Patterns and predictors of repeat fecal immunochemical and occult blood test screening in four large health care systems in the United States

Adherence to mt-sDNA testing for colorectal cancer screening among new users in a US Black population

OBJECTIVE

Colorectal cancer (CRC) poses significant mortality risks, particularly among Black individuals, who experience the highest CRC incidence and mortality rates in the United States. This study examined adherence to multi-target stool DNA (mt-sDNA) testing in this population.

METHODS

This retrospective cohort analysis used Exact Sciences Laboratories (ESL)-linked claims data from January 2017 to December 2023 on Black patients in the United States aged 45 and older. High-risk individuals, those with payers other than commercial plans, managed care organizations, Medicare Advantage, Medicaid, or Medicare, and individuals with mt-sDNA prescriptions outside the study period were excluded. Adherence was defined as the percentage of patients returning the test kit with valid results within 365 days of shipment. Logistic regression analysis was used to identify factors associated with adherence.

RESULTS

Among 434,951 patients included in the study, the overall adherence to mt-sDNA testing was 62.0% (N = 266,981), with a mean time to adherence of 27.6 days (SD = 44.17). Females, older adults (76+ years), and non-metropolitan residents had higher adherence than males, younger adults, and metropolitan patients (all p < 0.001), respectively. Patients with orders from GI specialists had higher adherence than other prescribing clinicians (NP/PA: OR = 0.39, OB/GYN: OR = 0.54, Other: OR = 0.38, PCP: OR = 0.50; all p < 0.001). Digital outreach, especially SMS and email combination, was also associated with higher adherence (OR = 1.25, p < 0.001).

CONCLUSIONS

This large, national study found a 62.0% adherence rate to mt-sDNA testing among Black individuals. Higher adherence was associated with being female, older age, non-metropolitan residence, and digital outreach. While the findings highlight the promise of mt-sDNA, further research is needed to explore its full potential in improving CRC screening adherence across different demographic groups.

Re-screening adherence to multi-target stool DNA test for colorectal cancer: real-world study in a large national population

PURPOSE

Adherence to colorectal cancer (CRC) re-screening is essential to maximize screening effectiveness. This study assessed adherence to a multi-target stool DNA (mt-sDNA) test among previous users in the USA across different payer types.

METHODS

Data from Exact Sciences Laboratories LLC (01/01/2023-12/31/2023) were used. Insured patients (45-85 years) who were shipped an mt-sDNA test during the data coverage period and had previously completed mt-sDNA screening with a negative result ≥ 2.5 years prior were included. Mt-sDNA re-screening adherence rate and mean time to test return were compared across payer types, and their associations with patient characteristics were assessed using multivariable regression models.

RESULTS

Of 793,567 patients (50-75 years: 89.0%; female: 62.0%), the re-screening adherence rate was 84.0% (from 66.5% for Medicaid to 90.2% for Medicare); mean (standard deviation) time to test return was 20.7 (20.8) days (from 19.2 [19.7] for Medicare to 22.4 [22.2] for Medicaid). Characteristics associated with higher likelihood of re-screening adherence included older ages (odds ratio [OR] = 1.25 and 1.11 for 65-75 and 76-85 years, respectively, relative to 45-49 years), living in a ZIP code with higher median household income (OR = 1.80 for > $200,000 relative to < $50,000), full digital outreach (OR = 1.84 relative to no digital outreach), and ≥ 3rd rounds of screening (OR = 2.44 relative to 2nd round of screening).

CONCLUSION

Adherence to CRC re-screening with mt-sDNA test was high across payer types, with sustained adherence in later rounds of screening. Strategies to improve re-screening rates in subgroups associated with lower re-screening adherence are warranted.

Utility of Stool-Based Tests for Colorectal Cancer Detection: A Comprehensive Review

Colorectal cancer (CRC) is a significant global health issue where early detection is crucial for improving treatment outcomes and survival rates. This comprehensive review assesses the utility of stool-based tests in CRC screening, including traditional fecal occult blood tests (FOBT), both chemical (gFOBT) and immunochemical techniques (FIT), as well as multitarget stool DNA (mt-sDNA) as a novel and promising biomarker. The advancements, limitations and the impact of false positives and negatives of these methods are examined. The review analyzed various studies on current screening methods, focusing on laboratory tests and biomarkers. Findings indicate that while FIT and mt-sDNA tests offer enhanced sensitivity and specificity over traditional guaiac-based FOBT, they also come with higher costs and potential for increased false positives. FIT shows better patient adherence due to its ease to use, but incorrect usage and interpretation of FOBT can lead to significant diagnostic errors. In conclusion, despite the improvements in FOBT methods like FIT in CRC detection, careful consideration of each method's benefits and drawbacks is essential. Effective CRC screening programs should combine various methods tailored to specific population needs, aiming for early detection and reduced mortality rates.

Improving Colorectal Cancer Screening in a Regional Safety-Net Health System over a 10-Year Period: Lessons for Population Health

BACKGROUND

Despite national policy efforts to increase colorectal cancer (CRC) screening, rates in vulnerable populations remain suboptimal. Many types of interventions have been employed, but their impact on improving population-level rates of CRC screening over time is uncertain.

OBJECTIVE

Assess the impact of 10 years of different in-reach and outreach strategies to improve CRC screening and identify factors associated with being screen up-to-date (SUTD).

DESIGN

Observational cohort study.

PARTICIPANTS

Patients aged 50-74 years from 12 community-based primary care clinics in an integrated, regional safety-net health system.

INTERVENTIONS

Multiple system-level interventions were implemented over time (visit-based electronic health record [EHR] reminders, quality measurement, annual preventive service letters, and mailed fecal immunohistochemical stool tests [FIT]).

MAIN MEASURES

CRC SUTD rates by calendar year among those with a primary care (PC) visit in the prior 1 and 3 years and their multivariable correlates.

KEY RESULTS

The sample included 31,786-40,405 patients/year. In 2011, mean age was 58.9, 63.9% were women, 37.0% were Hispanic, 39.3% Black, 16.8% White, and 6.6% Asian/Other, and 60.5% were uninsured/Medicaid. Three-quarters of patients had ≥ 1 PC visit in the prior year. Lower-intensity interventions (EHR reminders, quality measurement, annual prevention letters) had limited impact on SUTD rates (2-3% rise). Implementing system-wide mailed FIT increased rates from 51.2 to 61.9% among those with a PC visit in the past year (40.5 to 46.8% with a PC visit ≤ 3 years). Stopping mailed FIT due to COVID wiped out these gains. Higher screening rates were associated with the following: older age; female; more comorbidities, PC clinic visits, and prior FITs; and better insurance coverage. Hispanics had the highest SUTD rates followed by Asians, Blacks, and Whites (p < 0.05).

CONCLUSIONS

Implementation of a system-wide mailed FIT program had the greatest impact on SUTD rates. Lower-intensity interventions (EHR reminders, quality measurement, and patient letters) had limited effects.

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.

Cost Effectiveness of Mailed Outreach Programs for Colorectal Cancer Screening: Analysis of a Pragmatic, Randomized Trial

BACKGROUND & AIMS

Clinical guidelines for colorectal cancer (CRC) screening suggest use of either stool-based tests or colonoscopy - modalities that differ in recommended screening intervals, adherence, and costs. We know little about the long-term cost differences in population-health outreach strategies to promote these strategies.

METHODS

We conducted a cost-effectiveness analysis to compare 2 mailed outreach strategies to increase CRC screening from a pragmatic, randomized clinical trial: mailed fecal immunochemical test (FIT) kits vs invitations to complete a screening colonoscopy. We built a 10-year Markov chain Monte Carlo microsimulation model to account for differences in screening intervals, adherence, and costs.

RESULTS

Mailed FIT kits had a lower 10-year average per-person cost of screening relative to colonoscopy invitations ($1139 vs $1725) but with 10.89 fewer months of compliance and 60 fewer advanced neoplasia detected (37 advanced adenomas and 23 CRC). Incremental cost effectiveness ratios for colonoscopy invitations compared with mailed FIT kits were $55.23, $15.84, and $25.48 per additional covered month, advanced adenoma, and CRC, respectively. Although FIT was the preferred strategy at low willingness-to-pay thresholds, the 2 strategies were equal at a willingness-to-pay threshold of $41.31 per covered month gained.

CONCLUSION

Mailed FIT or colonoscopy invitations are both options to improve CRC screening completion and advanced neoplasia detection, and the choice of outreach strategy may differ by a health system's willingness-to-pay threshold. Mailed FIT kits are less expensive than colonoscopy invitations but result in fewer months of screening compliance and advanced neoplasia detected.

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

BACKGROUND AND AIMS

Screening for colorectal cancer (CRC) can effectively reduce CRC incidence and mortality. Besides colonoscopy, tests for the detection of biomarkers in stool, blood, or serum, including the fecal immunochemical test (FIT), ColoGuard, Epi proColon, and PolypDx, have recently been advanced. We aimed to identify the characteristics of theoretic, highly efficient screening tests and calculated the effectiveness and cost effectiveness of available screening tests.

METHODS

Using the microsimulation-based colon modeling open-source tool (CMOST), we simulated 142,501 theoretic screening tests with variable assumptions for adenoma and carcinoma sensitivity, specificity, test frequency, and adherence, and we identified highly efficient tests outperforming colonoscopy. For available screening tests, we simulated 10 replicates of a virtual population of 2 million individuals, using epidemiologic characteristics and costs assumptions of the United States.

RESULTS

Highly efficient theoretic screening tests were characterized by high sensitivity for advanced adenoma and carcinoma and high patient adherence. All simulated available screening tests were effective at 100% adherence to screening and at expected real-world adherence rates. All tests were cost effective below the threshold of 100,000 U.S. dollars per life year gained. With perfect adherence, FIT was the most effective and cost-efficient intervention, whereas Epi proColon was the most effective at expected real-world adherence rates. In our sensitivity analysis, assumptions for patient adherence had the strongest impact on effectiveness of screening.

CONCLUSIONS

Our microsimulation study identified characteristics of highly efficient theoretic screening tests and confirmed the effectiveness and cost-effectiveness of colonoscopy and available urine-, blood-, and stool-based tests. Better patient adherence results in superior effectiveness for CRC prevention in the whole population.

Measures of longitudinal adherence to fecal-based colorectal cancer screening: Literature review and recommended approaches

The success of fecal occult blood-based colorectal cancer screening programs is dependent on repeating screening at short intervals (ie, every 1-2 years). We conducted a literature review to assess measures that have been used to assess longitudinal adherence to fecal-based screening. Among 46 citations identified and included in this review, six broad classifications of longitudinal adherence were identified: (a) stratified single-round attendance, (b) all possible adherence permutations, (c) consistent/inconsistent/never attendance, (d) number of times attended, (e) program adherence and (f) proportion of time covered. Advantages and disadvantages of these measures are described, and recommendations on which measures to use based on data availability and scientific question are also given. Stratified single round attendance is particularly useful for describing the yield of screening, while programmatic adherence measures are best suited to evaluating screening efficacy. We recommend that screening programs collect detailed longitudinal, individual-level data, not only for the screening tests themselves but additionally for diagnostic follow-up and surveillance exams, to allow for maximum flexibility in reporting adherence patterns using the measure of choice.

Low Rate of Cancer Detection by Colonoscopy in Asymptomatic, Average-Risk Subjects with Negative Results From Fecal Immunochemical Tests

BACKGROUND & AIMS

Screening colonoscopies are of uncertain benefit for persons with negative results from a fecal immunochemical test (FIT). We investigated detection of CRC by colonoscopy in asymptomatic, average-risk, FIT-negative subjects.

METHODS

We conducted a retrospective, population-based cohort study of 96,804 subjects with an initial negative result from a FIT at ages 50-75 years, from 2008 through 2014, who then underwent colonoscopy, using the Kaiser Permanente California databases. We identified participants diagnosed with CRC from January 1, 2008 through December 31, 2015 from a cancer registry. Subjects were followed until initial colonoscopy, health plan disenrollment, death, or December 31, 2015. We reviewed records from 400 randomly selected persons without CRC (controls) for risk features to estimate the proportion who underwent screening colonoscopy. We performed logistic regression to identify variables associated with CRC detection.

RESULTS

Of 257 subjects with a diagnosis of CRC, 102 did not have a record of CRC risk factors; 86 of these patients (84.3%) had non-advanced-stage CRC (no regional node spread/distant metastases). Of the 400 controls, 299 (74.75%; 95% CI, 70.49%-79.01%) lacked CRC risk features, enabling estimation that 72,263 (mean age, 57.5 ± 7.0 y; 54.5% female) had undergone screening colonoscopy. CRC was detected in 1.4 per 1000 persons after 1 FIT, without association with increasing FITs (P = .97). CRC was detected in 1.3 per 1000 persons in 2 y or less after the last FIT and in 4.4 per 1000 persons more than 2 y after the last FIT (P < .001). When the last FIT was 2 y earlier or less, CRC increased from 0.7 per 1000 persons age 50-59 y to 3.1 per 1000 persons older than 70 y. Age and time from the last FIT were associated with CRC, with adjusted odds ratios of 1.08 (95% CI, 1.05-1.11) and 2.76 (95% CI, 1.28-5.95), respectively.

CONCLUSIONS

In asymptomatic, average-risk persons with a negative result from a FIT, CRC is infrequent within 2 y after the last FIT (especially for persons younger than 60 y), usually non-advanced, and unrelated to the number of FITs performed.

Framework and Strategies to Eliminate Disparities in Colorectal Cancer Screening Outcomes

Preventable differences in colorectal cancer (CRC) mortality across racial/ethnic, economic, geographic, and other groups can be eliminated by assuring equitable access and quality across the care continuum, but few interventions have been demonstrated to do so. Multicomponent strategies designed with a health equity framework may be effective. A health equity framework takes into account social determinants of health, multilevel influences (policy, community, delivery, and individual levels), screening processes, and community engagement. Effective strategies for increasing screening uptake include patient navigation and other interventions for structural barriers, reminders and clinical decision support, and data to continuously track metrics and guide targets for improvement. Community resource gaps should be addressed to assure high-quality services irrespective of racial/ethnic and socioeconomic status. One model combinespopulation-based proactive outreach screening with screening delivery at in-person or virtual points of contact, as well as community engagement. Patient- and provider-based behavioral interventions may be considered for increasing screening demand and delivery. Providing a choice of screening tests is recommended for CRC screening, and access to colonoscopy is required for completion of the CRC screening process.

Primary Care Provider Beliefs and Recommendations About Colorectal Cancer Screening in Four Healthcare Systems

Primary care provider's (PCP) perceptions of colorectal cancer screening test effectiveness and their recommendations for testing intervals influence patient screening uptake. Few large studies have examined providers' perceptions and recommendations, including their alignment with evidence suggesting comparable test effectiveness and guideline recommendations for screening frequency. Providers (n = 1,281) within four healthcare systems completed a survey in 2017-2018 regarding their perceptions of test effectiveness and recommended intervals for colonoscopy and fecal immunochemical testing (FIT) for patients ages 40-49, 50-74, and ≥75 years. For patients 50-74 (screening eligible), 82.9% of providers rated colonoscopy as very effective versus 59.6% for FIT, and 26.3% rated colonoscopy as more effective than FIT. Also, for this age group, 77.9% recommended colonoscopy every 10 years and 92.4% recommended FIT annually. For patients ages 40-49 and ≥75, more than one-third of providers believed the tests were somewhat or very effective, although >80% did not routinely recommend screening by either test for these age groups. Provider screening test interval recommendations generally aligned with colorectal cancer guidelines; however, 25% of providers believed colonoscopy was more effective than FIT for mortality reduction, which differs from some modeling studies that suggest comparable effectiveness. The latter finding may have implications for health systems where FIT is the dominant screening strategy. Only one-third of providers reported believing these screening tests were effective in younger and older patients (i.e., <50 and ≥75 years). Evidence addressing these beliefs may be relevant if cancer screening recommendations are modified to include older and/or younger patients.

Mailed fecal immunochemical test outreach for colorectal cancer screening: Summary of a Centers for Disease Control and Prevention-sponsored Summit

Uptake of colorectal cancer screening remains suboptimal. Mailed fecal immunochemical testing (FIT) offers promise for increasing screening rates, but optimal strategies for implementation have not been well synthesized. In June 2019, the Centers for Disease Control and Prevention convened a meeting of subject matter experts and stakeholders to answer key questions regarding mailed FIT implementation in the United States. Points of agreement included: 1) primers, such as texts, telephone calls, and printed mailings before mailed FIT, appear to contribute to effectiveness; 2) invitation letters should be brief and easy to read, and the signatory should be tailored based on setting; 3) instructions for FIT completion should be simple and address challenges that may lead to failed laboratory processing, such as notation of collection date; 4) reminders delivered to initial noncompleters should be used to increase the FIT return rate; 5) data infrastructure should identify eligible patients and track each step in the outreach process, from primer delivery through abnormal FIT follow-up; 6) protocols and procedures such as navigation should be in place to promote colonoscopy after abnormal FIT; 7) a high-quality, 1-sample FIT should be used; 8) sustainability requires a program champion and organizational support for the work, including sufficient funding and external policies (such as quality reporting requirements) to drive commitment to program investment; and 9) the cost effectiveness of mailed FIT has been established. Participants concluded that mailed FIT is an effective and efficient strategy with great potential for increasing colorectal cancer screening in diverse health care settings if more widely implemented.

Pilot study of the effect of gastrointestinal diets on fecal occult blood testing in cats

OBJECTIVES

The aim of this study was to assess the methodology of guaiac-based fecal occult blood (FOB) testing in healthy cats, and to examine the effect of feeding selected gastrointestinal diets (canned and dry) on FOB results.

METHODS

Stool obtained from three cats was mixed with incremental quantities of EDTA whole blood. FOB tests were performed in triplicate and interpreted at 5 mins, and at 24, 48 and 72 h post-test set-up. Ten cats were fed their normal diets, a dry hydrolyzed protein diet, a dry gastrointestinal diet and then transitioned back to their normal diet over a 7-week period. A subsequent study was repeated with similar hydrolyzed protein and gastrointestinal canned diets. Two fecal samples were tested per cat each week using human point-of-care guaiac tests.

RESULTS

Ten microliters of whole feline blood could be reliably detected in feline stool at all time points evaluated. There was no evidence of an association between the dry hydrolyzed and dry gastrointestinal diets and a positive FOB test result (P = 0.33). Cats fed a canned gastrointestinal diet had a significantly higher probability of producing a positive FOB result than when on their normal diet (P <0.01). Feeding the canned hydrolyzed diet was not associated with an increased probability of a positive FOB test vs the normal diet (P = 0.94).

CONCLUSIONS AND RELEVANCE

Small amounts of blood in feline stool can be reliably and repeatedly detected as early as 5 mins post-FOB test set-up, making this a user-friendly bench-top screening test in a veterinary setting. Cats fed a single dry hydrolyzed, dry gastroenteric or canned hydrolyzed diet in this study had a low chance of false-positive FOB test results, while those fed the canned gastrointestinal diet had a significantly greater likelihood of producing false-positive results.

Making FIT Count: Maximizing Appropriate Use of the Fecal Immunochemical Test for Colorectal Cancer Screening Programs

Colorectal cancer (CRC) remains one of the most common and deadly malignancies despite advancements in screening, diagnostic capabilities, and treatment. The ability to detect and remove precancerous and cancerous lesions via screening has altered the epidemiology of the disease, decreasing incidence, mortality, and late-stage disease presentation. The fecal immunochemical test (FIT) is a screening test that aims to detect human hemoglobin in the stool. FIT is the most common CRC screening modality worldwide and second most common in the United States. Its use in screening programs has been shown to increase screening uptake and improve CRC outcomes. However, FIT-based screening programs vary widely in quality and effectiveness. In health systems with high-quality FIT screening programs, only superior FIT formats are used, providers order FIT appropriately, annual patient participation is high, and diagnostic follow-up after an abnormal result is achieved in a timely manner. Proper utilization of FIT involves multiple steps beyond provider recommendation of the test. In this commentary, we aim to highlight ongoing challenges in FIT screening and suggest interventions to maximize FIT effectiveness. Through active engagement of patients and providers, health systems can use FIT to help optimize CRC screening rates and improve CRC outcomes.

Challenges and Approaches to Measuring Repeat Fecal Immunochemical Test for Colorectal Cancer Screening

BACKGROUND

Colorectal cancer screening with fecal immunochemical testing (FIT) can reduce colorectal cancer-related mortality. Effectiveness of FIT may be compromised when patients do not adhere to a regular schedule. However, having no standard measure of repeat FIT presents challenges for assessing effectiveness across populations and settings. We compared three measures of repeat FIT in a large, integrated health care system in Dallas, Texas.

METHODS

We identified 18,257 patients age-eligible (50-60 years) for FIT in January 1-December 31, 2010 and followed over four rounds of screening. Measures included: (i) repeat FIT in prior screeners, or completion of FIT within 9-15 months of the previous; (ii) yes-no patterns, whereby patients were assigned yes or no in 9-15 month windows; and 3) proportion of time covered (PTC), or the amount of time patients were up-to-date with screening relative to time eligible.

RESULTS

Repeat FIT varied by measure. Using a prior screeners measure, 15.8% of patients with a normal FIT in round 1 completed repeat FIT in round 2. Repeat FIT was notably higher (52.3%) using PTC. The most common yes-no pattern was YNNN or "one-and-done," and only 9.4% of patients completed two consecutive FITs across all rounds (YYNN).

CONCLUSIONS

Different measures of repeat FIT yielded a range of estimates, making comparison across studies difficult. Researchers should weigh the advantages and disadvantages of each measure and select the most appropriate to their research question.

IMPACT

Our study highlights the need for future research of repeat FIT measures that best approximate screening effectiveness.

A Systematic Review of Repeat Fecal Occult Blood Tests for Colorectal Cancer Screening

Screening with fecal occult blood tests (FOBT) reduces colorectal cancer mortality. Failure to complete repeat tests may compromise screening effectiveness. We conducted a systematic review of repeat FOBT across diverse health care settings. We searched MEDLINE, Embase, and the Cochrane Library for studies published from 1997 to 2017 and reported repeat FOBT over ≥2 screening rounds. Studies (n = 27 reported in 35 articles) measured repeat FOBT as (i) proportion of Round 1 participants completing repeat FOBT in Round 2; (ii) proportion completing two, consecutive FOBT; or (iii) proportion completing ≥3 rounds. Among those who completed FOBT in Round 1, 24.6% to 89.6% completed repeat FOBT in Round 2 [median: 82.0%; interquartile range (IQR): 73.7%-84.6%]. The proportion completing FOBT in two rounds ranged from 16.4% to 80.0% (median: 46.6%; IQR: 40.5%-50.0%), and in studies examining ≥3 rounds, repeat FOBT ranged from 0.8% to 64.1% (median: 39.2%; IQR: 19.7%-49.4%). Repeat FOBT appeared higher in mailed outreach (69.1%-89.6%) compared with opportunistic screening (24.6%-48.6%). Few studies examined correlates of repeat FOBT. In summary, we observed a wide prevalence of repeat FOBT, and prevalence generally declined in successive screening rounds. Interventions that increase and maintain participation in FOBT are needed to optimize effectiveness of this screening strategy.

Comparative effectiveness and cost-effectiveness analysis of a urine metabolomics test vs. alternative colorectal cancer screening strategies

PURPOSE

Despite the success of provincial screening programs, colorectal cancer (CRC) is still the third most common cancer in Canada and the second most common cause of cancer-related death. Fecal-based tests, such as fecal occult blood test (FOBT) and fecal immunochemical test (FIT), form the foundation of the provincial CRC screening programs in Canada. However, those tests have low sensitivity for CRC precursors, adenomatous polyps and have low adherence. This study evaluated the effectiveness and cost-effectiveness of a new urine metabolomic-based test (UMT) that detects adenomatous polyps and CRC.

METHODS

A Markov model was designed using data from the literature and provincial healthcare databases for Canadian at average risk for CRC; calibration was performed against statistics data. Screening strategies included the following: FOBT every year, FIT every year, colonoscopy every 10 years, and UMT every year. The costs, quality adjusted life years (QALY) gained, and incremental cost-effectiveness ratios (ICERs) for each strategy were estimated and compared.

RESULTS

Compared with no screening, a UMT strategy reduced CRC mortality by 49.9% and gained 0.15 life years per person at $42,325/life year gained in the base case analysis. FOBT reduced CRC mortality by 14.9% and gained 0.04 life years per person at $25,011/life year gained. FIT reduced CRC mortality by 35.8% and gained 0.11 life years per person at $25,500/life year while colonoscopy reduced CRC mortality by 24.7% and gained 0.08 life years per person at $50,875/life year.

CONCLUSIONS

A UMT strategy might be a cost-effective strategy when used in programmatic CRC screening programs.

Urinary Metabolomics to Identify a Unique Biomarker Panel for Detecting Colorectal Cancer: A Multicenter Study

BACKGROUND

Population-based screening programs are credited with earlier colorectal cancer diagnoses and treatment initiation, which reduce mortality rates and improve patient health outcomes. However, recommended screening methods are unsatisfactory as they are invasive, are resource intensive, suffer from low uptake, or have poor diagnostic performance. Our goal was to identify a urine metabolomic-based biomarker panel for the detection of colorectal cancer that has the potential for global population-based screening.

METHODS

Prospective urine samples were collected from study participants. Based upon colonoscopy and histopathology results, 342 participants (colorectal cancer, 171; healthy controls, 171) from two study sites (Canada, United States) were included in the analyses. Targeted liquid chromatography-mass spectrometry (LC-MS) was performed to quantify 140 highly valuable metabolites in each urine sample. Potential biomarkers for colorectal cancer were identified by comparing the metabolomic profiles from colorectal cancer versus controls. Multiple models were constructed leading to a good separation of colorectal cancer from controls.

RESULTS

A panel of 17 metabolites was identified as possible biomarkers for colorectal cancer. Using only two of the selected metabolites, namely diacetylspermine and kynurenine, a predictor for detecting colorectal cancer was developed with an AUC of 0.864, a specificity of 80.0%, and a sensitivity of 80.0%.

CONCLUSIONS

We present a potentially "universal" metabolomic biomarker panel for colorectal cancer independent of cohort clinical features based on a North American population. Further research is needed to confirm the utility of the profile in a prospective, population-based colorectal cancer screening trial.

IMPACT

A urinary metabolomic biomarker panel was identified for colorectal cancer with the potential of clinical application.

Factors Affecting Adherence in a Pragmatic Trial of Annual Fecal Immunochemical Testing for Colorectal Cancer

BACKGROUND

Colorectal cancer screening by fecal immunochemical test (FIT) reduces the burden of colorectal cancer. However, effectiveness relies on annual adherence, which presents challenges for clinic staff and patients.

OBJECTIVE

Describe FIT return rates and identify factors associated with FIT adherence over 2 years in a mailed FIT outreach program in federally qualified health centers.

DESIGN

Observational study nested in the Strategies and Opportunities to Stop Colon Cancer in Priority Populations (STOP CRC) trial. Five thousand one hundred ninety-five patients had an initial FIT order and were followed for ≥ 2 years (3574 also had a FIT order in the second year).

MAIN MEASURES

FIT return percent in each year and patient- and neighborhood-level characteristics associated with FIT adherence.

KEY RESULTS

Overall, the proportion of FIT orders that were completed was 46% in the patients' first year and 41% in the patients' second year. Of the 5195 patients with a FIT order in year 1, 3574 (69%) also had a FIT order in year 2 (71% of year 1 adherers and 67% of year 1 non-adherers, p = 0.009). Among those with a FIT order in the second year, the FIT return rate was about twice as high among those who were adherent in the first year (952/1674, or 57%) as among those who were not (531/1900, or 28%, p < 0.0001). Patient-level characteristics associated with higher odds of FIT return were a history of FIT screening at baseline, age over 65 (vs 50-65), no current tobacco use, recent receipt of a mammogram or flu vaccine, Asian ancestry (compared to non-Hispanic white), and non-English preference. The only neighborhood factor associated with lower FIT return rate was patient's larger residential city size.

CONCLUSION

Our findings can inform the customization of programs to promote FIT return among patients who receive care at federally qualified health centers.

TRIAL REGISTRATION

http://www.clinicaltrials.gov.

Influence of Varying Quantitative Fecal Immunochemical Test Positivity Thresholds on Colorectal Cancer Detection: A Community-Based Cohort Study

Background

The fecal immunochemical test (FIT) is commonly used for colorectal cancer (CRC) screening. Despite demographic variations in stool hemoglobin concentrations, few data exist regarding optimal positivity thresholds by age and sex.

Objective

To identify programmatic (multitest) FIT performance characteristics and optimal FIT quantitative hemoglobin positivity thresholds in a large, population-based, screening program.

Design

Retrospective cohort study.

Setting

Kaiser Permanente Northern and Southern California.

Participants

Adults aged 50 to 75 years who were eligible for screening and had baseline quantitative FIT results (2013 to 2014) and 2 years of follow-up. Nearly two thirds (411 241) had FIT screening in the previous 2 years.

Measurements

FIT programmatic sensitivity for CRC and number of positive test results per cancer case detected, overall and by age and sex.

Results

Of 640 859 persons who completed a baseline FIT and were followed for 2 years, 481 817 (75%) had at least 1 additional FIT and 1245 (0.19%) received a CRC diagnosis. Cancer detection (programmatic sensitivity) increased at lower positivity thresholds, from 822 in 1245 (66.0%) at 30 µg/g to 925 (74.3%) at 20 µg/g and 987 (79.3%) at 10 µg/g; the number of positive test results per cancer case detected increased from 43 at 30 µg/g to 52 at 20 µg/g and 85 at 10 µg/g. Reducing the positivity threshold from 20 to 15 µg/g would detect 3% more cancer cases and require 23% more colonoscopies. At the conventional FIT threshold of 20 µg/g, programmatic sensitivity decreased with increasing age (79.0%, 73.4%, and 68.9% for ages 50 to 59, 60 to 69, and 70 to 75 years, respectively; P = 0.009) and was higher in men than women (77.0% vs. 70.6%; P = 0.011).

Limitation

Information on advanced adenoma was lacking.

Conclusion

Increased cancer detection at lower positivity thresholds is counterbalanced by substantial increases in positive tests. Tailored thresholds may provide screening benefits that are more equal among different demographic groups, depending on local resources.

Primary Funding Source

National Cancer Institute.