Average-risk Colorectal Cancer Screening Research Articles

Extended flexible sigmoidoscopy using water exchange facilitates a complete colon examination without sedation in participants undergoing average risk colorectal cancer screening: results from a randomized trial

Lay Summary Colon cancer is a leading cause of cancer deaths. Leading guidelines recommend flexible sigmoidoscopy (FS) every 10 years as a screening option for average-risk people. One area of progress involves a method called water exchange (WE). This is useful for cancer screening. We performed a randomized controlled trial on 90 average-risk individuals aged 50-74. They were tested with 2 methods: unsedated extended FS using either WE or the standard method of gas insufflation (GAS). Both methods showed similar success in examining the whole colon. More participants were satisfied with WE than GAS. Both groups felt little pain. Our study shows that modern methods, especially using WE, are effective and safe. They may remove the need for sedation, making it easier to include in large-scale screening programs.

Real-world multi-target stool DNA longitudinal adherence for colorectal cancer re-screening in a large, national population.

e15633 Background: Colorectal cancer (CRC) is the fourth most diagnosed cancer, as well as the second leading cause of cancer death in the United States – with an estimated 152,810 diagnoses and 53,010 fatal cases in 2024. Regular screening and early detection can reduce CRC incidence and improve overall survival; however, recent national survey data (2021) demonstrate that only 59% of the US screen-eligible population (≥ age 45) is up to date. Home-based, non-invasive CRC screening test options, such as the multi-target stool DNA (mt-sDNA) test, have the potential to improve patient outcomes and overcome CRC screening adherence barriers at multiple levels. Given that the recommended interval for mt-sDNA is three years, a better understanding of use in repeat users is warranted. We evaluated the effective rescreen rate of previous mt-sDNA test users. Methods: In this retrospective cohort study, we included patients between the ages of 45 and 75 years who were shipped an mt-sDNA test kit between January 1st – December 31st, 2023, and had previously completed mt-sDNA screening with a negative result > 2.5 years prior. Our primary variable of interest was mt-sDNA completion rate on repeat testing, defined as kit receipt with a valid result within 120 days of the shipment date. Regression analysis was performed to determine baseline characteristics associated with repeat test completion rate. Results: During the analysis period, a total of 481,748 patients who met the inclusion criteria received an mt-sDNA kit. The majority of the cohort was female (61.4%) and between the ages of 65-75 years (50.9%). Overall repeat test completion rate was 83.6%, with the average time to kit return being 18.9 days. Completion rates were similar between males (83.8%) and females (83.6%), and patients receiving included navigation support via mobile phones demonstrated the shortest average time to kit return (18.7 days). Completion rates increased concordantly with patient age: 81.6%, (45-49 years), 82.2% (50-64 years), and 85% (65-75 years). For first-time rescreen participants (2nd lifetime mt-sDNA test), the completion rate was 83.1%. For second-time rescreen participants (3rd lifetime mt-sDNA test), the completion rate was even higher at 93.6%. Logistic regression analyses revealed that patients re-screening for a second-time were three times more likely to return the mt-sDNA kit for CRC screening (OR = 3.118; p < 0.001). Conclusions: Data from this large, retrospective cohort study revealed that repeat CRC screening with the mt-sDNA test is associated with high adherence to triennial follow-up among participants. suggesting a high-level of perceived patient confidence in repeat performance of the mt-sDNA test. These novel data provide relevant insights regarding strong patient willingness to continue with home-based, non-invasive mt-sDNA testing over multiple cycles of average-risk CRC screening.

National Trends in the Incidence of Sporadic Malignant Colorectal Polyps in Young Patients (20-49 Years): An 18-Year SEER Database Analysis.

Background and Objectives: Conflicting guidelines exist for initiating average-risk colorectal cancer screening at the age of 45 years. The United States Preventive Services Task Force (USPSTF) changed its guidelines in 2021 to recommend initiating screening at 45 years due to an increasing incidence of young-onset colorectal cancer. However, the American College of Physicians (ACP) recently recommended not screening average-risk individuals between 45 and 49 years old. We aim to study the national trends in the incidence of sporadic malignant polyps (SMP) in patients from 20 to 49 years old. Materials and Methods: We analyzed the Surveillance, Epidemiology, and End Results database (2000-2017) on patients aged 20-49 years who underwent diagnostic colonoscopy with at least a single malignant sporadic colorectal polyp. Results: Of the 10,742 patients diagnosed with SMP, 42.9% were female. The mean age of incidence was 43.07 years (42.91-43.23, 95% CI). Approximately 50% of malignant polyps were diagnosed between 45 and 49 years of age, followed by 25-30% between 40 and 45. There was an upward trend in malignant polyps, with a decreased incidence of malignant villous adenomas and a rise in malignant adenomas and tubulovillous adenomas. Conclusions: Our findings suggest that almost half of the SMPs under 50 years occurred in individuals under age 45, younger than the current screening threshold recommended by the ACP. There has been an upward trend in malignant polyps in the last two decades. This reflects changes in tumor biology, and necessitates further research and support in the USPSTF guidelines to start screening at the age of 45 years.

Commentary: Liquid Biopsy for Average-Risk Colorectal Cancer Screening

Commentary: Liquid Biopsy for Average-Risk Colorectal Cancer Screening

Estimate of Increase in Colorectal Cancer Diagnoses with Expansion of Fecal Immunochemical Testing in an Urban Safety-Net Population.

Fecal immunochemical test (FIT) is less effective in detecting advanced adenomas (AA) than colonoscopy. Increase in FIT for colorectal cancer (CRC) screening may lead to an increased number of undetected AAs which may develop into future CRCs. We determined the potential impact of FIT expansion on missed AAs and future CRC diagnoses in an urban, tertiary-care, safety-net hospital. CRC and AA diagnoses were identified in patients undergoing colonoscopy for average-risk CRC screening or positive FIT between 2017 and 2019 at Boston Medical Center. Poisson regression modeling was used to estimate the frequency of AAs per year by age group using data from 2017 to 2019, assuming average outpatient volume and proportion of screening colonoscopies. Total number of patients who received FIT was extrapolated from those who underwent colonoscopy for positive FIT. We estimated AAs per year if 'one-time' FIT was used for screening in 75% and 100% of the population and subtracted this from the estimated AAs per year under the Poisson model to determine missed AAs. We used previously described, age and gender specific estimates of the annual progression of AA to CRC. The estimated number of CRCs detected per year is 4.6/1785 males and 4.6/2086 females screened. With 75% FIT expansion, we estimate an additional 3.5 (95% CI 1.3, 9.5) and 2.2 (95% CI 0.64, 7.6) CRCs; with 100% FIT expansion, we estimate an additional 7.4 (95% CI 3.7, 14.9) and 4.2 (95% CI 1.7, 10.5) CRCs, in 5years, in males and females, respectively. Expansion of FIT may substantially increase CRC incidence.

Personalized Multilevel Intervention for Improving Appropriate Use of Colorectal Cancer Screening in Older Adults

Despite guideline recommendations, clinicians do not systematically use prior screening or health history to guide colorectal cancer (CRC) screening decisions in older adults. To evaluate the effect of a personalized multilevel intervention on screening orders in older adults due for average-risk CRC screening. Interventional 2-group parallel unmasked cluster randomized clinical trial conducted from November 2015 to February 2019 at 2 US Department of Veterans Affairs (VA) facilities: 1 academic VA medical center and 1 of its connected outpatient clinics. Randomization at the primary care physician/clinician (PCP) level, stratified by study site and clinical full-time equivalency. Participants were 431 average-risk, screen-due US veterans aged 70 to 75 years attending a primary care visit. Data analysis was performed from August 2018 to August 2023. The intervention group received a multilevel intervention including a decision-aid booklet with detailed information on screening benefits and harms, personalized for each participant based on age, sex, prior screening, and comorbidity. The control group received a multilevel intervention including a screening informational booklet. All participants received PCP education and system-level modifications to support personalized screening. The primary outcome was whether screening was ordered within 2 weeks of clinic visit. Secondary outcomes were concordance between screening orders and screening benefit and screening utilization within 6 months. A total of 436 patients were consented, and 431 were analyzed across 67 PCPs. Patients had a mean (SD) age of 71.5 (1.7) years; 424 were male (98.4%); 374 were White (86.8%); 89 were college graduates (21.5%); and 351 (81.4%) had undergone prior screening. A total of 258 (59.9%) were randomized to intervention, and 173 (40.1%) to control. Screening orders were placed for 162 of 258 intervention patients (62.8%) vs 114 of 173 control patients (65.9%) (adjusted difference, -4.0 percentage points [pp]; 95% CI, -15.4 to 7.4 pp). In a prespecified interaction analysis, the proportion receiving orders was lower in the intervention group than in the control group for those in the lowest benefit quartile (59.4% vs 71.1%). In contrast, the proportion receiving orders was higher in the intervention group than in the control group for those in the highest benefit quartile (67.6% vs 52.2%) (interaction P = .049). Fewer intervention patients (106 of 256 [41.4%]) utilized screening overall at 6 months than controls (96 of 173 [55.9%]) (adjusted difference, -13.4 pp; 95% CI, -25.3 to -1.6 pp). In this cluster randomized clinical trial, patients who were presented with personalized information about screening benefits and harms in the context of a multilevel intervention were more likely to receive screening orders concordant with benefit and were less likely to utilize screening. ClinicalTrials.gov Identifier: NCT02027545.

Effect of aspirin, warfarin, and proton-pump inhibitors on performance of fecal immunochemical test in colorectal cancer screening: a systematic review and meta-analysis.

This study aims to investigate the impact of antithrombotic agents and proton-pump inhibitors (PPIs) on fecal immunochemical test (FIT). PubMed, EMBASE, Web of Science, Cochrane Central, and Google Scholar were searched from inception until September 3, 2023. Studies comparing the diagnostic performance of FIT between medicine users and non-users in average-risk colorectal cancer screening populations were included. Pooled sensitivity, specificity, and positive predictive values (PPVs) for advanced neoplasia (AN) of FIT were compared by reporting pooled odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects model. Twenty-two studies enrolling 5,572,367 individuals were included. For aspirin, pooled sensitivity and specificity for AN were 57.2% and 88.4% in users versus 60.2% and 93.2% in non-users; while pooled ORs were 1.49 (95% CI 0.89-2.48, P = 0.13) and 0.72 (95% CI 0.62-0.83, P < 0.001), respectively. In subgroup analysis, there was no difference in sensitivity and specificity between the two groups at the cutoff of 20μg Hb/g (P = 0.57 and 0.29, respectively) but a significantly lower specificity in users compared with non-users at lower cutoffs (P < 0.001). Moreover, a significantly lower PPVAN in users compared with non-users was observed after matching age and sex confounders (P = 0.001). Warfarin had no significant influence on PPVAN of FIT (P = 0.43). PPIs were associated with a significantly lower PPVAN in users (P < 0.001). Aspirin use was associated with lower specificity and PPV of FIT. Aspirin discontinuation before FIT to reduce false-positive results should be interpreted with caution given concerns about cardiovascular events. Increasing cutoff values of FIT in aspirin users may be another possible approach. Additionally, warfarin withdrawal before FIT is unnecessary but PPIs withdrawal before FIT is recommended to reduce false-positive results.

The impact on clinical outcomes and healthcare resources from discontinuing colonoscopy surveillance subsequent to low-risk adenoma removal: A simulation study using the OncoSim-Colorectal model.

To estimate the impact on clinical outcomes and healthcare resource use from recommending that patients with 1-2 low-risk adenomas (LRAs) return to routine fecal immunochemical test (FIT) screening instead of surveillance colonoscopy, from a Canadian provincial healthcare system perspective. The OncoSim-Colorectal microsimulation model simulated average-risk individuals eligible for FIT-based colorectal cancer (CRC) screening in Alberta, Canada. We simulated two surveillance strategies that applied to individuals with 1-2 LRAs (<10 mm) removed as part of the average risk CRC screening program: (a) Surveillance colonoscopy (status quo) and (b) return to FIT screening (new strategy); both at 5 years after polypectomy. A 75 ng/mL FIT positivity threshold was used in the base case. The simulations projected average annual CRC outcomes and healthcare resource use from 2023 to 2042. We conducted alternative scenarios and sensitivity analyses on key variables. Returning to FIT screening (versus surveillance colonoscopy) after polypectomy was projected to have minimal impact on long-term CRC incidence and deaths (not statistically significant). There was a projected decrease of one (4%) major bleeding event and seven (5%) perforation events per year. There was a projected increase of 4800 (1.5%) FIT screens, decrease of 3900 (5.1%) colonoscopies, and a decrease of $3.4 million (1.2%) in total healthcare costs per year, on average. The annual colonoscopies averted and healthcare cost savings increased over time. Results were similar in the alternative scenarios and sensitivity analyses. Returning to FIT screening would have similar clinical outcomes as surveillance colonoscopy but could reduce colonoscopy demand and healthcare costs.

The cost-effectiveness of non-invasive stool-based colorectal cancer screening offerings from age 45 for a commercial and medicare population

AimThe United States Preventive Services Taskforce (USPSTF) recently recommended lowering the age for average-risk colorectal cancer (CRC) screening from 50 to 45 years. While initiating screening at age 45 versus 50 provides a greater opportunity for CRC early detection and prevention, the full profile of benefits, risks, and cost-effectiveness of expanding the screen-eligible population requires further evaluation.Materials and methodsThe costs and clinical outcomes for screening at age 45 for triennial multi-target stool DNA [mt-sDNA], and other non-invasive stool-based modalities (annual fecal immunochemical test [FIT] and annual fecal-occult blood test [FOBT]), were estimated using the validated CRC-AIM microsimulation model over a lifetime horizon. Test sensitivity and specificity inputs were based on 2021 USPSTF modeling analyses; adherence rates were based on published real-world data and the costs of the screening test, follow-up colonoscopies, complications, and CRC care were included. Outcomes are reported from the perspective of a United States payer as clinical, life-years gained (LYG), and incremental cost-effectiveness ratio (ICER); stool-based and follow-up colonoscopy adherence ranges were explored in one-way, probabilistic and threshold analyses.ResultsWhen compared to initiation of CRC screening at age 45 versus 50, all modalities reduced both the incidence of and mortality from CRC and increased LYG. Initiating CRC screening at age 45 was cost-effective with an ICER of $59,816 and $35,857 per quality-adjusted life year (QALY) for mt-sDNA versus FIT and FOBT, respectively. In the threshold analyses, at equivalent rates to stool-based screening, mt-sDNA was always cost-effective at a willingness-to-pay threshold of $100,000 per QALY versus FIT and FOBT.ConclusionsInitiating average-risk CRC screening at age 45 instead of age 50 increases the estimated clinical benefit by reducing disease burden while remaining cost-effective. Among stool-based screening modalities, mt-sDNA provides the most clinical benefit in a Commercial and Medicare population.

A111 CLINICAL AND PATHOLOGICAL OUTCOMES BETWEEN WATER EXCHANGE AND AIR INSUFFLATION USING NON-SEDATED EXTENDED FLEXIBLE SIGMOIDOSCOPY FOR AVERAGE RISK COLORECTAL CANCER SCREENING: PRELIMINARY FINDINGS FROM A RANDOMIZED CONTROL TRIAL

Abstract Background Colorectal cancer (CRC) is Canada's third most common cancer type and represents approximately 11% of all cancer deaths. While sedated colonoscopy or flexible sigmoidoscopy (FS) continues to be considered for CRC screening, these modalities have limitations and risks. Another unevaluated screening modality, known as an extended FS (EFS), attempts to capitalize on the benefits of a FS while minimizing the risks involved with a sedated colonoscopy. EFS provides a scope-based examination up to the splenic flexure and then attempts to examine beyond, often to the point of the caecum. Providing the option for EFS may produce improvements in the patient experience and performance, which may improve the feasibility of using scope-based screening more broadly in screening programs. Purpose To determine the extent non-sedated EFS using the water exchange method (WE) is associated with a complete colon examination compared to the traditional air insufflation (AI) method using CO2 in an average-risk screening population. Method This randomized control trial included 90 non-sedated participants, screened by trained general surgery and gastroenterology clinicians at Kelowna General Hospital, British Columbia, Canada, using two different scope insufflation techniques, WE and AI. The primary outcome of interest was the cecal intubation rates (CIR), while secondary outcomes included the adenoma detection rate (ADR) and reported pain scores. Other metrics, such as patient satisfaction rates, sessile serrated adenoma detection rates (SSADR), and serrated lesion detection rates (SLDR) were also recorded. Result(s) The demographic characteristics between the WE and AI groups were statistically similar, with the mean age of participants being 58 and 57, respectively. During the study period, four endoscopists performed the EFS. There were higher initial satisfaction rates in the WE group vs the AI (95% vs 77%, satisfaction of ≥ 9/10 p = 0.028). CIR and ADR were similar between the WE and AI group (CIR = 93% vs 91%, p = 0.710), (ADR = 40% vs 34%, p = 0.660). The SSADR and SLDR were also similar between the WE and AI group (SSADR = 21% vs 14%, p = 0.408), (SLDR = 42% vs 36%, p = 0.528). Conclusion(s) EFS without sedation using either technique exceeds quality benchmarks recommended for sedated screening colonoscopy while maintaining adequate patient safety and comfort. The WE method optimizes a patient's overall experience making a strategy of average risk colorectal cancer screening with non-sedated WE EFS feasible. Please acknowledge all funding agencies by checking the applicable boxes below CAG, Other Please indicate your source of funding; Kelowna General Hospital, Interior Health Disclosure of Interest None Declared

Clinical performance of a multimodal screening blood test for advanced adenomas and CRC in an average-risk cohort of 1,038 participants.

75 Background: The National Polyp Study and 2021 USPSTF CRC-update highlight that the detection and removal of precancerous advanced adenomas (AA) prevents colorectal cancer (CRC), decreases mortality, and leads to higher cost savings than early cancer detection. Performance of a multimodal blood-based test for the detection of CRC and AA that integrates sensitive and accurate detection of circulating gastrointestinal epithelial cells and somatic oncologic variants as well as SEER data of the impact of sex and age is described. Methods: The prospective study included average-risk, asymptomatic screening subjects from 18 geographically dispersed US colonoscopy centers with blood drawn before colonoscopy. Monte Carlo cross-validation (MCCV) methods were used to evaluate the robustness of test performance through 2000 iterations of independent training and validation using bootstrap resampling with stratification to balance patient histopathology, age, and gender. Results include point estimates, confidence intervals, and distributions of sensitivity and specificity to detect AA and CRC. Results: The study cohort (53.2% female; mean age 56.7 yrs.) consisted of 1,038 subjects (White 65.1%; Black 8.5%; Hispanic 24.8%; Asian 1.7%); of which 954 (92%) were asymptomatic, average-risk screening subjects without age enrichment (including 11 CRC and 93 AA) and 84 (8%) were enriched case-control (65 CRC and 19 AA) subjects. The algorithm derives a test score from 0 (low risk) to 100 (high risk) as a quantitative measure of AA and CRC risk. A pre-defined cut point of 47.2 yields a test specificity &gt; 90%, and 92.1% and 54.5% sensitivity for the detection of CRC and AA, respectively. Estimated sensitivities and selected Clopper-Pearson (Exact) 95% confidence intervals based on validation results from MCCV are presented. A split analysis shows for the 954 intended-use, asymptomatic, average-risk screening subjects, the sensitivity for CRC and AA are 100% and 55.9%. Conclusions: A multi-site, prospective, average-risk CRC screening study using a multimodal assay had high sensitivity and specificity for AA and CRC. The quantitative correlation of test scores with disease pathology indicates that the modes of the assay interrogate the primary underlying pathophysiology of disease. The results demonstrate the potential of this novel test to meet the clinically unmet need for a noninvasive strategy for CRC screening and prevention that detects CRC and AA. Clinical trial information: NCT05127096 . [Table: see text]

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.

S343 The Effects of the COVID-19 Pandemic on Average-Risk Colorectal Cancer Screening: A Quality Assurance Evaluation to Assess Policy Success at the Facility Level

S343 The Effects of the COVID-19 Pandemic on Average-Risk Colorectal Cancer Screening: A Quality Assurance Evaluation to Assess Policy Success at the Facility Level

S2220 A Solitary Extramedullary Plasmacytoma Found in the Sigmoid Colon

Introduction: Plasmacytomas are rare tumors made of a single line of plasma cells that can appear anywhere in the body, but the majority arise in the bone marrow. Extramedullary plasmacytomas (EMPs) represent less than 5% of cases, and only 5% of EMPs occur in the gastrointestinal (GI) tract. GI EMPs occur most commonly in the small intestine, followed by the stomach; colonic EMPs are rare. We present a case of a solitary extramedullary plasmacytoma found in the sigmoid colon on routine colonoscopy. Case Description/Methods: A 75-year-old female with a history of hypertension and diabetes presented for evaluation of sour taste in her mouth and epigastric pain, and also for average-risk colorectal cancer screening. Esophagogastroduodenoscopy showed Los Angeles Classification grade A esophagitis and patchy gastric erythema with Helicobacter pylori infection confirmed from random gastric biopsies. Colonoscopy showed an erythematous nodule in the sigmoid colon, and polypectomy was performed (Figure). Pathology showed plasma cell population with immunostaining that was overwhelmingly positive for IgG and kappa consistent with extraosseous plasmacytoma. A repeat colonoscopy was performed in 4 months which confirmed complete removal of the plasmacytoma. The patient was referred to a hematologist with evaluation pending. Discussion: Colonic EMPs are rare. Patients can either be asymptomatic or present with abdominal pain, melena, and hematochezia. Once confirmed on pathology, patients should undergo extensive work-up including a complete blood count, comprehensive metabolic panel, and positron emission tomography to assess for more extensive involvement. Radiation therapy is warranted if complete surgical resection is not achieved, and these patients must be monitored closely for signs and symptoms of multiple myeloma. It is crucial for gastroenterologists to understand the significance of this rare finding to facilitate a comprehensive evaluation.Figure 1.: An erythematous nodule in the sigmoid colon.

Abstract 6203: Evaluating cost-effectiveness and clinical utility of a blood-based colorectal cancer (CRC) early detection assay, ColonAiQ࣪, through a real-world study in average-risk population (PreC)

Abstract Background: Effective non-invasive colorectal cancer (CRC) screening assays, with high sensitivity and specificity, are desired to increase patient compliance, improve early detection, and reduce CRC mortality. Current stool-based tests suffer with the handling difficulties with specimen, while blood-based tests that rely on single gene methylation have limited sensitivity. We have developed a multi-locus blood-based assay targeting circulating tumor DNA methylation, ColonAiQ, which was demonstrated the ability of early detection for CRC and advanced adenoma (AA) [1]. Study Design: We further organized a real-world cohort aiming for recruiting 120,000 average-risk population to evaluate ColonAiQ’s cost-effectiveness and clinical utility over a 3-year period. This Prospective evaluation of ColonAiQ, PreC study, is organized in Yangzhou city in China being supported by the local government and hospitals. Results: From Jan. 2021 to Aug. 2021, 21,735 apparently healthy volunteers aging from 40 to 80 (median 61.8) were recruited with 10ml blood draw to process with ColonAiQ assay. One thousand six hundred and thirty (7.5%) were tested positive in ColonAiQ, among which 650 were further examined by colonoscopy followed by pathological diagnosis on the biopsy specimen. We successfully identified 330 patients with neoplasm, including 14 (4.3%) asymptomatic CRC, 99 (30%) AA, 184 (43.9%) multi-adenoma or non-advanced adenoma, 33 (10%) polyps, together with 19 patients with non-neoplastic GI disorders. The positive predictive value (PPV) is primarily estimated as 2.2% for CRC and 15.2% for AA (43.5% for adenoma), although these numbers can be largely influenced by the scale of the sample size. Among those 14 identified CRC cases, none of them were tested positive in fecal immunochemical test (FIT), the current screening method locally available. Conclusion: Results from this real-world analysis of ColonAiQ performance, although a preliminary subset, demonstrates the assay robustness, tester compliance, patient adherence to the test result, substantially maximizing its potential benefits for average-risk CRC screening. ColonAiQ significantly increases the detection rate for precancerous adenomas and early-stage CRC when compared to existing molecular screening tests, which could greatly improve preventative care and CRC patient survival. Citation Format: Yanbing Ding, Jun Liu, Yongsheng Li, Cuiping Wang, Huisong Luo, Yang Li, Tingdong Tang, Hui Wang, Wenjun Pan, Huimin Yang, Haipeng Jia, Yunzhi Zhang, Rui Liu. Evaluating cost-effectiveness and clinical utility of a blood-based colorectal cancer (CRC) early detection assay, ColonAiQ࣪, through a real-world study in average-risk population (PreC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6203.

Modeling analysis of COVID 19-related delays in colorectal cancer screening on simulated clinical outcomes.

e13631 Background: Colorectal cancer (CRC) screening disruptions have been observed with the COVID-19 pandemic, putting patients at risk for more advanced-stage disease at the time of diagnosis. We estimated the impact of increased use of stool-based tests for screening during the COVID-19 pandemic on near-term clinical outcomes in a simulated United States (US) population. Methods: A previously developed budget impact model was adapted to assess the impact of increasing use of multi-target stool DNA [mt-sDNA] or fecal immunochemical [FIT] tests to offset the COVID-19 related disruption in colonoscopy screening. Adults, ages 50 – 75 years, at average risk for CRC were included over a 3-year time horizon (2020 – 2023) to explore the impact of increased screening for CRC using mt-sDNA or FIT, from the perspective of a US payer. Compared to the base case (S0; 85% colonoscopy and 15% non-invasive tests), the estimated number of missed CRCs and advanced adenomas (AAs) were determined for four COVID-19-affected screening scenarios: S1, 9 months of CRC screening at 50% capacity, followed by 21 months at 75% capacity; S2, S1 followed by increasing stool-based testing by an average of 10% over 3-years; S3, 18 months of CRC screening at 50% capacity, followed by 12 months of 75% capacity; and S4, S3 followed by increasing stool-based testing by an average of 13% over 3-years. Results: Increasing the proportional use of mt-sDNA, the detection of AAs improved by 6.0% (Scenario 2 versus 1) to 8.4% (Scenario 4 versus 3) and the number of missed CRCs decreased by 15.1% to 17.3% respectively. Increasing FIT utilization improved the detection of AAs by 3.3% (Scenario 2 versus 1) to 4.6% (Scenario 4 versus 3) and the number of missed CRCs decreased by 12.9% (Scenario 2 versus 1) to 14.9% (Scenario 4 versus 3). Across all scenarios, the number of AAs detected was higher for mt-sDNA than for FIT, and the number of missed CRCs was lower for mt-sDNA than for FIT. Conclusions: Using home-based stool tests for average-risk CRC screening can mitigate the consequences of reduced colonoscopy screening resulting from the COVID-19 pandemic. Use of mt-sDNA led to fewer missed CRCs and more AAs detected, compared to FIT.

Age-Stratified Prevalence and Predictors of Neoplasia Among U.S. Adults Undergoing Screening Colonoscopy in a National Endoscopy Registry

Background & AimsSeveral U.S. organizations now recommend starting average-risk colorectal cancer screening at age 45 years, but the prevalence of colonic neoplasia in individuals younger than 50 years has not been well characterized. We used a national endoscopic registry to calculate age-stratified prevalence and predictors of colorectal neoplasia. MethodsOutpatient screening colonoscopies performed during 2010–2020 in the GI Quality Improvement Consortium registry were analyzed. We measured the prevalence of advanced neoplasia and adenomas by age, sex, and race/ethnicity, as well as the prevalence ratio of neoplasia compared with the reference group of 50- to 54-year-olds. Multivariable logistic regression models were used to identify predictors of neoplasia. ResultsWe identified 3,928,727 screening colonoscopies, of which 129,736 (3.3%) were performed on average-risk individuals younger than 50 years. The prevalence of advanced neoplasia was 6.2% for 50- to 54-year-olds and 5.0% (prevalence ratio, 0.81; 95% confidence interval, 0.78–0.83) for average-risk 45- to 49-year-olds. Men had higher prevalence of neoplasia than women for all age groups. White individuals had higher prevalence of advanced neoplasia than persons of other racial/ethnic groups in most age groups, which was partially driven by serrated lesions. On multivariable regression, White individuals had higher odds of advanced neoplasia than Black, Hispanic, and Asian individuals in both younger and older age groups. ConclusionsIn a large U.S. endoscopy registry, the prevalence of advanced neoplasia in 45- to 49-year-olds was substantial and supports beginning screening at age 45 years. White individuals had higher risk of advanced neoplasia than Black, Hispanic, and Asian individuals across the age spectrum. These findings may inform adenoma detection benchmarks and risk-based screening strategies.

Cancer Prevention in a Postpandemic World: A One-Stop-Shop Approach

Cancer Prevention in a Postpandemic World: A One-Stop-Shop Approach

Prevention of colorectal cancer through multiomics blood testing: The PREEMPT CRC study.

TPS208 Background: The USPSTF recently recommended colorectal cancer (CRC) screening for adults aged 45 to 49 years in addition to those aged 50 to 75 years. This guideline update, which increases the number of screen-eligible individuals by ̃19 million, is similar to the recommendation in 2018 by the American Cancer Society (ACS) and is based on the modeling studies that reflect rising CRC incidence rates in younger adults. Currently, only 67% of average-risk individuals over the age of 50 years are up-to-date on CRC screening, and adherence to screening is lower in younger individuals (e.g., 50-54 years). Despite the non-invasive nature of existing stool-based CRC tests, barriers remain to adoption, including a dislike for manipulating stool and a requirement for substantial navigational support. Blood tests may overcome these barriers through ease of sample collection and integration into routine blood work. Methods: Here we describe our prospective, multi-center registrational study for validating a blood-based multiomics test for average-risk CRC screening: PREEMPT CRC. Eligible participants include those aged 45-85 with no known history of CRC or colorectal adenomas who are undergoing CRC screening by colonoscopy. The target enrollment is 25,000 participants, and primary outcome measures are sensitivity for CRC and specificity for advanced colorectal neoplasia, which includes CRC and advanced adenomas. Secondary outcome measures include positive predictive value for CRC, negative predictive value for advanced colorectal neoplasia, and sensitivity for advanced adenomas. Novel recruitment methods have been implemented by combining traditional, site-based recruitment and virtual recruitment using an online web portal, coupled with mobile phlebotomy, to make participation broadly accessible, especially during the COVID-19 pandemic. Participants have been enrolled from 40 states as of August 2021, and virtual recruitment has enabled widespread participation, potentially from any zip code in the continental US. To ensure adequate representation of the intended use population, community organizations, federally qualified health centers (FQHCs), and universities have been engaged to reach underserved and minority patient populations. The study was initiated in May 2020 and to our knowledge will be the largest prospective, multi-center registrational validation study of an average-risk CRC screening test to date. Clinical trial information: NCT04369053.

Patterns of colorectal cancer (CRC) screening rates among the average risk U.S. population.

65 Background: There is consensus that the proportion of the average-risk US population up-to-date with CRC screening (58-65%) is insufficient. However, estimates of average risk CRC screening rates are inconsistent and impacted by inclusion of higher-risk individuals, and differing study designs. Accurate measurement of population screening rates is key to addressing gaps in care and assessing the impact of newer CRC screening tests. Methods: The study included individuals aged 50-75 years in a large de-identified claims database, with continuous enrollment during year of analysis, and a variable length baseline enrollment of 1-10 years. Average-risk designation excluded higher risk diagnoses (CRC familial syndromes, colorectal polyp or history of colorectal polyp, history of/current CRC, family history of gastrointestinal cancer, and inflammatory bowel disease). Up-to-date status was assessed within guideline-based time periods: colonoscopy (10 years); FIT or FOBT (annually); mt-sDNA (3 years); flexible sigmoidoscopy/CT colonography (5 years). Analyses assessed the proportion estimated as up-to-date and examined the sensitivity to: a) patient population (average-risk only vs. including higher-risk); b) study design (yearly cross-sectional vs. cohort of 50-year-old patients; c) methods (percent in patients with 10 years of enrollment vs. Kaplan Meier (KM) of censored variable pre-screening period). Results: The cross-sectional analysis average-risk population included 5.3 million individuals. Estimates of the proportion of those up-to-date with screening guidelines for average-risk patients varied by study design, population, and estimation method. KM estimates among the average-risk population (50-75) showed 49-50% were up-to-date in each calendar year. Including higher-risk patients in the KM analysis resulted in 70% up-to-date among the mixed average+higher-risk population. Using a cohort study design (average-risk patients aged 60 with 10 years of baseline data), 65% were up-to-date by age 60. Conclusions: In the base case analysis only half of average risk individuals were up-to-date with CRC screening, a rate lower than typically cited. Sensitivity analyses resulted in substantially different estimates and demonstrate the importance of clearly communicating the methodology used to define the study population. Higher rates quoted in the lay press and medical publications may be based on mixed populations of average+higher-risk individuals or on study designs that do not represent the full population at risk.