Itzkowitz, Steven H.

Abstract Background and Aims The FDA-approved multitarget stool-DNA [mt-sDNA] test is a successful colorectal cancer [CRC] screening tool in average-risk individuals but is not indicated for patients with inflammatory bowel disease [IBD]. We determined the performance of the mt-sDNA assay without the haemoglobin component [mt-sDNAHgb-] in patients with IBD, while measuring sensitivity for colorectal cancer and advanced colorectal neoplasia [ACRN]. Methods This was a multi-centre, proof-of-concept investigation in persons aged 18–84 years with a diagnosis of IBD, or primary sclerosing cholangitis [PSC] with IBD. Enrolment occurred between March 2013 and May 2016. Stool was tested with the mt-sDNA molecular markers only, minus the immunochemical haemoglobin component. Results The analysis set contained 355 samples. The median age was 52 [range 39–62] years, 45.6% were female and 93% were White. Two-thirds [63%] had ulcerative colitis [UC] and 10.1% had PSC/IBD. Colonoscopy revealed cancer in 8.5% [N = 30], advanced precancerous lesions [APLs] in 9.3% [N = 33] and non-advanced precancerous lesions in 7.6% [N = 27], and three-quarters [74.7%, N = 265] had negative findings. mt-sDNAHgb- sensitivity was 73.3% for any stage cancers, and 76.2% for ACRN. Sensitivity was highest for IBD-associated high-grade dysplasia at 100% and 84.6% for IBD-associated low-grade dysplasia ≥1 cm. The test showed higher sensitivity and lower specificity in UC than in Crohn’s disease. Increasing inflammation score was associated with a significant decrease in mt-sDNAHgb- test score [ = 0.028] amongst neoplasia-negative individuals, but not in patients with ACRN. Conclusions These data highlight the potential of multitarget stool-DNA marker testing as an important addition to colorectal cancer surveillance by complementing colonoscopic evaluations in IBD patients.

Abstract Background Current guidelines recommend endoscopic resection of visible and endoscopically resectable colorectal colitis-associated neoplasia (CAN) in patients with inflammatory bowel disease (IBD). However, patients with high risk CAN are often not amenable to conventional resections techniques and a consensus approach for the endoscopic management of these lesions is presently lacking. This Delphi study aims to reach consensus amongst experts on the endoscopic management of these lesions. Methods A three-round modified Delphi process was conducted to reach consensus amongst worldwide IBD and/or endoscopy experts (n=18) from three continents. Experts were chosen based on the extensive clinical experience with IBD and/or EMR/ESD in patients with IBD, and the authorship on multiple peer-reviewed publications on CAN, the endoscopic resection of CAN and/or EMR/ESD. Consensus was considered if ≥ 75% agreed or disagreed. Quality of evidence was assessed by the criteria of the Cochrane Collaboration group. Results Consensus was reached on all statements (n=14). Experts agreed on a definition for CAN and high-risk CAN (HR-CAN). Consensus was reached on the examination of the colon with enhanced endoscopic imaging prior to resection, the endoscopic resectability of a HR-CAN lesion and endoscopic assessment and standard report of CAN lesions. In addition, experts agreed on type of resections of HR-CAN (< 20mm, >20 mm, with or without good lifting), endoscopic success (technical success and outcomes), histologic assessment and follow-up in HR-CAN. Conclusion This is the first step in developing international consensus-based recommendations for endoscopic management of (HR-)CAN. Although the quality of available evidence was considered low, consensus was reached on several aspects of the management of (HR-)CAN. The present work and proposed standardization might benefit future studies.

Abstract Data supporting the clinical utility of multi-target stool DNA (mt-sDNA) at the guideline-recommended 3-year interval have not been reported. Between April 2015 and July 2016, candidates for colorectal cancer screening whose providers prescribed the mt-sDNA test were enrolled. Participants with a positive baseline test were recommended for colonoscopy and completed the study. Those with a negative baseline test were followed annually for 3 years. In year 3, the mt-sDNA test was repeated and colonoscopy was recommended independent of results. Data were analyzed using the Predictive Summary Index (PSI), a measure of the gain in certainty for dichotomous diagnostic tests (where a positive value indicates a net gain), and by comparing observed versus expected colorectal cancers and advanced precancerous lesions. Of 2,404 enrolled subjects, 2,044 (85%) had a valid baseline mt-sDNA result [284 (13.9%) positive and 1,760 (86.1%) negative]. Following participant attrition, the year 3 intention to screen cohort included 591 of 1,760 (33.6%) subjects with valid mt-sDNA and colonoscopy results, with no colorectal cancers and 63 advanced precancerous lesions [22 (34.9%) detected by mt-sDNA] and respective PSI values of 0% (P = 1) and 9.3% (P = 0.01). The observed 3-year colorectal cancer yield was lower than expected (one-sided P = 0.09), while that for advanced precancerous lesions was higher than expected (two-sided P = 0.009). Repeat mt-sDNA screening at a 3-year interval resulted in a statistically significant gain in detection of advanced precancerous lesions. Due to absence of year 3 colorectal cancers, the PSI estimate for colorectal cancer was underpowered and could not be reliably quantified. Larger studies are required to assess the colorectal cancer study findings. Prevention Relevance: Understanding the 3-year yield of mt-sDNA for colorectal cancer and advanced precancerous polyps is required to ensure the clinical appropriateness of the 3-year interval and to optimize mt-sDNA's screening effectiveness.

10545 Background: Approximately 20–30% of colorectal cancers (CRC) arise from the serrated polyp pathway. The multitarget stool DNA (mt-sDNA) test has greater sensitivity to detect sessile serrated polyps (SSPs) than a leading fecal immunochemical test (FIT). However, most modeling analyses do not account for the contribution of the SSP pathway to risk of CRC. We used the CRC-AIM model to assess the impact of the SSP pathway on predicted CRC outcomes with mt-sDNA or FIT screening. Methods: A simulated cohort of average-risk US patients underwent triennial mt-sDNA or annual FIT screening from ages 50–75. The percentage of CRCs arising from the SSP pathway were modeled at 0% (base case), 20%, and 30%, with stool screening adherence based on theoretical (100%) or previously reported (mt-sDNA 71%; FIT 43%) rates. Published SSP sensitivities for mt-sDNA and FIT were used. All other model inputs were identical to CISNET models. Sensitivity analyses used screening adherence rates of 40–70%. Key outcomes were life-years gained (LYG), CRC incidence and CRC mortality per 1000 patients. Results: Including SSPs in the model demonstrated a greater loss of LYG with FIT than mt-sDNA (Table). At 100% adherence, compared with base case, modeling 20% or 30% SSP pathway CRCs resulted in a decrease of 9–15 LYG with FIT and 2–4 LYG with mt-sDNA, a decrease in CRC incidence reduction of 3.9–6.1% with FIT and 0.7–1.1% with mt-sDNA, and a decrease in CRC mortality reduction of 2.6–4.0% with FIT and 0.4–0.8% with mt-sDNA. Using previously reported adherence, compared with base case, modeling 20% or 30% SSP pathway CRCs resulted in a decrease of 13–20 LYG with FIT and 2–5 LYG with mt-sDNA, a decrease in CRC incidence reduction of 4.4–6.9% with FIT and 0.6–1.1% with mt-sDNA, and a decrease in CRC mortality reduction of 3.5–5.4% with FIT and 0.4–0.9% with mt-sDNA. Assuming reported adherence and 30% SSP pathway CRCs, mt-sDNA had 48 more LYG, 14.6% greater CRC incidence reduction, and 12.4% greater CRC mortality reduction than FIT. Assuming 30% SSP pathway CRCs, outcomes favored mt-sDNA vs FIT even after modeling equivalent adherence rates ranging from 40–70%. Conclusions: After incorporating the SSP pathway into the model, outcomes with mt-sDNA neared those of FIT at 100% screening adherence rates and surpassed FIT at more realistic reported screening adherence rates.[Table: see text]

Abstract High-specificity colorectal cancer screening is desirable to triage patients <50 years for colonoscopy; however, most endorsed colorectal cancer screening tests have not been rigorously evaluated in younger populations. This prospective cross-sectional study determined the specificity of the multitarget stool DNA (mt-sDNA) test in an average-risk screening population of 45 to 49 year-olds. Specificity was the primary outcome and was measured in participants without colorectal cancer or advanced precancerous lesions [APL– advanced adenomas (AA), and sessile serrated lesions ≥10 mm], and in the subgroup of participants with negative colonoscopic findings. APL sensitivity was a secondary outcome. The evaluable cohort included those who completed the study without protocol deviations and had a usable mt-sDNA test. Of 983 enrolled participants, 816 formed the evaluable cohort, with a mean age of 47.8 (SD, 1.5) years; 47.7% were women. No participants had colorectal cancer, 49 had APL, 253 had nonadvanced adenomas (NAA), and 514 had negative colonoscopic findings. mt-sDNA test specificity was 95.2% (95% CI, 93.4–96.6) in participants with NAA or negative findings [96.3% (confidence interval (CI), 94.3%–97.8%)] in those with negative findings, and did not differ by sex (P = 0.75) or race (P = 0.36) in participants with NAA or negative findings. Sensitivity for APL was 32.7% (CI, 19.9–47.5%), with most APL (83.7%) measuring 10–19 mm and none having high-grade dysplasia. The area under the ROC curve for discriminating between APL and lesser findings was 0.72 (CI, 0.64–0.81). mt-sDNA's high specificity would help minimize risk from unnecessary diagnostic procedures in this age group. This study shows that mt-sDNA has high specificity among average-risk 45 to 49-year olds, supporting its use as a noninvasive option for colorectal cancer screening. Prevention Relevance: This study shows that mt-sDNA has high specificity among average-risk 45–49 year olds, supporting its use as a non-invasive option for colorectal cancer screening.

INTRODUCTION: Due to the rising incidence and mortality of colorectal cancer (CRC) in individuals < 55 years (Siegel R, et al, JNCI, 2017), American Cancer Society (ACS) guidelines now recommend average-risk CRC screening beginning at age 45 years. The multi-target stool DNA (mt-sDNA) test, an FDA-approved screening test for average-risk individuals ≥50 years, is one ACS-recommended option for this age group. To minimize invasive testing in the younger age group, a screening test with high specificity is necessary to triage patients for diagnostic colonoscopy. To date, most endorsed CRC screening tests have not been rigorously studied in younger age groups. The objective of this study (the Act Now study [NCT03728348]) is to quantify the specificity of the mt-sDNA test in average risk individuals ages 45-49. METHODS: Act Now is an ongoing prospective, cross-sectional, multi-center study in subjects ages 45-49 at average risk for CRC. 942 subjects are targeted for enrollment and will complete a mt-sDNA test prior to undergoing a screening colonoscopy (blinded to mt-sDNA test results). Specificity for advanced colorectal neoplasia will be determined by comparing mt-sDNA test results to the most advanced finding on colonoscopy, based on procedure report and histopathological findings. Due to the low prevalence of CRC in this age group, mt-sDNA test sensitivity will be a secondary measure. RESULTS: To date, 480 subjects have completed a mt-sDNA test and screening colonoscopy. A total of 468 subjects (97.5%) have no first-degree relative (FDR) with CRC and 12 subjects (2.5%) have an FDR diagnosed at age ≥60 years. No subject has had a previous screening colonoscopy. The study population has a mean age of 47.4 years and is 48.8% female. Self-reported race includes 84.2% white, 11.5% black/African American, 3.3% Asian, and 1.0% other. Self-reported ethnicity includes 95.2% not Hispanic or Latino, 4.6% Hispanic or Latino, and 0.2% other. The mean BMI of subjects is 29.6 kg/m 2 . Most subjects (67.1%) have never smoked cigarettes, while 21.9% are former smokers and 11.0% are current smokers. CONCLUSION: The ongoing Act Now study will quantify the specificity of the mt-sDNA test in average risk individuals ages 45-49. Given concerns regarding the resources required to screen this age group for CRC, a noninvasive screening test with high specificity and sensitivity will help to optimize use of colonoscopy resources.

SummaryBackgroundCurrent approaches to the detection of colorectal neoplasia associated with inflammatory bowel disease (IBD‐CRN) are suboptimal.AimTo test the feasibility of using stool assay of exfoliated DNA markers to detect IBD‐CRN.MethodsThis investigation comprised tissue and stool studies. In the tissue study, gene sequencing and methylation assays were performed on candidate genes using tissue DNA from 25 IBD‐CRNs and from 25 IBD mucosae without CRN. Mutations on p53, APC, KRAS, BRAF or PIK3CA genes were insufficiently informative, but several aberrantly methylated genes were highly discriminant. In the stool study, we evaluated candidate methylated genes (vimentin, EYA4, BMP3, NDRG4) in a prospective blinded study on buffered stools from 19 cases with known IBD‐CRN and 35 age‐ and sex‐matched IBD controls without CRN. From stool‐extracted DNA, target genes were assayed using quantitative allele‐specific real‐time target and signal amplification method.ResultsIBD‐CRN cases included 17 with ulcerative colitis (UC) and two with Crohn's disease (CD); nine had cancer and 10 had dysplasia. Controls included 25 with UC and 10 with CD. Individually, BMP3, vimentin, EYA4 and NDRG4 markers showed high discrimination in stools with respective areas under the ROC curve of 0.91, 0.91, 0.85 and 0.84 for total IBD‐CRN and of 0.97, 0.97, 0.95 and 0.85 for cancer. At 89% specificity, the combination of BMP3 and mNDRG4 detected 9/9 (100%) of CRC and 80% of dysplasia, 4/4 (100%) of high grade and 4/6 (67%) of low grade.ConclusionThese findings demonstrate the feasibility of stool DNA testing for non‐invasive detection of colorectal neoplasia associated with inflammatory bowel disease.