRD detection strategies, discuss the limitations of the current approaches, and highlight the promising potential of novel biomarker solutions. The fecal immunochemical test remained the cornerstone of CRC screening, but its sensitivity has been improved by assays that combined its performance with other stool analytes. However, their sensitivity for advanced adenomas and the patient compliance both remain suboptimal. Blood-based tests promise to increase compliance but require further refinement to compete with stool-based biomarker tests. The ideal scenario involves leveraging blood tests to increase screening participation, and simultaneously promote stool- and endoscopy-based screening among those who are compliant. Once solely reliant on upfront surgery followed by stage and pathology-driven adjuvant chemotherapy, the treatment of stage II and III colon cancer has undergone a revolutionary transformation with the advent of MRD testing after surgery. A decade ago, the concept of using a post-surgical test instead of stage and pathology to determine the need for adjuvant chemotherapy was disruptive. Today, a blood test may be more informative of the need for chemotherapy than the stage at diagnosis.

CONCLUSION

Biomarker research is not just improving, but bringing a transformative change to CRC clinical management. Early detection is not just getting better, but improving thanks to a multi-modality approach, and personalized treatment plans are not just becoming a reality, but a promising future with MRD testing.

Colorectal cancer screening: Modalities and adherence

In the last decade, several studies have explored various modalities and strategies for colorectal cancer (CRC) screening, taking into account epidemiological data, individual characteristics, and socioeconomic factors. In this editorial, we comment further on a retrospective study by Agatsuma et al published in the recent issue of the World Journal of Gastroenterology. Our focus is on screening trends, particularly in relation to efforts to improve the currently suboptimal uptake among the general population worldwide, aiming to enhance early diagnosis rates of CRC. There is a need to raise awareness through health edu-cation programs and to consider the use of readily available, non-invasive screening methods. These strategies are crucial for attracting screen-eligible populations to participate in first-line screening, especially those in high- or average-risk groups and in regions with limited resources. Liquid biopsies and biomarkers represent rapidly evolving trends in screening and diagnosis; however, their clinical relevance has yet to be standardized.

Current Quality of Videos on Colorectal Cancer Screening for General Public

BACKGROUND

One-third of American adults encompassed by current colorectal cancer screening guidelines fail to obtain recommended screening evaluations. Educational videos are a valuable medium through which to educate and encourage recommended health behaviors in patients.

METHODS

A cross-sectional study reviewing the quality of patient education videos addressing colorectal cancer screening. Video quality was assessed in 3 domains: accountability, content, and production.

RESULTS

Forty-four videos met inclusion criteria. Out of 33 possible points, videos scored a median of 15.0 (interquartile range 12.9-16.6). Videos scored 1.0 (interquartile range .8-1.0) out of 4.0 for accountability, 6.0 (interquartile range 4.4-8.0) out of 20 for content, and 8.0 (interquartile range 7.4-8.0) out of 9.0 for production. Colonoscopy was the most frequently discussed method of screening (38, 86%). While 13 (34%) videos discussed the risk of colorectal cancer in the general population and 15 (32%) discussed the risk in those with a family history, few videos addressed those with other risk factors. Most (31, 70%) videos discussed the medical consequences of not receiving screening, but only 1 (2%) video discussed the social consequences. Similarly, medical benefits were discussed in 34 (77%) videos while other benefits were not discussed by any video. Only one-fifth of the videos address three or more barriers to screening.

CONCLUSIONS

Videos on colorectal cancer screening have excellent production quality but need improvement in the domains of accountability and content. The videos included in this analysis did not adequately address the concerns of viewers nor the benefits of colorectal cancer screening.

Efficient organized colorectal cancer screening in Shenzhen: a microsimulation modelling study

BACKGROUND

Colorectal cancer (CRC) is a global health issue with noticeably high incidence and mortality. Microsimulation models offer a time-efficient method to dynamically analyze multiple screening strategies. The study aimed to identify the efficient organized CRC screening strategies for Shenzhen City.

METHODS

A microsimulation model named CMOST was employed to simulate CRC screening among 1 million people without migration in Shenzhen, with two CRC developing pathways and real-world participation rates. Initial screening included the National Colorectal Polyp Care score (NCPCS), fecal immunochemical test (FIT), and risk-stratification model (RS model), followed by diagnostic colonoscopy for positive results. Several start-ages (40, 45, 50 years), stop-ages (70, 75, 80 years), and screening intervals (annual, biennial, triennial) were assessed for each strategy. The efficiency of CRC screening was assessed by number of colonoscopies versus life-years gained (LYG).

RESULTS

The screening strategies reduced CRC lifetime incidence by 14-27 cases (30.9-59.0%) and mortality by 7-12 deaths (41.5-71.3%), yielded 83-155 LYG, while requiring 920 to 5901 colonoscopies per 1000 individuals. Out of 81 screening, 23 strategies were estimated efficient. Most of the efficient screening strategies started at age 40 (17 out of 23 strategies) and stopped at age 70 (13 out of 23 strategies). Predominant screening intervals identified were annual for NCPCS, biennial for FIT, and triennial for RS models. The incremental colonoscopies to LYG ratios of efficient screening increased with shorter intervals within the same test category. Compared with no screening, when screening at the same start-to-stop age and interval, the additional colonoscopies per LYG increased progressively for FIT, NCPCS and RS model.

CONCLUSION

This study identifies efficient CRC screening strategies for the average-risk population in Shenzhen. Most efficient screening strategies indeed start at age 40, but the optimal starting age depends on the chosen willingness-to-pay threshold. Within insufficient colonoscopy resources, efficient FIT and NCPCS screening strategies might be CRC initial screening strategies. We acknowledged the age-dependency bias of the results with NCPCS and RS.

Why is early detection of colon cancer still not possible in 2023?

Colorectal cancer (CRC) screening is a fundamental tool in the prevention and early detection of one of the most prevalent and lethal cancers. Over the years, screening, particularly in those settings where it is well organized, has succeeded in reducing the incidence of colon and rectal cancer and improving the prognosis related to them. Despite considerable advancements in screening technologies and strategies, the effectiveness of CRC screening programs remains less than optimal. This paper examined the multifaceted reasons behind the persistent lack of effectiveness in CRC screening initiatives. Through a critical analysis of current methodologies, technological limitations, patient-related factors, and systemic challenges, we elucidated the complex interplay that hampers the successful reduction of CRC morbidity and mortality rates. While acknowledging the advancements that have improved aspects of screening, we emphasized the necessity of addressing the identified barriers comprehensively. This study aimed to raise awareness of how important CRC screening is in reducing costs for this disease. Screening and early diagnosis are not only important in improving the prognosis of patients with CRC but can lead to an important reduction in the cost of treating a disease that is often diagnosed at an advanced stage. Spending more sooner can mean saving money later.

The Non-Invasive Prediction of Colorectal Neoplasia (NIPCON) Study 1995-2022: A Comparison of Guaiac-Based Fecal Occult Blood Test (FOBT) and an Anti-Adenoma Antibody, Adnab-9

Given the need to improve the sensitivity of non-invasive methods to detect colorectal neoplasia, particularly adenomas, we compared a fecal test using a monoclonal antibody (Mab) raised against constituents of colonic adenomas designated Adnab-9 (Adenoma Antibody 9), recognizing an N-linked 87 kDa glycoprotein, to gFOBT, which is shown to reduce CRC mortality. p87 immunohistochemistry testing is significantly more sensitive (OR 3.64[CI 2.37-5.58]) than gFOBT (guaiac-based fecal occult blood test) for adenomas (<3 in number), advanced adenomas (OR 4.21[CI 2.47-7.15]), or a combination of the two (OR 3.35[CI 2.47-4.53]). p87 immunohistochemistry shows regional Paneth cell (PC) expression mainly in the right-sided colon and is significantly reduced in the ceca of African Americans (p < 0.0001). In a subset of patients, we obtained other body fluids such as urine, colonic effluent, and saliva. Urine tests (organ-specific neoantigen) showed a significant difference for advanced adenomas (p < 0.047). We conclude that fecal p87 testing is more sensitive than gFOBT and Adnab-9 and could be used to better direct the colonoscopy screening effort.

Health Economic Evidence and Modeling Challenges for Liquid Biopsy Assays in Cancer Management: A Systematic Literature Review

BACKGROUND

Cancer-derived material circulating in the bloodstream and other bodily fluids, referred to as liquid biopsies (LBs), has become an appealing adjunct or alternative to tissue biopsies, showing vital promise in several clinical applications.

PURPOSE

A systematic literature review was conducted to (1) summarize the current health economic evidence for LB assays and (2) identify and analyze the studies addressed or reported on the challenges of health economic modeling in precision medicine.

METHODS

Relevant studies were identified in the EMBASE, MEDLINE, Cochrane Library, EconLit, and the University of Melbourne Full Text Journal databases from 1 January 2013 to 16 September 2022. Included papers were selected if they were economic evaluations and/or budget impact analyses.

RESULTS

A total of 24 studies were included and analyzed, with the majority being full economic evaluations (n = 19, 79.2%). Four studies (16.7%) were health and budget impact analyses, and one study (4.1%) incorporated both an economic evaluation and a budget impact analysis. Cohort-level modeling techniques were the most common approach (n = 16; 80%). LB technologies were cost-effective in 15 studies (75%) considering different biomarkers, cancer types and stages, and economic analyses. These studies evaluated LBs for screening and early detection (66.7%), treatment selection (26.7%), and monitoring treatment response (6.6%). Budget impact analysis results were varied among included studies, with the majority of studies (n = 4; 80%) reporting either cost savings, minimal, or modest budget impact, while one study (20%) reported LBs as an efficient strategy. The reviewed studies often inadequately reported or addressed modeling challenges, such as patient-level processes, the combination of tests and treatments, preferences, and uncertainty.

CONCLUSION

LBs could provide a cost-effective approach for treatment selection in lung cancer and aid in the screening and early detection of other cancers, including colorectal, gastric, breast, and brain cancers. This is in comparison with various alternatives, such as the standard of care (SOC) and no screening scenario. However, it is important to mention that in some comparisons, LBs were used in combination with SOC instead of replacing it. Importantly, few studies have pointed toward LBs' cost-effectiveness for monitoring treatment response. Most health and budget impact analyses, especially those focused on lung cancer, suggest potential cost savings or a minimal-to-moderate budget impact. Nevertheless, additional research is needed to ascertain their effectiveness across various stages of lung and colorectal cancer, as well as to address potential modeling challenges.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022307939.

Effectiveness of Colorectal Cancer (CRC) Screening on All-Cause and CRC-Specific Mortality Reduction: A Systematic Review and Meta-Analysis

(1) Background: The aim of this study was to pool and compare all-cause and colorectal cancer (CRC) specific mortality reduction of CRC screening in randomized control trials (RCTs) and simulation models, and to determine factors that influence screening effectiveness. (2) Methods: PubMed, Embase, Web of Science and Cochrane library were searched for eligible studies. Multi-use simulation models or RCTs that compared the mortality of CRC screening with no screening in general population were included. CRC-specific and all-cause mortality rate ratios and 95% confidence intervals were calculated by a bivariate random model. (3) Results: 10 RCTs and 47 model studies were retrieved. The pooled CRC-specific mortality rate ratios in RCTs were 0.88 (0.80, 0.96) and 0.76 (0.68, 0.84) for guaiac-based fecal occult blood tests (gFOBT) and single flexible sigmoidoscopy (FS) screening, respectively. For the model studies, the rate ratios were 0.45 (0.39, 0.51) for biennial fecal immunochemical tests (FIT), 0.31 (0.28, 0.34) for biennial gFOBT, 0.61 (0.53, 0.72) for single FS, 0.27 (0.21, 0.35) for 10-yearly colonoscopy, and 0.35 (0.29, 0.42) for 5-yearly FS. The CRC-specific mortality reduction of gFOBT increased with higher adherence in both studies (RCT: 0.78 (0.68, 0.89) vs. 0.92 (0.87, 0.98), model: 0.30 (0.28, 0.33) vs. 0.92 (0.51, 1.63)). Model studies showed a 0.62-1.1% all-cause mortality reduction with single FS screening. (4) Conclusions: Based on RCTs and model studies, biennial FIT/gFOBT, single and 5-yearly FS, and 10-yearly colonoscopy screening significantly reduces CRC-specific mortality. The model estimates are much higher than in RCTs, because the simulated biennial gFOBT assumes higher adherence. The effectiveness of screening increases at younger screening initiation ages and higher adherences.

Screening for Colorectal Cancer

Colorectal cancer (CRC) is the second-leading cause of cancer death in the United States. Screening reduces CRC incidence and mortality. 2021 US Preventive Service Task Force (USPSTF) guidelines and available evidence support routine screening from ages 45 to 75, and individualized consideration of screening ages 76 to 85. USPSTF guidelines recommend annual guaiac fecal occult blood testing, annual fecal immunochemical testing (FIT), annual to every 3-year multitarget stool DNA-FIT, every 5-year sigmoidoscopy, every 10-year sigmoidoscopy with annual FIT, every 5-year computed tomographic colonography, and every 10-year colonoscopy as options for screening. The "best test is the one that gets done."