Stool DNA Research Articles

Next-generation Multi-target Stool DNA Panel Accurately Detects Colorectal Cancer and Advanced Precancerous Lesions.

This study highlights performance of the next-generation mt-sDNA test, which exhibits high sensitivity and specificity for detecting colorectal cancer and APLs. This noninvasive option has potential to increase screening participation and clinical outcomes. A multi-center, clinical validation trial is underway. See related commentary by Bresalier, p. 93.

Effect of green banana and pineapple fibre powder consumption on host gut microbiome.

To determine whether green banana powder (GBP) and pineapple fibre powder (PFP) promote beneficial bacterial species, directly improve human gut health and modulate the gut microbiome and understand their utility as functional foods and dietary supplements. Over 14 days, 60 adults followed protocol requirements, completed food diaries and study questionnaires, avoided consuming supplements with prebiotics, probiotics or postbiotics, and ingested food containing 5 g of total daily fibre [placebo (10.75 g), GBP (10.75 g) or PFP (7.41 g)]. Participants' medical and baseline wellness histories, as well as stool samples, were collected at baseline, day 7 and 14. Stool DNA was processed for sequencing. Dietary fibre and resistant starches (RS) in GBP and PFP promoted temporal increases in beneficial bacteria. GBP significantly elevated 7 species (F. prausnitzii, B. longum, B. bifidum, B. adolescentis, B. pseudocatenulatum, B. obeum, and R. inulinivorans), while PFP enriched 6 species (B. ovatus, B. cellulosilyticus, B. bifidum, B. intestinalis, R. inulinivorans, and E. siraeum). These bacteria, found to be deficient in younger adults, were promoted by both powders. PFP benefitted both genders aged 16-23, while GBP benefitted overweight/obese individuals, including females. GBP and PFP fiber and RS improved bowel regularity and health as well as metabolism by promoting histidine, branched-chain amino acids, short-chain fatty acids, and biotin production. The additional fiber caused "low" bloatedness and reduced "fairly bad" sleep disruptions, without affecting sleep durations. GBP and PFP supplementation increased beneficial bacteria and metabolites, improved host gut health, and present a valuable nutritional strategy for enhancing human health. AMILI Institutional Review Board, Identifier 2023/0301.

Algorithm Development and Early Performance Evaluation of a Next-Generation Multitarget Stool DNA Screening Test for Colorectal Cancer

Background and AimsThe multitarget stool DNA (mt-sDNA) assay is a non-invasive average-risk colorectal cancer (CRC) screening test. A new biomarker panel was developed for a next-generation test to improve specificity while maintaining/increasing sensitivity. We aimed first to establish an algorithm and cutoff for the next-generation mt-sDNA test and then to validate it using archived samples from the pivotal DeeP-C study (NCT01397747) of the first-generation test. MethodsAlgorithm development and cross-validation included 3011 samples from 2 specimen collection studies (NCT03821948, NCT03789162). The algorithm and cutoff were locked before validation. Validation test set samples included 57 CRC, 583 advanced precancerous lesions (APLs), and 7022 samples negative for CRC or APLs from the DeeP-C study, which prospectively enrolled average-risk, asymptomatic adults aged 50 to 84 years before screening colonoscopy. Next-generation biomarkers included methylated DNA markers LASS4, LRRC4, PPP2R5C, and ZDHHC1 (reference marker), and fecal hemoglobin. Primary validation endpoints were CRC sensitivity and specificity for the absence of advanced neoplasia. Secondary endpoints included APL sensitivity and specificity for non-neoplastic findings or negative colonoscopy. ResultsCross-validation and best-fit results from algorithm development closely matched, confirming algorithm reliability and reproducibility. For the test set, next-generation mt-sDNA test sensitivity was 93.0% (95% CI, 83.0%-98.1%) for CRC and 48.4% (95% CI, 44.2%-52.5%) for APLs. Specificity was 88.5% (95% CI, 87.7%-89.2%) for the absence of advanced neoplasia and 90.4% (95% CI, 89.5%-91.2%) for the combination of non-neoplastic findings or negative colonoscopy. ConclusionsBased on archived samples, the next-generation mt-sDNA test demonstrated promising CRC screening performance characteristics that will be further assessed in a prospective clinical validation study (BLUE-C; NCT04144738).

The frequency of NRAS mutation in stool samples of Iranian colorectal cancers compared to Finnish patients

Abstract Background: Stools from colorectal cancer patients are noninvasive samples that could be used to compare the frequency of hotspot mutations between two different ethnic cohorts. Materials and Methods: We collected stool samples from the Iranian cohort (52 patients and 49 controls) and the Finnish cohort (40 patients and 14 controls). Following stool DNA extraction, we used the AmpliSeq Colon and Lung Cancer panel to prepare DNA libraries before sequencing. Results: The Iranian cohort exhibited 35 hotspot mutations in the BRAF, ERBB4, FBXW7, FGFR1, FGFR3, KRAS, MAP2K, MET, NRAS, PIK3C, SMAD4, and TP53 genes. In the Finnish cohort, 13 hotspot mutations were found in the AKT1, APC, KIT, KRAS, SMO, STK11, and TP53 genes. Mutations in NRAS and FGFR3 were observed only in the Iranian cohort, while APC mutations were exclusive for the Finnish cohort. Conclusion: Genes involved in MAPK and PI3K-MAPK pathways showed a higher frequency of mutations in Iranian patients which may have therapeutic implications.

Comparative immunological study of children infected with Entamoeba spp. parasites in Thi-Qar province

Background. Amoebiasis is a one of the major public health problems, it is caused by the genus Entamoeba which includes several species, such as E. histolytica, E. dispar and E. moshkovskii. Purposes. The present study aimed to differentiate among Entamoeba spp. by using molecular method (PCR) and to identify characteristic serum markers (IgG and IL-6) according to species. Methods. About 697 stool samples were collected from children under five years old, and blood samples (3 ml) of venous blood were collected from patients with positive microscopic examination to evaluate some immune parameters (IL-6, IgG) for children infected with the parasite using the ELISA test. DNA extraction was carried out from fecal samples using a special stool DNA extraction kit and Multiplex PCR primers were designed to detect E. histolytica, E. dispar and E. moshkovskii. Results. About 100(14.34%) were infected with Entamoeba spp. by microscopic examination and 68 samples DNA-samples were positive. Fifty samples 50% were infected with E. histolytica, and 12% with a mixed infection. A significant increase (p≤0.05) in the concentration of IgG immunoglobulin in the sera of children infected with the E. histolytica parasite. A significant increase (p≤0.05) in the concentration of interleukin-6 in the sera of patients groups infected with Entamoeba spp., the highest significant increase (p≤0.05) was recorded in patients group infected with the E. moshkovskii. Conclusion. Molecular tests have the ability to detect and distinguish between the Entamoeba species infecting humans. Amoebiasis caused an increase in the concentration of IgG and interleukin-6.

Current implications and challenges of artificial intelligence technologies in therapeutic intervention of colorectal cancer

Irrespective of men and women, colorectal cancer (CRC), is the third most common cancer in the population with more than 1.85 million cases annually. Fewer than 20% of patients only survive beyond five years from diagnosis. CRC is a highly preventable disease if diagnosed at the early stage of malignancy. Several screening methods like endoscopy (like colonoscopy; gold standard), imaging examination [computed tomographic colonography (CTC)], guaiac-based fecal occult blood (gFOBT), immunochemical test from faeces, and stool DNA test are available with different levels of sensitivity and specificity. The available screening methods are associated with certain drawbacks like invasiveness, cost, or sensitivity. In recent years, computer-aided systems-based screening, diagnosis, and treatment have been very promising in the early-stage detection and diagnosis of CRC cases. Artificial intelligence (AI) is an enormously in-demand, cost-effective technology, that uses various tools machine learning (ML), and deep learning (DL) to screen, diagnose, and stage, and has great potential to treat CRC. Moreover, different ML algorithms and neural networks [artificial neural network (ANN), k-nearest neighbors (KNN), and support vector machines (SVMs)] have been deployed to predict precise and personalized treatment options. This review examines and summarizes different ML and DL models used for therapeutic intervention in CRC cancer along with the gap and challenges for AI.

Top 4 Research Studies of the month for Italian Primary Care Physicians: November 2023.

This monthly article provides a collection of summaries of the most relevant studies identified as POEMs (patient-oriented evidence that matters) for Italian primary care physicians. 1) Based on efficacy, safety, and cost, a regimen of terbinafine 250 mg once daily for 12 weeks, followed by a 12-week period of no therapy, and then a 4-week booster of terbinafine 250 mg is preferred for onychomycosis in adults for the outcome of complete cure at 1 year. 2) A high-quality randomized trial found that standard-course antibiotic therapy for children with uncomplicated urinary tract infection was superior to short-course therapy. However, the number needed to treat of 28 suggests that offering short-course therapy is not unreasonable, especially if there is good follow-up in the subsequent weeks. 3) An updated guideline of the American College of Physicians on screening of colorectal cancer adds 2 new recommendations. One is to consider not screening patients aged 45 to 49 years. The other recommendation is against screening using stool Dna, computed tomography colonography, capsule endoscopy, urine, or serum screening tests for colorectal cancer. 4) The US Preventive Services Task Force found additional evidence on the benefit of folic acid supplementation for preventing neural tube defects. Since the critical period starts at least 1 month before conception, the task force recommends a daily supplement of 0.4 mg to 0.8 mg folic acid for all women who plan to or could become pregnant.

Abstract A138: Impact of racial disparities in follow-up colonoscopy for abnormal stool-screening test results on colorectal cancer incidence and mortality: A simulation modeling analysis

Abstract Introduction: The benefits of colorectal cancer (CRC) screening programs for average-risk adults rely on completion of follow-up colonoscopy (FU-Col) after a positive result from either the stool-based fecal immunochemical test (FIT) or multi-target stool DNA (mt-sDNA) test. Existing data demonstrate significantly lower rates of FU-Col for Black Americans than White Americans. However, the contribution of differential FU-Col rates on disparate CRC outcomes among Black and White Americans has not been rigorously evaluated. Methods: We used the CRC-Adenoma Incidence and Mortality (CRC-AIM) model as our analysis platform, with inputs from published literature that report Black adults are approximately 15% less likely to complete FU-Col compared to White adults. CRC-AIM was validated against United Kingdom Flexible Sigmoidoscopy Screening Trial and three National Cancer Institute’s Cancer Intervention and Surveillance Modeling Network (CISNET) CRC models. We simulated screening with annual FIT and triennial mt-sDNA between ages 45 and 75 versus no screening. We considered two scenarios that assumed perfect adherence to FIT/mt-sDNA screening: 1) FU-Col rates for Black adults are 15% lower than those for White adults; 2) Black adults have the same FU-Col rates as White adults. In a secondary analysis, we considered real-world adherence to FIT (43%) and mt-sDNA (66%) and reran these two scenarios. Lifetime outcomes per 1,000 individuals were reported. Results: Assuming perfect adherence to FIT/mt-sDNA screening and 15% lower FU-Col rates, estimated life-year gains (LYG) from annual FIT and triennial mt-sDNA screening strategies compared to no screening was 227 and 239 per 1,000 individuals, respectively. If Black adults had the same FU-Col rates as White adults, the LYG would increase to 243 and 256 for FIT and mt-sDNA screening, respectively, which corresponds to a 7% improvement in LYG. Furthermore, elimination of racial disparities in FU-Col rates would reduce CRC incidence by 8% and 9% for FIT and mt-sDNA screening, respectively and reduce CRC mortality by 10% for both FIT and mt-sDNA screening. Secondary analysis shows that eliminating disparities in FU-Col would lead to 9-11% improvement in LYGs, 5-9% improvement in CRC incidence, and 7-11% improvement in CRC mortality for Black adults considering the real-world adherence to FIT/mt-sDNA screening. Conclusions: Data from this novel simulation modeling study that accounts for differences in FU-Col rates between Black and White Americans suggest that focused efforts to eliminate this gap would improve the anticipated LYG, CRC incidence, and CRC mortality benefits associated with stool-based CRC screening by over 7%, 8%, and 10%, respectively. Further investigation of this under-appreciated contributor to established racial disparities in CRC control may lead to innovative solutions for improving health equity. Citation Format: Oguz Alagoz, A. Mark Fendrick, Vahab Vahdat, Chris Estes, A. Burak Ozbay, Travelle Ellis, Paul J. Limburg, Durado Brooks. Impact of racial disparities in follow-up colonoscopy for abnormal stool-screening test results on colorectal cancer incidence and mortality: A simulation modeling analysis [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr A138.

Abstract C133: Identifying sexual and gender minority colorectal cancer screening disparities via the 2020 Behavioral Risk Factor Surveillance System

Abstract Introduction: Health disparities exist for US sexual and gender minorities (SGM) relative to the general population, including cancer screening disparities with variation across disease sites. Limited data exist to describe the frequency of guideline-concordant colorectal cancer screening (CRC) among SGM people, with few studies using nationally-representative samples. This study aims to assess CRC screening participation among SGM people leveraging nationally-representative US health survey data. Methods: Data from the 2020 Behavioral Risk Factor Surveillance System (BRFSS) were used to compare CRC screening participation among screening-eligible SGM to that of the straight, cisgender population. 86,519 individuals aged 50 and older without a lifetime cancer diagnosis and with complete information on demographics, health access, and sexual orientation and gender identity (collected in 33 of 53 participating US states/territories) were included in the analysis. Odds of lifetime CRC screening participation by test type (colonoscopy, sigmoidoscopy, blood stool test, stool DNA test, virtual colonoscopy) for gender minority (GM: transgender man, transgender woman, gender non-conforming) vs. cisgender individuals and sexual minority (SM: gay/lesbian, bisexual, something else) vs. straight individuals were compared via weighted logistic regression models adjusted for age, demographics, and health access. Results: Of the overall sample, 0.44% and 3.6% identified as GM and SM, respectively. Prevalence of lifetime CRC screening by any test was 65.4% vs. 78.9% for GM vs. cisgender individuals and 77.1% vs. 78.9% for SM vs. straight individuals. GM reported lower odds of screening participation relative to cisgender individuals in 4 of 5 test types: colonoscopy adjusted odds ratio (AOR) 0.38 (95% CI 0.13, 1.08); sigmoidoscopy 0.58 (0.28, 1.22); blood stool test 0.84 (0.31, 2.28); stool DNA test 0.52 (0.22, 1.20); virtual colonoscopy 1.36 (0.64, 2.90). SM reported lower odds of screening participation relative to straight individuals in 2 of 5 test types: colonoscopy 1.05 (0.83, 1.32); sigmoidoscopy 0.94 (0.74, 1.19); blood stool test 0.95 (0.77, 1.17); stool DNA test 1.11 (0.81, 1.51); virtual colonoscopy 1.12 (0.81, 1.53). None of the AORs were statistically significant. Conclusions: Disparities in CRC screening participation persist for GM relative to cisgender individuals. These findings suggest the need for additional subgroup analyses among GM, study replication in other data sources, and interventions to improve access to CRC screening for GM. Citation Format: Frank M. Wolf, Ash Alpert, Molly Schwalb, Danielle German. Identifying sexual and gender minority colorectal cancer screening disparities via the 2020 Behavioral Risk Factor Surveillance System [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr C133.

Developing a Novel Non-invasive Serum-based Diagnostic Test for Early Detection of Colorectal Cancer

Abstract Introduction/Objective Colorectal cancer (CRC) is the third-most common cancer worldwide, and early detection is vital for successful treatment and improved outcomes. Current screening methods such as colonoscopy, fecal occult blood tests, and stool DNA tests have limitations such as patient discomfort, cost, and low sensitivity and specificity most commonly diagnosed cancer worldwide with a high mortality rate. Early detection remains a crucial factor in reducing the burden of CRC. Currently, the gold standard for CRC diagnosis is colonoscopy, but it may not be feasible for widespread screening due to its invasiveness, cost, and patient compliance issues. Therefore, there is a great need to identify reliable biomarkers that can detect CRC at an early stage. This study aimed to evaluate the effectiveness of updated novel biomarkers for early detection of CRC. Methods/Case Report This study was conducted on 158 patients with suspected or confirmed CRC. The study population included patients of both genders, aged above 18 years, and with a history of CRC or other relevant risk factors. Blood samples were collected from all included patients, and the biomarkers (CTCS, miRNAs, ctDNA, and Methylated DNA markers ) were measured using enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) tests. Novel biomarkers compared their diagnostic performance with existing biomarkers such as fecal occult blood tests (FOBTs), fecal immunochemical tests (FITs), and CEA. Results (if a Case Study enter NA) The studied biomarkers (CTCs, microRNAs, ctDNA, and Methylated DNA markers) have high sensitivity from 78.8 % to 96.72% and accuracy from 83.76% to 94.83% as well as their cut-off which approved the objective of this study. Overall, these novel biomarkers show promise for early detection of colorectal cancer and may improve screening and early detection efforts. Conclusion The evaluation of the studied biomarkers (Circulating Tumor Cells, microRNAs, Circulating tumor DNA, and Methylated DNA markers) for early detection of CRC has substantial clinical and public health implications. The identification of reliable biomarkers for CRC screening can avoid unnecessary colonoscopies, reduce the burden on healthcare costs, and improve the detection of early-stage CRC.

Cost-Effectiveness of Liquid Biopsy for Colorectal Cancer Screening in Patients Who Are Unscreened

Despite recommendations for universal screening, adherence to colorectal cancer screening in the US is approximately 60%. Liquid biopsy tests are in development for cancer early detection, but it is unclear whether they are cost-effective for colorectal cancer screening. To estimate the cost-effectiveness of liquid biopsy for colorectal cancer screening in the US. In this economic evaluation, a Markov model was developed to compare no screening and 5 colorectal cancer screening strategies: colonoscopy, liquid biopsy, liquid biopsy following nonadherence to colonoscopy, stool DNA, and fecal immunochemical test. Adherence to first-line screening with colonoscopy, stool DNA, or fecal immunochemical test was assumed to be 60.6%, and adherence for liquid biopsy was assumed to be 100%. For colonoscopy, stool DNA, and fecal immunochemical test, patients who did not adhere to testing were not offered other screening. In colonoscopy-liquid biopsy hybrid, liquid biopsy was second-line screening for those who deferred colonoscopy. Scenario analyses were performed to include the possibility of polyp detection for liquid biopsy. No screening, colonoscopy, fecal immunochemical test, stool DNA, liquid biopsy, and colonoscopy-liquid biopsy hybrid screening. Model outcomes included life expectancy, total cost, and incremental cost-effectiveness ratios. A strategy was considered cost-effective if it had an incremental cost-effectiveness ratio less than the US willingness-to-pay threshold of $100 000 per life-year gained. This study used a simulated cohort of patients aged 45 years with average risk of colorectal cancer. In the base case, colonoscopy was the preferred, or cost-effective, strategy with an incremental cost-effectiveness ratio of $28 071 per life-year gained. Colonoscopy-liquid biopsy hybrid had the greatest gain in life-years gained but had an incremental cost-effectiveness ratio of $377 538. Colonoscopy-liquid biopsy hybrid had a greater gain in life-years if liquid biopsy could detect polyps but remained too costly. In this economic evaluation of liquid biopsy for colorectal cancer screening, colonoscopy was a cost-effective strategy for colorectal cancer screening in the general population, and the inclusion of liquid biopsy as a first- or second-line screening strategy was not cost-effective at its current cost and screening performance. Liquid biopsy tests for colorectal cancer screening may become cost-effective if their cost is substantially lowered.

Patterns of colorectal cancer screening and adherence rates among an average-risk population enrolled in a national health insurance provider during 2009–2018 in the United States

While colorectal cancer (CRC) is the second leading cause of cancer-related mortality in the United States (US), outcomes can be improved through timely screening. Despite the benefits and widespread availability of screening tests, adherence to recommended screening strategies is low. The study aimed to provide recent evidence regarding screening rates and adherence to screening recommendations among adults at average risk for CRC in a commercially insured and Medicare Advantage population. De-identified administrative data from a large US research database were examined to determine screening rates for the years 2009 through 2018. The study population included adults aged 50–75 years and annual study population counts ranged from 1,390,594 in 2009 to 1,654,544 in 2018. Incident screening rates were found to be relatively stable across the study years (approximately 15 %) with adherence lowest in the youngest age group (ages 50–54 years). Colonoscopies accounted for approximately 50 % of all screening tests performed, while there was a substantial increase in the use of home-based screening tests over the study timeframe. The use of the fecal immunochemical test increased from 17.2 % in 2009 to 28.9 % in 2018 and the multi-target stool DNA test increased from 0.4 % in 2015 to 9.0 % in 2018. Overall though, CRC screening and adherence rates remain relatively low among adults at average risk for CRC in the US. Improving adherence rates with CRC screening recommendations among individuals at average risk for CRC is required to improve health outcomes.

Provider- and System-Level Barriers and Facilitators to Colonoscopy and Multi-Target Stool DNA for Colorectal Cancer Screening in Rural/Remote Alaska Native Communities.

The Alaska Tribal Health System is working to increase colorectal cancer (CRC) screening among Alaska Native people, who experience the highest CRC rates in the world. This study examined CRC screening provider- and system-level barriers and facilitators from the perspective of healthcare providers serving Alaska Native people in rural/remote communities. A total of 28 provider (physicians, advanced practice, and Community Health Aides/Practitioners) interviews were held from 1 February to 30 November 2021. Colonoscopy provider-level barrier themes included time, competing priorities, and staffing, while system-level barriers included travel costs, weather, and the COVID-19 pandemic. Multi-target stool DNA (mt-sDNA) barrier themes included test viability and unfamiliarity, and previous stool tests experiences. For both tests, limited medical record reminders was a major barrier. Facilitator themes for both tests included community outreach, cultural competency and patient navigation, and clinic/system improvements. In-depth interviews with tribal health providers showed that adding mt-sDNA testing may help address system-level colonoscopy barriers such as waitlists and travel costs, but other barriers remain. Further research is needed into patient barriers and facilitators, as well as the effectiveness of integrating mt-sDNA into a geographically dispersed tribal health system to reduce cancer disparities and build equity in CRC prevention among Alaska Native people.

Sociodemographic Factors and Screening CT Colonography Use Among Medicare Beneficiaries.

BACKGROUND. Approximately one-third of the eligible U.S. population have not undergone guideline-compliant colorectal cancer (CRC) screening. Guidelines recognize various screening strategies to increase adherence. CMS provides coverage for all recommended screening tests except CT colonography (CTC). OBJECTIVE. The purpose of this study was to compare CTC and other CRC screening tests in terms of associations of utilization with income, race and ethnicity, and urbanicity in Medicare fee-for-service beneficiaries. METHODS. This retrospective study used CMS Research Identifiable Files from January 1, 2011, through December 31, 2020. These files contain claims information for 5% of Medicare fee-for-service beneficiaries. Data were extracted for individuals 45-85 years old, and individuals with high CRC risk were excluded. Multivariable logistic regression models were constructed to determine the likelihood of undergoing CRC screening tests (as well as of undergoing diagnostic CTC, a CMS-covered test with similar physical access as screening CTC) as a function of income, race and ethnicity, and urbanicity while controlling for sex, age, Charlson comorbidity index, U.S. census region, screening year, and related conditions and procedures. RESULTS. For 12,273,363 beneficiary years (mean age, 70.5 ± 8.2 [SD] years; 2,436,849 unique beneficiaries: 6,774,837 female beneficiaries, 5,498,526 male beneficiaries), there were 785,103 CRC screenings events, including 645 for screening CTC. Compared with individuals living in communities with per capita income of less than US$25,000, individuals in communities with income of US$100,000 or more had OR for undergoing screening CTC of 5.73, optical colonoscopy (OC) of 1.36, sigmoidoscopy of 1.03, guaiac fecal occult blood test or fecal immunochemical test of 1.50, stool DNA of 1.43, and diagnostic CTC of 2.00. The OR for undergoing screening CTC was 1.00 for Hispanic individuals and 1.08 for non-Hispanic Black individuals compared with non-Hispanic White individuals. Compared with the OR for undergoing screening CTC for residents of metropolitan areas, the OR was 0.51 for residents of micropolitan areas and 0.65 for residents of small or rural areas. CONCLUSION. The association with income was substantially larger for screening CTC than for other CRC screening tests or for diagnostic CTC. CLINICAL IMPACT. Medicare's noncoverage for screening CTC may contribute to lower adherence with CRC screening guidelines for lower-income beneficiaries. Medicare coverage of CTC could reduce income-based disparities for individuals avoiding OC owing to invasiveness, need for anesthesia, or complication risk.

FRI076 Colchicine Treatment Effects On The Gut Microbiome In Adults With Metabolic Syndrome, Insulin Resistance, And High C-reactive Protein (CRP): A Secondary Analysis Of A Randomized, Placebo-controlled Clinical Trial

Abstract Disclosure: C.M. Kisimba: None. J.L. Donahue: None. K.K. Chivukula: None. P. Subramanian: None. S.D. Mistry: None. A. Wolska: None. A.T. Remaley: None. J.A. Yanovski: None. A.P. Demidowich: None. Background: Obesity-induced inflammation plays a substantial role in the development of insulin resistance and type 2 diabetes. The altered gut flora in obesity can also contribute to metabolic dysregulation and systemic inflammation. However, it remains unclear how dysregulation of systemic inflammation in obesity affects the gut microbiome. We hypothesized that colchicine’s systemic anti-inflammatory effects in obesity would be associated with improvements in gut microbial diversity. Methods: This study was a secondary analysis of a double-blind randomized placebo-controlled trial, in which 40 adults with obesity, high CRP (≥ 2.0 mg/L), insulin resistance (HOMA-IR ≥ 2.6 mg/L), and metabolic syndrome (MetS) were randomized to three months of colchicine 0.6mg or placebo tablets twice daily. Serum and stool samples were collected at baseline and final visit. Gut microbiota composition was characterized from stool DNA by dual-index amplification and sequencing of 16S ribosomal RNA. Results: Pre- and post-intervention stool samples were available for 15 colchicine- and 12 placebo-treated subjects. Circulating hsCRP, interleukin-6, resistin, white blood count, and neutrophils were significantly decreased in the colchicine arm as compared to placebo. However, changes in stool microbiome alpha diversity, as assessed by the Chao1, Shannon, and Pielou indices, were not significant between groups. Sequence variant counts were unchanged among all examined phyla or families. Oscillibacter was the only genus to demonstrate even a nominally significant change. Conclusion: Among adults with obesity and MetS, colchicine significantly improved systemic inflammation. However, this anti-inflammatory effect was not associated with significant changes in the gut microbiome. Further studies are warranted to investigate this relationship. Presentation: Friday, June 16, 2023

S175 Variability in Follow-up Recommendations After a Diagnostic Colonoscopy Performed for a Positive Multitarget Stool DNA Test

S175 Variability in Follow-up Recommendations After a Diagnostic Colonoscopy Performed for a Positive Multitarget Stool DNA Test

S327 Improving Colorectal Cancer Screening Rates With Multitarget Stool DNA Testing by Implementing a Comprehensive Program of Tailored Patient Navigation in an Inner-City Population

S327 Improving Colorectal Cancer Screening Rates With Multitarget Stool DNA Testing by Implementing a Comprehensive Program of Tailored Patient Navigation in an Inner-City Population

S354 Performance Evaluation of a Next-Generation Multitarget Stool DNA (mt-sDNA) Screening Test for Colorectal Cancer (CRC)

S354 Performance Evaluation of a Next-Generation Multitarget Stool DNA (mt-sDNA) Screening Test for Colorectal Cancer (CRC)

S416 Factors Associated With False-Positive Results in Multitarget Stool DNA Test for Colorectal Cancer Screening

S416 Factors Associated With False-Positive Results in Multitarget Stool DNA Test for Colorectal Cancer Screening

S417 Colonoscopy Findings in Patients With a Positive Multitarget Stool DNA Test: A Cross-Sectional Study

S417 Colonoscopy Findings in Patients With a Positive Multitarget Stool DNA Test: A Cross-Sectional Study