Increasing uptake of colon cancer screening in a medically underserved population with the addition of blood-based testing

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.

Blood-based colorectal cancer screening in an integrated health system: a randomised trial of patient adherence

OBJECTIVE

We evaluated whether people who had not completed a faecal immunochemical test (FIT) for colorectal cancer (CRC) screening would complete a blood-based testing option if offered one during health encounters. Blood-based screening tests for CRC could add to the total number of people screened for CRC by providing another testing alternative.

DESIGN

Study participants were patients aged 45-75 years at a large, integrated health system who were offered but did not complete an FIT in the prior 3-9 months and were scheduled for a clinical encounter. Individuals were randomised (1:1) to be offered a commercially available CRC blood test (Shield, Guardant Health) versus usual care. We compared 3-month CRC screening proportions in the two groups.

RESULTS

We randomised 2026 patients; 2004 remained eligible following postrandomisation exclusions (1003 to usual care and 1001 to blood draw offer; mean age: 60, 62% female, 80% non-Hispanic white). Of the 1001 allocated to the blood test group, 924 were recruited following chart-review exclusions; 548 (59.3%) were reached via phone, of which 280 (51.1%) scheduled an appointment with the research team. CRC screening proportions were 17.5 percentage points higher in the blood test group versus usual care (30.5% vs 13.0%; OR 2.94, 95% CI 2.34 to 3.70; p<0.001).

CONCLUSION

Among adults who had declined prior CRC screening, the offer of a blood-based screening test boosted CRC screening by 17.5 percentage points over usual care. Further research is needed on how to balance the favourable adherence with lower advanced adenoma detection compared with other available tests.

TRIAL REGISTRATION NUMBER

NCT05987709.

Description of an activity-based enzyme biosensor for lung cancer detection

BACKGROUND

Lung cancer is associated with the greatest cancer mortality as it typically presents with incurable distributed disease. Biomarkers relevant to risk assessment for the detection of lung cancer continue to be a challenge because they are often not detectable during the asymptomatic curable stage of the disease. A solution to population-scale testing for lung cancer will require a combination of performance, scalability, cost-effectiveness, and simplicity.

METHODS

One solution is to measure the activity of serum available enzymes that contribute to the transformation process rather than counting biomarkers. Protease enzymes modify the environment during tumor growth and present an attractive target for detection. An activity based sensor platform sensitive to active protease enzymes is presented. A panel of 18 sensors was used to measure 750 sera samples from participants at increased risk for lung cancer with or without the disease.

RESULTS

A machine learning approach is applied to generate algorithms that detect 90% of cancer patients overall with a specificity of 82% including 90% sensitivity in Stage I when disease intervention is most effective and detection more challenging.

CONCLUSION

This approach is promising as a scalable, clinically useful platform to help detect patients who have lung cancer using a simple blood sample. The performance and cost profile is being pursued in studies as a platform for population wide screening.

Differential impact of test performance characteristics on burden-to-benefit tradeoffs for blood-based colorectal cancer screening: A microsimulation analysis

OBJECTIVES

To inform the development and evaluation of new blood-based colorectal cancer (CRC) screening tests satisfying minimum United States (US) coverage criteria, we estimated the impact of the different test performance characteristics on long-term testing benefits and burdens.

METHODS

A novel CRC-Microsimulation of Adenoma Progression and Screening (CRC-MAPS) model was developed, validated, then used to assess different screening tests for CRC. We compared multiple, hypothetical blood-based CRC screening tests satisfying minimum coverage criteria of 74% CRC sensitivity and 90% specificity, to measure how changes in a test's CRC sensitivity, specificity, and adenoma sensitivity (sizes 1-5 mm, 6-9 mm, ≥10 mm) affect total number of colonoscopies (COL), CRC incidence reduction (IR), CRC mortality reduction (MR), and burden-to-benefit ratios (incremental COLs per percentage-point increase in IR or MR).

RESULTS

A blood test meeting minimum US coverage criteria for performance characteristics resulted in 1576 lifetime COLs per 1000 individuals, 46.7% IR and 59.2% MR compared to no screening. Tests with increased CRC sensitivity of 99% ( + 25%) vs. increased ≥10 mm adenoma sensitivity of 13.6% ( + 3.6%) both yielded the same MR, 62.7%. Test benefits improved the most with increases in all-size adenoma sensitivity, then size-specific adenoma sensitivities, then specificity and CRC sensitivity, while increases in specificity or ≥10 mm adenoma sensitivity resulted in the most favorable burden-to-benefit tradeoffs (ratios <11.5).

CONCLUSIONS

Burden-to-benefit ratios for blood-based CRC screening tests differ by performance characteristic, with the most favorable tradeoffs resulting from improvements in specificity and ≥10 mm adenoma sensitivity.

Barriers and facilitators of colorectal cancer screening using the 5As framework: A systematic review of US studies

Despite clear evidence that regular screening reduces colorectal cancer (CRC) mortality and the availability of multiple effective screening options, CRC screening continues to be underutilized in the US. A systematic literature search of four databases - Ovid, Medline, EBSCHOhost, and Web of Science - was conducted to identify US studies published after 2017 that reported on barriers and facilitators to CRC screening adherence. Articles were extracted to categorize relevant CRC screening barriers or facilitators that were assessed against CRC screening outcomes using the 5As dimensions: Access, Affordability, Acceptance, Awareness, Activation. Sixty-one studies were included. Fifty determinants of screening within the 5As framework and two additional dimensions including Sociodemographics and Health Status were identified. The Sociodemographics, Access, and Affordability dimensions had the greatest number of studies included. The most common factor in the Access dimension was contact with healthcare systems, within the Affordability dimension was insurance, within the Awareness dimension was knowledge CRC screening, within the Acceptance dimension was health beliefs, within the Activation dimension was prompts and reminders, within the Sociodemographics dimension was race/ethnicity, and among the Health Status dimension was chronic disease history. Among all studies, contact with healthcare systems, insurance, race/ethnicity, age, and education were the most common factors identified. CRC screening barriers and facilitators were identified across individual, clinical, and sociocontextual levels. Interventions that consider multilevel strategies will most effectively increase CRC screening adherence.

Progress in the field of noninvasive diagnostics for colorectal cancer: a systematic review for the accuracy of blood-based biomarkers for detection of advanced pre-cancerous lesions

BACKGROUND

Early detection of pre-cancerous adenomas through screening can reduce colorectal cancer (CRC) incidence. Fecal immunochemical tests are commonly used, but have limited sensitivity for pre-cancerous lesions. Blood-based screening may improve test sensitivity. This systematic review and meta-analysis was conducted to evaluate the accuracy of blood-based biomarkers for detection of advanced pre-cancerous lesions.

RESEARCH DESIGN AND METHODS

We present the accuracy of blood-based biomarkers for the detection of advanced pre-cancerous lesions. EMBASE, Web of Science and PubMed databases were searched, with study populations limited to adults diagnosed with advanced pre-cancerous lesions at colonoscopy, who had a blood-based biomarker test analyzed with reports of sensitivity and specificity.

RESULTS

69 studies were identified, which assessed 133 unique biomarkers sets. The best performing test was a panel of 6 miRNAs, with a sensitivity of 95% and specificity of 90% for advanced pre-cancerous lesions. Only 6 biomarkers demonstrated sensitivity ≥ 50% and specificity ≥ 90% for the detection of advanced pre-cancerous lesions.

CONCLUSION

Many different blood-based biomarkers have been assessed for detection of advanced pre-cancerous lesions, but few have progressed beyond the discovery stage. While some biomarkers have reported high sensitivity and specificity, larger prospective studies in unbiased intended-use screening populations are required for validation.

Analysis of a Community Health Screening Program and the Factors Affecting Access to Care

Introduction Free community health fairs and screening initiatives can be effective in broadening access to care and improving health outcomes in historically marginalized communities. UTHealthCares is a community health-focused organization developed at the University of Texas Health Science Center in Houston. At the beginning of 2023, UTHealthCares oversaw a free community health fair in the Eastex-Jensen Area - a medically underserved area in Northeast Houston. The health fair consisted of four stations - vitals and body mass index collection, vision screening, blood glucose screening, and dental screening. Participants also received coronavirus disease 2019 vaccinations, referrals, and health education. The purpose of this study is to evaluate the effectiveness of the UTHealthCares community health fair while assessing the factors that influence participants' access to medical care. Methods After completing the health fair, participants filled out an optional questionnaire. The questionnaire contained items that assessed satisfaction with the health fair, improvements in managing health, and access to resources. We calculated descriptive statistics, including mean response and 95% confidence intervals for rating scale questions. We used the chi-squared test to evaluate the independence of categorical variables and the Mann-Whitney U test to evaluate differences in means between distributions. Results A total of 111 people participated in the health fair, 91 of which completed a questionnaire. When participants rated their satisfaction with the health fair, the average response was 4.62 out of five. Participants also reported that they were more comfortable managing areas of health related to the stations offered at the fair. Many participants reported limited access to fresh food and long travel times to the physician. Participants that traveled further to reach one resource also tended to have significantly higher travel times for the other: X2 (4, N=78)=28.04, p<0.0001. However, 77.8% of respondents reported that the lack of insurance or cost was their greatest barrier to seeing a medical provider, while only 2.47% reported the lack of transportation as their greatest barrier. Participants who reported having health insurance also had a significantly higher probability of visiting a medical provider when they had a health issue: U=928.5, p=0.0006. Conclusion Overall, participants reported high satisfaction with the health fair. Participants also gave valuable feedback for improving future community health initiatives. Although many participants reported travel times greater than 30 minutes to reach community resources, very few participants indicated that transportation was their largest barrier to accessing medical care. Instead, the lack of insurance and high costs seem to be participants' most significant hindrances. Therefore, interventions in the Eastex-Jensen area focused on expanding access to care should also include components that improve access to insurance.

Acceptability of alternative technologies compared with faecal immunochemical test and/or colonoscopy in colorectal cancer screening: A systematic review

OBJECTIVE

Colorectal cancer (CRC) is the third most common cancer and the second largest cause of cancer-related death worldwide. Current CRC screening in various countries involves stool-based faecal immunochemical testing (FIT) and/or colonoscopy, yet public uptake remains sub-optimal. This review assessed the literature regarding acceptability of alternative CRC screening modalities compared to standard care in average-risk adults.

METHOD

Systematic searches of MEDLINE, EMBASE, CINAHL, Cochrane and Web of Science were conducted up to February 3^rd, 2022. The alternative interventions examined were computed tomography colonography, flexible sigmoidoscopy, colon capsule endoscopy and blood-based biomarkers. Outcomes for acceptability were uptake, discomfort associated with bowel preparation, discomfort associated with screening procedure, screening preferences and willingness to repeat screening method. A narrative data synthesis was conducted.

RESULTS

Twenty-one studies met the inclusion criteria. Differences between intervention and comparison modalities in uptake did not reach statistical significance in most of the included studies. The findings do suggest FIT as being more acceptable as a screening modality than flexible sigmoidoscopy. There were no consistent significant differences in bowel preparation discomfort, screening procedure discomfort, screening preference and willingness to repeat screening between the standard care and alternative modalities.

CONCLUSION

Current evidence comparing standard colonoscopy and stool-based CRC screening with novel modalities does not demonstrate any clear difference in acceptability. Due to the small number of studies available and included in each screening comparison and lack of observed differences, further research is needed to explore factors influencing acceptability of alternative CRC modalities that might result in improvement in population uptake within different contexts.