Stool DNA Research Articles

The stool syndecan2 methylation test is more robust than blood tests for methylated septin9, CEA, CA19-9 and CA724: a diagnostic test for the early detection of colorectal neoplasms.

Methylated syndecan2 (mSDC2) in stool samples has been found to be associated with colorectal cancer (CRC) and precancerous lesions. However, the available data are limited, and no previous studies have compared the analysis of mSDC2 with other diagnostic tests. Thus, we aimed to evaluate the clinical performance of a stool mSDC2 test and compare its performance with that of blood-based tests for methylated septin9 (mSEPT9), carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9) and carbohydrate antigen 724 (CA724) in detecting colorectal neoplasms. The gold standard diagnostic technique that was used was colonoscopy combined with a pathological analysis of biopsied tissue. Stool DNA was extracted from 1,002 stool samples (445 from CRCs, 115 from adenomas, and 442 from controls) and then bisulfite-converted, followed by real-time quantitative methylation-specific polymerase chain reaction. Blood mSEPT9 levels were quantified by the Epi proColon 2.0 assay, and serum CEA, CA19-9 and CA724 levels were measured by electrochemiluminescence. The main indexes used during the evaluation were sensitivity, specificity and the area under the receiver operating characteristic curve (AUC). Stool mSDC2 detected 69.7% of CRCs, which was significantly higher than 53.8% by plasma mSEPT9, 37.2% by CEA, 13.1% by CA19-9 and 17.5% by CA724; for adenoma, the detection rates were 31.3%, 11.1%, 2.3% and 11.9%, respectively. The AUC of mSDC2 in detecting CRC was 0.83, compared to 0.72, 0.75, 0.63 and 0.54 for mSEPT9, CEA, CA19-9 and CA724, respectively. mSDC2 identified patients with stage I-III CRC with a sensitivity of 71.6%, which was significantly higher than that of mSEPT9, CEA, CA19-9 and CA724 (54.2%, 35.5%, 11.9%, and 15.0%, respectively); for stage IV CRC, the sensitivities of mSDC2, mSEPT9, CEA, CA19-9 and CA724 were 75.9%, 82.6%, 79.3%, 36.0% and 56.5%, respectively. SDC2 and CEA had a significantly higher sensitivity for distal CRC than for proximal CRC. The stool SDC2 methylation test had a better performance in detecting nonmetastatic CRC and adenoma than evaluations of mSEPT9, CEA, CA19-9 and CA724 in blood. Our findings could be used to modify approaches for CRC prevention and early detection.

Colchicine effects on the gut microbiome in adults with metabolic syndrome.

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. We conducted a secondary analysis of a double-blind randomized placebo-controlled trial, in which 40 adults with obesity, high C-reactive protein (CRP) (≥2.0 mg/L), insulin resistance (homeostatic model of insulin resistance: HOMA-IR ≥2.6 mg/L), and metabolic syndrome (MetS) were randomized to three months of colchicine 0.6 mg 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. Pre- and post-intervention stool samples were available for 15 colchicine- and 12 placebo-treated subjects. Circulating high sensitivity CRP (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. Amplicon sequence variant counts were unchanged among all examined phyla or families. Oscillibacter was the only genus to demonstrate even a nominally significant change. 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.

Stool DNA testing for early detection of colorectal cancer: systematic review using the HTA Core Model® for Rapid Relative Effectiveness Assessment.

Stool DNA testing for early detection of colorectal cancer (CRC) is a non-invasive technology with the potential to supplement established CRC screening tests. The aim of this health technology assessment was to evaluate effectiveness and safety of currently CE-marked stool DNA tests, compared to other CRC tests in CRC screening strategies in an asymptomatic screening population. The assessment was carried out following the guidelines of the European Network for Health Technology Assessment (EUnetHTA). This included a systematic literature search in MED-LINE, Cochrane and EMBASE in 2018. Manufacturers were asked to provide additional data. Five patient interviews helped assessing potential ethical or social aspects and patients' experiences and preferences. We assessed the risk of bias using QUADAS-2, and the quality of the body of evidence using GRADE. We identified three test accuracy studies, two of which investigated a multitarget stool DNA test (Cologuard®, compared fecal immunochemical test (FIT)) and one a combined DNA stool assay (ColoAlert®, compared to guaiac-based fecal occult blood test (gFOBT), Pyruvate Kinase Isoenzyme Type M2 (M2-PK) and combined gFOBT/M2-PK). We found five published surveys on patient satisfaction. No primary study investigating screening effects on CRC incidence or on overall mortality was found. Both stool DNA tests showed in direct comparison higher sensitivity for the detection of CRC and (advanced) adenoma compared to FIT, or gFOBT, respectively, but had lower specificity. However, these comparative results may depend on the exact type of FIT used. The reported test failure rates were higher for stool DNA testing than for FIT. The certainty of evidence was moderate to high for Cologuard® studies, and low to very low for the ColoAlert® study which refers to a former version of the product and yielded no direct evidence on the test accuracy for ad-vanced versus non-advanced adenoma. ColoAlert® is the only stool DNA test currently sold in Europe and is available at a lower price than Cologuard®, but reliable evidence is lacking. A screening study including the current product version of ColoAlert® and suitable comparators would, therefore, help evaluate the effectiveness of this screening option in a European context.

Positive Predictive Value for Multitarget Stool DNA After Bariatric and Metabolic Surgery.

Bariatric and metabolic surgery (BMS) may adversely affect noninvasive stool tests for colorectal cancer (CRC) screening through several mechanisms. Multitarget stool DNA (mt-sDNA) is approved for CRC screening; however, performance in post-BMS patients is unknown. As the rates of BMS are anticipated to increase with rising incidence of obesity, it is important to evaluate mt-sDNA test performance among these patients. In a multisite academic and community-based practice, we obtained mt-sDNA results from 10/2014 to 12/2019 through electronic records and an institutional BMS registry. Average CRC risk patients with BMS prior to a positive mt-sDNA underwent a detailed chart review. Follow-up colonoscopy findings were compared to those among BMS patients screened with colonoscopy alone and a historical cohort of patients without BMS, screened by mt-sDNA. The primary study endpoint was the positive predictive value (PPV) for advanced colorectal neoplasia. Among 336 average-risk patients who had mt-sDNA after BMS, mt-sDNA was positive in 49 (14.6%), 47/49 (96%) underwent follow-up colonoscopy, and the PPV for advanced neoplasia was 12/47 (25.5%). This is similar to the PPV for advanced colorectal neoplasia (425/1542, 28%) in a historical cohort of persons without prior BMS, screened by mt-sDNA at our center (P = .86). Among those who had prior BMS, the rate of advanced neoplasia was higher after mt-sDNA compared to screening colonoscopy alone. Despite anatomic and physiologic mechanisms that could alter blood or DNA content in stool, BMS does not appear to adversely affect the PPV of mt-sDNA.

Correlation between Stool DNA-based SDC2 Methylation Tests Combined with Tumor Markers with Pathological Features in Colorectal Cancer.

Colorectal cancer (CRC) screening is the most efficient strategy to reduce disease-related mortality. In this study, we aimed to investigate the association of a methylation-based stool DNA test with serum protein biomarker panel (CEA, CA125, CA199, and AFP) in CSC patients and their relationship with pathological features to improve the diagnostic efficacy and applicability in CSC in the Chinese population. In this double-blinded case-control study, we enrolled 150 participants from our hospital, including 50 CRC patients, 50 adenomas, and 50 healthy controls. We compared the cycling threshold (Ct) values of stool DNA-based SDC2 measured by quantitative methylation-specific PCR (MSP) in the three groups. We also evaluated the differences and correlation between serum concentrations of tumor biomarker and pathological features in patients with CSC, including TNM stage (I, II, III), tumor size, and lymph node metastasis. The discrimination performance of indexes was assessed using sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC). CSC was more common in middle-aged people and men. The methylation-based stool DNA test was not significantly correlated with other tumor indicators except CEA, and the difference was statistically significant. Compared with the normal control group, the combined diagnostic value of the methylation-based stool DNA test and tumor indicators was significantly higher than individual biomarkers alone, especially the methylation-based stool DNA test combined with CEA and AFP, which improved the AUC to 0.96. This combination can increase the positive rate of pathological stage diagnosis. Combining a methylation-based stool DNA test with CEA and AFP can significantly improve the diagnostic value of CRC and can be used to confirm the diagnosis of colorectal cancer. This combination can also be used as a reliable indicator identifying early-stage CRC patients and pathology. A large-scale study is underway to further define the clinical application of this method for the diagnosis of CRC among Chinese populations.

Attitudes and Experiential Factors Associated with Completion of mt-sDNA Test Kit for Colorectal Cancer Screening.

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in the United States. Despite the availability of multiple screening options, CRC screening is underutilized. We conducted a survey of patients (n = 2973) who were prescribed the multi-target stool DNA (mt-sDNA) screening test (commercialized as Cologuard® and manufactured by Exact Sciences Corporation) to understand attitudes and experiences that influence test completion and likelihood of future test completion. Using exploratory factor analyses, we developed three scales: Perceived Effectiveness, Perceived Ease of Use, and Perceived Comfort.

Physical activity and diet associations with the gut microbiota in the Coronary Artery Risk Development in Young Adults (CARDIA) study

BackgroundGut microbiota may influence metabolic pathways related to chronic health conditions. Evidence for physical activity and diet influences on gut microbial composition exists, but data from diverse population-based cohort studies are limited. ObjectivesWe hypothesized that gut microbial diversity and genera are associated with physical activity and diet quality. MethodsData were from 537 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) Study, a prospective cohort, who attended the year 30 follow-up examination (2015–2016; aged 47–61 y; 45% Black race/55% White race; 45% men/55% women). The 16S ribosomal RNA marker gene was sequenced from stool DNA, and genus-level taxonomy was assigned. Within-person microbial diversity (α-diversity) was assessed with Shannon diversity index and richness scores; between-person diversity (β-diversity) measures were generated with principal coordinates analysis (PCoA). Current and long-term physical activity and diet quality measures were derived from data collected over 30 y of follow-up. Multivariable-adjusted regression analysis controlled for: sociodemographic variables (age, race, sex, education, and field center), other health behaviors (smoking, alcohol consumption, and medication use), and adjusted for multiple comparisons with the false discovery rate (<0.20). ResultsBased on PCoA β-diversity, participants’ microbial community compositions differed significantly (P < 0.001), with respect to both current and long-term physical activity and diet quality. α-Diversity was associated only with current physical activity (positively) in multivariable-adjusted analysis. Multiple genera (n = 45) were associated with physical activity and fewer with diet (n = 5), including positive associations with Lachnospiraceae UCG-001 and Ruminococcaceae IncertaeSedis with both behaviors. ConclusionsPhysical activity and diet quality were associated with gut microbial composition among 537 participants in the CARDIA study. Multiple genera were associated with physical activity. Physical activity and diet quality were associated with genera consistent with pathways related to inflammation and short-chain fatty acid production.

An insight into the commercial piglet’s microbial gut colonization: from birth towards weaning

BackgroundThe establishment of the gut microbiota can be influenced by several perinatal factors, including, most importantly, the maternal microbiota. Moreover, early-life environmental variation affects gut microbial colonization and the intestinal health of offspring throughout life. The present study aimed to explore the development of piglet gut microbiota from birth to weaning in the commercial practice and also to assess how different farm environments could condition this process. Although it is possible to find in the literature other studies with similar objectives this work probably represents one of the few studies that make a systematic evaluation of such differential factors under a real scenario. To achieve this objective, we performed two trials. In a first Trial, we selected 2 farms in which we performed an intensive sampling (5 samples /animal) to characterize the gut colonization pattern during the first days of life and to identify the time window with the greatest impact. Both farms differed in their health status and the use of antimicrobials in the piglets. In a second Trial, we selected 4 additional farms with variable rearing conditions and a distinctive use of antimicrobials in the sows with a simplified sampling pattern (2 samples/animal). Faecal samples were obtained with swabs and DNA was extracted by using the PSP® Spin Stool DNA Kit and sequencing of the 16S rRNA gene (V3-V4 region) performed by Illumina MiSeq Platform.ResultsThe present study contributes to a better understanding of microbiome development during the transition from birth to weaning in commercial conditions. Alpha diversity was strongly affected by age, with an increased richness of species through time. Beta diversity decreased after weaning, suggesting a convergent evolvement among individuals. We pinpointed the early intestinal colonizers belonging to Bacteroides, Escherichia-Shigella, Clostridium sensu stricto 1, and Fusobacterium genera. During lactation(d7-d21 of life), the higher relative abundances of Bacteroides and Lactobacillus genera were correlated with a milk-oriented microbiome. As the piglets aged and after weaning (d36 of life), increasing abundances of genera such as Prevotella, Butyricimonas, Christensenellaceae R-7 group, Dorea, Phascolarctobacterium, Rikenellaceae RC9 gut group, Subdoligranulum, and Ruminococcaceae UCG-002 were observed. These changes indicate the adaptation of the piglets to a cereal-based diet rich in oligosaccharides and starch. Our results also show that the farm can have a significant impact in such a process, evidencing the influence of different environments and rearing systems on the gut microbiota development of the young piglet. Differences between farms were more noticeable after weaning than during lactation with changes in alpha and beta biodiversity and specific taxa. The analysis of such differences suggests that piglets receiving intramuscular amoxicillin (days 2–5 of life) and being offered an acidifying rehydrating solution (Alpha farm in Trial 1) have a greater alpha diversity and more abundant Lactobacillus population. Moreover, the only farm that did not offer any rehydrating solution (Foxtrot farm in Trial 2) showed a lower alpha diversity (day 2 of life) and increased abundance of Enterobacteriaceae (both at 2 and 21 days). The use of in-feed antibiotics in the sows was also associated with structural changes in the piglets’ gut ecosystem although without changes in richness or diversity. Significant shifts could be registered in different microbial groups, particularly lower abundances of Fusobacterium in those piglets from medicated sows.ConclusionsIn conclusion, during the first weeks of life, the pig microbiota showed a relevant succession of microbial groups towards a more homogeneous and stable ecosystem better adapted to the solid dry feed. In this relevant early-age process, the rearing conditions, the farm environment, and particularly the antimicrobial use in piglets and mothers determine changes that could have a relevant impact on gut microbiota maturation. More research is needed to elucidate the relative impact of these farm-induced early life-long changes in the growing pig.

Gut microbial indicators of metabolic health underlie age-related differences in obesity and diabetes risk among Native Hawaiians and Pacific Islanders.

Native Hawaiians and Pacific Islanders (NHPIs) suffer from higher prevalence of and mortality to type 2 diabetes mellitus (T2DM) than any other major race/ethnic group in Hawaii. Health inequities in this indigenous population was further exacerbated by the SARS-CoV-2 pandemic. T2DM progression and medical complications exacerbated by COVID-19 are partially regulated by the gut microbiome. However, there is limited understanding of the role of gut bacteria in the context of inflammation-related diseases of health disparities including T2DM and obesity. To address these gaps, we used a community-based research approach from a cohort enriched with NHPI residents on the island of Oahu, Hawaii (N=138). Gut microbiome profiling was achieved via 16s rDNA metagenomic sequencing analysis from stool DNA. Gut bacterial capacity for butyrate-kinase (BUK)-mediated fiber metabolism was assessed using quantitative PCR to measure the abundance of BUK DNA and RNA relative to total bacterial load per stool sample. In our cohort, age positively correlated with hemoglobin A1c (%; R=0.39; P<0.001) and body mass index (BMI; R=0.28; P<0.001). The relative abundance of major gut bacterial phyla significantly varied across age groups, including Bacteroidetes (P<0.001), Actinobacteria (P=0.007), and Proteobacteria (P=0.008). A1c was negatively correlated with the relative levels of BUK DNA copy number (R=-0.17; P=0.071) and gene expression (R=-0.33; P=0.003). Interestingly, we identified specific genera of gut bacteria potentially mediating the effects of diet on metabolic health in this cohort. Additionally, α-diversity among gut bacterial genera significantly varied across T2DM and BMI categories. Together, these results provide insight into age-related differences in gut bacteria that may influence T2DM and obesity in NHPIs. Furthermore, we observed overlapping patterns between gut bacteria and T2DM risk factors, indicating more nuanced, interdependent interactions among these factors as partial determinants of health outcomes. This study adds to the paucity of NHPI-specific data to further elucidate the biological characteristics associated with pre-existing health inequities in this racial/ethnic group that is significantly underrepresented in biomedical research.

Endoscopists’ recommendations after a false positive multitarget stool DNA test: results from a multicenter study

Endoscopists’ recommendations after a false positive multitarget stool DNA test: results from a multicenter study

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

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

Diagnostic accuracy of multitarget stool DNA testing for colorectal cancer screening: A systematic review and meta-analysis

Diagnostic accuracy of multitarget stool DNA testing for colorectal cancer screening: A systematic review and meta-analysis

Detection of Schistosoma mekongi DNA in Human Stool and Intermediate Host Snail Neotricula aperta via Loop-Mediated Isothermal Amplification Assay in Lao PDR.

Schistosomiasis mekongi infection represents a public health concern in Laos and Cambodia. While both countries have made significant progress in disease control over the past few decades, eradication has not yet been achieved. Recently, several studies reported the application of loop-mediated isothermal amplification (LAMP) for detecting Schistosoma DNA in low-transmission settings. The objective of this study was to develop a LAMP assay for Schistosoma mekongi using a simple DNA extraction method. In particular, we evaluated the utility of the LAMP assay for detecting S. mekongi DNA in human stool and snail samples in endemic areas in Laos. We then used the LAMP assay results to develop a risk map for monitoring schistosomiasis mekongi and preventing epidemics. A total of 272 stool samples were collected from villagers on Khon Island in the southern part of Laos in 2016. DNA for LAMP assays was extracted via the hot-alkaline method. Following the Kato-Katz method, we determined that 0.4% (1/272) of the stool samples were positive for S. mekongi eggs, as opposed to 2.9% (8/272) for S. mekongi DNA based on the LAMP assays. Snail samples (n = 11,762) were annually collected along the riverside of Khon Island from 2016 to 2018. DNA was extracted from pooled snails as per the hot-alkaline method. The LAMP assay indicated that the prevalence of S. mekongi in snails was 0.26% in 2016, 0.08% in 2017, and less than 0.03% in 2018. Based on the LAMP assay results, a risk map for schistosomiasis with kernel density estimation was created, and the distribution of positive individuals and snails was consistent. In a subsequent survey of residents, schistosomiasis prevalence among villagers with latrines at home was lower than that among villagers without latrines. This is the first study to develop and evaluate a LAMP assay for S. mekongi detection in stools and snails. Our findings indicate that the LAMP assay is an effective method for monitoring pathogen prevalence and creating risk maps for schistosomiasis.

The impact of multi-target stool DNA testing in clinical practice in the United States: A real-world evidence retrospective study

Widely endorsed screening modalities for colorectal cancer (CRC) include structural visualization (e.g. colonoscopy) and stool-based tests including multitarget stool DNA (mt-sDNA), fecal immunochemical tests (FIT), or high-sensitivity guaiac-based fecal occult blood tests (gFOBT). However, CRC screenings are underutilized, hence understanding the screening utilization trends is important, particularly with respect to the newest guideline-endorsed option (mt-sDNA). The objective of this study was to assess patterns in overall CRC screenings following clinical availability of the mt-sDNA test among average-risk individuals in the Ascension Wisconsin healthcare system focusing primarily on individuals aged 50–75 years old. We also reported CRC screening behaviors among individuals < 50 and > 75 years old. Electronic medical records of individuals aged ≥ 40 years from 2015 to 2018 were reviewed to identify average-risk and screen-eligible members. For those with screening data available, we determined the proportion who were up-to-date with any United States Preventive Services Task Force (USPSTF) recommended screening strategy; the number of screening tests performed in the measurement year; and the distribution of screening modalities. Temporal trends were assessed using regression analysis, including subgroup analyses across age groups and screening modalities. A total of 172,045 unique patients aged ≥ 40 years were included, of which 115,708 individuals aged 50–75 years. When considering all individuals up-to-date and screened in the measurement year, overall adherence increased significantly over the 4-year study period, from 39,105 to 49,698 patients or 47 % to 59 % (p < 0.0001). The screening incidence between 2015 and 2018 increased from 19.44 to 23.66 tests per 1,000 persons for gFOBT and FIT, a 1.2-fold increase, and from 6.54 to 29.78 tests per 1,000 persons for mt-sDNA (p < 0.05), a 4.6-fold increase. During the same time period, the screening incidence of colonoscopy decreased from 119.99 to 110.58 tests per 1,000 persons, corresponding to a decrease of 8 %. Similar patterns in screening incidence rates were observed among those aged < 50 and > 75 years old. Growing adoption, higher preference, and the broad availability of mt-sDNA testing may be associated with an increase in overall CRC screening rates in the average-risk population, in parallel with a slight increase in the use of other non-invasive CRC screening tests.

ODP630 Antibiotics Transiently Reduce Circulating Cortisol and Inflammatory Biomarker Levels in Healthy Sprague Dawley Rats

Abstract Introduction Antibiotics are over-used in healthcare, but little is known regarding their effects on cortisol levels in healthy individuals. Furthermore, antibiotics influence the gut microbiome, but the interrelationships between these drugs, cortisol and the microbiome are unknown. Here, we exposed the gut microbiome of rats to a multi-drug antibiotic cocktail and examined effects on circulating cortisol and inflammatory biomarker levels. Methods Male and female (M,F) Sprague-Dawley rats (aged 8 weeks) were housed with phytoestrogen-free bedding, and received a phytoestrogen-free diet with water from glass bottles. Exposed rats received vancomycin (0.5g/L), ampicillin (1g/L), neomycin (1g/L), and metronidazole (1g/L) in their water for 8 days, then returned to normal water for another 13 days. Control rats received normal water throughout the study. Stool and serum samples were collected before starting antibiotics (Abx) (baseline), on day 8 of Abx (AbxD8), and at 13 days post-Abx (PAbxD13). Circulating levels of cortisol and a panel of 12 inflammatory biomarkers were analyzed using MILLIPLEX Hormone Panels and RECYTMAG-65K multiplex panels, respectively. Stool DNA was extracted and 16S V3/V4 libraries were sequenced on an Illumina MiSeq. Operational Taxonomic Unit (OTU) clustering and taxonomic analyses were performed using CLC Microbial Genomics Module v.2.5 (Qiagen). Results A total of 31 rats (M=16, F=15) received Abx and 17 (M=9, F=8) were controls. At baseline, mean cortisol levels were similar between groups (control=34. 08±10.21ng/mL, exposed=35. 05±9.72ng/mL, P=0.96). On AbxD8, cortisol levels decreased in the exposed group relative to controls (control=29.77±9.34ng/mL, exposed=17.35±8.21ng/mL, P&amp;lt;0. 0001), and returned to normal in the exposed group at PAbxD13 (control=33.88±16.65ng/mL, exposed=36.62±8.68ng/mL, P=0.85). Levels of all 12 inflammatory biomarkers were also decreased at AbxD8, and all except MCP1 returned to baseline levels by PAbxD13. Antibiotic exposure resulted in significant decreases in total stool DNA levels in exposed rats relative to controls on AbxD8 (P&amp;lt;0. 0001), but returned to baseline levels by PAbxD13. Stool microbial diversity was also decreased in exposed rats on AbxD8 relative to controls (P=1e-08 and P&amp;lt;0. 0001, respectively), and gut microbiome alterations were seen at multiple taxonomic levels. At PAbxD13, the stool microbiome of exposed rats remained perturbed, and only one phylum, Bacteroidetes, returned to baseline. Abx exposure changed associations between different phyla and levels of cortisol on AbxD8 relative to baseline, and although most of the associations reestablished at PAbxD13, the RA of phylum Proteobacteria was positively associated with levels of cortisol (R=0.243, P=0. 04), as opposed to baseline (R=-0.144, P=0.4). Conclusions Antibiotic exposure results in significant decreases in levels of cortisol as well as inflammatory biomarkers that are associated with perturbations of the gut microbiome, the majority of which returned to baseline following a 13-day antibiotic recovery period. These interrealtionships between cortisol, the gut microbiome and inflammatory biomarkers may have clinical significance. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

Cross-sectional adherence with the multi-target stool DNA test for colorectal cancer screening in a medicaid population

Colorectal cancer (CRC) is the third leading cause of cancer death in the US. Early detection improves CRC outcomes and multiple options are endorsed for CRC screening; however, adherence remains challenging. Among Medicaid enrollees, the fecal immunochemical test (FIT) is often used for average-risk CRC screening, with suboptimal adherence rates reported (12.3–23.2 %). The navigation-supported (personalized outreach by phone, mail, email and text), at home collection, multi-target stool DNA (mt-sDNA) test represents a relatively recent and broadly accessible option for average-risk CRC screening in Medicaid enrollees. We assessed cross-sectional mt-sDNA adherence in a national sample of Medicaid patients. Data from Exact Sciences Laboratories LLC (ESL; Madison, WI) were retrospectively analyzed. Participants included individuals 45 + years covered by Fee-For-Service (FFS)- or Managed-Medicaid. Primary analysis focused on the 50–74 age cohort and included those with valid mt-sDNA orders between January 1–December 31, 2018. Data from 25,794 individuals who received valid orders for mt-sDNA were included in analysis (61.2 % women; mean age at order 57.5 years). Overall adherence – completion of an ordered test – was 51.3 %. Adherence was 54.6 % in Managed-Medicaid and 38.9 % in FFS-Medicaid. Adherence by age was: 51.5 % for 50–64 years and 47.7 % for 65–74 years. Mt-sDNA tests ordered by gastroenterologists had higher adherence (60.5 %) compared with primary care clinicians (51.3 %). These data from a large, national sample of Medicaid-insured patients substantiate mt-sDNA testing as a viable patient-supported, home-based option to improve average-risk CRC screening participation in Medicaid enrollees.

Comprehensive Cost Implications of Commercially Available Noninvasive Colorectal Cancer Screening Modalities: Results of a Large National Insurer Claims Database Analysis

INTRODUCTION: There is increasing use of non-invasive screening modalities for colorectal cancer (CRC), primarily the fecal immunochemical test (FIT) and multi-target stool DNA test (mt-sDNA; Cologuard [CG]). We perform a comprehensive cost comparison of these modalities. METHODS: Using our national insurer-based administrative dataset, patients screened for CRC from January 1, 2019 to December 31, 2019 were analyzed. We employed a hierarchical logic system to attribute primary screening modality. Using Medicare reimbursement rates, total annual cost in US dollars ($) were extrapolated using number of patients screened, cost per test, screening interval, and cost incurred from false results. Patients within our tumor registry diagnosed with CRC were matched to their claims data, and cancer stage distribution was compared. RESULTS: Of 117,519 members who underwent non-invasive screening, 45,487 (38.7%) underwent screening with FIT and 46,110 (39.2%) with CG. The total annual cost for these modalities alone was $6.6 million ($1.1 m FIT; $5.6 m CG). Using our advanced analytics, transitioning all non-invasive screening to FIT would result in $3.9 m savings annually (Figure). Combining our network cancer registry to our insurer-based claims dataset, we matched 533 members who both underwent screening and were diagnosed with CRC. Cancer patients screened with FIT or CG presented with early (stage 0-II) disease at similar rate (59.5% FIT vs 63.2% CG; p = 0.77). CONCLUSION: With quality efficacy, there is opportunity for substantial cost savings through widespread adoption of FIT for non-invasive CRC screening. Through advanced analytics, these findings identify major value implications to a large population health system.Figure

Development of a colorectal cancer screening intervention for Alaska Native people during a pandemic year

ObjectivesAlaska Native (AN) people experience twice the rate of colorectal cancer (CRC) as US Whites. There is a need for increased screening and early detection. We describe the development and implementation of a randomized controlled trial of the multi-target stool DNA test (mt-sDNA; Cologuard® Exact Sciences, Madison WI) to increase CRC screening among AN people. MethodsA total of 32 rural/remote AN communities were randomized to a varied intensity intervention (patient navigation vs mailed health education) compared to 14 communities receiving usual opportunistic care. Outcome measures include screening completion and method used (mt-sDNA vs colonoscopy). Health care provider interviews and AN patient focus groups will be used to assess patient-, provider-, and system-level CRC screening promoters and barriers. ResultsThe study began in April 2020 during the COVID-19 pandemic, resulting in a number of challenges and study adaptations. These included difficulty finding laboratory space, lack of timely mail service due to flight reductions across the state, and travel restrictions that led to postponement of in-person focus groups. Videoconferencing platforms for Tribal engagement replaced face-to-face interactions. After an extensive search, a laboratory with space available was identified and the preprocessing laboratory established. Study staff will work closely with patients to monitor mail service to get mt-sDNA kits sent on time. We are also exploring the use of videoconferencing platforms as alternatives to in-person focus groups. ConclusionsDespite the challenges encountered during the COVID-19 pandemic, we successfully initiated the intervention and established the first mt-sDNA preprocessing laboratory in Alaska.

A simplified multiplex methylated DNA testing for early detection of colorectal cancer in stool DNA

BackgroundColoDefense1.0 assay has demonstrated its excellent sensitivity and specificity for early detection of colorectal cancer (CRC) by detecting the methylation levels of SDC2 and SEPT9, while exhibited limitations on relatively large sample capacity required and limited detection throughput by applying triplicate PCR reactions for each sample. In this study, ColoDefense1.0 was simplified and optimized into ColoDefense2.0 in a single PCR reaction.MethodsA total 529 stool specimens were collected, and 244 CRC patients, 34 patients with advanced adenomas (AA), 64 with small polyps (SP) and 187 control subjects were divided in training and validation cohorts. Methylation levels of SEPT9 and SDC2 were examined by qPCR reactions in triplicate or single.ResultsThe stool DNA quantity stored in preservative buffer at 37 °C up to 7 days exhibited no significant decrease. In the training cohort, when the number of replicates reduced from 3 to 1, the overall performance of ColoDefense2.0 was identical to that of ColoDefense1.0, showing sensitivities of 71.4% for AA and 90.8% for all stage CRC with a specificity of 92.9%. In the validation cohort, sensitivities of SP, AA and CRC using ColoDefense2.0 were 25.0%, 55.0% and 88.2%, increased from 14.1% (20.3%), 40.0% (40.0%) and 79.4% (67.6%) using SDC2 (SEPT9) alone; along with an overall specificity of 90.2%, decreased from 94.1% (95.1%) using SDC2 (SEPT9) alone.ConclusionThe simplified ColoDefense test maintained the overall performance while reduced the number of PCR reactions to 1/3, and provided an effective and convenient tool to detect early CRC and precancerous lesions and potentially improve the compliance of screening.

Incident colorectal cancer screening and associated healthcare resource utilization and Medicare cost among Medicare beneficiaries aged 66–75 years in 2016–2018

BackgroundWhile prevalence of up-to-date screening status is the usual reported statistic, annual screening incidence may better reflect current clinical practices and is more actionable. Our main purpose was to examine incident colorectal cancer (CRC) screening rates in Medicare beneficiaries and to explore characteristics associated with CRC screening.MethodsUsing 20% Medicare random sample data, the study population included 2016–2018 Medicare fee-for-service beneficiaries covered by Parts A and B aged 66–75 years at average CRC risk. For each study year, we excluded individuals who had a Medicare claim for a colonoscopy within 9 years, flexible sigmoidoscopy within 4 years, and multitarget stool DNA test (mt-sDNA) within 2 years prior; therefore, any observed screening during study year was considered an “incident screening”. Incident screening rates were calculated as number of incident screenings per 1000 Medicare beneficiaries. Overall rates were normalized to 2018 Medicare population distributions of age, sex, and race.ResultsEach year, > 1.4 million individuals met the inclusion/exclusion criteria from > 6.5 million Medicare beneficiaries. The overall adjusted incident CRC screening rate per 1000 Medicare beneficiaries increased from 85.2 in 2016 to 94.3 in 2018. Incident screening rates decreased 11.4% (22.9 to 20.3) for colonoscopy and 2.4% (58.3 to 56.9) for fecal immunochemical test/guaiac-based fecal occult blood test; they increased 201.5% (6.5 to 19.6) for mt-sDNA. The 2018 unadjusted rate was 76.0 for men and 110.4 for women. By race/ethnicity, the highest 2018 rate was for Asian individuals and the lowest rate was for Black individuals (113.4 and 72.8, respectively).ConclusionsThe 2016–2018 observed incident CRC screening rate in average-risk Medicare beneficiaries, while increasing, was still low. Our findings suggest more work is needed to improve CRC screening overall and, especially, among male and Black Medicare beneficiaries.