Association of Ultra-processed Food and Unprocessed or Minimally Processed Food Consumption With Bowel Habits Among U.S. Adults.

BACKGROUND & AIMS: Ultra-processed foods (UPFs) may have a negative impact on bowel habits. We aimed to assess the association between UPF and unprocessed or minimally processed food (MPF) intake and bowel habits among adults in the United States (U.S.). METHODS: We performed a cross-sectional study using data from the National Health and Nutrition Examination Survey (2005-2010). We used two 24-hour dietary recalls and, based on the Nova classification, calculated intakes of UPFs and MPFs. Constipation and diarrhea were defined using the Bristol Stool Form Scale and stool frequency. We performed survey-weighted logistic regression and substitution analysis to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Among 12,716 U.S. adults, there were 1290 cases of constipation and 1067 cases of diarrhea. Median UPF and MPF intakes were 26.5% and 66.2% of total grams per day, respectively. Greater UPF consumption (in % gram/d) was associated with higher odds of constipation (adjusted OR [aORQ4 vs Q1], 2.20; 95% CI, 1.76-2.74) (Ptrend < .001) but not diarrhea (aORQ4 vs Q1, 0.82; 95% CI, 0.62-1.09) (Ptrend = .12). Increased MPF consumption was associated with lower odds of constipation (aORQ4 vs Q1, 0.46; 95% CI, 0.370-0.57) (Ptrend < .001). Associations with constipation were attenuated after adjusting for diet quality (aORQ4 vs Q1, UPF, 1.53; MPF, 0.69). Substituting 10% of UPF intake with an equivalent proportion of MPFs was associated with lower odds of constipation (aOR, 0.90; 95% CI, 0.87-0.93). CONCLUSIONS: UPF intake was associated with higher odds of constipation, whereas the odds were lower with greater MPF consumption. The effect of food processing on bowel habits was independent of diet quality.

Lead Time and Immortal Time Biases Impact the Calculation of Post-colonoscopy Colorectal Cancer Survival.

The World Endoscopy Organization (WEO) standardized the reporting of post-colonoscopy colorectal cancers (PCCRCs), which account for 7% to 10% of colorectal cancers (CRCs).1 PCCRCs are diagnosed 6 to 36 months after a false negative colonoscopy. Detected CRCs (dCRCs) are diagnosed ≤6 months after an index true positive colonoscopy.2 PCCRC prognosis is unclear, with outcomes reported as comparable,3 superior,4 or inferior5,6 to those of dCRC. Because WEO terminology defines cases relative to the index colonoscopy, conventional survival analyses of PCCRC are susceptible to lead time and immortal time biases. We evaluated the influence of these biases on mortality in a population-based retrospective cohort of 10,938 dCRCs (93.8%) and 717 PCCRCs (6.2%). This study was set within Kaiser Permanente Northern California (KPNC), a large integrated health system, whose members are similar in demographic and socioeconomic characteristics to the Northern California region.7.

Surveillance Colonoscopy Findings in Older Adults With a History of Colorectal Adenomas.

Importance: Postpolypectomy surveillance is a common colonoscopy indication in older adults; however, guidelines provide little direction on when to stop surveillance in this population. Objective: To estimate surveillance colonoscopy yields in older adults. Design, Setting, and Participants: This population-based cross-sectional study included individuals 70 to 85 years of age who received surveillance colonoscopy at a large, community-based US health care system between January 1, 2017, and December 31, 2019; had an adenoma detected 12 or more months previously; and had at least 1 year of health plan enrollment before surveillance. Individuals were excluded due to prior colorectal cancer (CRC), hereditary CRC syndrome, inflammatory bowel disease, or prior colectomy or if the surveillance colonoscopy had an inadequate bowel preparation or was incomplete. Data were analyzed from September 1, 2022, to February 22, 2024. Exposures: Age (70-74, 75-79, or 80-85 years) at surveillance colonoscopy and prior adenoma finding (ie, advanced adenoma vs nonadvanced adenoma). Main Outcomes and Measures: The main outcomes were yields of CRC, advanced adenoma, and advanced neoplasia overall (all ages) by age group and by both age group and prior adenoma finding. Multivariable logistic regression was used to identify factors associated with advanced neoplasia detection at surveillance. Results: Of 9740 surveillance colonoscopies among 9601 patients, 5895 (60.5%) were in men, and 5738 (58.9%), 3225 (33.1%), and 777 (8.0%) were performed in those aged 70-74, 75-79, and 80-85 years, respectively. Overall, CRC yields were found in 28 procedures (0.3%), advanced adenoma in 1141 (11.7%), and advanced neoplasia in 1169 (12.0%); yields did not differ significantly across age groups. Overall, CRC yields were higher for colonoscopies among patients with a prior advanced adenoma vs nonadvanced adenoma (12 of 2305 [0.5%] vs 16 of 7435 [0.2%]; P = .02), and the same was observed for advanced neoplasia (380 of 2305 [16.5%] vs 789 of 7435 [10.6%]; P < .001). Factors associated with advanced neoplasia at surveillance were prior advanced adenoma (adjusted odds ratio [AOR], 1.65; 95% CI, 1.44-1.88), body mass index of 30 or greater vs less than 25 (AOR, 1.21; 95% CI, 1.03-1.44), and having ever smoked tobacco (AOR, 1.14; 95% CI, 1.01-1.30). Asian or Pacific Islander race was inversely associated with advanced neoplasia (AOR, 0.81; 95% CI, 0.67-0.99). Conclusions and Relevance: In this cross-sectional study of surveillance colonoscopy yield in older adults, CRC detection was rare regardless of prior adenoma finding, whereas the advanced neoplasia yield was 12.0% overall. Yields were higher among those with a prior advanced adenoma than among those with prior nonadvanced adenoma and did not increase significantly with age. These findings can help inform whether to continue surveillance colonoscopy in older adults.

Maximizing scarce colonoscopy resources: the crucial role of stool-based tests.

During the COVID-19 pandemic, health systems, including federally qualified health centers, experienced disruptions in colorectal cancer (CRC) screening. National organizations called for greater use of at-home stool-based testing followed by colonoscopy for those with abnormal test results to limit (in-person) colonoscopy exams to people with acute symptoms or who were high risk. This stool-test-first strategy may also be useful for adults with low-risk adenomas who are due for surveillance colonoscopy. We argue that colonoscopy is overused as a first-line screening method in low- and average-risk adults and as a surveillance tool among adults with small adenomas. Yet, simultaneously, many people do not receive much-needed colonoscopies. Delivering the right screening tests at intervals that reduce the risk of CRC, while minimizing patient inconvenience and procedural risks, can strengthen health-care systems. Risk stratification could improve efficiency of CRC screening, but because models that adequately predict risk are years away from clinical use, we need to optimize use of currently available technology-that is, low-cost fecal testing followed by colonoscopy for those with abnormal test results. The COVID-19 pandemic highlighted the urgent need to adapt to resource constraints around colonoscopies and showed that increased use of stool-based testing was possible. Learning how to adapt to such constraints without sacrificing patients' health, particularly for patients who receive care at federally qualified health centers, should be a priority for CRC prevention research.

Predicting Risk of Colorectal Cancer After Adenoma Removal in a Large Community-Based Setting.

INTRODUCTION: Colonoscopy surveillance guidelines categorize individuals as high or low risk for future colorectal cancer (CRC) based primarily on their prior polyp characteristics, but this approach is imprecise, and consideration of other risk factors may improve postpolypectomy risk stratification. METHODS: Among patients who underwent a baseline colonoscopy with removal of a conventional adenoma in 2004-2016, we compared the performance for postpolypectomy CRC risk prediction (through 2020) of a comprehensive model featuring patient age, diabetes diagnosis, and baseline colonoscopy indication and prior polyp findings (i.e., adenoma with advanced histology, polyp size ≥10 mm, and sessile serrated adenoma or traditional serrated adenoma) with a polyp model featuring only polyp findings. Models were developed using Cox regression. Performance was assessed using area under the receiver operating characteristic curve (AUC) and calibration by the Hosmer-Lemeshow goodness-of-fit test. RESULTS: Among 95,001 patients randomly divided 70:30 into model development (n = 66,500) and internal validation cohorts (n = 28,501), 495 CRC were subsequently diagnosed; 354 in the development cohort and 141 in the validation cohort. Models demonstrated adequate calibration, and the comprehensive model demonstrated superior predictive performance to the polyp model in the development cohort (AUC 0.71, 95% confidence interval [CI] 0.68-0.74 vs AUC 0.61, 95% CI 0.58-0.64, respectively) and validation cohort (AUC 0.70, 95% CI 0.65-0.75 vs AUC 0.62, 95% CI 0.57-0.67, respectively). DISCUSSION: A comprehensive CRC risk prediction model featuring patient age, diabetes diagnosis, and baseline colonoscopy indication and polyp findings was more accurate at predicting postpolypectomy CRC diagnosis than a model based on polyp findings alone.

Randomized Trial of Patient Outreach Approaches to De-implement Outdated Colonoscopy Surveillance Intervals.

BACKGROUND AND AIMS: Guidelines now recommend patients with low-risk adenomas receive colonoscopy surveillance in 7-10 years and those with the previously recommended 5-year interval be re-evaluated. We tested 3 outreach approaches for transitioning patients to the 10-year interval recommendation. METHODS: This was a 3-arm pragmatic randomized trial comparing telephone, secure messaging, and mailed letter outreach. The setting was Kaiser Permanente Northern California, a large integrated healthcare system. Participants were patients 54-70 years of age with 1-2 small (<10 mm) tubular adenomas at baseline colonoscopy, due for 5-year surveillance in 2022, without high-risk conditions, and with access to all 3 outreach modalities. Patients were randomly assigned to the outreach arm (telephone [n = 200], secure message [n = 203], and mailed letter [n = 201]) stratified by age, sex, and race/ethnicity. Outreach in each arm was performed by trained medical assistants (unblinded) communicating in English with 1 reminder attempt at 2-4 weeks. Participants could change their assigned interval to 10 years or continue their planned 5-year interval. RESULTS: Sixty-day response rates were higher for telephone (64.5%) and secure messaging outreach (51.7%) vs mailed letter (31.3%). Also, more patients adopted the 10-year surveillance interval in the telephone (37.0%) and secure messaging arms (32.0%) compared with mailed letter (18.9%) and rate differences were significant for telephone (18.1%; 97.5% confidence interval: 8.3%-27.9%) and secure message outreach (13.1%; 97.5% confidence interval: 3.5%-22.7%) vs mailed letter outreach. CONCLUSIONS: Telephone and secure messaging were more effective than mailed letter outreach for de-implementing outdated colonoscopy surveillance recommendations among individuals with a history of low-risk adenomas in an integrated healthcare setting. (ClinicalTrials.gov, Number: NCT05389397).

Endoscopic Evaluation of PET/CT Abnormalities in the Gastrointestinal Tract: Yield and Approach.

BACKGROUND: Unexpected hypermetabolic activity is often encountered in the gastrointestinal tract when PET/CT is performed for various indications, prompting endoscopic evaluation. Our aim was to characterize the types of lesions seen in segments of the gastrointestinal tract with unexpected PET/CT abnormalities as well as clinically significant lesions seen on endoscopy which did not produce a PET/CT abnormality to guide the endoscopist tasked with evaluating these imaging findings. METHODS: We retrospectively reviewed a database of endoscopies performed at City of Hope Comprehensive Cancer Center between January 1, 2016 and September 30, 2021 for an indication of "abnormal PET." We divided the gastrointestinal tract into segments and defined categories of endoscopic/histologic findings for each segment. We counted the number of segments with an abnormal PET/CT finding and corresponding endoscopic/histologic abnormality as well as the number of segments with an endoscopic/histologic abnormality but normal PET/CT. RESULTS: PET/CT identified 209 segments with hypermetabolic activity, 109 of which had corresponding endoscopic/histologic abnormalities. In the jejunum and ileum, all corresponding lesions were malignant. Seventy-three percent of corresponding lesions in the stomach were H. pylori positive. PET/CT failed to detect 34.7% of clinically significant lesions diagnosed endoscopically, including 1 malignancy in the transverse colon and many inflammatory or low-risk premalignant lesions. CONCLUSION: PET/CT abnormalities seen in the small bowel should be evaluated urgently as nearly all correlates were malignant, while abnormalities in the stomach should prompt workup for H. pylori. Most lesions missed by PET/CT were inflammatory or low-risk premalignant yet clinically significant, confirming the need to inspect the entirety of the upper or lower gastrointestinal tract during endoscopy.

Combining Asian and European genome-wide association studies of colorectal cancer improves risk prediction across racial and ethnic populations.

Polygenic risk scores (PRS) have great potential to guide precision colorectal cancer (CRC) prevention by identifying those at higher risk to undertake targeted screening. However, current PRS using European ancestry data have sub-optimal performance in non-European ancestry populations, limiting their utility among these populations. Towards addressing this deficiency, we expand PRS development for CRC by incorporating Asian ancestry data (21,731 cases; 47,444 controls) into European ancestry training datasets (78,473 cases; 107,143 controls). The AUC estimates (95% CI) of PRS are 0.63(0.62-0.64), 0.59(0.57-0.61), 0.62(0.60-0.63), and 0.65(0.63-0.66) in independent datasets including 1681-3651 cases and 8696-115,105 controls of Asian, Black/African American, Latinx/Hispanic, and non-Hispanic White, respectively. They are significantly better than the European-centric PRS in all four major US racial and ethnic groups (p-values < 0.05). Further inclusion of non-European ancestry populations, especially Black/African American and Latinx/Hispanic, is needed to improve the risk prediction and enhance equity in applying PRS in clinical practice.

American Society for Gastrointestinal Endoscopy guideline on the role of endoscopy in the diagnosis of malignancy in biliary strictures of undetermined etiology: summary and recommendations.

This clinical practice guideline from the American Society for Gastrointestinal Endoscopy provides an evidence-based approach for the diagnosis of malignancy in patients with biliary strictures of undetermined etiology. This document was developed using the Grading of Recommendations Assessment, Development and Evaluation framework and addresses the role of fluoroscopic-guided biopsy sampling, brush cytology, cholangioscopy, and EUS in the diagnosis of malignancy in patients with biliary strictures. In the endoscopic workup of these patients, we suggest the use of fluoroscopic-guided biopsy sampling in addition to brush cytology over brush cytology alone, especially for hilar strictures. We suggest the use of cholangioscopic and EUS-guided biopsy sampling especially for patients who undergo nondiagnostic sampling, cholangioscopic biopsy sampling for nondistal strictures and EUS-guided biopsy sampling distal strictures or those with suspected spread to surrounding lymph nodes and other structures.

American Society for Gastrointestinal Endoscopy guideline on role of endoscopy in the diagnosis of malignancy in biliary strictures of undetermined etiology: methodology and review of evidence.

Biliary strictures of undetermined etiology pose a diagnostic challenge for endoscopists. Despite advances in technology, diagnosing malignancy in biliary strictures often requires multiple procedures. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to rigorously review and synthesize the available literature on strategies used to diagnose undetermined biliary strictures. Using a systematic review and meta-analysis of each diagnostic modality, including fluoroscopic-guided biopsy sampling, brush cytology, cholangioscopy, and EUS-guided FNA or fine-needle biopsy sampling, the American Society for Gastrointestinal Endoscopy Standards of Practice Committee provides this guideline on modalities used to diagnose biliary strictures of undetermined etiology. This document summarizes the methods used in the GRADE analysis to make recommendations, whereas the accompanying article subtitled "Summary and Recommendations" contains a concise summary of our findings and final recommendations.

American Society for Gastrointestinal Endoscopy guideline on role of endoscopy in the diagnosis of malignancy in biliary strictures of undetermined etiology: methodology and review of evidence

Biliary strictures of undetermined etiology pose a diagnostic challenge for endoscopists. Despite advances in technology, diagnosing malignancy in biliary strictures often requires multiple procedures. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to rigorously review and synthesize the available literature on strategies used to diagnose undetermined biliary strictures. Using a systematic review and meta-analysis of each diagnostic modality, including fluoroscopic-guided biopsy sampling, brush cytology, cholangioscopy, and EUS-guided FNA or fine-needle biopsy sampling, the American Society for Gastrointestinal Endoscopy Standards of Practice Committee provides this guideline on modalities used to diagnose biliary strictures of undetermined etiology. This document summarizes the methods used in the GRADE analysis to make recommendations, whereas the accompanying article subtitled "Summary and Recommendations" contains a concise summary of our findings and final recommendations.

Epidemiologic Burden and Projections for Eosinophilic Esophagitis-Associated Emergency Department Visits in the United States: 2009-2030.

BACKGROUND & AIMS: Patients with poorly controlled eosinophilic esophagitis (EoE) may require unplanned emergency department (ED) visits for the management of dysphagia or food impactions. We evaluated the epidemiologic burden of EoE on ED utilization in the United States. METHODS: Data from the US Nationwide Emergency Department Sample were used to estimate weighted annual EoE-associated ED visits from 2009 to 2019. Temporal trends in population-adjusted rates of EoE visits were assessed using joinpoint regression. Autoregressive integrated moving average models were used to project EoE-associated ED visits to 2030. We also evaluated endoscopic utilization, requirement for hospitalization, and ED-related charges in patients with EoE presenting to the ED. RESULTS: A total of 11,125 unweighted (49,507 weighted) ED visits for EoE were included (69.0% male; mean age, 32.4 y). The annual volume of EoE-associated ED visits increased from 2934 (95% CI, 2437-3431) in 2009 to 8765 (95% CI, 7514-10,015) in 2019, and is projected to reach 15,445 (95% prediction interval, 14,672-16,218) by 2030. From 2009 to 2019, the number of EoE-associated ED visits increased by an average of 11.5% per year (95% CI, 10.3%-12.7%). The proportion of patients admitted to the hospital from the ED decreased from 25.6% in 2009 to 2011 to 14.0% in 2017 to 2019. Half of EoE patients presenting to the ED required an endoscopy, and nearly 40% required an esophageal foreign body removal. Total mean inflation-adjusted charges for an EoE-associated ED visit were $9025 US dollars in 2019. CONCLUSIONS: The volume of EoE-associated ED visits tripled between 2009 and 2019 and is projected to further double by 2030. This represents a substantial burden of unanticipated health care resource utilization and highlights a potential opportunity to optimize outpatient EoE care.

The Contemporary Probability of Occult Colorectal Cancer in Patients With Colitis-Related Dysplasia Undergoing Colectomy.

Occult colorectal cancer (CRC) has historically driven recommendations for colectomy in patients with inflammatory bowel disease with dysplasia . We defined the contemporary risk of occult CRC at colectomy among 93 patients with inflammatory bowel disease with dysplasia based on endoscopic appearance, resection, and concordance between site of cancer at colectomy and dysplasia at colonoscopy. Contrary to our hypothesis, we found that occult CRC at colectomy remains elevated in high-grade polypoid and invisible dysplasia. It was infrequent in other visible lesions. When present, occult cancer occurred in the same segment as dysplasia, suggesting the historic concern of missing a remote cancer is low.

Impact of a scalable training program on the quality of colonoscopy performance and risk of postcolonoscopy colorectal cancer.

BACKGROUND AND AIMS: Endoscopist adenoma detection rates (ADRs) vary widely and are associated with patients' risk of postcolonoscopy colorectal cancers (PCCRCs). However, few scalable physician-directed interventions demonstrably both improve ADR and reduce PCCRC risk. METHODS: Among patients undergoing colonoscopy, we evaluated the influence of a scalable online training on individual-level ADRs and PCCRC risk. The intervention was a 30-minute, interactive, online training, developed using behavior change theory, to address factors that potentially impede detection of adenomas. Analyses included interrupted time series analyses for pretraining versus posttraining individual-physician ADR changes (adjusted for temporal trends) and Cox regression for associations between ADR changes and patients' PCCRC risk. RESULTS: Across 21 endoscopy centers and all 86 eligible endoscopists, ADRs increased immediately by an absolute 3.13% (95% confidence interval [CI], 1.31-4.94) in the 3-month quarter after training compared with .58% per quarter (95% CI, .40-.77) and 0.33% per quarter (95% CI, .16-.49) in the 3-year pretraining and posttraining periods, respectively. Posttraining ADR increases were higher among endoscopists with pretraining ADRs below the median. Among 146,786 posttraining colonoscopies (all indications), each 1% absolute increase in screening ADR posttraining was associated with a 4% decrease in their patients' PCCRC risk (hazard ratio, .96; 95% CI, .93-.99). An ADR increase of ≥10% versus <1% was associated with a 55% reduced risk of PCCRC (hazard ratio, .45; 95% CI, .24-.82). CONCLUSIONS: A scalable, online behavior change training intervention focused on modifiable factors was associated with significant and sustained improvements in ADR, particularly among endoscopists with lower ADRs. These ADR changes were associated with substantial reductions in their patients' risk of PCCRC.

Dietary inflammatory and insulinemic potential, risk of hepatocellular carcinoma, and chronic liver disease mortality.

BACKGROUND: Diet modulates inflammation and insulin response and may be an important modifiable factor in the primary prevention of hepatocellular carcinoma (HCC) and chronic liver disease (CLD). We developed the empirical dietary inflammatory pattern (EDIP) and empirical dietary index for hyperinsulinemia (EDIH) scores to assess the inflammatory and insulinemic potentials of diet. We prospectively examined the associations of EDIP and EDIH at baseline with the following HCC risk and CLD mortality. DESIGN: We followed 485 931 individuals in the National Institutes of Health-American Association of Retired Persons Diet and Health Study since 1995. Cox proportional hazards regression was used to calculate multivariable hazard ratios (HRs) and 95% confidence intervals (CIs). RESULTS: We confirmed 635 incident HCC cases and 993 CLD deaths. Participants in the highest compared with those in the lowest EDIP quartile had a 1.35 times higher risk of developing HCC (95% CI = 1.08 to 1.70, Ptrend = .0005) and a 1.70 times higher CLD mortality (95% CI = 1.41 to 2.04, Ptrend < .0001). For the same comparison, participants with the highest EDIH were at increased risk of HCC (HR = 1.53, 95% CI = 1.20 to 1.95, Ptrend = .0004) and CLD mortality (HR = 1.72, 95% CI = 1.42 to 2.01, Ptrend < .0001). Similar positive associations of scores with HCC risk and CLD mortality were observed for both women and men. Moreover, individuals in both the highest EDIP and EDIH tertiles had a 92% increased HCC risk (95% CI = 1.43 to 2.58) and 98% increased CLD mortality (95% CI = 1.27 to 3.08) compared with those in both lowest tertiles. CONCLUSIONS: Our findings suggest that inflammation and hyperinsulinemia are potential mechanisms linking diet to HCC development and CLD mortality.

Increased Risk of Hospitalization, Surgery, and Venous Thromboembolism Among Patients With Inflammatory Bowel Disease and Malnutrition in a Large, Community-Based Health Care System.

INTRODUCTION: Patients with inflammatory bowel disease (IBD) constitute a high-risk population for malnutrition. Routine screening with standardized tools is recommended but can be challenging. Outcome data specific to IBD are sparse. METHODS: We performed a retrospective cohort study (2009-2019) and electronically screened a large community-based population with IBD for malnutrition risk by extracting height and longitudinal weight, data elements used in the Malnutrition Universal Screening Tool (MUST). We used Cox proportional hazards regression to evaluate whether an electronic medical record-derived modified MUST malnutrition risk score was associated with IBD-related hospitalization, surgery, and venous thromboembolism. RESULTS: Malnutrition risk was categorized as low in 10,844 patients with IBD (86.5%), medium in 1,135 patients (9.1%), and high in 551 patients (4.4%). In the 1-year follow-up period, medium and high malnutrition risks, compared with low risk, were associated with IBD-related hospitalization (medium-risk adjusted hazard ratio [aHR] 1.80, 95% confidence interval [CI] 1.34-2.42; high-risk aHR 1.90, 95% CI 1.30-2.78) and IBD-related surgery (medium risk aHR 2.28, 95% CI 1.60-3.26; high risk aHR 2.38, 95% CI 1.52-3.73). Only high malnutrition risk was associated with venous thromboembolism (aHR 2.79, 95% CI 1.33-5.87). DISCUSSION: Malnutrition risk is significantly associated with IBD-related hospitalization, surgery, and venous thromboembolism. Application of the MUST score to the electronic medical record can efficiently identify patients at risk for malnutrition and adverse outcomes, permitting concentration of nutritional and nonnutritional resources to those at greatest risk.

Risk-Stratified Screening for Colorectal Cancer Using Genetic and Environmental Risk Factors: A Cost-Effectiveness Analysis Based on Real-World Data.

BACKGROUND & AIMS: Previous studies on the cost-effectiveness of personalized colorectal cancer (CRC) screening were based on hypothetical performance of CRC risk prediction and did not consider the association with competing causes of death. In this study, we estimated the cost-effectiveness of risk-stratified screening using real-world data for CRC risk and competing causes of death. METHODS: Risk predictions for CRC and competing causes of death from a large community-based cohort were used to stratify individuals into risk groups. A microsimulation model was used to optimize colonoscopy screening for each risk group by varying the start age (40-60 years), end age (70-85 years), and screening interval (5-15 years). The outcomes included personalized screening ages and intervals and cost-effectiveness compared with uniform colonoscopy screening (ages 45-75, every 10 years). Key assumptions were varied in sensitivity analyses. RESULTS: Risk-stratified screening resulted in substantially different screening recommendations, ranging from a one-time colonoscopy at age 60 for low-risk individuals to a colonoscopy every 5 years from ages 40 to 85 for high-risk individuals. Nevertheless, on a population level, risk-stratified screening would increase net quality-adjusted life years gained (QALYG) by only 0.7% at equal costs to uniform screening or reduce average costs by 1.2% for equal QALYG. The benefit of risk-stratified screening improved when it was assumed to increase participation or costs less per genetic test. CONCLUSIONS: Personalized screening for CRC, accounting for competing causes of death risk, could result in highly tailored individual screening programs. However, average improvements across the population in QALYG and cost-effectiveness compared with uniform screening are small.