Average-risk Population Research Articles

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

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

Reappraisal of fibrosis-4 index and non-alcoholic fatty liver disease fibrosis score for advanced fibrosis in average-risk population.

The current cut-offs for fibrosis-4 (FIB-4) and non-alcoholic fatty liver disease fibrosis score (NFS) are suboptimal for screening because of low accuracy and high false-negative rates in average-risk populations. This study aimed to reappraisal the performance of FIB-4 and NFS in such average-risk populations. This is a cross-sectional study, which retrospectively reviewed the magnetic resonance elastography (MRE) data of 8,522 subjects. Individuals with history of significant alcohol consumption and those with positive viral serologic markers were excluded. Finally, 6,215 average-risk individuals were analyzed. The area under the receiver operating characteristic curves (AUROCs) of FIB-4 for the diagnosis of advanced hepatic fibrosis was higher than that in the NFS especially in the metabolically healthy. The AUROCs of FIB-4 for in the average-risk population was also higher than that in the NFS (0.840 in FIB-4 vs. 0.798, P = 0.036). However, the sensitivity of FIB-4 and NFS was low (69.6 and 61.4%, respectively) in applying the current cut-off of FIB-4 [1.3 (2.0)] and NFS [-1.455 (0.12)]. At cut-off of FIB-4 at 1.0, sensitivity (90.2%), and negative predictive value (99.7%) were improved. The diagnostic performance of FIB-4 was better than that of NFS for screening hepatic fibrosis in average-risk populations. It is recommended to use FIB-4 rather than NFS, when screening for hepatic fibrosis in general population.

How effective are digital technology-based interventions at promoting colorectal cancer screening uptake in average-risk populations? A systematic review and meta-analysis of randomized controlled trials

Despite the global prevalence of colorectal cancer (CRC) and efforts in screening advocacy, screening uptake remains relatively low. Considering the greater accessibility and popularity of telemedicine in behaviour change interventions, this meta-analysis seeks to examine the usefulness of digital interventions in promoting CRC screening uptake as compared to existing non-digital strategies. A systematic search on five databases identified articles published before September 2022. Randomized controlled trials comparing the effectiveness of digital interventions to usual care were included and assessed using the Cochrane's Risk of Bias tool. Effectiveness of interventions was measured by CRC screening completion rates, and pooled effect sizes were computed for both digital intervention subtypes identified – decision-making aids and tailored educational interventions. 14 studies (17,075 participants) assessed to have low or some risk of bias were included in this meta-analysis. A random-effects model revealed that digital interventions were more likely to promote CRC screening uptake (OR = 1.31, 95% CI: 1.11–1.56), and using a decision-making aid was almost 1.5 times more likely to result in screening completion (i.e., completed a colorectal investigation using stool-based or direct visualization test) (OR = 1.42, 95% CI: 1.24–1.63). Meanwhile, the tailored educational intervention subtype failed to achieve statistical significance in promoting screening uptake, bearing in mind the significant heterogeneity across studies (I2 = 88.6%). Digital decision-making aids significantly improved CRC screening uptake compared to tailored digital educational interventions and usual care. However, as all included studies were conducted in Western settings, its role in augmenting existing CRC screening promotion strategies especially among Asians should be further evaluated.

CT Colonography Versus Optical Colonoscopy: Cost-Effectiveness in Colorectal Cancer Screening

Purpose: CT colonography (CTC) has been accepted as an optical colonoscopy (OC) alternative for colorectal cancer (CRC) screening by some guidelines, while others maintain that the data is insufficient. CTC’s less invasive nature may improve compliance; however, cost and need for colonoscopy, if lesions are detected, remain an obstacle for implementation. As a result, the authors set out to determine the cost-effectiveness of CTC in the context of its drawbacks and advantages when compared with OC within a Canadian context. Methods: Using a decision analysis software, an economic analysis was performed comparing CTC to OC for CRC screening in asymptomatic patients. The 10-year primary outcome measure was study cost, cost difference of screening 100,000 patients, and the cost of one quality adjusted life year gained. The sensitivities, specificities, and polyp prevalence rates were derived from literature. The cost of each test was derived from local data. Results: Local cost of OC is 764.36 CAD compared to 580.01 CAD for CTC. In the case of a normal OC, reassessment would not be necessary for 10 years, whereas in an asymptomatic average-risk population CTC must be repeated every 5 years. The incremental cost-effectiveness ratio, or the additional cost per life year of OC compared to CTC was calculated to be 3,390.76 CAD.

Proteomic signature for detection of high-grade ovarian cancer in germline BRCA mutation carriers.

No current screening methods for high-grade ovarian cancer (HGOC) guarantee effective early detection for high-risk women such as germline BRCA mutation carriers. Therefore, the standard-of-care remains risk-reducing salpingo-oophorectomy (RRSO) around age 40. Proximal liquid biopsy is a promising source of biomarkers, but sensitivity has not yet qualified for clinical implementation. We aimed to develop a proteomic assay based on proximal liquid biopsy, as a decision support tool for monitoring high-risk population. Ninety Israeli BRCA1 or BRCA2 mutation carriers were included in the training set (17 HGOC patients and 73 asymptomatic women), (BEDOCA trial; ClinicalTrials.gov Identifier: NCT03150121). The proteome of the microvesicle fraction of the samples was profiled by mass spectrometry and a classifier was developed using logistic regression. An independent cohort of 98 BRCA mutation carriers was used for validation. Safety information was collected for all women who opted for uterine lavage in a clinic setting. We present a 7-protein diagnostic signature, with AUC >0.97 and a negative predictive value (NPV) of 100% for detecting HGOC. The AUC of the biomarker in the independent validation set was >0.94 and the NPV >99%. The sampling procedure was clinically acceptable, with favorable pain scores and safety. We conclude that the acquisition of Müllerian tract proximal liquid biopsies in women at high-risk for HGOC and the application of the BRCA-specific diagnostic assay demonstrates high sensitivity, specificity, technical feasibility and safety. Similar classifier for an average-risk population is warranted.

S287 Comparison of Cost-Effectiveness Outcomes Between a Novel Multitargeted Stool-Based RNA Test and Alternative Non-Invasive Stool and Blood Tests for Colorectal Cancer Screening

Introduction: Colorectal cancer (CRC) mortality has been significantly mitigated by increased CRC screening via colonoscopy. Colonoscopy has low compliance rates due to invasiveness, procedure-associated risks, bowel preparation, and time requirements. Existing non-invasive screening methods are limited by relatively low sensitivity for precancerous lesions, especially advanced adenomas (AAs). Using a Markov model, cost-effectiveness outcomes were compared between a novel multitargeted stool RNA (mt-sRNA) test, existing stool-based screening tests (fecal immunochemical test [FIT], and multitarget stool DNA [mt-sDNA]), no screening, and a recently introduced triennial blood-based screening test. Methods: The Markov model compared morbidity, mortality, and cost using 1,000 average-risk patients 45-75 years of age over a 30-year time horizon. The model input included test-specific sensitivity and specificity with a fixed incidence and prevalence of CRCs/AAs to assess lesion detection rates across each screening method. Reimbursement rates were assumed equal for blood, mt-sDNA, and mt-sRNA tests ($508). Data on distribution across disease stages and five-year survival rates predicted long-term outcomes for patients with CRC. The model accounts for the cost of screening, complications associated with colonoscopy, surveillance/follow-up requirements, and the cost of CRC treatment. For the primary analysis, adherence was assumed to be 100%. For secondary research, adherence was set at 40%, 60%, and 80%. Results: At 100% adherence, the mt-sRNA test resulted in an additional reduction in CRC cases by 68.1% (blood test), 42.5% (mt-sDNA test), 30.8% (FIT test), and 82.1% (no screening). The mt-sRNA screening strategy also resulted in the reduction of deaths by 64.7% (blood test), 39.8% (mt-sDNA test), 29.8% (FIT test), and 78.3% (no screening). When adherence is set at 40%, 60%, or 80%, use of the mt-sRNA test results in an increased number of pre-cancerous adenomas detected relative to all other screening strategies. Incremental costs associated with the mt-sRNA test were intermediary with higher costs associated with follow-on colonoscopy/surveillance, and lower costs associated with CRC treatment. Conclusion: This model suggests that CRC screening tests that target advanced adenomas detection have superior cost-effectiveness due to better cancer prevention. The mt-sRNA test is a more cost-effective alternative for colorectal cancer screening in the average-risk population than other non-invasive strategies (Table). Table 1. - Cost-effectiveness of mt-sRNA against other screening modalities at variable adherence rates, per 1000 patients over a 30-year time horizon Adherence rate mt-sRNA test vs. Incremental CRC cases prevented CRC cases reduction (%) CRC deaths reduction (%) Incremental costs per CRC case prevented Incremental costs per CRC case prevented 40% for all tests Blood test 14 39.5% 35.1% -$175,379 -$311,289 mt-sDNA 6 22.7% 19.9% -$168,747 -$302,667 FIT 6 21.2% 19.0% $8,666 $14,681 No screening 20 48.1% 42.8% $67,232 $122,252 60% for all tests Blood test 16 51.5% 47.0% -$182,381 -$309,202 mt-sDNA 7 30.8% 27.7% -$178,940 -$293,907 FIT 5 23.0% 21.2% $188,435 $296,188 No screening 27 63.6% 58.3% $29,789 $52,683 80% for all tests Blood test 17 60.3% 56.2% -$188,028 -$306,278 mt-sDNA 7 37.2% 34.2% -$182,141 -$284,899 FIT 4 26.1% 24.6% $409,606 $607,669 No screening 31 73.9% 69.2% $19,817 $34,312 100% for all tests Blood test 16 68.1% 64.7% -$3,104,328 -$103,478 mt-sDNA 6 42.5% 39.8% -$1,073,985 -$35,799 FIT 3 30.8% 29.8% $2,289,314 $76,310 No screening 35 82.1% 78.3% $612,243 $20,408

Patterns of initial colorectal cancer screenings after turning 50 years old and follow-up rates of colonoscopy after positive stool-based testing among the average-risk population

Objectives Effective colorectal cancer (CRC) screening requires proper adherence beginning at the recommended screening age. For those with positive results on stool-based tests (SBTs), a follow-up colonoscopy is warranted. The objectives of this study were to 1) examine initial screening rates after turning 50 years old; and 2) assess rates of follow-up colonoscopy after a positive SBT. Methods This retrospective study used de-identified administrative claims data from 01/01/2006 to 06/30/2020 for commercially insured and Medicare Advantage enrollees. For objective 1, the index year was the year enrollees turned 50. Rates of CRC screening during and after the index year were captured. For objective 2, the index date was the claim date of a fecal immunochemical test (FIT) or multitarget stool DNA test (mt-sDNA) where linked lab data indicated a positive test result. Rates and time to follow-up colonoscopy after a positive SBT were assessed. Results Approximately 53% of enrollees initiated CRC screening within five years after turning 50 (50+ cohort N = 718,562). Among enrollees with an available lab result indicating a positive SBT (N = 7329; 2110 FIT and 5219 mt-sDNA), overall follow-up colonoscopy within 6 months of the positive result was less than optimal (65%) and varied by modality; 72% vs 46% (p < .001) among enrollees with a positive mt-sDNA test compared to FIT test, respectively. Conclusion There is potential for improving CRC screening among the eligible average-risk population, both to start screening once they reach the screening-eligible age, and to complete the CRC screening paradigm after a positive stool-based screen.

Commencing colorectal cancer screening at age 45 years in U.S. racial groups.

Screening for colorectal cancer (CRC) is cost-effective for reducing its mortality among the average-risk population. In the US, CRC incidence and mortality differ among racial/ethnic groups, with non-Hispanic Blacks (NHB) and American Indian/Alaska Natives showing highest incidence and mortality and earlier presentation. Since 2005, some professional societies have recommended CRC screening for NHB to commence at 45 years or earlier; this was not implemented due to lack of recommendation from key groups that influence insurance payment coverage. In 2017 the highly influential U.S. Multi-Society Task Force for Colorectal Cancer recommended screening to commence at 45 years for NHB; this recommendation was supplanted by data showing an increase in early-onset CRCs in non-Hispanic Whites approaching the under-50-year rates observed for NHB. Subsequently the American Cancer Society and the USPSTF recommended that the entire average-risk population move to commence CRC screening at 45 years. Implementing screening in 45–49-year-olds has its challenges as younger groups compared with older groups participate less in preventive care. The US had made extensive progress pre-COVID-19 in closing the disparity gap for CRC screening in NHB above age 50 years; implementing screening at younger ages will take ingenuity, foresight, and creative strategy to reach a broader-aged population while preventing widening the screening disparity gap. Approaches such as navigation for non-invasive and minimally invasive CRC screening tests, removal of financial barriers such as co-pays, and complete follow up to abnormal non-invasive screening tests will need to become the norm for broad implementation and success across all racial/ethnic groups.

Precise, Genotype-First Breast Cancer Prevention: Experience With Transferring Monogenic Findings From a Population Biobank to the Clinical Setting.

Although hereditary breast cancer screening and management are well accepted and established in clinical settings, these efforts result in the detection of only a fraction of genetic predisposition at the population level. Here, we describe our experience from a national pilot study (2018–2021) in which 180 female participants of Estonian biobank (of >150,000 participants in total) were re-contacted to discuss personalized clinical prevention measures based on their genetic predisposition defined by 11 breast cancer–related genes. Our results show that genetic risk variants are relatively common in the average-risk Estonian population. Seventy-five percent of breast cancer cases in at-risk subjects occurred before the age of 50 years. Only one-third of subjects would have been eligible for clinical screening according to the current criteria. The participants perceived the receipt of genetic risk information as valuable. Fluent cooperation of project teams supported by state-of-art data management, quality control, and secure transfer can enable the integration of research results to everyday medical practice in a highly efficient, timely, and well-accepted manner. The positive experience in this genotype-first breast cancer study confirms the value of using existing basic genomic data from population biobanks for precise prevention.

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.

Applicability of a web app for breast cancer risk calculation and personalized recommendations for screening in Mexico.

1567 Background: A minority of women with breast cancer in Mexico are being diagnosed through a screening program, which translates into late diagnosis and a worse prognosis. It is imperative to develop easy access and low-cost interventions to increase the screening rate. Methods: We developed a web app tailored to guide patients to seek medical consultation if they were at high risk for breast cancer or standard screening recommendations based on the predicted risk for age (https://cuccuanl.com/calcula-tu-riesgo-de-cancer-de-mama/). The web app consisted of an 8-question survey designed using object-based programming with HTML5, the additional logic was programmed on JavaScript. The program logic automatically guided patients to medical consultation if they were at high risk for breast cancer, or standard screening recommendations based on their predicted risk for age. On each confirmation page, the contact information of the hospital appeared, also, consultation at the clinic could be scheduled within the web app. The web app was distributed via social media on International Breast Cancer Awareness Day. Results: A total of 1,012 persons answered the survey after a follow-up period of two weeks. The median age of respondents was 34 years. Among participants, 10.8% were considered at very high risk for breast cancer due to symptoms, 22% were classified as high risk based on family history or more than 5 years of contraceptive use, and 19% were considered as average-risk population for whom age-based screening tests were recommended. The remaining 48% of participants were considered at low risk for breast cancer development and were directed to educational information about breast cancer awareness. Among all persons that answered our survey, 21 requested a specialized medical appointment within the web app. Conclusions: This pilot study showed a high response of Mexican population seeking breast cancer risk evaluation, 11% of women that responded to our survey had symptoms highly suggestive of breast cancer. The use of web apps can result in mass diffusion which will help reach people with less medical access, a common scenario in many developing countries. Further analysis should be made to measure the real impact on breast cancer diagnosis and oncological outcomes. This study shows how effective social media is as a means of diffusion on health topics. [Table: see text]

Colorectal cancer screening participation among citizens not recommended to be screened: a cohort study

BackgroundGuidelines on colorectal cancer (CRC) screening recommend screening of average-risk adults only. In addition, screening of individuals with active inflammatory bowel disease (IBD) might result in too many false-positive cases. However, the organisers of CRC screening programmes are often uninformed of whom to exclude due to an elevated CRC risk or active IBD. It is therefore unknown how often high-risk individuals (i.e. individuals with a previous diagnosis of CRC or polyps associated with hereditary CRC syndromes and certain patient groups with a diagnosis of inflammatory bowel disease (IBD) or multiple polyps) and individuals with active IBD participate in CRC screening following invitation.Materials and methodsWe used data from the first two years of the Danish CRC screening programme (2014–2015). Information on invitations, participations and FIT test results were obtained from the national screening database, while information on previous CRC, hereditary CRC syndromes, IBD or multiple polyps diagnoses were obtained from the Danish Cancer Registry and the Danish Patient Register. Screening participation rates and FIT-positive rates were calculated and compared for high-risk invitees, invitees having IBD and an average risk group of remaining invitees not diagnosed with colorectal polyps in 10 years preceding the invitation.ResultsWhen invited to CRC screening, 28–48% of high-risk residents (N: 29; 316; 5584) and 55% of residents with IBD (N: 2217; 6927) chose to participate. The participation rate was significantly higher (67%) among residents without previous colorectal disease, i.e. the average risk group (N = 585,624). In this average group 6.7% of the participants had a positive FIT test. The proportion of positive FIT results was higher among all disease groups (7.7–14.8%), though not statistically significant for participants with prior CRC diagnosis and participants with high-risk IBD.ConclusionWhen high-risk residents and residents with IBD receive an invitation to CRC screening, many participate despite being recommended not to. The screening program was not intended for these groups and further research is needed as several of these groups have a higher rate of positive screening result than the average risk population.

Detección y vigilancia pospolipectomía de pólipos colónicos

Colorectal cancer is a major cause of morbidity and mortality worldwide. Their prevention is based on screening the average risk population (age 50-75, asymptomatic without personal and family history) and the identification of high-risk groups. The vast majority arise from premalignant polyps (adenomas, serrated lesions). Endoscopic polypectomy is effective in reducing colorectal cancer incidence and mortality. The adenoma detection rate is the most important quality measure in colonoscopy and is inversely correlated with the risk of interval cancer and mortality. Over the last years, several new technical-quality recommendations and new devices became available to improve polyp’s detection and new post-polypectomy surveillance guidelines have been published. The quality and findings of the baseline colonoscopy will determine surveillance intervals. On the other hand, the newest guidelines from the United States recommend colorectal cancer screenings begin at the age of 45 based on new epidemiological data. However, not all countries followed this recommendation. The purpose of this review is to analyze techniques and devices to improve the adenoma detection rate, new post-polypectomy surveillance guidelines and the age to start and stop colorectal cancer screening. Contextualize data in Argentina and discuss the relevant ongoing research.

Multicancer Early Detection Technologies: A Review Informed by Past Cancer Screening Studies.

More than 75% of cancer-related deaths occur from cancers for which we do not screen. New screening liquid biopsies may help fill these clinical gaps, although evidence of benefit still needs to be assessed. Which lessons can we learn from previous efforts to guide those of the future? Screening trials for ovarian, prostate, pancreatic, and esophageal cancers are revisited to assess the evidence, which has been limited by small effect sizes, short duration of early-stage disease relative to screening frequency, study design, and confounding factors. Randomized controlled trials (RCT) to show mortality reduction have required millions of screening-years, two-decade durations, and been susceptible to external confounding. Future RCTs with late-stage incidence as a surrogate endpoint could substantially reduce these challenges, and clinical studies demonstrating safety and effectiveness of screening in high-risk populations may enable extrapolation to broader average-risk populations. Multicancer early detection tests provide an opportunity to advance these practical study designs. Conditional approvals based on RCTs with surrogate endpoints, contingent upon real world evidence generation and continuation of trials to definitive endpoints, may lower practical barriers to innovation in cancer screening and enable greater progress.

Gastroscopic results for the asymptomatic, average-risk population in Northern China: a cross-sectional study of 60,519 adults

Background Studies on average-risk individuals undergoing gastroscopy screening in China are scarce. Objective To determine and compare the prevalence of lesions found by gastroscopy and the association between sex, age, Helicobacter pylori infection and gastric premalignant lesions. Methods Gastroscopy results were analysed for 60,519 individuals enrolled from January 2013 to December 2019. Results The median age was 49.84 years (SD, 9.47 years) for women and 48.90 years (SD, 8.82 years) for men, and the ratio of females to males was 35.10% (n = 21,240) to 64.90% (n = 39,279). The most common lesions detected by endoscopy were chronic gastritis, reflux oesophagitis, duodenitis and gastric polyps, detected in 24.48%, 10.28%, 3.96% and 3.61%, respectively. Oesophageal cancer and gastric cancer were detected in 0.33% and 0.47% of patients, respectively. The prevalence of chronic gastritis increased with age and was higher in males than in females (26.47% [n = 10396] versus 20.80% [n = 4417], p < .001). The prevalence of gastric ulcers was highest in the elderly group, and the H. pylori infection rate of gastric ulcer patients was 47.28%. The prevalence of gastric polyps was higher in females than in males (5.47% [n = 1161] versus 2.61% [n = 1024], p < .001), and the H. pylori infection rate in inflammatory polyp patients was higher than that in fundic gland polyp patients (28.32% [n = 442] versus 7.29% [n = 29], p < .001). Conclusion The prevalence of upper gastrointestinal endoscopic lesions is high in the asymptomatic population undergoing physical examination and is associated with sex, age, and H. pylori infection.

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.

New considerations for colorectal cancer screening based on the demographic profile of colorectal cancer in a Greek population.

Colorectal cancer screening has long been recommended for middle age and older individuals. Recent evidence indicates increasing incidence and mortality among young adults. Therefore, the present study re-examined the current recommendations using an asymptomatic average-risk population screened by colonoscopy. A total of 716 participants of a wide age range were prospectively enrolled in an open-access endoscopic screening program based on self-referral. Comparisons between different age, gender and location groups, and receiver operating characteristic curves (ROC) curves for best age selection for detection of lesions were employed. Increased incidence of advanced lesions was observed in adults <50 years old. Although the polyp size was <1 cm in 85% of the cohort, a significant number of participants harbored advanced lesions. A disturbing incidence of lesions in women 30-49 years was located mainly in the left colon. One-third of the important pathology resides exclusively in the right colon. ROC curves demonstrated that with the current starting age of screening at 50 years, 92% of polyps and 95% of adenomas could be detected by colonoscopy, but a number of potential precancerous lesions will appear at an earlier age and therefore will be missed. The present study supported the notion that it is critical to reduce screening initiation below the currently accepted age of 50 years. Colonoscopy is a suitable method for addressing the increased prevalence of proximal lesions and the meticulous resection of smaller polyps.

Adherence to colonoscopy in cascade screening of colorectal cancer: A systematic review and meta‐analysis

This study aims to systematically evaluate adherence to colonoscopy and related factors in cascade screening of colorectal cancer (CRC) among average-risk populations, which is crucial to achieve the effectiveness of CRC screening. We searched PubMed, Embase, Web of Science, and Cochrane Library for studies published in English up to October 16, 2020, and reporting the adherence to colonoscopy following positive results of initial screening tests. A random-effects meta-analysis was applied to estimate pooled adherence and 95% confidence intervals. Subgroup analysis and mixed-effects meta-regression analysis were performed to evaluate heterogeneous factors for adherence level. A total of 245 observational and 97 experimental studies were included and generated a pooled adherence to colonoscopy of 76.6% (95% confidence interval: 74.1-78.9) and 80.4% (95% confidence interval: 77.2-83.1), respectively. The adherence varied substantially by calendar year of screening, continents, CRC incidence, socioeconomic status, recruitment methods, and type of initial screening tests, with the initial tests as the most modifiable heterogeneous factor for adherence across both observational (Q=162.6, P<0.001) and experimental studies (Q=23.2, P<0.001). The adherence to colonoscopy was at the highest level when using flexible sigmoidoscopy as an initial test, followed by using guaiac fecal occult blood test, quantitative or qualitative fecal immunochemical test, and risk assessment. The pooled estimate of adherence was positively associated with specificity and positive predictive value of initial screening tests, but negatively with sensitivity and positivity rate. Colonoscopy adherence is at a low level and differs by study-level characteristics of programs and populations. Initial screening tests with high specificity or positive predictive value may be followed by a high adherence to colonoscopy.

Increased prevalence of colorectal neoplasia in patients with intraductal papillary mucinous neoplasms.

Background:The association between intraductal papillary mucinous neoplasms (IPMNs) and colorectal cancer (CRC) and polyps is controversial.Objectives:To compare the prevalence of CRC and colorectal polyps among patients with IPMN and matched average risk individuals.Methods:A match cross-sectional historical study comparing colonoscopy findings of 310 patients with IPMN cysts who underwent at least one colonoscopy examination from 2004 through 2019, with 310 age- and gender-matched average risk participants who underwent a screening colonoscopy. CRC and polyps were assessed in both groups. The prevalence and odds ratio were calculated.Results:CRC was diagnosed in 16 of 310 patients with IPMN (5.2%), and at least one polyp was detected in 96 patients (31%). The prevalence of CRC was greater among patients with IPMN than in matched individuals [5.2% versus 1.3%, p = 0.012, prevalence odds ratio (POR) 4, confidence interval (CI) 1.29–16.44]. The overall prevalence of polyps was not higher among patients with IPMN than in matched individuals (31% versus 26.8%, p = 0.291, POR 1.22, CI 0.85–1.76). However, the prevalence of colorectal adenomas with high-grade dysplasia was higher in patients with IPMN than in matched individuals (4.2% versus 1%, p = 0.02, POR 4.33, CI, 1.19–23.7). The prevalence of large polyps (i.e. more than 20 mm in size) was also greater in patients with IPMN than in matched individuals (6.1% versus 1.9%, p = 0.011, POR 3.6, CI, 1.29–12.40).Conclusion:Patients with IPMN have a significantly higher prevalence of CRC and advanced polyps than the average risk population. In view of our findings, we suggest that once the diagnosis of IPMN is made, special consideration of CRC should be undertaken.

Abstract PO-247: Is colorectal cancer screening in West Africa worthwhile? A prospective multi-institutional study of 2,330 average-risk Nigerians using fecal immunochemical testing (FIT)

Abstract Objective: The estimated incidence of CRC is rising in many African countries. In Nigeria, it is the fourth most common cause of cancer death. More than half of CRC patients in Nigeria present with metastatic disease. Early detection and screening for CRC is a goal of the Nigerian National Cancer Control Plan. This study assessed the performance of the fecal immunochemical test (FIT) as a CRC screening modality in an average-risk population in Nigeria. Methods: A population-based, cross-sectional study of FIT-based CRC screening was undertaken. Asymptomatic average-risk participants aged 45-75 years in three states in Southwest Nigeria were screened using a qualitative (50ng/mL) FIT test. Participants were invited to enroll using age- and sex-stratified convenience sampling following community outreach. Participants with positive test results underwent colonoscopy and the positive predictive value (PPV) of FIT-based CRC screening for CRC and advanced adenomas (tubulovillous, villous or high grade dysplasia) was calculated. Information on demographics, cancer knowledge, and acceptability of the FIT test and colonoscopy were also collected. Results: Between January-April 2021, 2330 participants in 3 states (Osun, Kwara, Lagos) were enrolled in the study. The median age was 57 years. 68% had at least secondary level education. Participants were evenly spread across wealth quintiles. Baseline knowledge of CRC symptoms among participants was low, especially outside of Lagos. The test return rate was 90.6%, and FIT positivity rate was 20.5% overall (n=432); 11.2% in Lagos, 20.4% in Osun, and 27.8% in Kwara states. Among the FIT positive patients who completed colonoscopy (n=285; 66.0%), the positive predictive value (PPV) for invasive adenocarcinoma was 1.1%, and for advanced adenoma was 1.8%.[KTP1] [AD2] The acceptability of fecal-based CRC screening among participants was very high. Conclusions: CRC screening with qualitative FIT testing in Southwest Nigeria is feasible and acceptable to average-risk asymptomatic participants. The high false-positive rates and low PPV for advanced neoplasia, however, suggest it is not an optimal screening tool in this environment, particularly given the health resources required for endoscopic evaluation. Citation Format: Olusegun I. Alatise, Anna J. Dare, Patrick A. Akinyemi, Fatima B. Abdulkareem, Samuel A. Olatoke, Gregg C. Knapp, Peter T. Kingham. Is colorectal cancer screening in West Africa worthwhile? A prospective multi-institutional study of 2,330 average-risk Nigerians using fecal immunochemical testing (FIT) [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-247.