Utilization of a Colorectal Cancer Screening Test Among Individuals With Average Risk

Barriers and proposed solutions to at-home colorectal cancer screening tests in medically underserved health centers across three US regions to inform a randomized trial

INTRODUCTION

At-home colorectal cancer (CRC) screening is an effective way to reduce CRC mortality, but screening rates in medically underserved groups are low. To plan the implementation of a pragmatic randomized trial comparing two population-based outreach approaches, we conducted qualitative research on current processes and barriers to at-home CRC screening in 10 community health centers (CHCs) that serve medically underserved groups, four each in Massachusetts and California, and two tribal facilities in South Dakota.

METHODS

We conducted 53 semi-structured interviews with clinical and administrative staff at the participating CHCs. Participants were asked about CRC screening processes, categorized into eight domains: patient identification, outreach, risk assessment, fecal immunochemical test (FIT) workflows, FIT-DNA (i.e., Cologuard) workflows, referral for a follow-up colonoscopy, patient navigation, and educational materials. Transcripts were analyzed using a Rapid Qualitative Analysis approach. A matrix was used to organize and summarize the data into four sub-themes: current process, barriers, facilitators, and solutions to adapt materials for the intervention.

RESULTS

Each site's process for stool-based CRC screening varied slightly. Interviewees identified the importance of offering educational materials in English and Spanish, using text messages to remind patients to return kits, adapting materials to address health literacy needs so patients can access instructions in writing, pictures, or video, creating mailed workflows integrated with a tracking system, and offering patient navigation to colonoscopy for patients with an abnormal result.

CONCLUSION

Proposed solutions across the three regions will inform a multilevel intervention in a pragmatic trial to increase CRC screening uptake in CHCs.

Analytical Validation of the Multitarget Stool RNA Test for Colorectal Cancer Screening

The multitarget stool RNA (mt-sRNA) test (ColoSense) is a noninvasive diagnostic test that screens for colorectal cancer and advanced adenomas in average-risk individuals aged 45 years and older. The mt-sRNA test incorporates a commercially available fecal immunochemical test, concentration of eight RNA transcripts, and participant-reported smoking status. As part of the CRC-PREVENT (Colorectal Cancer and Pre-Cancerous Adenoma Non-Invasive Detection Test) clinical trial, 12 analytical validation studies were conducted to assess analytical sensitivity, linearity, precision, interfering substances, cross-reactivity, carry-over, cross-contamination, and robustness. Analytical validation of the mt-sRNA test demonstrated limit of blank, limit of detection, and limit of quantification of <0.6, <0.7, and ≤2.5 copies/μL for all markers, respectively. The mt-sRNA test demonstrated linearity between 2.5 and 2500 copies/μL, and <20% coefficient of variation, and/or ≥95% concordance with regard to precision, interfering substances, carry-over, cross-contamination, and robustness. There was no significant impact of cross-reactivity from non-colorectal cancer diseases. These data provide a framework for laboratories to complete analytical validation for RNA-based panels that require premarket approval as a class III medical device from the US Food and Drug Administration.

Evaluating colonoscopy quality by performing provider type

BACKGROUND

Colorectal cancer is the third most diagnosed cancer and the second leading cause of cancer death in the United States. Colonoscopy is an essential tool for screening, used as a primary approach and follow-up to an abnormal stool-based colorectal cancer screening result. Colonoscopy quality is often measured with 4 key indicators: bowel preparation, cecal intubation, mean withdrawal time, and adenoma detection. Colonoscopies are most often performed by gastroenterologists (GI), however, in rural and medically underserved areas, non-GI providers often perform colonoscopies. This study aims to evaluate the quality and safety of screening colonoscopies performed by non-GI practitioner, comparing their outcomes with those of GI providers.

METHODS

Descriptive statistics were used to characterize the study population. Results for quality indicators were stratified by provider type and compared. Statistical significance was determined using a P value of less than .05 as the threshold for all comparisons; all P values were 2-sided.

RESULTS

No statistical difference was found when comparing performance by provider type. Median performance for gastroenterologists, general surgeons, and family medicine providers ranged from 98% to 100% for cecal intubation; 97.4% to 100% for bowel preparation; 57.4% to 88.9% for male adenoma detection rate; 47.7% to 62.13% for female adenoma detection rate; and 0:12:10 to 0:20:16 for mean withdrawal time. All provider types met and exceeded the goal metric for each of the quality indicators (P < .001).

CONCLUSIONS

As a result of this analysis, we can expect non-GI practitioner to perform colonoscopies with similar quality to GI practitioner given the performance outcomes for the key quality metrics.

Clinical diagnostic value of methylated SEPT9 combined with NLR, PLR and LMR in colorectal cancer

PURPOSE

This study aimed to investigate clinical diagnostic values of mSEPT9 combined with NLR, PLR and LMR in CRC.

METHODS

329 subjects composed of 120 CRC patients, 105 polyps patients and 104 healthy participants were prospectively recruited. Clinicopathologic features were collected and analyzed. Plasma samples were collected for mSEPT9, NLR, PLR and LMR test. The sensitivity, specificity and AUC of each biomarker separately or in combination were estimated by the ROC curve.

RESULTS

The levels of NLR, PLR and the PDR of mSEPT9 in CRC patients were significantly higher than those in non-CRC subjects, while LMR was the opposite. The PDR of mSEPT9 in CRC patients was significantly correlated with age, tumor size, tumor stage and M stage. ROC curve analysis demonstrated moderate diagnostic values of mSEPT9, NLR, PLR and LMR in CRC patients with AUC of 0.78 (Se = 0.68, and Sp = 0.89), 0.78 (Se = 0.68, and Sp = 0.83), 0.80 (Se = 0.68, and Sp = 0.81), and 0.77 (Se = 0.72, and Sp = 0.73), respectively. Moreover, combination of these four biomarkers dramatically enhanced the diagnostic accuracy of CRC (AUC = 0.92, Se = 0.90, and Sp = 0.87), especially for CRC patients with large tumors (AUC = 0.95) or distal metastasis (AUC = 0.95).

CONCLUSION

mSEPT9, NLR, PLR and LMR showed the potential to be reliable biomarkers for the diagnosis of CRC. And the combined application of these biomarkers further improved the diagnostic accuracy of CRC significantly.

Development and Validation of a Colorectal Cancer Prediction Model: A Nationwide Cohort-Based Study

BACKGROUND

Early diagnosis of colorectal cancer (CRC) is critical to increasing survival rates. Computerized risk prediction models hold great promise for identifying individuals at high risk for CRC. In order to utilize such models effectively in a population-wide screening setting, development and validation should be based on cohorts that are similar to the target population.

AIM

Establish a risk prediction model for CRC diagnosis based on electronic health records (EHR) from subjects eligible for CRC screening.

METHODS

A retrospective cohort study utilizing the EHR data of Clalit Health Services (CHS). The study includes CHS members aged 50-74 who were eligible for CRC screening from January 2013 to January 2019. The model was trained to predict receiving a CRC diagnosis within 2 years of the index date. Approximately 20,000 EHR demographic and clinical features were considered.

RESULTS

The study includes 2935 subjects with CRC diagnosis, and 1,133,457 subjects without CRC diagnosis. Incidence values of CRC among subjects in the top 1% risk scores were higher than baseline (2.3% vs 0.3%; lift 8.38; P value < 0.001). Cumulative event probabilities increased with higher model scores. Model-based risk stratification among subjects with a positive FOBT, identified subjects with more than twice the risk for CRC compared to FOBT alone.

CONCLUSIONS

We developed an individualized risk prediction model for CRC that can be utilized as a complementary decision support tool for healthcare providers to precisely identify subjects at high risk for CRC and refer them for confirmatory testing.

Colonoscopy Outreach for Rural Communities (CORC): A study protocol of a pragmatic randomized controlled trial of a patient navigation program to improve colonoscopy completion for colorectal cancer screening

BACKGROUND

Colonoscopy is one of the primary methods of screening for colorectal cancer (CRC), a leading cause of cancer mortality in the United States. However, up to half of patients referred to colonoscopy fail to complete the procedure, and rates of adherence are lower in rural areas.

OBJECTIVES

Colonoscopy Outreach for Rural Communities (CORC) is a randomized controlled trial to test the effectiveness of a centralized patient navigation program provided remotely by a community-based organization to six geographically distant primary care organizations serving rural patients, to improve colonoscopy completion for CRC.

METHODS

CORC is a type 1 hybrid implementation-effectiveness trial. Participants aged 45-76 from six primary care organizations serving rural populations in the northwestern United States are randomized 1:1 to patient navigation or standard of care control. The patient navigation is delivered remotely by a trained lay-person from a community-based organization. The primary effectiveness outcome is completion of colonoscopy within one year of referral to colonoscopy. Secondary outcomes are colonoscopy completion within 6 and 9 months, time to completion, adequacy of patient bowel preparation, and achievement of cecal intubation. Analyses will be stratified by primary care organization.

DISCUSSION

Trial results will add to our understanding about the effectiveness of patient navigation programs to improve colonoscopy for CRC in rural communities. The protocol includes pragmatic adaptations to meet the needs of rural communities and findings may inform approaches for future studies and programs.

TRIAL REGISTRATION

National Clinical Trial Identifier: NCT05453630.

TRIAL REGISTRATION

ClinicalTrials.gov. Identifier: NCT05453630. Registered July 6, 2022.

The utility of liquid biopsy-based methylation biomarkers for colorectal cancer detection

Colorectal cancer (CRC) is one of the most prevalent cancers and the second leading cause of cancer-related deaths in the United States. It is also one of the few cancers with established screening guidelines, however these methods have significant patient burden (e.g., time, invasive). In recent years, the development of liquid biopsy-based screening methods for biomarker detection have emerged as alternatives to traditional screening. Methylation biomarkers are of particular interest, and these markers can be identified and measured on circulating tumor and cell-free DNA. This perspective summarizes the current state of CRC screening and the potential integration of DNA methylation markers into liquid biopsy-based techniques. Finally, I discuss limitations to these methods and strategies for improvement. The continued development and implementation of liquid biopsy-based cancer screening approaches may provide an acceptable alternative to individuals unwilling to be screened by traditional methods.

Estimate of Increase in Colorectal Cancer Diagnoses with Expansion of Fecal Immunochemical Testing in an Urban Safety-Net Population

BACKGROUND

Fecal immunochemical test (FIT) is less effective in detecting advanced adenomas (AA) than colonoscopy. Increase in FIT for colorectal cancer (CRC) screening may lead to an increased number of undetected AAs which may develop into future CRCs.

AIM

We determined the potential impact of FIT expansion on missed AAs and future CRC diagnoses in an urban, tertiary-care, safety-net hospital.

METHODS

CRC and AA diagnoses were identified in patients undergoing colonoscopy for average-risk CRC screening or positive FIT between 2017 and 2019 at Boston Medical Center. Poisson regression modeling was used to estimate the frequency of AAs per year by age group using data from 2017 to 2019, assuming average outpatient volume and proportion of screening colonoscopies. Total number of patients who received FIT was extrapolated from those who underwent colonoscopy for positive FIT. We estimated AAs per year if 'one-time' FIT was used for screening in 75% and 100% of the population and subtracted this from the estimated AAs per year under the Poisson model to determine missed AAs. We used previously described, age and gender specific estimates of the annual progression of AA to CRC.

RESULTS

The estimated number of CRCs detected per year is 4.6/1785 males and 4.6/2086 females screened. With 75% FIT expansion, we estimate an additional 3.5 (95% CI 1.3, 9.5) and 2.2 (95% CI 0.64, 7.6) CRCs; with 100% FIT expansion, we estimate an additional 7.4 (95% CI 3.7, 14.9) and 4.2 (95% CI 1.7, 10.5) CRCs, in 5 years, in males and females, respectively.

CONCLUSION

Expansion of FIT may substantially increase CRC incidence.

Population health outcomes of blood-based screening for colorectal cancer in comparison to current screening modalities: insights from a discrete-event simulation model incorporating longitudinal adherence

AIM

Insufficient adherence to colorectal cancer (CRC) screening impedes individual and population health benefits, with about one-third of individuals non-adherent to available screening options. The impact of poor adherence is inadequately considered in most health economics models, limiting the evaluation of real-world population-level screening outcomes. This study introduces the CAN-SCREEN (Colorectal cANcer SCReening Economics and adherENce) model, utilizing real-world adherence scenarios to assess the effectiveness of a blood-based test (BBT) compared to existing strategies.

MATERIALS AND METHODS

The CAN-SCREEN model evaluates various CRC screening strategies per 1,000 screened individuals for ages 45-75. Adherence is modeled in two ways: (1) full adherence and (2) longitudinally declining adherence. BBT performance is based on recent pivotal trial data while existing strategies are informed using literature. The full adherence model is calibrated using previously published Cancer Intervention and Surveillance Modeling Network (CISNET) models. Outcomes, including life-years gained (LYG), CRC cases averted, CRC deaths averted, and colonoscopies, are compared to no screening.

RESULTS

Longitudinal adherence modeling reveals differences in the relative ordering of health outcomes and resource utilization, as measured by the number of colonoscopies performed per 1,000, between screening modalities. BBT outperforms the fecal immunochemical test (FIT) and the multitarget stool DNA (mtsDNA) test with more CRC deaths averted (13) compared to FIT and mtsDNA (7, 11), more CRC cases averted (27 vs. 16, 22) and higher LYG (214 vs. 157, 199). BBT yields fewer CRC deaths averted compared to colonoscopy (13, 15) but requires fewer colonoscopies (1,053 vs. 1,928).

LIMITATIONS

Due to limited data, the CAN-SCREEN model with longitudinal adherence leverages evidence-informed assumptions for the natural history and real-world longitudinal adherence to screening.

CONCLUSIONS

The CAN-SCREEN model demonstrates that amongst non-invasive CRC screening strategies, those with higher adherence yield more favorable health outcomes as measured by CRC deaths averted, CRC cases averted, and LYG.

Associations Between Patient Experience With Care, Race and Ethnicity, and Receipt of CRC Treatment Among SEER-CAHPS Patients With Multiple Comorbidities

BACKGROUND

Patients with colorectal cancer (CRC) and multiple comorbidities are less likely to receive guideline-concordant treatment (GCT), a disparity exacerbated by racial and ethnic disparities in GCT. Yet, positive patient experiences with care are associated with more appropriate care use. We investigated associations between patient experiences with care, race and ethnicity, and receipt of GCT for CRC among older adults with multiple comorbidities.

METHODS

We used SEER-Consumer Assessment of Healthcare Providers and Systems (CAHPS) data to identify participants diagnosed with CRC from 2001 to 2017 at age ≥67 years with additional chronic conditions. Stage-specific GCT was identified following recommendations in the NCCN Guidelines for Colon and Rectal Cancer. Patient experiences with care were identified from CAHPS surveys. Multivariable log-binomial regression estimated associations between race and ethnicity and receipt of GCT by experiences with care.

RESULTS

A total of 2,612 patients were included. Those reporting excellent experience with getting care quickly were 5% more likely to receive GCT than those reporting less-than-excellent experience (relative risk [RR], 1.05; 95% CI, 1.04-1.05). When reporting less-than-excellent experience with getting care quickly, non-Hispanic Black (NHB) patients were less likely than non-Hispanic White (NHW) patients to receive GCT (RR, 0.80; 99.38% CI, 0.78-0.82), yet NHB patients were more likely to receive GCT than NHW patients when reporting excellent experience (RR, 1.05; 99.38% CI, 1.02-1.09). When reporting less-than-excellent experience with getting needed care, Hispanic patients were less likely than NHW patients to receive GCT (RR, 0.91; 99.38% CI, 0.88-0.94), yet Hispanic patients were more likely to receive GCT than NHW patients when reporting excellent experience (RR, 1.06; 99.38% CI, 1.03-1.08).

CONCLUSIONS

Although excellent patient experience among those with multiple comorbidities may not be strongly associated with receipt of GCT for CRC overall, improvements in experiences of accessing care among NHB and Hispanic patients with CRC and additional comorbidities may aid in mitigating racial and ethnic disparities in receipt of GCT.

Incidence of Colorectal Cancer in Patients Diagnosed With Pyogenic Liver Abscess

Importance

Colorectal cancer (CRC) can compromise the mucosal barrier and subsequently allow a route for bacterial invasion into the portal system or systemic circulation. Despite preliminary data suggesting that patients who experienced pyogenic liver abscess (PLA) have higher CRC incidence rates, data from outside the Southeast Asian population are sparse.

Objective

To investigate whether there is an association between PLA and the subsequent incidence of diagnosed CRC using the Veterans Health Administration (VHA) cohort.

Design, Setting, and Participants

A patient-level matched retrospective cohort study was conducted at 127 VHA hospitals across the US from January 1, 2003, to December 31, 2020. Patients were followed up to 10 years from PLA diagnosis. Data analysis was performed from April 14, 2002, to October 31, 2023. All patients who were admitted to VHA hospitals with a diagnosis of PLA were included. For each patient with PLA, up to 3 controls without diagnosis of PLA, matching age, sex, and health care facility, were selected.

Exposure

Pyogenic liver abscess.

Main Outcomes and Measures

The primary outcome was CRC diagnosis during the follow-up period. A multivariable Fine-Gray subdistribution regression model with time-dependent coefficient was used to estimate the time-varying hazard ratio (HR) of CRC incidence while accounting for mortality as a competing event.

Results

A total of 8286 patients with PLA (male, 96.5%; mean [SD] age, 65.8 [11.9] years) and 23 201 patient-level matched controls (male, 96.3%; mean age, 65.3 [11.7] years) were included. A diagnosis of CRC was found in a significantly higher proportion of patients with PLA compared with controls (1.9% [159 of 8286] vs 0.8% [196 of 23 201]; P < .001). The incidence of CRC was significantly higher among patients with PLA during the first 3 years from PLA diagnosis (HR, 3.64; 95% CI, 2.70-4.91 at 0.5 years; HR, 2.51; 95% CI, 1.93-3.26 at 1 year; HR, 1.74; 95% CI, 1.33-2.28 at 2 years; and HR, 1.41; 95% CI, 1.05-1.89 at 3 years), but not significant after 3 years. This association was not observed among patients whose PLA was likely secondary to cholangitis or cholecystitis (HR, 1.78; 95% CI, 0.89-3.56 at 0.5 years).

Conclusions and Relevance

In this patient-level matched retrospective cohort study, a significantly higher incidence of CRC was observed up to 3 years from PLA diagnosis. The findings suggest that offering CRC screening for patients with cryptogenic PLA may be useful, especially patients who have not been screened according to guidelines.

Early Detection of Lung Cancer Using Small RNAs

INTRODUCTION

Lung cancer remains the deadliest cancer in the world, and lung cancer survival is heavily dependent on tumor stage at the time of detection. Low-dose computed tomography screening can reduce mortality; however, annual screening is limited by low adherence in the United States of America and still not broadly implemented in Europe. As a result, less than 10% of lung cancers are detected through existing programs. Thus, there is a great need for additional screening tests, such as a blood test, that could be deployed in the primary care setting.

METHODS

We prospectively recruited 1384 individuals meeting the National Lung Screening Trial demographic eligibility criteria for lung cancer and collected stabilized whole blood to enable the pipetting-free collection of material, thus minimizing preanalytical noise. Ultra-deep small RNA sequencing (20 million reads per sample) was performed with the addition of a method to remove highly abundant erythroid RNAs, and thus open bandwidth for the detection of less abundant species originating from the plasma or the immune cellular compartment. We used 100 random data splits to train and evaluate an ensemble of logistic regression classifiers using small RNA expression of 943 individuals, discovered an 18-small RNA feature consensus signature (miLung), and validated this signature in an independent cohort (441 individuals). Blood cell sorting and tumor tissue sequencing were performed to deconvolve small RNAs into their source of origin.

RESULTS

We generated diagnostic models and report a median receiver-operating characteristic area under the curve of 0.86 (95% confidence interval [CI]: 0.84-0.86) in the discovery cohort and generalized performance of 0.83 in the validation cohort. Diagnostic performance increased in a stage-dependent manner ranging from 0.73 (95% CI: 0.71-0.76) for stage I to 0.90 (95% CI: 0.89-0.90) for stage IV in the discovery cohort and from 0.76 to 0.86 in the validation cohort. We identified a tumor-shed, plasma-bound ribosomal RNA fragment of the L1 stalk as a dominant predictor of lung cancer. The fragment is decreased after surgery with curative intent. In additional experiments, results of dried blood spot collection and sequencing revealed that small RNA analysis could potentially be conducted through home sampling.

CONCLUSIONS

These data suggest the potential of a small RNA-based blood test as a viable alternative to low-dose computed tomography screening for early detection of smoking-associated lung cancer.

Impact of Eliminating Cost-Sharing by Medicare Beneficiaries for Follow-Up Colonoscopy After a Positive Stool-based Colorectal Cancer Screening Test

Medicare coverage of a follow-up colonoscopy after a positive stool-based colorectal cancer screening test with no patient cost-sharing started January 2, 2023, which may favorably affect screening behavior. This analysis estimated the clinical and economic effects of increased colorectal cancer screening participation potentially resulting from this policy change in Medicare beneficiaries. The validated Colorectal Cancer and Adenoma Incidence & Mortality (CRC-AIM) model simulated three guideline-endorsed colorectal cancer screening strategies for average-risk individuals (colonoscopy every 10 years, annual fecal immunochemical test, triennial multitarget stool DNA) from ages 65-75 years. The base-case scenario assumed 0% coinsurance for initial screening and follow-up colonoscopy, real-world screening test use (colonoscopy = 45.3%, stool-based test = 24.4%, unscreened = 30.3%), and real-world follow-up colonoscopy rates. Comparative scenarios assumed an increase in the overall screening rate from 0% to 15% (5% increments) and an increase in the follow-up colonoscopy rate from 0% to 15% (5% increments). The base-case scenario resulted in 128 life-years gained (LYG)/1,000 individuals versus no screening and total screening and treatment costs of $7,938/person. The changes resulted in an increase of up to 26 LYG/1,000 individuals and a decrease in total screening and treatment costs by as much as $128/person. Follow-up colonoscopy at $0 coinsurance became cost-saving with any increase in either overall screening or follow-up colonoscopy. Policies that remove cost barriers to completing colorectal cancer screening may increase rates of screening participation, potentially improving economic and clinical outcomes.

SIGNIFICANCE

A follow-up colonoscopy after a positive stool-based colorectal cancer screening test is necessary to complete the full screening process. Policies that remove cost barriers to completing colorectal cancer screening may lead to increases in overall participation rates and use of follow-up colonoscopy, improving clinical and economic outcomes.

Trends in colorectal cancer screening in the United States, 2012 to 2020

OBJECTIVES

Despite recommendations to increase the uptake of colorectal cancer (CRC) screening, trends in CRC screening vary with sociodemographic status. We aimed to evaluate trends in CRC screening in the US population and subpopulations.

METHODS

A total of 1,082,924 participants aged 50 to 75 from five cycles (2012, 2014, 2016, 2018, and 2020) of the Behavioral Risk Factor Surveillance System were involved. Multivariable logistic regression models were performed to evaluate linear trends in CRC screening utilization from 2012 to 2018. Rao-Scott chi-square tests were used to assess the differences in CRC screening utilization between 2018 and 2020.

RESULTS

The estimated percentage reporting up-to-date with CRC screening increased significantly (P for trend <0.001), from 62.8% (95% CI, 62.4%-63.2%) in 2012 to 66.7% (95% CI, 66.3%-67.2%) in 2018 and 70.4% (95% CI, 69.8%-71.0%) in 2020, in accordance with 2008 US Preventive Services Task Force recommendations. Trends followed similar patterns in most subgroups, although with different magnitudes in several subgroups, primarily those underweight showed a stable percentage over time (P for trend  =  0.170). In 2020, 72.4% of participants reported they were up to date with CRC screening, including the utilization of stool DNA tests and virtual colonoscopy. Colonoscopy was the most commonly used test in 2020 (64.5%), followed by FOBT (12.6%), stool DNA test (5.8%), sigmoidoscopy (3.8%), and virtual colonoscopy (2.7%).

CONCLUSIONS

In this nationally representative survey of the US population from 2012 through 2020, the percentage reporting up to date with CRC screening has increased, but not equally among all subgroups.

Opportunities and Challenges in Screening for Colorectal Cancer

Colorectal cancer (CRC) is a leading cause of mortality in the United States. Outcomes are greatly improved if CRC is detected early; hence, screening is currently recommended for adults aged 45 years and older at average risk for the disease. Despite this recommendation and the availability of accurate screening tests, the CRC screening rates are below those recommended. The goal of this study was to identify temporal trends (from 2015 to 2019) in CRC screening rates and the utilization of screening tests recommended for CRC detection among average-risk individuals within the St Elizabeth Healthcare system in Kentucky, United States. The primary population of interest was patients aged 50-75 years (the CRC screening was recommended for this age group at the time of the study). Deidentified data were sourced from patients' electronic health records, and the results showed that screening rates increased significantly from 26% in 2015 to 49% in 2019 (<0.0001). The incidence of any screening test also increased significantly from 2015 to 2019, for those who were due for screening (P < 0.05) and for the entire cohort (P < 0.1). The use of multitarget stool DNA (mt-sDNA) increased 40-fold over the study timeframe (P < 0.05). These study results confirm that CRC screening rates remain suboptimal, although incidence and adherence improved significantly in those aged 50-75 years from 2015 to 2019. The growing adoption and availability of mt-sDNA may be correlated with an increase in overall screening in this average-risk population.

Association of Health Care Utilization and Access to Care With Vascular Assessment Before Major Lower Extremity Amputation Among US Veterans

Importance

Patient-level characteristics alone do not account for variation in care among US veterans with peripheral artery disease (PAD). Presently, the extent to which health care utilization and regional practice variation are associated with veterans receiving vascular assessment prior to major lower extremity amputation (LEA) is unknown.

Objective

To assess whether demographics, comorbidities, distance to primary care, the number of ambulatory clinic visits (primary and medical specialty care), and geographic region are associated with receipt of vascular assessment prior to LEA.

Design, Setting, and Participants

This national cohort study used US Department of Veterans Affairs' Corporate Data Warehouse data from March 1, 2010, to February 28, 2020, for veterans aged 18 or older who underwent major LEA and who received care at Veterans Affairs facilities.

Exposures

The number of ambulatory clinic visits (primary and medical specialty care) in the year prior to LEA, geographic region of residence, and distance to primary care.

Main Outcomes and Measures

The main outcome was receipt of a vascular assessment (vascular imaging study or revascularization procedure) in the year prior to LEA.

Results

Among 19 396 veterans, the mean (SD) age was 66.78 (10.20) years and 98.5% were male. In the year prior to LEA, 8.0% had no primary care visits and 30.1% did not have a vascular assessment. Compared with veterans with 4 to 11 primary care clinic visits, those with fewer visits were less likely to receive vascular assessment in the year prior to LEA (1-3 visits: adjusted odds ratio [aOR], 0.90; 95% CI, 0.82-0.99). Compared with veterans who lived less than 13 miles from the closest primary care facility, those who lived 13 miles or more from the facility were less likely to receive vascular assessment (aOR, 0.88; 95% CI, 0.80-0.95). Veterans who resided in the Midwest were most likely to undergo vascular assessment in the year prior to LEA than were those living in other regions.

Conclusions and Relevance

In this cohort study, health care utilization, distance to primary care, and geographic region were associated with intensity of PAD treatment before LEA, suggesting that some veterans may be at greater risk of suboptimal PAD care practices. Development of clinical programs, such as remote patient monitoring and management, may represent potential opportunities to improve limb preservation rates and the overall quality of vascular care for veterans.

Mechanism of inflammasomes in cancer and targeted therapies

Inflammasomes, composed of the nucleotide-binding oligomerization domain(NOD)-like receptors (NLRs), are immune-functional protein multimers that are closely linked to the host defense mechanism. When NLRs sense pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), they assemble into inflammasomes. Inflammasomes can activate various inflammatory signaling pathways, including nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, and produce a large number of proinflammatory cytokines, which are closely associated with multiple cancers. They can also accelerate the occurrence and development of cancer by providing suitable tumor microenvironments, promoting tumor cell proliferation, and inhibiting tumor cell apoptosis. Therefore, the exploitation of novel targeted drugs against various inflammasomes and proinflammatory cytokines is a new idea for the treatment of cancer. In recent years, more than 50 natural extracts and synthetic small molecule targeted drugs have been reported to be in the research stage or have been applied to the clinic. Herein, we will overview the mechanisms of inflammasomes in common cancers and discuss the therapeutic prospects of natural extracts and synthetic targeted agents.

Emerging Tests for Noninvasive Colorectal Cancer Screening

Colorectal cancer (CRC) is among the most common cancers globally and a major cause of cancer-related deaths. The American Cancer Society estimates that CRC will kill 1 in 60 Americans, and CRC screening is recommended for all Americans ≥45 years of age. Current CRC screening methods are effective for preventing CRC and have been shown to reduce CRC-related mortality. However, none of the currently available tests is ideal, and many people are not compliant with screening recommendations. Novel screening tests based on advances in CRC molecular biology, genetics, and epigenetics, combined with developments in sequencing technologies and computational analytic methods, have been developed to address the shortcomings of current CRC screening tests. These emerging tests include blood-based assays that use plasma-derived circulating tumor DNA and serum proteins to detect early CRC and advanced adenomas, assays that use stool DNA or mRNA, and methods for profiling the gut microbiome. Here we review current screening modalities, and we discuss the principles behind the most promising emerging CRC screening tests and the data supporting their potential to be used in clinical practice.

Serrated Polyp Yield at Colonoscopy in Patients with Positive FIT, Positive mt-sDNA, and Colonoscopy Only: Data from the New Hampshire Colonoscopy Registry

BACKGROUND

Stool-based screening with fecal immunochemical (FIT) or multitarget-stool DNA (mt-sDNA) tests is associated with increased colonoscopy polyp yield. mt-sDNA includes methylated markers, which improve detection of serrated polyps (SP) versus FIT. We compared SP detection in colonoscopies performed for positive FIT or mt-sDNA tests, as well as in colonoscopies without a preceding stool test, using the New Hampshire Colonoscopy Registry, a comprehensive statewide population-based registry.

METHODS

Across the three groups, we compared the frequency of clinically relevant SPs (CRSP: sessile SPs, hyperplastic polyps ≥10 mm, and traditional serrated adenomas). We also compared SP size, histology, number, and bulk (combined sizes).

RESULTS

Our sample included 560 mt-sDNA+ (age ± SD: 66.5 ± 7.9), 414 FIT+ (age ± SD: 66.3 ± 8.8), and 59,438 colonoscopy-only patients (age ± SD: 61.7 ± 8.0). mt-sDNA+ patients were more likely to have a higher yield of CRSPs and CRSP bulk than FIT+ (P < 0.0001) or colonoscopy-only patients (P < 0.0001). More mt-sDNA+ patients had CRSPs without large adenomas or colorectal cancers (17.9% vs. 9.9% of FIT+ and 8% of colonoscopy-only patients). After adjusting for synchronous large adenomas, colorectal cancers, and other risk factors, mt-sDNA+ patients were more likely (OR, 1.82; 95% CI, 1.18-2.85) than FIT+ patients to have CRSPs.

CONCLUSIONS

mt-sDNA+ patients had a higher SP yield than FIT+ or colonoscopy-only patients, particularly in the absence of synchronous large adenomas or colorectal cancer.

IMPACT

Our results suggest that screening with mt-sDNA tests could improve colorectal cancer screening by identifying more patients at increased risk from the serrated pathway.

Patterns of initial colorectal cancer screenings after turning 50 years old and follow-up rates of colonoscopy after positive stool-based testing among the average-risk population

OBJECTIVES

Effective colorectal cancer (CRC) screening requires proper adherence beginning at the recommended screening age. For those with positive results on stool-based tests (SBTs), a follow-up colonoscopy is warranted. The objectives of this study were to 1) examine initial screening rates after turning 50 years old; and 2) assess rates of follow-up colonoscopy after a positive SBT.

METHODS

This retrospective study used de-identified administrative claims data from 01/01/2006 to 06/30/2020 for commercially insured and Medicare Advantage enrollees. For objective 1, the index year was the year enrollees turned 50. Rates of CRC screening during and after the index year were captured. For objective 2, the index date was the claim date of a fecal immunochemical test (FIT) or multitarget stool DNA test (mt-sDNA) where linked lab data indicated a positive test result. Rates and time to follow-up colonoscopy after a positive SBT were assessed.

RESULTS

Approximately 53% of enrollees initiated CRC screening within five years after turning 50 (50+ cohort N = 718,562). Among enrollees with an available lab result indicating a positive SBT (N = 7329; 2110 FIT and 5219 mt-sDNA), overall follow-up colonoscopy within 6 months of the positive result was less than optimal (65%) and varied by modality; 72% vs 46% (p < .001) among enrollees with a positive mt-sDNA test compared to FIT test, respectively.

CONCLUSION

There is potential for improving CRC screening among the eligible average-risk population, both to start screening once they reach the screening-eligible age, and to complete the CRC screening paradigm after a positive stool-based screen.

Real‐world application of a fast stool DNA test for colorectal cancer screening in primary screening positive population

BACKGROUND

Stool DNA test has been emerged as an effective noninvasive method for colorectal cancer (CRC) screening, but the real-world performance of stool DNA test in Chinese population has rarely been reported.

METHODS

A total of 36,527 subjects were recruited in Haining City from January 2021 to December 2021. Participants underwent primary screening by taking both two-samples fecal immunochemical tests (FITs) and high-risk factor questionnaire (HRFQ), and those who tested either positive by FITs or evaluated to be high risk by HRFQ were recommended to undertake subsequent stool DNA test and colonoscopy.

RESULTS

Of 36,527 participants, 34,778 (95%) completed both HRFQ and FITs, 9947 (29%) showed positive results during primary screening, and the colonoscopy compliance rate was 49%. Of primary screening positives, 8733 (88%) completed stool sample collections, and colonoscopy results from 4293 eligible participants were used for analyzing the performance of stool DNA test. The sensitivities for detecting CRC and advanced adenomas (AA) were 100% (95% CI: 60-100%) and 40% (95% CI: 34-46%), and the area under curve (AUC) was 0.961 (95% CI:0.954-0.967) and 0.625 (95% CI: 0.609-0.641), respectively. The specificity of stool DNA test was 84% (95% CI: 82-85%). The false-positive rate for stool DNA test is about 10% less than that of primary screening.

CONCLUSION

Stool DNA test is a cost-effective and promising alternative strategy for CRC screening in China.

Cost-Effectiveness of Waiving Coinsurance for Follow-Up Colonoscopy after a Positive Stool-Based Colorectal Screening Test in a Medicare Population

Commercial insurance covers a follow-up colonoscopy after a positive colorectal cancer-screening test with no patient cost-sharing. Instituting a similar policy for Medicare beneficiaries may increase screening adherence and improve outcomes. The cost-effectiveness of stool-based colorectal cancer screening was compared across adherence scenarios that assumed Medicare coinsurance status quo (20% for follow-up colonoscopy) or waived coinsurance. The CRC-AIM model simulated previously unscreened eligible Medicare beneficiaries undergoing stool-based colorectal cancer screening at age 65 for 10 years. Medicare costs, colorectal cancer cases, colorectal cancer-related deaths, life-years gained (LYG), and quality-adjusted life-years (QALY) were estimated versus no screening. Scenario 1 (S1) assumed 20% coinsurance for follow-up colonoscopy. Scenario 2 (S2) assumed waived coinsurance without adherence changes. Scenarios 3-7 (S3-S7) assumed that waiving coinsurance increased real-world stool-based screening and/or follow-up colonoscopy adherence by 5% or 10%. Sensitivity analyses assumed 1%-4% increased adherence. Cost-effectiveness threshold was ≤$100,000/QALY. Waiving coinsurance without adherence changes (S2) did not affect outcomes versus S1. S3-S7 versus S1 over 10 years estimated up to 3.6 fewer colorectal cancer cases/1,000 individuals, up to 2.1 fewer colorectal cancer deaths, up to 20.7 more LYG, and had comparable total costs per-patient (≤$6,478 vs. $6,449, respectively) as reduced colorectal cancer medical costs offset increased screening and colonoscopy costs. In sensitivity analyses, any increase in adherence after waiving coinsurance was cost-effective and increased LYG. In simulated Medicare beneficiaries, waiving coinsurance for follow-up colonoscopy after a positive stool-based test improved outcomes and was cost-effective when assumed to modestly increase colorectal cancer screening and/or follow-up colonoscopy adherence.

PREVENTION RELEVANCE

Follow-up colonoscopy after a positive stool-based test is necessary to complete the colorectal cancer-screening process. This analysis demonstrated that in a simulated Medicare population, waiving coinsurance for a follow-up colonoscopy improved estimated outcomes and was cost-effective when it was assumed that waiving the coinsurance modestly increased screening adherence. See related Spotlight, p. 641.

Methylated Septin9 has moderate diagnostic value in colorectal cancer detection in Chinese population: a multicenter study

BACKGROUND

The detection rate of methylated Septin9 (mSEPT9) in colorectal cancer (CRC) is varied greatly across the studies. This study aimed to evaluate the diagnostic ability of mSEPT9 in CRC, and compare the diagnostic efficacy with fecal immunochemical test (FIT).

METHODS

326 subjects from four centers were prospectively recruited, including 179 CRC and 147 non-CRC subjects. The plasma was collected for mSEPT9 and CEA, AFP, CA125, CA153 and CA199 test, and fecal samples for FIT tests. Sensitivity, specificity and area under the curve (AUC) of receiver operating characteristic curve were calculated to evaluate the diagnostic value of each biomarker.

RESULTS

The positive rate in mSEPT9 and FIT, and the level of CEA, CA125 and CA199 were significantly higher in CRC compared with non-CRC subjects. The mSEPT9 positive rate was not associated with TNM stage and tumor stage. The sensitivity, specificity and AUC of mSEPT9 in diagnostic CRC were 0.77, 0.88 and 0.82, respectively, while the value in FIT was 0.88, 0.80 and 0.83, respectively. mSEPT9 and FIT have higher AUC value than that of CEA, CA125 and CA199. Combination of both mSEPT9 and FIT positive increased sensitivity and AUC to 0.98 and 0.83, respectively, but the specificity was declined. mSEPT9 has a slightly low sensitivity in diagnosis of colon cancer (0.87) compared with rectal cancer (0.93).

CONCLUSION

mSEPT9 demonstrated moderate diagnostic value in CRC detection, which was similar to the FIT but superior to the CEA, CA125 and CA199. Combination of mSEPT9 and FIT further improved diagnostic sensitivity in CRC.

TRIAL REGISTRATION

ChiCTR2000038319.

Implications of the United States recommendations for early-age-at-onset colorectal cancer screening in Canada

The United States Preventive Services Task Force (USPSTF) recently issued an updated recommendation for population-based colorectal cancer (CRC) screening starting at age 45, due to a sustained increase in the incidence of early-age-at-onset CRC (eoCRC). A similar increase in the incidence of eoCRC has been observed in Canada since the early 2000s. However, the inherent differences between the US and Canadian health care systems with many different reimbursement and capacity considerations limit the applicability of the recommendations to the Canadian context. In order to facilitate further discussion around Canadian guidelines and recommendations, several research gaps need to be addressed: 1) a detailed understanding of trends in histology, topography, initial stage at diagnosis, and mortality among eoCRC; 2) a detailed analysis of cost-effectiveness outlining the impacts to the current screening programs with potential harms and benefits; 3) a comprehensive understanding of risk factor profiles that may lead to meaningful recommendations for screening decisions within the 40-49 age group in the absence of wide-spread screening programs; and 4) an evaluation of the effectiveness of current and novel screening tests or biomarkers specifically in the 40-49 age group. In the meantime, we suggest that physicians and patients begin discussions about screening at age 45 by reviewing family history and alerting patients to symptoms of CRC, which may increase screening adherence at age 50. This issue will remain an active area of debate with Canada as a careful laggard in changing recommendations, while attempting to balance system considerations with eoCRC trends and patient outcomes.