Reduce Colorectal Cancer Mortality Research Articles

Introducing Colorectal Cancer Screening in Romania - Preliminary Results from the Regional Pilot Programs (ROCCAS).

Colorectal cancer (CRC) is the third cause of cancer-related death worldwide. Screening programs can reduce CRC mortality rates by up to 60%. In line with the European Union recommendations, Romania started the first four regional pilot screening programs in 2020 (the ROCCAS II projects). This study reports the interim screening performance indicators. People aged 50 to 74 years were invited to the screening program. General practitioners (GPs) evaluated CRC risk based on a survey. High-risk or symptomatic individuals were referred directly to colonoscopy. The average risk participants received a fecal immunochemical test (FIT). Positive cases were invited to colonoscopy. Three regions were screened using the OC-SENSOR® (South-Muntenia, Bucharest-Ilfov, South-East) and one region (South-West) used the FOB GOLD®. The data was collected in the ROCCAS screening electronic registry. The following FIT parameters were evaluated: rates of return, invalidity, positivity, and colonoscopy acceptance rate according to age group, gender, region of provenience, and vulnerability status. We included all cases screened between January 1, 2022 and September 30, 2023. In total, 168,958 people received the FIT test within the projects. The global FIT return rate was 90%. Factors associated with a higher return rate were female gender (90.77% vs 88.83%, p<0.0001), vulnerable status (91.23% vs 88.83%; p<0.00001), and rural residence (91.84% vs 88.42%, p<0.00001). The overall positivity rate was 5.75%. It was higher in males (7.64% vs 4.57% in females, p<0.00001) and progressively increased with the age group. The total invalid FIT rate was 5.87%, significantly lower for OC-SENSOR® (2.24%) than for the FOB GOLD® (13.6%). The overall acceptability rate for colonoscopy was 51.3%. According to our preliminary data, GP's participation in the pilot programs ensured adequate adherence to screening through FIT. The rate for FIT return and positivity were acceptable for both tests, while the invalid rate was much higher in FOB GOLD® compared to the OC-SENSOR®. Moreover, colonoscopy acceptance needs to be improved. Our preliminary analysis revealed the screening performance indicators meet the EU recommendations and fulfill the premises for national-level expansion of the program starting in 2024.

Contributions of early detection and cancer prevention to colorectal cancer mortality reduction by screening colonoscopy: a validated modelling study

Background and aimsScreening colonoscopy, recommended every ten years, reduces mortality from colorectal cancer (CRC) by early detection of prevalent but undiagnosed CRC, as well as by prevention of CRC by removal of precursor lesions. The aim of this study was to assess the relative contribution of both components to total CRC mortality reduction over time. MethodsUsing a validated multistate Markov model, we simulated hypothetical cohorts of 100,000 individuals aged 55-64 with and without use of screening at baseline. Main outcomes included proportions of prevented CRC deaths arising from (asymptomatic) CRC already prevalent at baseline and from newly developed CRC during 15-years of follow-up, and mortality rate ratios of screened versus unscreened groups over time. ResultsEarly detection of prevalent cases accounted for 52%, 30% and 18% of deaths prevented by screening colonoscopy within 5, 10 and 15 years, respectively. Relative reduction of mortality was estimated to be much larger for mortality from incident cancers than for mortality from cancers that were already present and early detected at screening endoscopy and for total CRC mortality (i.e., 88% versus 67% and 79% within 10 years from screening). ConclusionsReduction of CRC mortality mainly arises from early detection of prevalent cancers during the early years after screening colonoscopy, but prevention of incident cases accounts for the majority of prevented deaths in the longer run. Prevention of incident cases leads to sustained strong reduction of colorectal cancer mortality, possibly warranting an extension of screening intervals.

Evaluation of the effectiveness of colorectal cancer screening intervention.

The effectiveness of the Colorectal Cancer (CRC) screening program is assessed based on the reduction in CRC mortality and incidence rates over time. To accurately estimate the long-term impact, it is advisable to monitor additional indicators such as age and stage-specific incidence rates. Our objective is to evaluate the effectiveness of the National CRC Screening Program in Turkey and analyze its influence on disease stage at diagnosis and survival rates. The National CRC Screening Program was considered an intervention and the distribution of local, regional, and distant diseases, and survival estimates were assessed before and after the intervention to evaluate the effectiveness of the intervention. 518 patients were included in the study. At the time of diagnosis, localized, regional, and distant disease in pre-intervention were 31.3%, 42.9%, 25.8%, while post-intervention were 42.8%, 33.3%, 23.9%, respectively (p = 0.020). The relative effectiveness of the intervention in males, females, and 50-70 ages were calculated as 1.2[95% CI 0.95-1.73], 1.5[95% CI 1.04-2.18], and 1.6[95% CI 1.21-2.28] in localized disease, 0.8[95% CI 0.67-1.18], 0.6[95% CI 0.43-0.90], and 0.6[95% CI 0.46-0.81] in regional diseases, 0.8[95% CI 0.57-1.20], 1.1[95% CI 0.66-1.84], and 1.0[95% CI 0.70-1.57] in distant disease, respectively. A noticeable shift in the disease stage at the time of diagnosis was observed; however, this shift varied among gender and age groups. To effectively evaluate the impact of a cancer screening program on reducing the incidence and mortality rates of the disease, it is essential to monitor and analyze these indicators alongside 5-10-year survival estimates and stage changes at the time of diagnosis.

Impact of family history of cancer on colorectal cancer screening: a propensity score-matched analysis from the Health Information National Trends Survey (HINTS)

BackgroundEarly detection of colon cancer leads to better survival outcomes. This can be achieved through colorectal cancer (CRC) screening. People with a family history of cancer (FHC) have increased risk of developing CRC. Increasing screening in this group will reduce CRC mortality. This study evaluated CRC screening in people with FHC.MethodsThe study used data from the Health Information National Trends Survey (HINTS) 5, cycle 3. This is an annual cross-sectional survey with a nationally representative sample of American adults. The objective was to study the association between FHC and performing CRC screening. Propensity score matching was used to create a matched population with variables that constituted beliefs in cancer from the survey. Replication procedure, which is based on repeated sampling and allows for accurate computation of standard errors, was used for calculating statistical tests. Multivariable models were fitted in the matched population to assess the association between FHC and performing CRC screening.ResultsPeople with FHC were 14% (OR = 1.14; 95% CI: 0.81–1.60) more likely to perform CRC screening than those without FHC, even though not statistically significant. Age in years (OR = 1.14; 95% CI: 1.12–5.27) had increased likelihood of performing CRC screening, while other races such as American Indians/Alaskan Natives (except African Americans) compared to Caucasians (OR = 0.49; 95% CI: 0.29–0.84) had significantly decreased likelihood of performing CRC screening.ConclusionFHC was not significantly associated with having a colorectal cancer screening test. Public health advocacy should be directed towards increasing awareness of CRC screening among people with FHC.

Abstract B137: Examining racial disparities in the association between food swamps, liquor store density, and colorectal cancer mortality among Georgia cancer patients

Abstract Introduction: Colorectal cancer (CRC) is the third-most common cancer in the United States (U.S.) and racial/ethnic disparities regarding CRC death continue to persist. Increased healthy food consumption and decreased processed food consumption are key factors in reducing CRC mortality. However, living in geographical areas with no access to healthy food options and more pro-inflammatory foods (i.e. food swamps) decreases healthy food access. The influx of liquor stores, or businesses that advertise and sell unhealthy food products including processed foods and alcohol, may contribute to elevated CRC death. We investigated whether liquor store density modified the association between residing in food swamps with risk of CRC death among a multiethnic sample of cancer patients in Georgia. Methods: We conducted a retrospective cohort analysis utilizing 2012, 2014, 2015, 2017, and 2020 data from the U.S. Department of Agriculture Food Environment Atlas along, U.S. Census County Health Patterns data, and linked them via county FIPS codes with patient data years 2010 – 2020 from the Surveillance, Epidemiology, and End Results (SEER) Program. Food swamp score (FS) was calculated as the ratio of fast-food and convenience stores to grocery stores and farmer’s markets. Liquor store density was calculated as the proportion of beer, wine, and liquor stores to Georgia county populations per 100,000. We categorized FS and liquor store density to low or high; higher scores indicated patients living in counties with poorer healthy food resources. Multilevel Cox proportional hazard models were used to estimate the association between FS, liquor store density and CRC death. Results: Among 56,861 SEER patients in Georgia, majority of CRC death was in high liquor store density counties. NH-Black and Other patients at both levels of FS counties had an increased risk of CRC death (low: adjusted hazard ratio (aHR) = 1.21, 95% CI = 1.16 – 1.26; high: aHR = 1.06, 95% CI = 1.01 – 1.12) when compared to NH-white patients-low-FS counties. In sub-analyses by liquor store density, NH-Black and Other patients-low-FS counties had an increased risk of CRC death among high (aHR = 1.24, 95% CI = 1.19 – 1.31) and low (aHR = 1.12, 95% CI = 1.03 – 1.21) liquor store density counties. Conclusions: NH-Black patients living in the worst food environments, including effect modification by liquor store density, had increased risk of CRC death. We strongly recommend local and state representatives and community stakeholders create and implement sustainable approaches at combating CRC in underserved racial communities by increasing access to healthier food sources (e.g. building more community gardens, fixing barriers to walkability). Citation Format: Malcolm S. Bevel, April Parham, Aashka Sheth, Meng-Han Tsai, Sydney E. Andrzejak, Samantha R. Jones, Justin X. Moore. Examining racial disparities in the association between food swamps, liquor store density, and colorectal cancer mortality among Georgia cancer patients [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B137.

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

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

Colorectal cancer screening-what does the recent NordICC trial mean for the U.S. population?

The incidence of colorectal cancer (CRC) has declined over time, though it remains a significant cause of morbidity and mortality in the U.S. It has the third highest incidence in incidence among all cancers and is the second leading cause of cancer death in both men and women. Screening reduces the incidence and mortality from CRC. There are several modalities for CRC screening, but the most common ones are a choice between a non-invasive stool-based test, such as fecal immunochemical testing (FIT) or an invasive endoscopic modality, such as colonoscopy. In the U.S. colonoscopy is the predominant CRC screening modality, with observational studies reporting large reductions in CRC incidence and mortality. Recently, a large randomized controlled trial (RCT) on effectiveness of colonoscopy reported smaller than expected reduction in CRC incidence and no reduction in CRC mortality with colonoscopy screening. Explanations of the lower than expected benefit include low uptake of colonoscopy, short follow-up for mortality endpoints and quality indicators (QIs) for some of the endoscopists participating in the screening colonoscopies. The findings of the study need to be taken in context with other literature on effectiveness of colonoscopy, with the overall message of reassuring patients of the benefits of screening, and colonoscopy. Here, we discuss the latest evidence on colonoscopy screening and it in the context of other screening modalities and the landscape.

NordICC Trial Results in Line With Expected Colorectal Cancer Mortality Reduction After Colonoscopy: A Modeling Study

NordICC Trial Results in Line With Expected Colorectal Cancer Mortality Reduction After Colonoscopy: A Modeling Study

Progress of regulatory RNA in small extracellular vesicles in colorectal cancer.

Colorectal cancer (CRC) is the second most common malignant tumor of the gastrointestinal tract with the second highest mortality rate and the third highest incidence rate. Early diagnosis and treatment are important measures to reduce CRC mortality. Small extracellular vesicles (sEVs) have emerged as key mediators that facilitate communication between tumor cells and various other cells, playing a significant role in the growth, invasion, and metastasis of cancer cells. Regulatory RNAs have been identified as potential biomarkers for early diagnosis and prognosis of CRC, serving as crucial factors in promoting CRC cell proliferation, invasion and metastasis, angiogenesis, drug resistance, and immune cell differentiation. This review provides a comprehensive summary of the vital role of sEVs as biomarkers in CRC diagnosis and their potential application in CRC treatment, highlighting their importance as a promising avenue for further research and clinical translation.

Differential impact of test performance characteristics on burden-to-benefit tradeoffs for blood-based colorectal cancer screening: A microsimulation analysis.

To inform the development and evaluation of new blood-based colorectal cancer (CRC) screening tests satisfying minimum United States (US) coverage criteria, we estimated the impact of the different test performance characteristics on long-term testing benefits and burdens. A novel CRC-Microsimulation of Adenoma Progression and Screening (CRC-MAPS) model was developed, validated, then used to assess different screening tests for CRC. We compared multiple, hypothetical blood-based CRC screening tests satisfying minimum coverage criteria of 74% CRC sensitivity and 90% specificity, to measure how changes in a test's CRC sensitivity, specificity, and adenoma sensitivity (sizes 1-5 mm, 6-9 mm, ≥10 mm) affect total number of colonoscopies (COL), CRC incidence reduction (IR), CRC mortality reduction (MR), and burden-to-benefit ratios (incremental COLs per percentage-point increase in IR or MR). A blood test meeting minimum US coverage criteria for performance characteristics resulted in 1576 lifetime COLs per 1000 individuals, 46.7% IR and 59.2% MR compared to no screening. Tests with increased CRC sensitivity of 99% ( + 25%) vs. increased ≥10 mm adenoma sensitivity of 13.6% ( + 3.6%) both yielded the same MR, 62.7%. Test benefits improved the most with increases in all-size adenoma sensitivity, then size-specific adenoma sensitivities, then specificity and CRC sensitivity, while increases in specificity or ≥10 mm adenoma sensitivity resulted in the most favorable burden-to-benefit tradeoffs (ratios <11.5). Burden-to-benefit ratios for blood-based CRC screening tests differ by performance characteristic, with the most favorable tradeoffs resulting from improvements in specificity and ≥10 mm adenoma sensitivity.

Cost-effectiveness of ColoSTAT for primary colorectal cancer screening in the United States.

e15525 Background: Colorectal cancer (CRC) screening is at the cornerstone of strategies for reducing the mortality, healthcare and societal cost burden of CRC, the third most common cancer in the United States (US). ColoSTAT immunoassay is a simple, highly accurate, minimally invasive blood-based screening test for CRC that will be launched in the US market. Using a de novo decision analytic model, we compared the health benefits and cost-effectiveness of CRC screening with ColoSTAT with current screening offered by private insurers assuming a 5-yearly colonoscopy (COL) or biennial fecal immunochemical test (FIT) for the US population. Methods: For the three screening strategies, the expected number of CRC cases detected, and total screening program cost were estimated using a decision-analytic model based on: published CRC incidence in the US, tests performance characteristics, adherence rates to screening (61% for COL; 46% for FIT) and to diagnostic assessment via COL after a positive FIT or ColoSTAT test (80.4%). The gain in quality-adjusted life year (QALY) associated with every CRC case detected through screening, and confirmed by diagnostic assessment, was estimated by linking US-specific estimates of: CRC deaths by age-subgroups, life expectancies at the time of CRC death, quality of life projections for the general population and reduction in CRC mortality associated with screening. Healthcare cost savings associated with every CRC case detected through screening were estimated based on the distribution of CRC across disease stages by diagnosis method (screening versus symptomatically) and stage-specific CRC treatment costs. Results: Biennial screening with ColoSTAT, compared with 5-yearly COL screening offered by private insurers, is estimated to generate cost savings on screening programs of around $40 million per 100,000 people of screening age (PoSA) per one-off screening. When scaled up to the total US population within screening age covered by private insurance (66%), the estimated cost savings with ColoSTAT exceed $30 billion per one-off screening. The reduction in the number of CRC cases detected would generate a modest loss of 58 discounted QALYs per 100,000 people, that could be mitigated if ColoSTAT were to boost screening uptake. In the context of government-sponsored screening programs, replacing FIT with ColoSTAT is estimated to increase the number of CRC cases detected via screening by 9% (to 50 cases per 100,000 PoSA), assuming an unchanged screening uptake of 46%. At the commonly used value of $100,000 per QALY, this would equate to a discounted benefit of $834,820 per 100,000 PoSA per one-off screening. Conclusions: CRC screening with ColoSTAT as an alternative to COL could result in multi-billion-dollar cost savings to US private insurers while still detecting most CRC cases and generate population-health gains if used as an alternative to FIT in government-sponsored screening programs.

The impact of extending CRC screening to the older population: Results from CRC-AIM microsimulation model.

10567 Background: Average-risk screening for colorectal cancer (CRC) is effective and recommended. The U.S. Preventive Services Task Force issued grade A and B recommendations for screening ages 50-75 and 45-49, respectively, however the recommendation for the older population (ages 76-85) is grade C (moderate certainty that the net benefit is small). With emerging blood-based CRC screening, we evaluated the benefits of screening the older population with continued multi-target stool DNA (mt-sDNA) or FIT strategies and/or with a modality shift to blood-based tests after age 75. Methods: Using the validated CRC-AIM microsimulation model, triennial mt-sDNA and annual FIT screening (ages 45-75) followed by four strategies for ages 76-85 (no screening, continued mt-sDNA/FIT, or a modality shift to blood-based screening using either CMS criteria [CMS] or recently reported blood test data from the ECLIPSE study1 [BT; Guardant Health, Inc.] were considered. For CMS criteria and BT, CRC sensitivity were set at 74% and 83%; and adenoma sensitivity was set to 20%, and 13%; and CRC specificity was set to 90% for both tests. Real-world (RWE) adherence for initial screening was set to 80% (CMS, BT), 65.6% (mt-sDNA), and 42.6% (FIT). Adherence for follow-up colonoscopy was set to 72.1% (mt-sDNA, CMS, BT) and 46.0% (FIT). Results: Screening among the population aged 45-85 resulted in 281 life years gained (LYG) with continued mt-sDNA as compared to 193 with continued FIT. Furthermore, mt-sDNA reduced CRC mortality by 70% as compared to 49% by FIT (Table). When screening modality was shifted to CMS (76-85 year olds), mt-sDNA/CMS resulted in 279 LYG as compared to 196 for FIT/CMS. CRC incidence was reduced by 59% (mt-sDNA/CMS) as compared to 38% (FIT/CMS), and mortality declined by 69% (mt-sDNA/CMS) as compared to 51% (FIT/CMS). Reductions in disease burden were lower when modality was switched to BT after age 75 due to reduced test performance. Conclusions: Extending CRC screening to the older population with continued mt-sDNA demonstrated the best health outcomes compared to other modalities. A modality shift after age 75 to blood-based testing resulted in greater LYG as compared to no screening, with performance at CMS criteria yielding better results than BT. Therefore, despite inferior performance, blood-based tests may offer a CRC screening option for older patients who are unable to complete stool testing. [Table: see text]

Polyp detection in the cecum and ascending colon by dye based chromoendoscopy - Is its routine use justified?

colonoscopy is the best method for detecting polyps, with a reduction in colorectal cancer mortality of 29% and reaching 47% for distal tumors. However, it fails to demonstrate a significant reduction in proximal colon cancer mortality, and is the most common segment with interval neoplasm. The present study aimed to evaluate the impact on detection of polyps of a second sequential evaluation of cecum and ascending colon, with or without the use of indigo carmine chromoendoscopy. prospective, non-randomized clinical trial. Patients were divided into two groups. The first (G1) underwent a routine colonoscopy, followed by a second endoscopy assessment of ascending colon and cecum. The second group (G2) underwent a routine colonoscopy, followed by a second assessment of the ascending colon and cecum with indigo carmine chromoendoscopy. In total, 203 patients were analyzed, 101 in the G1 and 102 in the G2. Newer polyps were identified in both groups after the second assessment with a significantly higher number of polyps detected in the patients in the G2 (p=0.0001). The number of patients who had at least one polyp in the two endoscopic assessments was significantly higher in the G2 (53 or 52% vs 27 or 26.7%, p=0.0002). In the second endoscopic assessment, the number of polyps found was also significantly higher in the G2 (50 or 76.9%) compared to the G1 (15 or 23.1%), p<0.0001. the second assessment with dye-based chromoendoscopy increases the detection of polyps in the ascending colon and cecum.

Implementation of a mailed faecal immunochemical test programme for colorectal cancer screening among Veterans

BackgroundScreening for colorectal cancer (CRC) with faecal immunochemical test (FIT) is effective at reducing CRC mortality. Unfortunately, the COVID-19 pandemic has been associated with deferred care, especially screening for CRC.AimWe...

Associations between serum vitamin D biomarkers and tumor expression of Ki67, p53, and COX-2 in colorectal cancer cases from the Southern Community Cohort Study

Higher 25-hydroxyvitamin D is associated with lower colorectal cancer (CRC) risk, with limited data from African Americans (AAs), who have greater risk for CRC and 25-hydroxyvitamin D deficiency. In a predominantly AA sample of CRC cases from the Southern Community Cohort Study (SCCS), we report associations between vitamin D biomarkers and tumor expression of proteins implicated in vitamin D’s anti-tumorigenic pathways (e.g. proliferation and inflammation) and CRC prognosis. SCCS participants with incident CRC were identified via state cancer registries. Serum 25-hydroxyvitamin D and vitamin D binding protein (VDBP) were measured at enrollment. ‘Free’ 25-hydroxyvitamin D was calculated via standard equation. Cellular Ki67, p53, and COX-2 were measured from tumor samples and categorized using literature-defined cut-points related to survival. Generalized linear models were used to measure associations between vitamin D exposures, tumor biomarkers, and stage. In total, 104 cases (40–79 years) were analyzed. 25-hydroxyvitamin D was not associated with high Ki67 (odds ratio (OR) per 1-standard deviation (SD) increase [95% confidence interval] 1.35[0.86–2.11]), p53 (0.75[0.47–1.20]), or COX-2 expression (1.25[0.78–2.01]), or metastatic disease (1.04[0.59–1.81]). Mean biomarker expression was unrelated to 25-hydroxyvitamin D (p-trend ≥.09). Null associations were observed for VDBP and free 25-hydroxyvitamin D. In AAs (n = 70), higher VDBP was associated with lower odds of high Ki67 expression (0.53[0.28–0.98], p-trend =.04). In conclusion, we observed no associations between 25-hydroxyvitamin D and prognostic marker expression in CRC. An inverse association between VDBP and tumor Ki67 in AAs is consistent with reports showing relationships with reduced CRC mortality.

S241 Colonoscopy Adenomatous Polyp Detection Rate in Patients With Inadequate Bowel Prep

Introduction: Colorectal cancer (CRC) is the second leading cause of cancer-related deaths amongst men and women together in the United States. Screening colonoscopies have been proven to reduce CRC mortality. However, the efficacy of colonoscopies can be hindered by poor bowel preparation due to poor visualization and a higher likelihood of missing polyps and other colonic lesions including CRC. Per ASGE, adenoma detection rate (ADR) for combined male and female population is 25%. This retrospective study aims to identify the ADR for patients with inadequate bowel preparation noted during colonoscopies at our institution to emphasize the importance of quality bowel preparation. Methods: During the years 2018-2020, a total of 250 inadequately prepared colonoscopies were examined at University of Louisville Hospital for our study. 28 colonoscopies were excluded due to being aborted prior to the procedure brown stool being present on exam. 14 colonoscopies did not have pathology reports and were also excluded. The study was a retrospective single-center cohort study reviewing risk factors in patients with inadequate bowel preparation noted during colonoscopy. A Boston Bowel Preparation Scale (BBPS) was used with score of < 6 (inadequate preparation) and ≥6 (adequate preparation). Results: This study specifically examined the adenomatous detection rate for patients with poor colonoscopy preparation. Of these, 27 patients with screening colonoscopy indications had adenomatous or high-risk polyps with an ADR of 10.8%. This was well below the ASGE quality indicator for ADR for screening colonoscopies. 18 non-screening colonoscopies had an ADR of 7.2%. Additionally, there was a total of 91 the patients who came back for repeat colonoscopy within a 3-year time span after having poor bowel preparation or aborted procedure initially. 2 patients were missing pathology reports and excluded. 29 patients were found to have adenomatous or high-risk polyps for a total of 32.5% of patients with repeat colonoscopy who initially had poor bowel preparation or aborted procedure. Conclusion: Having a BBPS score of 5 or less considerably decreased ADR compared to ASGE standards. It is critically important that patients who have poor bowel prep return for repeat colonoscopy due to high risk of missing adenomatous or high-risk polyps as shown by the follow-up data. ADR is far below the endoscopist expectation without adequate bowel preparation in both screening and non-screening colonoscopies.

Risk prediction of colorectal cancer

Background: Colorectal cancer (CRC) is considered as a significant worldwide health problem1 and there is strong suggestion that screening can reduce CRC mortality rate. Thus, the effectiveness of awareness toward screening may be encouraged screening performance and screening intensity to those at highest risk. Aim: to find out community awareness regarding risk prediction of colorectal cancer at port-said city , Egypt. Subject and methods: A descriptive cross-sectional study was carried out using A purposive sampling on 220 female from age more than 20 year at outpatient clinics from governmental hospitals (Alsalam general , Port-fouad general hospital Algawhara hospital at Port-Said city, Egypt responded to the self-administered online survey. Statistical tools such as frequency, percentage, were used for the descriptive analysis. Results: there are a statistically significant relation was found in all items of participant's attitude regarding colorectal cancer with ps= (0.001, 0.012) respectively. Furthermore, there are a statistically significant relation was found between participant’s intentions to be screened for colorectal cancer with their socio-demographic characteristics mainly in the items related to level of education and their occupation with ps= (0.015, 0.005) respectively.

Modelling cost-effective strategies for minimising socioeconomic inequalities in colorectal cancer screening outcomes in England

Colorectal cancer (CRC) incidence and mortality is higher in socioeconomically deprived groups for a variety of reasons, but is exacerbated by poorer screening uptake. However, many strategies for improving screening participation exist. This analysis aimed to model the impact of screening on CRC inequalities in England and then compare different strategies for increasing participation, to determine the most cost-effective methods for reducing screening-induced inequalities. An existing health economic model, Microsimulation Model in Cancer of the Bowel was adapted. Screening-eligible individuals were simulated to investigate the impact of screening on CRC inequalities. Following this, four strategies for promoting screening participation were compared: 1) annual re-invitation of screening non-participants; 2) a national media advertising campaign; 3) text message reminders for non-participants; 4) health promotion in deprived populations. Cost-effectiveness, CRC outcomes, resource impacts and effects on CRC inequalities were assessed. Inequalities analysis was based on age-standardised CRC mortality by socioeconomic group. Screening was found to be highly cost-effective but CRC inequalities increased as screening effectiveness improved. Annual re-invitation of non-participants was most cost-effective for promoting particiption (incremental cost-effectiveness ratio = £4404 per quality-adjusted life-year), reducing CRC mortality (11,129 deaths averted), and reducing screening-induced inequality (slope of inequalities reduced from 20.80 to 19.38), although it required 42% more screening kits to be sent out. Other strategies were cost-effective compared with screening alone, and improved CRC outcomes, but had varying impacts on inequalities. Whilst bowel cancer screening increases socioeconomic inequalities in CRC mortality, effective and cost-effective strategies are available for mitigating screening-induced inequalities.

Abstract 2240: Interception versus prevention in cancer screening: Results from the CRC-MAPS model

Abstract Purpose: This study examines the impact of detecting cancer (interception) versus adenomas and cancer (prevention + interception) on clinical outcomes for a hypothetical colorectal cancer (CRC) screening test or multicancer early detection (MCED) test that includes CRC. Methods: CRC-MAPS™, a validated microsimulation model of the adenoma-carcinoma pathway that reproduced incidence reduction (IR) and mortality reduction (MR) consistent with CISNET models and a randomized controlled trial, was used to simulate perfect adherence to a hypothetical annual screening test among previously unscreened individuals free of diagnosed CRC. Four scenarios were examined: two cancer interception and two cancer prevention + interception. Individuals were screened from age 45 to 75. CRC IR and MR outcomes compared to no screening were aggregated from age 40 until death. Threshold analysis identified the ≥10mm adenoma sensitivity needed for a base case cancer interception test to yield CRC MR equivalent to a near-perfect cancer interception test (#2). Results: The base case scenario (#1) resulted in 15.0% CRC IR and 34.2% MR compared to 14.7% CRC IR and 38.3% MR for the near-perfect interception scenario (#2). In the threshold analysis, a modified base case cancer interception test (#5) yielded MR equivalent to a near-perfect interception test (#2) when ≥10mm adenoma sensitivity was increased from 1% to 1.94%. Due to adenoma detection, the cancer prevention + interception scenarios (#3, #4) resulted in outcomes more than twice as favorable as either cancer interception scenario. Conclusions: This analysis highlights that even small improvements in the detection of precancerous lesions for certain cancers (e.g., adenomas for CRC), which enable cancer prevention, can yield clinical benefits that meaningfully exceed those from tests that primarily detect cancer. Future studies will apply this approach to other cancers, such as ovarian and breast, to better understand the clinical utility of MCED tests. Table. Clinical outcomes for cancer interception and cancer prevention + interception scenarios Scenario Specificity Adenoma Sensitivity CRC Sensitivity CRC IR CRC MR 1. Cancer Interception (base case) 99% 1-5mm: 1% 6-9mm: 1% ≥10mm: 1% 60% 15.0% 34.2% 2. Cancer Interception (near-perfect) 99% 1-5mm: 1% 6-9mm: 1% ≥10mm: 1% 99% 14.7% 38.3% 3. Cancer Prevention (with FIT-like adenoma sensitivity) + Interception 99% 1-5mm: 5% 6-9mm: 10% ≥10mm: 20% 60% 73.5% 79.1% 4. Cancer Prevention (with improved FIT-like adenoma sensitivity) + Interception 99% 1-5mm:10% 6-9mm: 20% ≥10mm: 30% 60% 82.8% 86.2% 5. Threshold analysis 99% 1-5mm: 1% 6-9mm: 1% ≥10mm: 1.94% 60% 20.3% 38.3% Citation Format: Girish Putcha, Lauren N. Carroll, Signe Fransen, Tarun Chandra, Andrew Piscitello. Interception versus prevention in cancer screening: Results from the CRC-MAPS model [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 2240.

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.