Guaiac-based Fecal Occult Blood Test Research Articles

FIT as a Comparator for Evaluating the Effectiveness of New Non-invasive CRC Screening Test.

Randomized Controlled Trials (RCT) demonstrated that guaiac-based fecal occult blood test (gFOBT), sigmoidoscopy, or colonoscopy are effective at reducing colorectal cancer (CRC) risk and mortality. Even if the impact of fecal immunochemical test (FIT) has not been evaluated within population-based RCT with mortality as the outcome, the results of comparative analyses with gFOBT provide strong indirect evidence of its effectiveness. Extensive information is also available on sensitivity and specificity of FIT, compared with gFOBT. FIT has almost universally replaced gFOBT in organized screening programs worldwide. Using FIT as a comparator is an efficient way to evaluate the effectiveness of new tests, with respect to test performance and relevant intermediate outcomes such as rates of interval cancer and late-stage cancer incidence. Direct comparison with FIT in the pre-screening evaluation of the accuracy of the new test will guide selection of the cut-off of the new test, and document the potential gain in sensitivity. Comparison in cross-sectional single-round screening evaluation can either use paired or parallel designs. Only parallel designs allow direct comparisons ofparticipation rates. Relative accuracy can be derived in both designs with an assumption of similar colorectal cancer and precursor prevalence between groups in parallel designs. Finally, multiple-rounds prospective comparison will document potential effect on risk of CRC and precancerous lesions, and on absolute reductions in late-stage incidence as a proxy of mortality. This paper provides an overview of evidence and rationale for using FIT as a comparator for evaluating new non-invasive tests with repeated testing at short intervals.

Utility of Stool-Based Tests for Colorectal Cancer Detection: A Comprehensive Review.

Colorectal cancer (CRC) is a significant global health issue where early detection is crucial for improving treatment outcomes and survival rates. This comprehensive review assesses the utility of stool-based tests in CRC screening, including traditional fecal occult blood tests (FOBT), both chemical (gFOBT) and immunochemical techniques (FIT), as well as multitarget stool DNA (mt-sDNA) as a novel and promising biomarker. The advancements, limitations and the impact of false positives and negatives of these methods are examined. The review analyzed various studies on current screening methods, focusing on laboratory tests and biomarkers. Findings indicate that while FIT and mt-sDNA tests offer enhanced sensitivity and specificity over traditional guaiac-based FOBT, they also come with higher costs and potential for increased false positives. FIT shows better patient adherence due to its ease to use, but incorrect usage and interpretation of FOBT can lead to significant diagnostic errors. In conclusion, despite the improvements in FOBT methods like FIT in CRC detection, careful consideration of each method's benefits and drawbacks is essential. Effective CRC screening programs should combine various methods tailored to specific population needs, aiming for early detection and reduced mortality rates.

Guaiac-based faecal occult blood tests versus faecal immunochemical tests for colorectal cancer screening in average-risk individuals

This publication is the Russian translation of the Plain Language Summary (PLS) of the Cochrane Systematic Review: GrobbeeEJ, WissePHA, SchreudersEH, van RoonA, van DamL, ZauberAG, Lansdorp-VogelaarI, BramerW, BerhaneS, DeeksJJ, SteyerbergEW, van LeerdamME, SpaanderMCW, KuipersEJ. Guaiac-based faecal occult blood tests versus faecal immunochemical tests for colorectal cancer screening in average-risk individuals. Cochrane Database of Systematic Reviews. 2022. Issue6. Art. No.: CD009276. doi: 10.1002/14651858.CD009276.pub2

Improving Fecal Immunochemical Test Collection for Colorectal Cancer Screening During the COVID-19 Pandemic.

Colonoscopy is a first-line method for colorectal cancer (CRC) screening. However, cost-effective noninvasive tests, such as high-sensitivity guaiac-based fecal occult blood test (gFOBT) and fecal immunochemical test (FIT), are also used. The COVID-19 pandemic had a substantial negative impact on CRC screening rates. The James A. Haley Veterans Affairs Hospital (JAHVAH) continued socially distant CRC screening using FITs, but encountered inefficiencies due to high rates of incorrectly collected FIT samples. A quality improvement (QI) project was conducted to increase correctly collected and testable FIT kits upon initial laboratory submission. The ambulatory QI project sought out root causes for incorrectly returned FITs and proposed Plan-Do-Study-Act (PDSA) cycles based on a series of approved action plans. A multidisciplinary team of laboratory, nursing, administrative, and primary care staff worked together to discover 6 major root causes. Our multipronged PDSA cycle attempted to set up redundant patient reminders, centralize the FIT dispersal process, and make the patient-FIT interface more user-friendly. All PDSA solutions were implemented over 4 months. Lack of collection date was the most common reason for incorrectly returned FIT kits and the focus of PDSA improvements. The rate of FITs with missing collection dates dropped from 24% prior to PDSA to 14% in April 2021. The rate of correctly returned FIT kits rose from 38% before the project to 72% afterwards, surpassing the 20% improvement goal. FIT is a useful method for CRC screening that can be particularly helpful when in-person visits are limited, as seen during the COVID-19 pandemic. The increase in demand for FITs during the pandemic revealed process deficiencies and gave JAHVAH an opportunity to improve workflow.

Utilization of colorectal cancer screening tests across European countries: a cross-sectional analysis of the European health interview survey 2018–2020

Colorectal cancer (CRC) screening has been shown to reduce CRC incidence and mortality, and most European countries have started to implement CRC screening programs in the past 20 years. Consequently, this study aimed to estimate the utilization of fecal tests and colonoscopy, as well as investigate factors associated with their utilization based on specific screening program characteristics in European countries. We analyzed data from the European Health Interview Survey 2018-2020 to determine the utilization of fecal tests [guaiac-based fecal occult blood test (gFOBT) or fecal immunochemical test (FIT)] within the preceding 2 years or colonoscopy within the preceding 10 years among people aged 50-74 years, based on the type of screening offered in each country. Using multivariable logistic regression and sub-group meta-analysis, factors associated with screening use were determined. The analyses included data from 129,750 respondents across 29 European countries, with participant counts ranging from 1511 individuals in Iceland to 11,755 individuals in Germany. Unit response rates ranged from 22% to 88%. The use of either test was highest among countries with fully rolled-out programs with fecal tests [from 37.7% (867/2379) in Croatia to 74.9% (2321/3085) in Denmark] and in countries offering colonoscopy as an alternative screening method [from 26.2% (854/3329) in Greece to 75.4% (1192/1760) in Luxembourg]. We observed the lowest utilization of either test in countries with no program or small-scale programs [6.3% (195/3179) in Bulgaria to 34.2% (722/2144) in Latvia]. Across all types of screening offers, younger age, being without a partner, low education, rural residence, and living in large households were associated with lower utilization, as were poor lifestyle scores and prolonged periods without physician consultation. Our findings point to large disparities and much room for improvement in CRC screening offers and utilization across Europe. There was no funding source for this study.

Routine Fecal Occult Blood Screening and Colorectal Cancer Mortality in Sweden

Population-based colorectal cancer (CRC) screening programs are implemented worldwide, but there are difficulties evaluating their effectiveness. The magnitude of routine CRC screening effectiveness regarding cancer-specific mortality is unclear. To evaluate cancer-specific mortality associated with early vs late or no invitation for routine CRC screening using fecal occult blood testing. This prospective cohort study was performed in the region of Stockholm-Gotland, Sweden, between January 1, 2008, and December 31, 2021. All individuals of the target population of screening born from 1938 to 1954 were included. Data were analyzed from December 12, 2022, to June 25, 2023. Individuals were invited early (2008-2012), late (2013-2015), or not at all to screening with biennial guaiac-based fecal occult blood test. The early invitation group was considered the exposure group and the late or no invitation group was considered the control group. The main outcome was cancer-specific mortality, defined as CRC registered in the Cancer Register with CRC as underlying cause of death in the Cause of Death Register. Excess mortality was calculated as all-cause deaths among the individuals with CRC subtracted from the expected number of deaths had they not had CRC. Poisson regression analysis based on deaths and person-years was used to estimated mortality rate ratio (RR) with 95% CIs, adjusted for follow-up years and attained age. In total, 379 448 individuals (193 436 [51.0%] female) were invited for CRC screening, including 203 670 individuals in the exposure group and 175 778 in the control group. The mean screening participation rate was 63.3%, and there was a maximum of 14 years follow-up. There were 834 CRC deaths in 2 190 589 person-years in the exposure group, compared with 889 CRC deaths in 2 249 939 person-years in the control group. Individuals who underwent early CRC screening had reduced adjusted risk of CRC mortality (RR, 0.86; 95% CI, 0.78-0.95) and excess mortality (RR, 0.84; 95% CI, 0.75-0.93). This prospective cohort study of routine screening with fecal occult blood testing found a 14% decrease in CRC mortality associated with screening. The true association of screening with reduced mortality is expected to be higher due to some coexistence of testing in the control group and CRC deaths diagnosed more than 2 years after screening.

Projected Colorectal Cancer Incidence and Mortality Based on Observed Adherence to Colonoscopy and Sequential Stool-Based Screening.

Modeling supporting recommendations for colonoscopy and stool-based colorectal cancer (CRC) screening tests assumes 100% sequential participant adherence. The impact of observed adherence on the long-term effectiveness of screening is unknown. We evaluated the effectiveness of a program of screening colonoscopy every 10 years vs annual high-sensitivity guaiac-based fecal occult blood testing (HSgFOBT) using observed sequential adherence data. The MIcrosimulation SCreening ANalysis (MISCAN) model used observed sequential screening adherence, HSgFOBT positivity, and diagnostic colonoscopy adherence in HSgFOBT-positive individuals from the National Colonoscopy Study (single-screening colonoscopy vs ≥4 HSgFOBT sequential rounds). We compared CRC incidence and mortality over 15 years with no screening or 10 yearly screening colonoscopy vs annual HSgFOBT with 100% and differential observed adherence from the trial. Without screening, simulated incidence and mortality over 15 years were 20.9 (95% probability interval 15.8-26.9) and 6.9 (5.0-9.2) per 1,000 participants, respectively. In the case of 100% adherence, only screening colonoscopy was predicted to result in lower incidence; however, both tests lowered simulated mortality to a similar level (2.1 [1.6-2.9] for screening colonoscopy and 2.5 [1.8-3.4] for HSgFOBT). Observed adherence for screening colonoscopy (83.6%) was higher than observed sequential HSgFOBT adherence (73.1% first round; 49.1% by round 4), resulting in lower simulated incidence and mortality for screening colonoscopy (14.4 [10.8-18.5] and 2.9 [2.1-3.9], respectively) than HSgFOBT (20.8 [15.8-28.1] and 3.9 [2.9-5.4], respectively), despite a 91% adherence to diagnostic colonoscopy with FOBT positivity. The relative risk of CRC mortality for screening colonoscopy vs HSgFOBT was 0.75 (95% probability interval 0.68-0.80). Findings were similar in sensitivity analyses with alternative assumptions for repeat colonoscopy, test performance, risk, age, and projection horizon. Where sequential adherence to stool-based screening is suboptimal and colonoscopy is accessible and acceptable-as observed in the national colonoscopy study, microsimulation, comparative effectiveness, screening recommendations.

The Non-Invasive Prediction of Colorectal Neoplasia (NIPCON) Study 1995-2022: A Comparison of Guaiac-Based Fecal Occult Blood Test (FOBT) and an Anti-Adenoma Antibody, Adnab-9.

Given the need to improve the sensitivity of non-invasive methods to detect colorectal neoplasia, particularly adenomas, we compared a fecal test using a monoclonal antibody (Mab) raised against constituents of colonic adenomas designated Adnab-9 (Adenoma Antibody 9), recognizing an N-linked 87 kDa glycoprotein, to gFOBT, which is shown to reduce CRC mortality. p87 immunohistochemistry testing is significantly more sensitive (OR 3.64[CI 2.37-5.58]) than gFOBT (guaiac-based fecal occult blood test) for adenomas (<3 in number), advanced adenomas (OR 4.21[CI 2.47-7.15]), or a combination of the two (OR 3.35[CI 2.47-4.53]). p87 immunohistochemistry shows regional Paneth cell (PC) expression mainly in the right-sided colon and is significantly reduced in the ceca of African Americans (p < 0.0001). In a subset of patients, we obtained other body fluids such as urine, colonic effluent, and saliva. Urine tests (organ-specific neoantigen) showed a significant difference for advanced adenomas (p < 0.047). We conclude that fecal p87 testing is more sensitive than gFOBT and Adnab-9 and could be used to better direct the colonoscopy screening effort.

Healthcare costs, resource utilization, and productivity loss associated with colorectal cancer screening.

To evaluate healthcare costs, resource utilization, associated costs, and lost productivity for colorectal cancer (CRC) screening in an average-risk population. This retrospective cohort study identified average-risk individuals (50-75 years) with claims in the Optum Research Database for CRC screening test between 1 January 2014 to 31 December 2018. Index date was defined as the first date of a claim for colonoscopy, fecal immunochemical test (FIT), guaiac-based fecal occult blood test (FOBT) or multi-target stool DNA test (mt-sDNA). Screening costs were evaluated with descriptive statistics and multivariable analyses, adjusting for patient characteristics and index screening costs. In total, 903,831 individuals were identified by test groups: mt-sDNA (n = 29,614), FIT (n = 254,002), guaiac-based FOBT (n = 112,757) and colonoscopy (n = 507,458). Adjusted costs for index screening were, colonoscopy ($3,029), mt-sDNA ($752), FIT ($45), and (FOBT ($153). Adjusted costs across the six months following the index screening were $146 for colonoscopy, $329 for mt-sDNA, $306 for FIT, and $412 for FOBT. Colonoscopy had the highest costs for lost productivity. Screening colonoscopy had the highest productivity loss and healthcare costs up-front, suggesting potential cost benefits for noninvasive screening modalities. The more frequent screening interval required for FIT and FOBT resulted in a higher yearly cost than colonoscopy or mt-sDNA.

Colorectal Cancer Diagnostic Methods: The Present and Future.

To meet the needs of the colorectal cancer (CRC) patient population, colorectal cancer screening is continuously updated. The most significant advice is to start CRC screening exams at age 45 for people at average risk for CRC. CRC testing is divided into two categories: stool-based tests and visual inspections. High-sensitivity guaiac-based fecal occult blood testing, fecal immunochemical testing, and multitarget stool DNA testing are stool-based assays. Colon capsule endoscopy and flexible sigmoidoscopy are visualization examinations. There have been arguments about the importance of these tests in detecting and managing precursor lesions because of the lack of validation of screening results. Recent advancements in artificial intelligence and genetics have prompted the creation of newer diagnostic tests, which require validation in diverse populations and cohorts. In this article, we have discussed the present and emerging diagnostic tests.

Diagnostic Accuracy of Fecal Immunochemical Test (FIT) in Bleed-positive and Bleed-negative Colorectal Cancer (CRC) Among a Cohort of 5,090 Subjects who Participated in the Colorectal Neoplasia (CRN) Screening in Brazil.

This study assessed the diagnostic accuracy (DA) of fecal immunochemical test (FIT) ColonView (CV) and guaiac-based fecal occult blood test (HemoccultSENSA) among bleed-positive (history or signs of intestinal bleeding) and bleed-negative participants (no history or signs of intestinal bleeding) (n=5,090) in colorectal neoplasia (CRN) screening in Brazil. The eligible patients for the study (n=506) collected three consecutive stool samples, to be analyzed by both assays (CV, SENSA). Finally, 421/5090 (8.3%) patients returned both samples, which were subjected to final analysis. Receiver operating characteristic (ROC) analysis with different cut-offs was performed to assess the DA. The area under curve (AUC) values for i) visually analyzed (VA) CV for bleed-positive CRC, ii) automatically analyzed (AA) CV for bleed-positive CRC, iii) VA CV for bleed-negative CRC, and iv) AA CV for bleed-negative CRC as endpoints were as follows: i) AUC=0.864, ii) AUC=0.933, iii) AUC=0.836, and iv) AUC=0.892. In roccomp analysis, the differences in AUC values were: between i) and ii) p=0.068; between i) and iii) p=0.497; between i) and iv) p=0.488; between ii) and iii) p=0.0058; between ii) and iv) p=0.229; and between iii) and iv) p=0.138. This is the first investigation where two modes of CV test, VA, and AA, for bleed-positive and bleed-negative CRC patients were used as the endpoint. The AA reading of the CV test showed higher DA in bleed-positive than in bleed-negative CRC patients.

Effectiveness of Colorectal Cancer (CRC) Screening on All-Cause and CRC-Specific Mortality Reduction: A Systematic Review and Meta-Analysis.

(1) Background: The aim of this study was to pool and compare all-cause and colorectal cancer (CRC) specific mortality reduction of CRC screening in randomized control trials (RCTs) and simulation models, and to determine factors that influence screening effectiveness. (2) Methods: PubMed, Embase, Web of Science and Cochrane library were searched for eligible studies. Multi-use simulation models or RCTs that compared the mortality of CRC screening with no screening in general population were included. CRC-specific and all-cause mortality rate ratios and 95% confidence intervals were calculated by a bivariate random model. (3) Results: 10 RCTs and 47 model studies were retrieved. The pooled CRC-specific mortality rate ratios in RCTs were 0.88 (0.80, 0.96) and 0.76 (0.68, 0.84) for guaiac-based fecal occult blood tests (gFOBT) and single flexible sigmoidoscopy (FS) screening, respectively. For the model studies, the rate ratios were 0.45 (0.39, 0.51) for biennial fecal immunochemical tests (FIT), 0.31 (0.28, 0.34) for biennial gFOBT, 0.61 (0.53, 0.72) for single FS, 0.27 (0.21, 0.35) for 10-yearly colonoscopy, and 0.35 (0.29, 0.42) for 5-yearly FS. The CRC-specific mortality reduction of gFOBT increased with higher adherence in both studies (RCT: 0.78 (0.68, 0.89) vs. 0.92 (0.87, 0.98), model: 0.30 (0.28, 0.33) vs. 0.92 (0.51, 1.63)). Model studies showed a 0.62-1.1% all-cause mortality reduction with single FS screening. (4) Conclusions: Based on RCTs and model studies, biennial FIT/gFOBT, single and 5-yearly FS, and 10-yearly colonoscopy screening significantly reduces CRC-specific mortality. The model estimates are much higher than in RCTs, because the simulated biennial gFOBT assumes higher adherence. The effectiveness of screening increases at younger screening initiation ages and higher adherences.

The Clinical Significance of Septin 9 and Colon Cancer Specific Antigen-2 (CCSA-2) in Colorectal Cancer.

Colorectal cancer (CRC) is a major health problem Worldwide, Egypt shows a high rate of early CRC in the world as 35% of 1,600 Egyptian CRC patients were under 40 with threefold increased risk of death within 5 years. DNA methylation-based biomarkers as methylated Septin9 (mSEPT9) has a promising role for detecting CRC. As well as set of nuclear matrix proteins associated with changes in the nuclear structure/architecture. detection of these nuclear proteins resulted in identification of biomarkers that are specific for colon cancer. Particular interest has been placed on colon cancer specific antigen-2(CCSA-2). A total of 30 newly diagnosed CRC patients, 7 colonic adenoma patients, and 15 age- and sex-matched control subjects were recruited in this study. Plasma mSEPT9was assayed by Epi procolon kit, CCSA-2 by ELISA and, Occult blood in stool by Guaiac-based fecal occult blood test. The level of Colon Cancer mSEPT9 and CCSA-2 were carried on CRC patients both preoperatively and three months postoperatively. mSEPT9 has 96.7% sensitivity and 95.5% specificity in differentiating colorectal cancer patients from non-malignant cases. Also, our study showed a highly statistically significant difference between the pre and three months postoperative expression of mSEPT9 in colorectal cancer as there was a dramatically decrease in the expression of mSEPT9 postoperatively (p value < 0.001). The CCSA-2 at the cutoff level of >1.43 would provide 93.3% sensitivity and 90.9% specificity in differentiation between malignant and non-malignant cases. Also, the study showed that there is a statistically significant difference between colorectal cancer patients preoperatively and postoperatively according to CCSA-2 with dramatic decrease in its level postoperatively (p value > 0.001). The plasma SEPT9 DNA methylation level and Serum CCSA-2 could be used as promising non-invasive methods for observing the CRC patients postsurgical response to predict the occurrence of complete remission or relapses.

Stool DNA testing for early detection of colorectal cancer: systematic review using the HTA Core Model® for Rapid Relative Effectiveness Assessment.

Stool DNA testing for early detection of colorectal cancer (CRC) is a non-invasive technology with the potential to supplement established CRC screening tests. The aim of this health technology assessment was to evaluate effectiveness and safety of currently CE-marked stool DNA tests, compared to other CRC tests in CRC screening strategies in an asymptomatic screening population. The assessment was carried out following the guidelines of the European Network for Health Technology Assessment (EUnetHTA). This included a systematic literature search in MED-LINE, Cochrane and EMBASE in 2018. Manufacturers were asked to provide additional data. Five patient interviews helped assessing potential ethical or social aspects and patients' experiences and preferences. We assessed the risk of bias using QUADAS-2, and the quality of the body of evidence using GRADE. We identified three test accuracy studies, two of which investigated a multitarget stool DNA test (Cologuard®, compared fecal immunochemical test (FIT)) and one a combined DNA stool assay (ColoAlert®, compared to guaiac-based fecal occult blood test (gFOBT), Pyruvate Kinase Isoenzyme Type M2 (M2-PK) and combined gFOBT/M2-PK). We found five published surveys on patient satisfaction. No primary study investigating screening effects on CRC incidence or on overall mortality was found. Both stool DNA tests showed in direct comparison higher sensitivity for the detection of CRC and (advanced) adenoma compared to FIT, or gFOBT, respectively, but had lower specificity. However, these comparative results may depend on the exact type of FIT used. The reported test failure rates were higher for stool DNA testing than for FIT. The certainty of evidence was moderate to high for Cologuard® studies, and low to very low for the ColoAlert® study which refers to a former version of the product and yielded no direct evidence on the test accuracy for ad-vanced versus non-advanced adenoma. ColoAlert® is the only stool DNA test currently sold in Europe and is available at a lower price than Cologuard®, but reliable evidence is lacking. A screening study including the current product version of ColoAlert® and suitable comparators would, therefore, help evaluate the effectiveness of this screening option in a European context.

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.

Guaiac-based faecal occult blood tests versus faecal immunochemical tests for colorectal cancer screening in average-risk individuals.

Guaiac-based faecal occult blood tests versus faecal immunochemical tests for colorectal cancer screening in average-risk individuals.

The ColonView (CV) Quick Test for Fecal Occult Blood Shows Significantly Higher Diagnostic Accuracy in Detecting Distal than Proximal Colorectal Cancer.

The present study compared the accuracy of ColonView (CV) quick test in detecting proximal versus distal colorectal cancer (CRC). A traditional guaiac-based fecal occult blood test (gFOBT) (Hemoccult SENSA) was used as a reference. A cohort of 368 colonoscopy-referral patients were asked to collect 3 consecutive fecal samples, to be analyzed by both assays (CV, SENSA). Receiver operating characteristic (ROC) analysis was used to find the optimal cut-off values for both Hb and Hb/Hp of the CV test. Summary hierarchical ROC (HSROC) curves were used to visualize the pooled overall accuracy of visually analysed (VA) and automatically analyzed (AA) reading modes in proximal and distal CRC detection. The overall specificity (Sp) of the AA reading mode for the proximal CRC and distal CRC endpoint was 73% and 76%, respectively. For proximal CRC, the two most sensitive AA tests showed 90% sensitivity (Se), while for distal CRC, the two most sensitive AA tests showed 100% Se. In the HSROC analysis, the AUC values were as follows: i) VA in proximal CRC: 0.765, ii) AA in proximal CRC: 0.878, iii) VA in distal CRC: 0.955 and iv) AA in distal CRC: 0.961. In roccomp analysis, AUC values were significantly different in: VA vs. AA in proximal CRC p=0.009; VA in proximal vs. VA in distal CRC p<0.0001; VA in proximal vs. AA in distal CRC p<0.0001; AA in proximal vs. VA in distal CRC p=0.021; AA in proximal CRC vs. AA in distal CRC p=0.006. The applicability of the CV test (a new-generation FIT) in CRC screening was confirmed. The AA reading was superior to VA (or SENSA) in its diagnostic accuracy in detecting proximal CRC patients. Distal CRCs were more accurately detected than proximal CRCs by both reading modes.

Optimal Noninvasive Colon Cancer Screening Modality in Patients Not Receiving Colonoscopy

Colon cancer is the third most common among cancer deaths in the US for both men and women. The incidence of colonoscopy has been soaring in younger patients, which led to changes in recent United States Preventive Services Task Force (USPSTF) guidelines to reduce the age for screening from 50 years to 45 years. Demand for colonoscopy services is surging due to increased incidences of colorectal cancer (CRC) in the both aging and younger population. Increased referrals have led to an insufficient workforce in hospitals and long waiting lists. Further, results from colonoscopy reveal a low percentage of CRC or another severe bowel disease (SBD). Therefore, colon cancer screening is a growing concern, particularly in patients who otherwise have a very long-life expectancy, and who are most likely to benefit from screening. Another reason to boost CRC screening is to minimize the load on hospitals by reducing the patients that undergo colonoscopy unnecessarily because only a low percentage of CRC occurrence is observed in individuals undergoing colonoscopy. In recent years, there are a variety of screening options available for CRC. Noninvasive alternatives include fecal immunochemical test (FIT), multitarget stool DNA testing (MT-sDNA, available under the brand name Cologuard), computed tomography (CT) colonography (previously called virtual colonoscopy), guaiac-based fecal occult blood testing (gFOBT), and capsule colonoscopy (CC). These tests have varied the degree of evidence supporting their use. This study focuses on the most recent survey and efficacy of noninvasive methods to prevent and detect colorectal cancer (CRC).

Health Care Provider Characteristics Associated With Colorectal Cancer Screening Preferences and Use

ObjectiveTo assess health care provider (HCP) preferences related to colorectal cancer (CRC) screening overall, and by HCP and patient characteristics. Participants and MethodsWe developed a survey based on the Theoretical Domains Framework to assess factors associated with CRC screening preferences in clinical practice. The survey was administered online November 6 through December 6, 2019, to a validated panel of HCPs drawn from US national databases and professional organizations. The final analysis sample included 779 primary care clinicians (PCCs) and 159 gastroenterologists (GIs). ResultsHCPs chose colonoscopy as their preferred screening method for average-risk patients (96.9% (154/159) for GIs, 75.7% (590/779) for PCCs). Among PCCs, 12.2% (95/779) preferred multi-target stool DNA (mt-sDNA), followed by fecal immunochemical test (FIT), (7.3%; 57/779) and guaiac-based fecal occult blood test (gFOBT) (4.8%; 37/779). Preference among PCCs and GIs generally shifted toward noninvasive screening options for patients who were unable to undergo invasive procedures; concerned about taking time from work; unconvinced about need for screening; and refusing other screening recommendations. Among PCCs, preference for mt-sDNA over FIT and gFOBT was less frequent in larger compared with smaller clinical practices. Additionally, preference for mt-sDNA over FIT was more likely among PCCs with more years of clinical experience, higher patient volumes (> 25/day), and practice locations in suburban and rural settings (compared to urban). ConclusionBoth PCCs and GIs preferred colonoscopy for CRC screening of average-risk patients, although PCCs did so less frequently and with approximately a quarter preferring stool-based tests (particularly mt-sDNA). PCCs’ preference varied by provider and patient characteristics. Our findings underscore the importance of informed choice and shared decision-making about CRC screening options.

S239 Adherence to Colorectal Cancer Screening and Associated Healthcare Resource Utilization, a Longitudinal Analysis in US Medicare Population with Ten Years Follow-up

Introduction: Adherence to screening guidelines is critical for prevention and early detection of colorectal cancer (CRC). This study examined CRC screening adherence in Medicare beneficiaries and associated long-term healthcare resource utilization (HCRU) and Medicare costs. Methods: Using 20% Medicare random sample data, the study population included Medicare fee-for-service beneficiaries aged 66-75 years on 1/1/2009, at average-risk for CRC (no history of CRC, polyps, inflammatory bowel disease, or hereditary CRC syndrome), and continuously enrolled in Medicare part A/B from 2008 through 2018. The baseline year (2008) was used to define comorbidities and high-risk events. We excluded those who had a colonoscopy or flexible sigmoidoscopy (flex sig) during 2007-2008 and assumed everyone was due for screening in 2009; screening patterns were determined in the 10-year period, 2009-2018. Subjects were categorized as “adherent to screening” based on the USPSTF guidelines: colonoscopy every 10 years, flex sig every 5 years, multi-target stool DNA test every 3 years, or at least 8 fecal immunochemical or guaiac-based fecal occult blood tests in the 10-year period. Subjects were categorized as “not screened” if there were no tests observed; and “inadequately screened” if testing occurred but not enough to qualify as adherent. The long-term HCRU and inflation adjusted Medicare costs in the 10 years were calculated as mean per patient per year (PPPY). Results: In total, 895,846 eligible individuals were in the final sample. Of these, 13.2% were adherent to screening, 53.4% were inadequately screened, and 33.4% were not screened. Differences in baseline characteristics are presented in Table 1. Compared to those not screened, adherent or inadequately screened individuals were more likely to be female, of white race, and have comorbidities (Table 1). These individuals also used more healthcare services and therefore had higher Medicare costs (Figure 1). For example, physician visits were 14.6, 22.9, and 25.9 PPPY; total Medicare costs were $6,102, $8,469, and $9,102 PPPY for those not screened, inadequately screened, and adherent to screening, respectively. Conclusion: In Medicare beneficiaries at average-risk, adherence rate to CRC screening was low although the rate might be underestimated due to lack of early Medicare data. The link between HCRU and screened status suggests that screening initiatives not dependent on clinical visits may be needed to reach those who are unscreened or inadequately screened.Figure 1.: (a) Healthcare resource utilization measured as number of IP admissions, number of IP stay in days, or number of visits per patient per year (PPPY). (b) Mean Medicare cost measured as Medicare paid amount in 2018 US $PPPY. IP, inpatient; OP, outpatient; ED, emergency department; SNF, skilled nursing facility; HH, home health; DME, durable medical equipment; Part D, Medicare prescription drug.Table 1.: Table.Patient characteristic distribution by CRC screening patterns and odds ratio of adherence to or inadequately screened