Average Risk For Colorectal Cancer Research Articles

A multiple-dimension model for microbiota of patients with colorectal cancer from normal participants and other intestinal disorders.

Gut microbiota is a primary driver of inflammation in the colon and is linked to early colorectal cancer (CRC) development. Thus, a novel and noninvasive microbiome-based model could promote screening in patients at average risk for CRC. Nevertheless, the relevance and effectiveness of microbial biomarkers for noninvasive CRC screening remains unclear, and researchers lack the data to distinguish CRC-related gut microbiome biomarkers from those of other common gastrointestinal (GI) diseases. Microbiome-based classification distinguishes patients with CRC from normal participants and excludes other CRC-relevant diseases (e.g., GI bleed, adenoma, bowel diseases, and postoperative). The area under the receiver operator characteristic curve (AUC) was 92.2%. Known associations with oral pathogenic features, benefits-generated features, and functional features of CRC were confirmed using the model. Our optimised prediction model was established using large-scale experimental population-based data and other sequence-based faecal microbial community data. This model can be used to identify the high-risk groups and has the potential to become a novel screening method for CRC biomarkers because of its low false-positive rate (FPR) and good stability. KEY POINTS: • A total of 5744 CRC and non-CRC large-scale faecal samples were sequenced, and a model was constructed for CRC discrimination on the basis of the relative abundance of taxonomic and functional features. • This model could identify high-risk groups and become a novel screening method for CRC biomarkers because of its low FPR and good stability. • The association relationship of oral pathogenic features, benefits-generated features, and functional features in CRC was confirmed by the study.

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.

Deep learning in CT colonography: differentiating premalignant from benign colorectal polyps

ObjectivesTo investigate the differentiation of premalignant from benign colorectal polyps detected by CT colonography using deep learning.MethodsIn this retrospective analysis of an average risk colorectal cancer screening sample, polyps of all size categories and morphologies were manually segmented on supine and prone CT colonography images and classified as premalignant (adenoma) or benign (hyperplastic polyp or regular mucosa) according to histopathology. Two deep learning models SEG and noSEG were trained on 3D CT colonography image subvolumes to predict polyp class, and model SEG was additionally trained with polyp segmentation masks. Diagnostic performance was validated in an independent external multicentre test sample. Predictions were analysed with the visualisation technique Grad-CAM++.ResultsThe training set consisted of 107 colorectal polyps in 63 patients (mean age: 63 ± 8 years, 40 men) comprising 169 polyp segmentations. The external test set included 77 polyps in 59 patients comprising 118 polyp segmentations. Model SEG achieved a ROC-AUC of 0.83 and 80% sensitivity at 69% specificity for differentiating premalignant from benign polyps. Model noSEG yielded a ROC-AUC of 0.75, 80% sensitivity at 44% specificity, and an average Grad-CAM++ heatmap score of ≥ 0.25 in 90% of polyp tissue.ConclusionsIn this proof-of-concept study, deep learning enabled the differentiation of premalignant from benign colorectal polyps detected with CT colonography and the visualisation of image regions important for predictions. The approach did not require polyp segmentation and thus has the potential to facilitate the identification of high-risk polyps as an automated second reader.Key Points• Non-invasive deep learning image analysis may differentiate premalignant from benign colorectal polyps found in CT colonography scans.• Deep learning autonomously learned to focus on polyp tissue for predictions without the need for prior polyp segmentation by experts.• Deep learning potentially improves the diagnostic accuracy of CT colonography in colorectal cancer screening by allowing for a more precise selection of patients who would benefit from endoscopic polypectomy, especially for patients with polyps of 6–9 mm size.

Adaptation of clinical practice guideline for colorectal cancer screening in people with average risk in Isfahan province

Colorectal cancer (CRC) is the third most common cancer among adults in Iran. The aim of colorectal cancer screening is to reduce the cancer burden in the population by diagnosing the disease in its early stages. We adapted this guideline for the moderate CRC risk population for Isfahan to determine how to screen them and when to start and end the CRC screening. This guideline was developed by clinical appraisal and review of the evidence, available clinical guidelines, and in consultation with members of the Isfahan Chamber of Iranian association of gastroenterology and hepatology. In screening people with average risk for CRC who use personal resources and personally pay all the costs, colonoscopy is recommended as the first choice to be done every 10 years. In case of negative colonoscopy, we recommend FIT test to prevention of interval cancer every 5 years. In screening of people with average risk of CRC, FIT is suggested to be done every 2 years as a first-choice method test for those who use public resources and do not pay for this service personally. In screening individuals with average risk for CRC, g-FOBT is not recommended as the first method of choice. Repeating positive guaiac test is not recommended and if positive, colonoscopy is suggested.

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

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

Gallstone Disease and Risk of Conventional Adenomas and Serrated Polyps: A Prospective Study.

Gallstone disease has been associated with colorectal cancer and some form of polyps, although the findings are inconclusive. It remains unknown whether gallstone disease influences the initiation of colorectal cancer. We prospectively assessed the association of gallstone disease with risk of colorectal cancer precursors, including conventional adenomas and serrated polyps, in the Nurses' Health Study (1992-2012), the Nurses' Health Study II (1991-2011), and the Health Professionals Follow-up Study (1992-2012). Gallstone diseases were assessed using biennial follow-up questionnaires. Self-reported polyp diagnosis was confirmed by review of medical records. Logistic regression models were used to calculate the ORs with adjustment for smoking and other potential confounders. Among participants who had undergone a total of 323,832 endoscopies, 16.5% had gallstone disease and 11.3% received cholecystectomy. We documented 1,724, 1,212, and 1,943 cases of conventional adenomas and 1,470, 1,090, and 1,643 serrated polyps in patients with gallstones, cholecystectomy, and either of them, respectively. The OR for adenomas was 1.00 [95% confidence interval (CI): 0.95-1.06] for gallstones, 0.99 (95% CI, 0.93-1.06) for cholecystectomy, and 1.00 (95% CI, 0.95-1.05) for either exposure. The corresponding ORs for serrated polyps were 0.98 (95% CI, 0.92-1.04), 0.99 (95% CI, 0.93-1.06), and 0.97 (95% CI, 0.92-1.03), respectively. Gallstone disease is not associated with colorectal polyps. Patients with gallstones appear to have similar risk of colorectal polyps compared with those without and may therefore follow average-risk colorectal cancer screening guidelines.

Screening for Colorectal Cancer Leading into a New Decade: The "Roaring '20s" for Epigenetic Biomarkers?

Colorectal cancer (CRC) has an important bearing (top five) on cancer incidence and mortality in the world. The etiology of sporadic CRC is related to the accumulation of genetic and epigenetic alterations that result in the appearance of cancer hallmarks such as abnormal proliferation, evasion of immune destruction, resistance to apoptosis, replicative immortality, and others, contributing to cancer promotion, invasion, and metastasis. It is estimated that, each year, at least four million people are diagnosed with CRC in the world. Depending on CRC staging at diagnosis, many of these patients die, as CRC is in the top four causes of cancer death in the world. New and improved screening tests for CRC are needed to detect the disease at an early stage and adopt patient management strategies to decrease the death toll. The three pillars of CRC screening are endoscopy, radiological imaging, and molecular assays. Endoscopic procedures comprise traditional colonoscopy, and more recently, capsule-based endoscopy. The main imaging modality remains Computed Tomography (CT) of the colon. Molecular approaches continue to grow in the diversity of biomarkers and the sophistication of the technologies deployed to detect them. What started with simple fecal occult blood tests has expanded to an armamentarium, including mutation detection and identification of aberrant epigenetic signatures known to be oncogenic. Biomarker-based screening methods have critical advantages and are likely to eclipse the classical modalities of imaging and endoscopy in the future. For example, imaging methods are costly and require highly specialized medical personnel. In the case of endoscopy, their invasiveness limits compliance from large swaths of the population, especially those with average CRC risk. Beyond mere discomfort and fear, there are legitimate iatrogenic concerns associated with endoscopy. The risks of perforation and infection make endoscopy best suited for a confirmatory role in cases where there are positive results from other diagnostic tests. Biomarker-based screening methods are largely non-invasive and are growing in scope. Epigenetic biomarkers, in particular, can be detected in feces and blood, are less invasive to the average-risk patient, detect early-stage CRC, and have a demonstrably superior patient follow-up. Given the heterogeneity of CRC as it evolves, optimal screening may require a battery of blood and stool tests, where each can leverage different pathways perturbed during carcinogenesis. What follows is a comprehensive, systematic review of the literature pertaining to the screening and diagnostic protocols used in CRC. Relevant articles were retrieved from the PubMed database using keywords including: “Screening”, “Diagnosis”, and “Biomarkers for CRC”. American and European clinical trials in progress were included as well.

Centralized colorectal cancer screening outreach and patient navigation for vulnerable populations in North Carolina: study protocol for the SCORE randomized controlled trial

BackgroundAlthough colorectal cancer (CRC) screening is effective in reducing CRC mortality, screening rates in vulnerable populations served by community health centers (CHCs) remain below national targets. CHCs in North Carolina are challenged to reach CRC screening targets as they tend to be under-resourced, have limited capacity to implement and sustain population health interventions, and typically operate independently from one another and from regional colonoscopy providers. The Scaling Colorectal Cancer Screening Through Outreach, Referral, and Engagement (SCORE) project is designed to address barriers to CRC screening in partnership with CHCs by implementing a multilevel intervention that includes centralized support infrastructure for mailed fecal immunochemical test (FIT) outreach and patient navigation to follow-up colonoscopy. This paper describes protocols for the SCORE implementation trial.MethodsWe will conduct a type 2 hybrid effectiveness-implementation trial that will assess effectiveness at increasing CRC screening and follow-up rates while also assessing implementation outcomes. The planned trial sample will include 4000 CHC patients who are at average CRC risk and due for screening. Participants will be randomized 1:1 to receive either usual care or a multilevel intervention that includes mailed FIT outreach and patient navigation support to follow-up colonoscopy for those with abnormal FIT. The primary effectiveness outcome is completion of any CRC screening test at six months after randomization. We will also conduct a multilevel assessment of implementation outcomes and determinants.DiscussionThis hybrid effectiveness-implementation trial will evaluate the effectiveness and implementation of an intervention that provides centralized infrastructure for mailed FIT screening and patient navigation for CHCs that operate independently of other healthcare facilities. Findings from this research will enhance understanding of the effectiveness of a centralized approach and factors that determine successful implementation in vulnerable patient populations.Trial registrationThe trial was registered on May 28, 2020, at ClinicalTrials.gov (identifier NCT04406714).

S250 Increasing Fecal Immunochemical Test Return Rates by Patient Reminders: A Quality Improvement Study

Introduction: The incidence of colorectal cancer (CRC) in the United States is increasing, and it remains the second leading cause of cancer death in the United States for men and women combined. The American Cancer Society now recommends that adults aged 45 years and older with an average risk of CRC undergo regular screening with either a high sensitivity stool-based test or structural (visual) examination, depending on patient preference and test availability. The primary objective of this quality improvement project was to determine if reminder methods, such as telephone or letter reminders, increased the return rate of fecal immunochemical tests (FIT) for colorectal cancer screening. Methods: At public outreach events and daily clinics in the West Texas Panhandle area, participants in the GET FIT program were provided with FIT kits after completing the education on colorectal cancer. Participants who fit the inclusion criteria and had received a FIT kit from the program were included. They were instructed on how to perform the test and mail it back. Participants that did not return the completed kits within two weeks were reminded either by 1) through a reminder letter or 2) by telephone every 2 weeks (+/- 3 days) for 60 days or 5 attempts to contact. We de-identified and analyzed the FIT kit return data from June-November 2019 before instituting these reminder methods. We then calculated the change in return rates from December 2019 to February 2020. Our goal was to increase the FIT return rates by 25% over the baseline return rate. Results: The pre-intervention return rate of kits for June-November 2019 was 67.58%, and the postintervention return rate for December 2019-February 2020 was 81.87%. This rate was equal to an approximately 21% increase in return rates. The average return rate of FIT kits overall was 72.34%. The average rate of returned new patient kits was 69%, and the average % of new patient return kits was 68.51%. We also noticed a significant increase in return of FIT tests after a community cancer screening in October 2019. Conclusion: Fecal immunohistochemical test (FIT) remains one of the primary options for colorectal cancer screening. Due to its lower cost and noninvasiveness, FIT was offered to patients at average risk.We did achieve a significant increase in return rates, although we did not meet our target goal for this project. Our project was limited to studying 3 months post-intervention due to the COVID pandemic and barrier in returning tests. (Table Presented).

S1987 Go With Your Gut Feeling: A Case of Invasive Colonic Squamous Cell Carcinoma Not Detected by DNA-Based Stool Testing

Introduction: Though less common, colonic squamous cell carcinoma is a type of colorectal cancer. Current colorectal cancer screening recommendations for average-risk patients include the use of stool DNA-based testing as an alternative to screening colonoscopy. This clinical vignette is an example of colonic squamous cell carcinoma that went undetected by a stool DNA-based colorectal cancer screening test. Case Description/Methods: 57 year-old female with no prior medical history presented to outpatient gastroenterology office for evaluation of tenesmus, mucus in stool with associated diarrhea and LLQ pain of 3 months duration. Physical exam was unremarkable. Recent CBC, BMP, and albumin were within normal limits. Patient had undergone average-risk colorectal cancer screening with a stool DNA-based test 11 months prior to presentation (8 months prior to symptom onset) with a negative result. Patient was asymptomatic at the time of the screening test. Due to her new symptoms, it was recommended she undergo infectious stool studies and colonoscopy. C difficile screen, bacterial stool culture and parasitology exam were negative. Colonoscopy revealed a 6-cm partially circumferential frond-like/villous, infiltrative and ulcerated partially obstructing large mass 4-11cm from the anal verge (Figure 1A, B). Biopsy was positive for invasive squamous cell carcinoma. The patient was referred to oncology and completed definitive chemo-radiation therapy with no evidence on residual disease on most recent imaging. Discussion: This case demonstrates an average-risk patient who underwent stool DNA-based testing for colorectal cancer screening that was negative with subsequent presentation and diagnosis of invasive squamous cell carcinoma of the colon in less than one year’s time. It highlights the importance of colorectal cancer screening and the ability of colonoscopy to detect and diagnosis colorectal cancer. DNA-based stool testing is an alternative non-invasive screening test to colonoscopy in average-risk patients. The current data supports a false negative rate of DNA-based stool testing to be less than 1 in 1500. However, the presence of a false negative test provides patients with a false sense of confidence and reassurance that they do not have cancer. It is imperative that for any new lower GI symptoms or other clinical suspicion for colorectal malignancy, the patient should still undergo evaluation with colonoscopy – endoscopic evaluation should not be deferred because of a recent negative DNA-based stool test.Figure 1.: A. Colon with mass, B. Detailed view of ulcerated mas.

Colon capsule endoscopy in clinical practice: lessons from a national 5-year observational prospective cohort.

Background and study aims Colon capsule endoscopy (CCE) has been proposed as an alternative to colonoscopy for screening patients at average risk of colorectal cancer (CRC). A prospective national cohort was developed to assess relevance of CCE in real-life practice and its short- and long-term impacts on clinical management. Patients and methods All patients who underwent a CCE in France were prospectively enrolled from January 2011 to May 2016 and reached annually by phone until May 2017. All CCE and colonoscopy reports were systematically collected. Results During the study period, 689 CCEs were analyzed from 14 medical centers. Median follow-up time was 35 months [IQR: 12–50]. Indication for CCE was mainly for elderly patients (median age: 70 years, IQR: [61–79]) due to anesthetic or colonoscopy contraindication (n = 307; 44.6 %). Only 337 CCEs (48.9 %) were both complete and with adequate bowel preparation. Advanced neoplasia (adenoma with high-grade dysplasia or CRC) was diagnosed following 32 CCEs (4.6 %). Among patients who underwent colonoscopy or therapeutic surgery following CCE, 18.8 % of all advanced neoplasias (6/32) had not been diagnosed by CCE mainly due to technical issues. Performing a colonoscopy in the case of significant polyps or insufficient bowel cleansing or after an incomplete CCE allowed the diagnosis of 96.9 % of all identified advanced neoplasias (31/32). Conclusions Outside the scope of academic trials, improvement is needed to increase the reliability of CCE as less than half were considered optimal i. e. complete with adequate bowel cleansing. Most of missed colonic advanced neoplasia were due to incomplete CCE with distal neoplasia location.

Colorectal Cancer Screening Outcomes of 2412 Prostate Cancer Patients Considered for Carbon Ion Radiotherapy.

Simple SummaryColorectal cancer (CRC) screening is effective for cancer detection in average-risk adults. For prostate cancer (PCa) patients considered for carbon ion radiotherapy (CIRT), pre-treatment CRC screening is performed empirically to avoid post-treatment colonoscopic manipulation. However, the outcomes of screening remain unclear. To address this, we analyzed the outcomes of 2412 PCa patients at average risk for CRC who underwent routine pre-CIRT CRC screening and found that the estimated CRC prevalence was greater than that reported by 17 previous large-scale screening studies analyzing average-risk adults. These data indicate the possibility that the prevalence of CRC in PCa patients is greater than that in general average-risk adults, warranting further research.Colorectal cancer (CRC) screening is effective for detecting cancer in average-risk adults. For prostate cancer (PCa) patients considered for carbon ion radiotherapy (CIRT), pre-treatment CRC screening is performed empirically to avoid post-treatment colonoscopic manipulation. However, the outcomes of screening this population remain unclear. Here, we compared the outcomes of routine pre-CIRT CRC screening of 2412 PCa patients at average risk for CRC with data from two published datasets: the Japan National Cancer Registry (JNCR) and a series of 17 large-scale screening studies analyzing average-risk adults. The estimated prevalence rate was calculated using the pooled sensitivity elucidated by a previous meta-analysis. Consequently, 28 patients (1.16%) were diagnosed with CRC. CRC morbidity was significantly associated with high pre-treatment levels of prostate-specific antigen (p = 0.023). The screening positivity rate in this study cohort exceeded the annual incidence reported in the JNCR for most age brackets. Furthermore, the estimated prevalence rate in this study cohort (1.46%) exceeded that reported in all 17 large-scale studies, making the result an outlier (p = 0.005). These data indicate the possibility that the prevalence of CRC in PCa patients is greater than that in general average-risk adults, warranting further research in a prospective setting.

Utilization of a Colorectal Cancer Screening Test Among Individuals With Average Risk

Colorectal cancer (CRC) screening reduces CRC incidence and mortality. It is important to examine screening patterns over time, including after the introduction of new screening modalities. To compare use of CRC screening tests before and after the availability of the multitarget stool DNA (mt-sDNA) test, given that endorsed options have changed. This longitudinal cohort study used administrative claims data to examine CRC screening use in 2 discrete periods: before (August 1, 2011, to July 31, 2014) and after (August 1, 2016, to July 31, 2019) the mt-sDNA test became available. The MarketScan Commercial and Medicare Supplemental databases were queried for individuals aged 45 to 75 years between August 1, 2011, and July 31, 2019, with average risk of CRC and with continuous enrollment in the databases from August 1, 2001, to July 31, 2019. The proportion of individuals up to date or not due for CRC screening during each measurement year and the type of screening test used among individuals due for screening. Data were reported overall and among individuals aged 45 to 49 or 50 years and older on August 1, 2011. A total of 97 776 individuals with average risk were identified. Individuals had a mean (SD) age of 50.8 (3.5) years, and 54 227 (55.5%) were women. The proportion of individuals with average risk aged 50 to 75 years with commercial or Medicare supplemental insurance who were up to date with CRC screening increased from 50.4% in 2011 (30 605 of 60 770) to 69.7% in 2019 (42 367 of 60 770). Among individuals due for screening and screened, the use of high-sensitivity fecal occult blood test (FOBT) decreased between 2011 (1088 of 6241 eligible individuals [17.7%]) and 2019 (195 of 2943 eligible individuals [6.6%]), and the use of mt-sDNA increased between 2016 (58 of 3014 eligible individuals [1.9%]) and 2019 (418 of 2943 eligible individuals [14.2%]). No consistent trends were observed with fecal immunochemical test (FIT) or screening colonoscopy. Computed tomography colonography, double-contrast barium enema, and flexible sigmoidoscopy were rarely performed. In this cohort study, the proportion of individuals with average risk who were up to date with CRC screening increased between 2011 and 2019 but remained suboptimal. There were no substantial changes in the use of the colonoscopy or FIT; however, there was an increase in the adoption of mt-sDNA and a decrease in the use of FOBT during the study period.

Barriers to utilization of three colorectal cancer screening options – Data from a national survey

Colorectal cancer (CRC) screening continues to be underutilized in the United States. A better understanding of existing barriers is critical for improving uptake of, and adherence to, CRC screening. Using data from a population-based panel survey, we examined barriers to utilization of three commonly used screening options (FIT/gFOBT, mt-sDNA, and screening colonoscopy) and assessed differences by socio-demographic characteristics, healthcare access, and health status. Data were obtained from a questionnaire developed by the authors and implemented through a U.S. national panel survey conducted in November 2019. Among 5,097 invited panelists, 1,595 completed the survey (31.3%). Analyses were focused on individuals ages 50–75 at average risk for CRC. Results showed that among respondents who reported no prior CRC screening with FIT/gFOBT, mt-sDNA, or colonoscopy, the top barriers were lack of knowledge (FIT/gFOBT: 42.1%, mt-sDNA: 44.9%, colonoscopy: 34.7%), lack of provider recommendation (FIT/gFOBT: 32.1%, mt-sDNA: 27.3%, colonoscopy: 18.6%), and suboptimal access (FIT/gFOBT: 20.8%, mt-sDNA: 17.8%, colonoscopy: 26%). Among participants who had used one or two of the screening options, the top barriers to FIT/gFOBT and mt-sDNA were lack of provider recommendation (31.6% & 37.5%) and lack of knowledge (24.6% & 25.6%), while for colonoscopy top barriers were psychosocial barriers (31%) and lack of provider recommendation (22.7%). Differences by sex, race/ethnicity, income level, and health status were observed. Our research identified primary barriers to the utilization of three endorsed CRC screening options and differences by patient characteristics, highlighting the importance of improving CRC screening education and considering patient preferences in screening recommendations.

Patient preferences on general health and colorectal cancer screening decision-making: Results from a national survey

ObjectiveWe examined patient preferences regarding colorectal cancer (CRC) screening decision-making and factors associated with these preferences among screening-eligible US adults. MethodsThrough a national survey of 1595 US adults ages 40–75 (response rate: 31.3%), we measured general medical decision-making and CRC screening decision-making preferences (0–100, 100 = highest desire for involvement) and preferred control level over three CRC screening decisions (whether to screen, what method to use, and when to screen). Analyses focused on respondents aged 45–75 at average CRC risk (N = 1062). ResultsRespondents expressed strong desire for involvement in general medical decision-making and CRC screening decision-making (Mean = 68.1, 64.4). Over half of respondents reported preferring having equal control as their providers over whether to screen, what method to use, and when to screen. Women and people with higher education expressed higher desire for involvement in general medical decision-making. For CRC screening decision-making, variations exist in preferred level of involvement and control by race/ethnicity, educational attainment, insurance status, and recency of routine checkup. ConclusionMost respondents preferred a collaborative process of CRC screening decision-making, while variations existed across subgroups. Practice implicationsProviders should assess patients’ values and preferences and involve them in CRC screening decision-making at a level they are comfortable with.

"Rescue" of Nonparticipants in Colorectal Cancer Screening: A Randomized Controlled Trial of Three Noninvasive Test Options.

Few studies have directly targeted nonparticipants in colorectal cancer screening to identify effective engagement strategies. We undertook a randomized controlled trial that targeted nonparticipants in a previous trial of average-risk subjects which compared participation rates for mailed invitations offering a fecal test, a blood test or a choice of either. Nonparticipants (n = 899) were randomized to be offered a kit containing a fecal immunochemical test (FIT), directions on how to arrange a blood DNA test, or the option of doing either. Screening participation was assessed 12 weeks after the offer. To assess the cognitive and attitudinal variables related to participation and invitee choice, invitees were surveyed after 12 weeks, and associations were investigated using multinomial logistic regression. Participation rates were similar between groups (P = 0.88): 12.0% for FIT (35/292), 13.3% for the blood test (39/293), and 13.4% for choice (39/290). Within the choice group, participation was significantly higher with FIT (9.7%, 28/290) compared with the blood test (3.8%, 11/290, P = 0.005). The only variable significantly associated with participation was socioeconomic status when offered FIT, and age when offered choice but there was none when offered the blood test. Survey respondents indicated that convenience, time-saving, comfort, and familiarity were major influences on participation. There was no clear advantage between a fecal test, blood test, or choice of test although, when given a choice, the fecal test was preferred. Differences in variables associated with participation according to invitation strategy warrant consideration when deciding upon an invitation strategy for screening nonparticipants. PREVENTION RELEVANCE: This trial of screening for those at average risk for colorectal cancer targeted past fecal-test nonparticipants and compared participation rates for mailed invitations offering a fecal test, blood test, or choice of either. Although there was no clear advantage between strategies, factors associated with participation differed between each strategy.

Comparison of colorectal cancer location and metastasis site in patients aged 50 to 75 versus age 75 and older in community and academic practice.

e15595 Background: Current guidelines recommend cessation of average risk colorectal cancer screening at age 75, after which a more individualized approach is endorsed. There is limited data on characteristics of colorectal cancer in patients over the age of 75. We aimed to determine if colorectal cancer site and metastasis is greater in the community vs academic setting in patients aged 50-75 compared to those age 75 or older. Methods: Data were analyzed from the National Cancer Database (NCDB) between 2010-2014. Results were divided into two categories (50-75 year old, >75 year old) and included number of patients, site of cancer and site of metastasis. Patient characteristics and survival were compared with Mann-Whitney U, Pearson’s Chi-square, and the Kaplan-Meier method. Results: 167, 059 patients were included in the analysis. In the academic setting, group A (age 50-75) contained 36, 298 patients and group B (>75) contained 13,253 patients. In the community setting, group A involved 77, 657 patients and group B, 39,851 patients. In the academic setting, group A identified 57.7% of cases involving the colon vs 42.3% involving the rectum. In group B, 71.4% cases involved the colon vs 28.6% involving the rectum. In the community setting, group A identified 64.4% of cases involving the colon compared to 35.6% involving the rectum. For group B, 76.2% of cases diagnosed were in the colon vs. 23.8% of cases involving the rectum. Overall, indicating a statistically significant increase seen in colon involvement in the older age group (<0.001). In community and academic practice, there is a statistically significant increase in the cases involving metastasis for group A, compared to group B (p<0.001) This is seen for specific sites as well, including bone, liver and lung, (p< 0.001) but not brain involvement in academic practice. Conclusions: In this study, we found a statistically greater number of cases of involving metastasis in patients aged 50-75 compared to patients aged 75 and older in both academic and community practices. In both the academic and community setting, older patients demonstrated statistically greater involvement of the colon compared to patients aged 50-75. Overall, there were more cases of colon and rectal cancer for both age groups seen in the community setting compared to the academic setting.

Multimodal circulating tumor DNA (ctDNA) colorectal neoplasia detection assay for asymptomatic and early-stage colorectal cancer (CRC).

3536 Background: To improve average risk CRC screening compliance, additional options are needed, especially options that address patient and provider reported barriers such as time and convenience. LUNAR-2 is a multimodal blood-based colorectal neoplasia detection assay incorporating ctDNA assessment of somatic mutations and tumor derived methylation and fragmentomic patterns, aimed to maximize sensitivity for early stage CRC detection. We evaluated this test in a large patient cohort with newly diagnosed CRC. Methods: Individuals diagnosed with CRC between 2013-2016 consented to provide blood samples prior to surgical resection. Those treated with neoadjuvant chemotherapy were excluded. Isolated plasma samples (median 3mL from EDTA) from 434 individuals were analyzed with LUNAR-2 (Guardant Health, USA) and included in the analysis. Median age at CRC diagnosis was 63 years (range 28 - 89) and 41% were female. Control samples were from 271 age-matched cancer free individuals. “ctDNA detected” and “ctDNA not detected” results were generated by a model trained on a separate sample set (N=614) from both cancer free individuals and those with CRC. Calling threshold was determined based on this held-out set to target 90% specificity. ctDNA results and clinical characteristics were correlated. Results: Overall CRC sensitivity was 91% (393/434), with high sensitivity across all stages; 88% Stage I/II, 93% Stage III (Table). Specificity was 94% (255/271). There was no difference in sensitivity when excluding those with early (<45 years) or late (>84 years) onset CRC (90% sensitivity; 388/429; p=0.95; 88% Stage I/II, 93% Stage III). There were no differences in sensitivity for asymptomatic CRC (88%) compared to symptomatic CRC (91%; p=0.4; Table). However, higher cell-free DNA tumor fractions were observed in the symptomatic cohort. Sensitivity for detection of right-sided and left-sided CRC was similar (93% vs. 90%; p=0.5; Table). Conclusions: In this large early-stage CRC cohort, multimodal ctDNA assessment has high sensitivity for CRC detection with high specificity. Equivalent sensitivity in the asymptomatic cohort suggests this test will have clinically meaningful performance in an average risk screening population. A prospective registrational study is ongoing to evaluate the test in an average risk CRC screening cohort.[Table: see text]

Characterizing Health Literacy Among Spanish Language-Preferring Latinos Ages 50-75.

Cultural background, language, and literacy are factors that may affect access, healthcare utilization, and cancer screening behaviors. This study aimed to characterize health literacy among Spanish-preferring Hispanic/Latino individuals ages 50-75 and examine associations between sociodemographic characteristics, health beliefs, and health literacy. Participants self-identified as Hispanic/Latino, preferring health information in Spanish, were ages 50-75 years old, at average risk for colorectal cancer (CRC), not up to date with CRC screening, and enrolled in a CRC screening education intervention trial. Sociodemographic characteristics, health beliefs, and health literacy (i.e., difficulty understanding written health information and confidence completing health forms) were assessed at baseline. Descriptive and logistic regression analyses were performed. Fifty-three percent of participants reported either sometimes having difficulty or always having difficulty with written health information, and 25% reported always asking for help or being not so confident in completing health forms. Univariate predictors of adequate health literacy for written health information were lower cancer worry and lower religious beliefs. Higher educational attainment predicted confidence in completing health forms. Findings highlight the need for interventions that address health beliefs and health literacy among Hispanic/Latino patients who have low confidence in completing written forms and difficulty understanding written information and reinforce the use of plain language and salient design features when developing patient education materials.

National Survey of Patient Factors Associated with Colorectal Cancer Screening Preferences

Recommended colorectal cancer screening modalities vary with respect to safety, efficacy, and cost. Better understanding of the factors that influence patient preference is, therefore, critical for improving population adherence to colorectal cancer screening. To address this knowledge gap, we conducted a panel survey focused on three commonly utilized colorectal cancer screening options [fecal immunochemical test or guaiac-based fecal occult blood test (FIT/gFOBT), multi-target stool DNA (mt-sDNA) test, and colonoscopy] with a national sample of U.S. adults, ages 40-75 years and at average risk of colorectal cancer, in November 2019. Of 5,097 panelists invited to participate, 1,595 completed the survey (completion rate, 31.3%). Our results showed that when presented a choice between two colorectal cancer screening modalities, more respondents preferred mt-sDNA (65.4%) over colonoscopy, FIT/gFOBT (61%) over colonoscopy, and mt-sDNA (66.9%) over FIT/gFOBT. Certain demographic characteristics and awareness of and/or experience with various screening modalities influenced preferences. For example, uninsured people were more likely to prefer stool-based tests over colonoscopy [OR, 2.53; 95% confidence interval (CI), 1.22-5.65 and OR, 2.73; 95% CI, 1.13-7.47]. People who had heard of stool-based screening were more likely to prefer mt-sDNA over FIT/gFOBT (OR, 2.07; 95% CI, 1.26-3.40). People who previously had a stool-based test were more likely to prefer FIT/gFOBT over colonoscopy (OR, 2.75; 95% CI, 1.74-4.41), while people who previously had a colonoscopy were less likely to prefer mt-sDNA or FIT/gFOBT over colonoscopy (OR, 0.39; 95% CI, 0.24-0.63 and OR, 0.40; 95% CI, 0.26-0.62). Our survey demonstrated broad patient preference for stool-based tests over colonoscopy, contrasting the heavy reliance on colonoscopy for colorectal cancer screening in clinical practice and highlighting the importance of considering patient preference in colorectal cancer screening recommendations. PREVENTION RELEVANCE: Our national survey demonstrated broad patient preference for stool-based tests over colonoscopy, contrasting the heavy reliance on colonoscopy for colorectal cancer screening in clinical practice and highlighting the importance of considering patient preference in colorectal screening recommendations.