Multitarget Stool DNA Testing Has High Positive Predictive Value for Colorectal Neoplasia on the Second Round of Testing.

BACKGROUND & AIMS: Multitarget stool DNA (mt-sDNA) testing is a stool-based screening test for colorectal cancer (CRC). In a single instance of testing, the pivotal Food and Drug Administration-approval study (NCT01397747) found that 16% of mt-sDNA tests were positive, and the positive predictive value (PPV) for CRC or advanced precursor lesions (APL) was 27.3%. We aimed to examine real-world longitudinal performance by determining the test-positive rate and PPV of mt-sDNA on the second round of testing. METHODS: Colonoscopy and pathology reports were reviewed retrospectively for patients with a negative mt-sDNA on the first round of screening and a positive mt-sDNA on the second round. The test-positivity rate and PPV for CRC, APL, and any colorectal neoplasia were calculated for the second mt-sDNA and compared with baseline PPVs from a previously published cohort of patients from our institution who tested positive on the first round of screening. RESULTS: A total of 2758 patients completed a second test at a median of 3.2 years after the first test. Of these, 422 (15%) had a positive second mt-sDNA. The PPV was 0.25% for CRC, 24% for APL, and 67% for any colorectal neoplasia. There was no significant difference in PPV on the second mt-sDNA test compared with the first round (24% vs 28% for APL; P = .12). CONCLUSIONS: mt-sDNA test positive rate and PPV were similar between the first and second rounds of screening. These observations confirm the utility of a second round of mt-sDNA screening and may inform estimates of mt-sDNA effectiveness for CRC screening.

Neoplasia Diagnosis After Multi-target Stool DNA Is Enhanced Among Lowest Baseline Detectors.

BACKGROUND AND AIMS: Variation in colorectal neoplasia detection limits the effectiveness of screening colonoscopy. By evaluating neoplasia detection rates of individual colonoscopists, we aimed to quantify the effects of pre-procedural knowledge of a positive (+) multi-target stool DNA (mt-sDNA) on colonoscopy quality metrics. METHODS: We retrospectively identified physicians who performed a high volume of + mt-sDNA colonoscopies; colorectal neoplasia at post-mt-sDNA colonoscopy was recorded. These colonoscopists were stratified into quartiles based on baseline adenoma detection rates. Baseline colonoscopy adenoma detection rates and sessile serrated lesion detection rates were compared to post-mt-sDNA colonoscopy neoplasia diagnosis rates among each quartile. Withdrawal times were measured from negative exams. RESULTS: During the study period (2014-17) the highest quartile of physicians by volume of post-mt-sDNA colonoscopies were evaluated. Among thirty-five gastroenterologists, their median screening colonoscopy adenoma detection rate was 32% (IQR, 28-39%) and serrated lesion detection rate was 13% (8-15%). After + mt-sDNA, adenoma diagnosis increased to 47% (36-56%) and serrated lesion diagnosis increased to 31% (17-42%) (both p < 0.0001). Median withdrawal time increased from 10 (7-13) to 12 (10-17) minutes (p < 0.0001) and was proportionate across quartiles. After + mt-sDNA, lower baseline detectors had disproportionately higher rates of adenoma diagnosis in female versus male patients (p = 0.048) and higher serrated neoplasia diagnosis rates among all patients (p = 0.0092). CONCLUSIONS: Knowledge of + mt-sDNA enriches neoplasia diagnosis compared to average risk screening exams. Adenomatous and serrated lesion diagnosis was magnified among those with lower adenoma detection rates. Awareness of the mt-sDNA result may increase physician attention during colonoscopy. Pre-procedure knowledge of a positive mt-sDNA test improves neoplasia diagnosis rates among colonoscopists with lower baseline adenoma detection rates, independent of withdrawal time.

Multitarget Stool DNA Screening in Clinical Practice: High Positive Predictive Value for Colorectal Neoplasia Regardless of Exposure to Previous Colonoscopy.

OBJECTIVES: Multitarget stool DNA (MT-sDNA) testing has grown as a noninvasive screening modality for colorectal cancer (CRC), but real-world clinical data are limited in the post-FDA approval setting. The effect of previous colonoscopy on MT-sDNA performance is not known. We aimed to evaluate findings of colorectal neoplasia (CRN) at diagnostic colonoscopy in patients with positive MT-sDNA testing, stratified by patient exposure to previous colonoscopy. METHODS: We identified consecutive patients completing MT-sDNA testing over a 39-month period and reviewed the records of those with positive tests for neoplastic findings at diagnostic colonoscopy. MT-sDNA test positivity rate, adherence to diagnostic colonoscopy, and the positive predictive value (PPV) of MT-sDNA for any CRN and neoplastic subtypes were calculated. RESULTS: Of 16,469 MT-sDNA tests completed, testing returned positive in 2,326 (14.1%) patients. After exclusion of patients at increased risk for CRC, 1,801 patients remained, 1,558 (87%) of whom underwent diagnostic colonoscopy; 918 of 1,558 (59%) of these patients had undergone previous colonoscopy, whereas 640 (41%) had not. Any CRN was found in 1,046 of 1,558 patients (PPV = 67%). More neoplastic lesions were found in patients without previous colonoscopy (73%); however, the rates remained high among those who had undergone previous colonoscopy (63%, P < 0.0001). The large majority (79%) of patients had right-sided neoplasia. DISCUSSION: MT-sDNA has a high PPV for any CRN regardless of exposure to previous colonoscopy. Right-sided CRN was found at colonoscopy in most patients with positive MT-sDNA testing, representing a potential advantage over other currently available screening modalities for CRC.

Stool-Based Tests for Colorectal Cancer Screening: Performance Benchmarks Lead to High Expected Efficacy.

PURPOSE OF REVIEW: Participation goals for colorectal cancer (CRC) screening in the USA have not been met. Non-invasive screening strategies may improve CRC screening participation. We highlight recent literature on stool-based screening performance and expectations for emerging non-invasive screening tests. RECENT FINDINGS: Stool-based CRC screening detects screen-relevant colorectal neoplasia and outperforms a currently available plasma assay. Though modestly sensitive for CRC, adherence to annual fecal immunochemical testing (FIT) is sub-optimal. Multi-target stool DNA (MT-sDNA) has greater adherence, superior sensitivity for screen-relevant lesions (including those in the proximal colon and sessile serrated architecture), and equivalent specificity to FIT over a 3-year period. Stool-based CRC screening tests are anticipated to reduce the incidence and mortality of CRC through detection of early-stage cancers and high-risk polyps. These endpoints in performance will need to be met by emerging blood sample-based tests in order have meaningful impact in clinical practice.

Trends in Colorectal Cancer Screening from the National Health Interview Survey: Analysis of the Impact of Different Modalities on Overall Screening Rates.

Colorectal cancer is the second leading cause of cancer-related mortality in adults in the United States. Despite compelling evidence of improved outcomes in colorectal cancer, screening rates are not optimal. This study aimed to characterize colorectal cancer screening trends over the last two decades and assess the impact of various screening modalities on overall colorectal cancer screening rates. Using National Health Interview Survey data from 2005 to 2021, we examined colorectal cancer screening [colonoscopy, multitarget stool DNA (mt-sDNA), fecal occult blood test (FOBT)/fecal immunochemical test, sigmoidoscopy, CT colonography] rates among adults ages 50-75 years (n = 85,571). A pseudo-time-series cross-sectional (pseudo-TSCS) analysis was conducted including a random effects generalized least squares regression model to estimate the relative impact of each modality on changes in colorectal cancer screening rates. Among 50 to 75 year olds, the estimated colorectal cancer screening rate increased from 47.7% in 2005 to 69.9% in 2021, with the largest increase between 2005 and 2010 (47.7%-60.7%). Rates subsequently plateaued until 2015 but increased from 63.5% in 2015 to 69.9% in 2018. This was primarily driven by the increased use of mt-sDNA (2.5% in 2018 to 6.6% in 2021). Pseudo-TSCS analysis results showed that mt-sDNA contributed substantially to the increase in overall screening rates (77.3%; P < 0.0001) between 2018 and 2021. While colorectal cancer screening rates increased from 2005 to 2021, they remain below the 80% goal. The introduction of mt-sDNA, a noninvasive screening test may have improved overall rates. Sustained efforts are required to further increase screening rates to improve patient outcomes and offering a range of screening options is likely to contribute to achieving this goal. PREVENTION RELEVANCE: This retrospective study highlights the importance of convenient stool-based colorectal cancer screening options to achieve the national goal of 80% for overall colorectal cancer screening rates. Empowering screening-eligible individuals with a choice for their colorectal cancer screening tests is imperative.

Estimated impact and value of blood-based colorectal cancer screening at varied adherence compared with stool-based screening.

OBJECTIVE: This analysis estimated the outcomes of triennial blood-based colorectal cancer (CRC) screening at various adherence, including perfect adherence, compared with triennial multi-target stool DNA (mt-sDNA) screening at the reported real-world adherence rate. METHODS: The validated CRC-AIM model simulated a US cohort of average-risk individuals receiving triennial screening with mt-sDNA or blood-based test from ages 45 to 75 years. Modeled specificity and sensitivity were based on reported data. Adherence was set at a real-world rate of 65.6% for mt-sDNA and at 65.6%, relative 10% incremental increases from 65.6%, or 100% for the blood-based test. Costs of mt-sDNA and the blood-based test were based on prices for clinically available tests ($508.87 and $895, respectively). Value-based pricing was estimated at a willingness-to-pay threshold of $100,000. RESULTS: Both tests resulted in life-years gained (LYG), reduced CRC cases, and reduced deaths versus no screening. With adherence for mt-sDNA set at 65.6% and for blood-based test set at 100%, mt-sDNA resulted in 30% more LYG, 52% more averted CRC cases, and 32% more averted CRC deaths. At reported sensitivity and specificity rates, mt-sDNA at 65.6% adherence dominates (is more effective and less costly) the blood-based test at any adherence. There was no price at which triennial screening with the blood-based test at any adherence was cost-effective compared with mt-sDNA at 65.6% adherence. CONCLUSIONS: Triennial screening with mt-sDNA resulted in better clinical outcomes at a lower cost compared with the modeled blood-based test even at perfect adherence, supporting application of blood-based tests only as a secondary screening option.

Blood-based colorectal cancer screening has lower diagnostic accuracy, lower clinical and health outcomes, and is more expensive than mt-sDNA, even with perfect blood-based screening participation. Although better than no screening at all, blood-based testing is unlikely to exceed performance of stool-based assessment unless a blood-based test is able to meaningfully detect precancerous growths.

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

BACKGROUND AND AIMS: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Stool-Based Colorectal Cancer Screening Test Performance Characteristics in Those With and Without Hemorrhoids.

Objective: To evaluate the effect of hemorrhoids on noninvasive stool test performance for colorectal cancer (CRC) screening. Patients and Methods: We conducted a retrospective cohort study of test characteristics for the fecal immunochemical test (FIT) and the multitarget stool DNA (mt-sDNA) test, on the basis of hemorrhoid status, recorded at the time of colonoscopy, among patients enrolled in the pivotal prospective study for mt-sDNA that was conducted from June 2011, to May 2013. Test characteristics (sensitivity, specificity, positive, and negative predictive values) for FIT and mt-sDNA (performed < 90 days before colonoscopy) were stratified by the presence of hemorrhoids and compared. Results: Hemorrhoids were found in 51.7% (5163 of 9989) of the study cohort. Across all test characteristics, there were no statistically significant differences for FIT or mt-sDNA when stratified by hemorrhoid status. Analysis revealed mt-sDNA sensitivity of 44% and 41% for advanced precancerous lesions in nonhemorrhoidal and hemorrhoid patients, respectively (P=.41). The FIT sensitivity among the same lesion category was 24.9% in patients without hemorrhoids and 22.8% in those with hemorrhoids (P=.48). The mt-sDNA specificity was 86.4% in patients without hemorrhoids vs 87.7% in those with hemorrhoids (P=.67), although FIT specificity was 95.0% among patients without hemorrhoids vs 94.7% in those with hemorrhoids (P=.44). Conclusion: The presence of asymptomatic hemorrhoids did not adversely affect test performance in this large clinical study. These findings suggest that in the absence of overt gastrointestinal bleeding, FIT and mt-sDNA are options for CRC screening, irrespective of hemorrhoid status. Trial Registration: clinicaltrials.gov Identifier: NCT01397747.

High Positive Predictive Value of Multitarget Stool DNA After Aerodigestive Tract Radiotherapy.

BACKGROUND AND AIMS: Multitarget stool DNA (mt-sDNA) is approved for average-risk colorectal cancer screening; test performance in persons with prior radiation therapy (RT) has not been studied. RT can induce gastrointestinal bleeding and alter DNA methylation, which may affect mt-sDNA accuracy. Among patients previously treated with RT, we aimed to measure the positive predictive value (PPV) of mt-sDNA and compare these results to historical estimates of mt-sDNA PPV among average-risk patients. METHODS: After institutional review board approval, we conducted a retrospective cohort study of a multisite academic and community-based practice. Patients with RT and subsequent mt-sDNA use during the study period (2014-2016) were identified. The findings at diagnostic colonoscopy were compared with published reports among average-risk patients. Nominal P values were generated by 2-tailed Fisher's exact testing in comparisons of colorectal neoplasia (CRN) rates between groups. RESULTS: There were 220 patients who had RT before mt-sDNA testing. RT was delivered along the aerodigestive tract in 108 patients. Mt-sDNA tests were positive in 45 of 220 patients (20%), and colonoscopy findings were available for 42; 31 of 42 patients (74%) had CRN. PPV by mt-sDNA was similar when stratified by site of prior RT (along vs outside the aerodigestive tract; P = 1.00). Detection of advanced CRN (36%) was nominally higher than previously published retrospective (27%) and prospective (20%) studies. The median time from the start of RT to mt-sDNA use was 7 (interquartile range, 3-14) years. CONCLUSION: With a test positivity rate and PPV for CRN similar to reports among average-risk patients, prior RT does not appear to adversely affect mt-sDNA performance.

Detection of Postcolonoscopy Colorectal Neoplasia by Multi-target Stool DNA.

INTRODUCTION: Significant variability between colonoscopy operators contributes to postcolonoscopy colorectal cancers (CRCs). We aimed to estimate postcolonoscopy colorectal neoplasia (CRN) detection by multi-target stool DNA (mt-sDNA), which has not previously been studied for this purpose. METHODS: In a retrospective cohort of patients with +mt-sDNA and completed follow-up colonoscopy, positive predictive value (PPV) for endpoints of any CRN, advanced adenoma, right-sided neoplasia, sessile serrated polyps (SSP), and CRC were stratified by the time since previous colonoscopy (0-9, 10, and ≥11 years). mt-sDNA PPV at ≤9 years from previous average-risk screening colonoscopy was used to estimate CRN missed at previous screening colonoscopy. RESULTS: Among the 850 studied patients with +mt-sDNA after a previous negative screening colonoscopy, any CRN was found in 535 (PPV 63%). Among 107 average-risk patients having +mt-sDNA ≤9 years after last negative colonoscopy, any CRN was found in 67 (PPV 63%), advanced neoplasia in 16 (PPV 15%), right-sided CRN in 48 (PPV 46%), and SSP in 20 (PPV 19%). These rates were similar to those in 47 additional average risk persons with previous incomplete colonoscopy and in an additional 68 persons at increased CRC risk. One CRC (stage I) was found in an average risk patient who was mt-sDNA positive 6 years after negative screening colonoscopy. DISCUSSION: The high PPV of mt-sDNA 0-9 years after a negative screening colonoscopy suggests that lesions were likely missed on previous examination or may have arisen de novo. mt-sDNA as an interval test after negative screening colonoscopy warrants further study.

Multi-Target Stool DNA Testing for Colorectal Cancer Screening: Emerging Learning on Real-world Performance.

PURPOSE OF REVIEW: Multi-target stool DNA (MT-sDNA) was approved in 2014 for use in screening average-risk patients for colorectal cancer (CRC). Here, we highlight recent literature from post-market studies to provide an update on clinical use and utility not possible from pre-approval studies. RECENT FINDINGS: MT-sDNA has been included in major society guidelines as an option for colorectal cancer screening, and has seen exponentially increasing use in clinical practice. MT-sDNA appears to be attracting new patients to CRC screening, and patient adherence to diagnostic colonoscopy after a positive MT-sDNA test is high. Approximately two-thirds of these patients are found to have colorectal neoplasia (CRN), 80% of whom have at least one right-sided lesion; 1 in 3 will have advanced CRN. High yield of CRN is due not only to post-screening increase in probability but also likely improved endoscopist attention. In those with a negative high-quality colonoscopy after positive MT-sDNA test ("false positive MT-sDNA"), further interventions do not appear to be necessary. SUMMARY: MT-sDNA is a promising tool to improve rates and quality of CRC screening. Further investigation should examine MT-sDNA performance in populations at increased risk for CRC, and as an interval test after colonoscopy to detect potentially missed lesions.

Estimated Average-Risk Colorectal Cancer Screening-Eligible Population in the US.

This cross-sectional study estimates the number of average-risk colorectal cancer screening­eligible individuals in the US since the US Preventive Services Task Force updated its recommendations in 2021.