Participant-Related Risk Factors for False-Positive and False-Negative Fecal Immunochemical Tests in Colorectal Cancer Screening: Systematic Review and Meta-Analysis

Screening participants with inflammatory bowel disease or high colorectal cancer risk in Denmark: a cohort study

Individuals with inflammatory bowel disease (IBC) and high-risk individuals are advised to discuss participation with their doctor and not to participate in colorectal cancer (CRC) screening. Yet a substantial proportion still participate in the Danish faecal immunochemical test (FIT) screening and have a higher positive FIT rate than the average-risk population. We estimated the risk of false-positive screening among individuals with inflammatory bowel disease and high-risk individuals to improve recommendations regarding screening participation. We included 71,871 FIT-positive participants (2014-2017) who had a subsequent colonoscopy within 3 months. Screening outcome within 180 days was established by using registers. We determined that 26,591 of the included participants had a false-positive screening. Participants with IBC or high CRC risk had a significantly higher risk of getting a false-positive screening than the average risk population, resulting in too many screening-related colonoscopies being performed among these individuals, indicating a need to update the screening protocols.

The effect of antiplatelet therapy and oral anticoagulants on the accuracy of faecal immunochemical testing

INTRODUCTION

Faecal immunochemical testing (FIT) has been adopted to identify patients requiring further investigations on the colorectal cancer (CRC) referral pathway. We aimed to investigate the effect of antiplatelet and anticoagulant drugs on the accuracy of FIT results.

METHODS

This observational study categorised patients with suspected CRC symptoms, who completed both FIT and colonic investigations, into two groups (control and exposed) based on their use of antiplatelet and anticoagulant drugs. Two-by-two tables and receiver operating characteristic (ROC) curve analysis were used to determine accuracy.

RESULTS

A total of 928 patients were divided into a control (n=683) and an exposed group (n=245). A nonsignificant higher proportion of patients tested positive in the exposed group (24.1% vs 18.4%, p=0.063). For detection of CRC, improved sensitivity of 87% vs 81.2%, specificity of 84.8% vs 79.9% and negative predictive value of 99.2% vs 98.3% was calculated in the control vs exposed groups, respectively. The positive predictive value was comparable between the two groups (21.4% vs 22% in the control and exposed groups, respectively). In ROC analysis, there was no difference between the groups (AUC 90% vs 87%, p=0.56). The use of antiplatelet and anticoagulant drugs did not increase the risk of positive FIT results on multivariate logistic regression analysis.

CONCLUSIONS

FIT accuracy for CRC detection remained unaffected despite more patients testing positive in the exposed group. FIT should be considered a supplementary tool for triage. Antiplatelet and anticoagulant drugs do not need to be discontinued before collection of FIT.

Colonoscopy vs the Fecal Immunochemical Test: Which is Best?

Although there is no debate around the effectiveness of colorectal cancer screening in reducing disease burden, there remains a question regarding the most effective and cost-effective screening modality. Current United States guidelines present a panel of options that include the 2 most commonly used modalities, colonoscopy and stool testing with the fecal immunochemical test (FIT). Large-scale comparative effectiveness trials comparing colonoscopy and FIT for colorectal cancer outcomes are underway, but results are not yet available. This review will separately state the "best case" for FIT and colonoscopy as the screening tool of first choice. In addition, the review will examine these modalities from a health economics perspective to provide the reader further context about the relative advantages of these commonly used tests.

Factors associated with negative colonoscopy in participants with a positive faecal immunochemical test from the Danish Colorectal Cancer Screening Program - a population-based study

AIM

In the Danish Colorectal Cancer Screening Program (DCCSP), 37% of participants undergoing colonoscopy have a negative result with no obvious findings that can be attributed to a positive faecal immunochemical test (FIT). The aim of this work was to identify predictors for a negative colonoscopy in DCCSP participants with a positive FIT.

METHOD

We included 73 655 FIT-positive DCCSP participants using the Danish Colorectal Cancer Screening Database and linked their screening results with data from several other national health registers. We stratified participants by all predictors, and compared them using multivariate logistic regression analysis. Results are reported as odds ratios (ORs).

RESULTS

We found that having a condition linked to gastrointestinal bleeding, for example fissures, haemorrhoids and inflammatory bowel disease, was strongly associated with the probability of having a negative colonoscopy [OR 2.77 (95% CI 2.59, 2.96)]. FIT concentration was inversely related to the probability of a negative colonoscopy, the OR decreased steadily from 0.79 (95% CI 0.75, 0.83) in the 40-59 μg/g group, to 0.44 (95% CI 0.42, 0.46) in the ≥200 μg/g group. Women had a 1.64 (95% CI 1.59, 1.70) times higher probability of a negative colonoscopy than men.

CONCLUSION

Our findings indicate that baseline conditions linked to gastrointestinal bleeding are an associating factor with having a negative colonoscopy. The same is true for low FIT concentration and female sex. Further studies with similar findings could suggest that an incorporation of these factors into a personalized screening approach by differentiating between diagnostic modalities could improve the process for the participant while alleviating the health care system.

Adenoma location, size, and morphology are risk factors for FOBT false-negative results in inpatients with advanced colorectal adenoma

Recently, advanced adenoma (AA) has been recognized as a target for colorectal cancer (CRC) screening. However, the fecal occult blood test (FOBT), the primary non-invasive screening method, shows limited sensitivity in detecting AA. This study investigates the relationship between adenoma characteristics and FOBT false-negative results. In a retrospective cohort study conducted from 2015 to 2022, we examined 342 inpatients with AA who underwent colonoscopy and received qualitative FOBT. FOBT sensitivity was analyzed about various adenoma characteristics, and logistic regression models were employed to investigate the relationship between adenoma features and FOBT false-negative outcomes. FOBT sensitivity in AA inpatients was 52.63%. Significant differences in sensitivity were observed based on adenoma location (left vs. right), morphology (with or without pedunculation), and size (≤ 10 mm vs. > 10 mm). After adjusting for several potential confounders, FOBT showed a reduced false-negative rate in AA with large-sized (OR, 0.49; 95% CI 0.31-0.77), left-sided location (OR, 0.53; 95% CI 0.31-0.89), and pedunculated morphology (OR, 0.73; 95% CI 0.43-1.24). AA with large size, left-sided location, and pedunculated morphology independently contribute to a decreased rate of FOBT false-negative results. However, these adenoma characteristics are not actively modifiable. Therefore, novel non-invasive methods are needed to improve AA detection accuracy.

Role of demographics in noninvasive testing for colorectal cancer screening: do targeted cut-off values improve detection?

BACKGROUND

Fecal immunochemical test (FIT) is a yearly alternative colorectal screening modality for average risk individuals unwilling or unable to undergo invasive colorectal cancer (CRC) screening due to cost and accessibility. This study aimed to determine whether FIT should be interpreted within the context of patient demographics and medical history.

METHODS

Patients >50 years old who had a FIT followed by colonoscopy within 1 year were analyzed based on age, race, BMI, social and medical comorbidities. False positive (FP) and false negative (FN) FIT results within each patient demographic and medical history variable were determined by comparing with the gold standard of colonoscopy using χ2 analysis.

RESULTS

One thousand twenty-five patients were reviewed. 21.8% of FIT results were positive. Factors which differed in positive FIT rates were age (P=0.003), smoking (P<0.001), alcohol (P=0.001), and hypertension (P<0.001). The difference in rates of FP and FN FIT outcomes among each variable underwent further subanalysis. The FP was 66.8% and the FN rate was 12.8%. Higher FN outcomes were noted in those above 70, males and smokers, though the result was only statistically significant for males (P=0.009). Females were observed to have higher FP rates (P=0.019).

CONCLUSIONS

Females had higher FP FIT rates compared to males, indicating that sex may influence FIT outcomes and should be accounted for when interpreting FIT results. This information can be utilized to identify populations at higher risk of FP or FN FIT results to target CRC screening. Additionally, recalculating the FP and FN rates for each variable may help determine new FIT targets.

Noninvasive Colorectal Cancer Prevention Options in Older Adults

Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide and its incidence increases with age. The proportion of older adults in the United States continues to rise, making CRC prevention a key health priority for our aging population. CRC is a largely preventable disease through screening and polyp surveillance, and noninvasive modalities represent an important option for older adults in whom the burdens and risks of invasive testing are higher compared with younger adults. This review highlights the evidence, risks, and benefits of noninvasive CRC screening and surveillance options in older adults and discusses the challenges of CRC prevention in this cohort.

Evaluation of a Multi-Gene Methylation Blood-Test for the Detection of Colorectal Cancer

Circulating tumour DNA biomarkers are an expanding field in oncology research that offer great potential but are currently often limited in value by overall cost. The aim of this study was to evaluate the efficacy of a novel multi-gene methylation blood test for the identification of colorectal cancer and throughout the spectrum of colorectal disease. Participants were recruited either prior to resection for known CRC or prior to screening colonoscopy after a positive faecal immunochemical test. Blood was collected from participants prior to their procedure being performed. The plasma was separated, and multiplex MethylLight droplet digital PCR was used to analyse for the presence of four methylated genes: SDC2, NPY, IKZF1 and SEPT9. A total of 537 participants underwent analysis. The SDC2/NPY genes showed a sensitivity of 33-54% and a specificity of 72-96%, whilst the IKZF1/SEPT9 genes showed a sensitivity of 19-42% and a specificity of 88-96%. Combining the two tests did not significantly increase the test accuracy. The sensitivity for advanced adenoma was 2-15%. There was a significant difference in the frequency of detectable methylation between the participants with CRC and those without CRC. However, neither the sensitivity nor the specificity was superior to current diagnostic screening tests.

Stool-Based Colorectal Cancer Screening Test Performance Characteristics in Those With and Without Hemorrhoids

Objective

To evaluate the effect of hemorrhoids on noninvasive stool test performance for colorectal cancer (CRC) screening.

Patients and Methods

We conducted a retrospective cohort study of test characteristics for the fecal immunochemical test (FIT) and the multitarget stool DNA (mt-sDNA) test, on the basis of hemorrhoid status, recorded at the time of colonoscopy, among patients enrolled in the pivotal prospective study for mt-sDNA that was conducted from June 2011, to May 2013. Test characteristics (sensitivity, specificity, positive, and negative predictive values) for FIT and mt-sDNA (performed < 90 days before colonoscopy) were stratified by the presence of hemorrhoids and compared.

Results

Hemorrhoids were found in 51.7% (5163 of 9989) of the study cohort. Across all test characteristics, there were no statistically significant differences for FIT or mt-sDNA when stratified by hemorrhoid status. Analysis revealed mt-sDNA sensitivity of 44% and 41% for advanced precancerous lesions in nonhemorrhoidal and hemorrhoid patients, respectively (P=.41). The FIT sensitivity among the same lesion category was 24.9% in patients without hemorrhoids and 22.8% in those with hemorrhoids (P=.48). The mt-sDNA specificity was 86.4% in patients without hemorrhoids vs 87.7% in those with hemorrhoids (P=.67), although FIT specificity was 95.0% among patients without hemorrhoids vs 94.7% in those with hemorrhoids (P=.44).

Conclusion

The presence of asymptomatic hemorrhoids did not adversely affect test performance in this large clinical study. These findings suggest that in the absence of overt gastrointestinal bleeding, FIT and mt-sDNA are options for CRC screening, irrespective of hemorrhoid status.

Trial Registration

clinicaltrials.gov Identifier: NCT01397747.

The effect of numeric information about the likelihood of receiving a false negative or false positive result on people's attitudes towards colorectal cancer screening using faecal immunochemical testing (FIT)

OBJECTIVE

To examine the impact of numeric risk information about false negative (FN) and false positive (FP) rates in fecal immunochemical testing (FIT) on attitudes towards screening.

METHODS

102 people aged 45-55, living in the UK, read 6 hypothetical vignettes presented online about the use of FIT kits to detect colorectal cancer, in which information about FN and FP rates was systematically varied.

RESULTS

Numeric FN risk information reduced people's interest in screening, perception of screening effectiveness and lowered trust in screening compared to verbal FN information. Verbal FN information reduced perceptions of screening effectiveness and trust compared to no FN information. People with high subjective numeracy reported lower trust in screening following the provision of numeric FN information but numeracy did not moderate any other associations. FP information did not affect attitudes towards FIT testing.

CONCLUSION

Numeric FN risk information decreased people's perceptions of screening effectiveness and trust in the results of screening. While it influenced people's interest in screening, the effect was small.

PRACTICE IMPLICATIONS

Numeric FN information has a small effect on interest in screening and could promote informed decision making without affecting screening uptake.

Antithrombotic drug use does not affect the fecal immunochemical test PPV for colorectal cancer, but warfarin may have an impact in a Japanese cohort

BACKGROUND

The fecal immunochemical test (FIT) is used for colorectal cancer (CRC) screening. Patients on antithrombotic drugs (ATs) are often screened for CRC, but the effect of ATs on FIT results is controversial.

METHODS

We divided individuals with FIT-positive results into two groups, patients treated with and without ATs, and retrospectively compared invasive CRC rates, advanced neoplasia detection rates (ANDRs), adenoma detection rates (ADRs), and polyp detection rates (PDRs) between the two groups. We evaluated the factors influencing the FIT positive predictive value (PPV) using propensity matching, adjusting for age, sex, and bowel preparation.

RESULTS

We enrolled 2327 individuals (54.9% male; mean age, 66.7  ±  12.7 years). We grouped 463 individuals into the AT user group and 1864 into the nonuser group. Patients in the AT user group were significantly older and more likely to be male. After propensity score matching for age, sex, and Boston bowel preparation scale, the ADR and PDR in the AT user group were significantly lower than those in the nonuser group. Univariate logistic analysis revealed that multiple AT use (odds ratio [OR]: .39, p < 0.001) had the lowest OR for FIT PPV, followed by age- and sex-adjusted factors for the ADR and any AT use (OR: .67, p = 0.0007). No significant factors related to AT use were observed among age-adjusted predictive factors for invasive CRC, but warfarin use was a borderline significant positive predictive factor (OR: 2.23, p = 0.059).

CONCLUSION

AT use may not affect the PPV for detecting invasive CRC in patients with positive FIT results, but warfarin may have an impact.

Positive Results from the Fecal Immunochemical Test Can Be Related to Dementia: A Nationwide Population-Based Study in South Korea

BACKGROUND

The fecal immunochemical test (FIT) is widely used in screening for colorectal cancer (CRC), but FIT results can be positive for diseases other than CRC.

OBJECTIVE

We investigated the association between positive results of FIT and the incidence of dementia using a nationwide database.

METHODS

FIT-positive participants were collected from a database provided by the Korean National Health Insurance Service.

RESULTS

The incidence of all kinds of dementia was higher in FIT-positive than FIT-negative subjects (p < 0.0001). FIT-positive participants had a higher risk of Alzheimer's disease (AD) (p < 0.0001) and vascular dementia (p = 0.0002), compared to participants with FIT negativity. The risk of all kinds of dementia or AD in FIT-positive participants was higher in younger (age < 65 years) than older participants (p < 0.0001 for all kinds of dementia; p = 0.0002 for AD).

CONCLUSION

FIT positivity was correlated with an increased risk of dementia, especially in participants under 65 years of age. The study suggests that clinicians can consider dementia when FIT-positive participants fail to show any malignancies.

Comparison of Findings From Fecal Occult Blood Test and Esophagogastroduodenoscopy With Histopathology Among Symptomatic Saudi Adults: A Retrospective Study

Background A fecal occult blood test is an established way to detect blood in stool samples. However, this diagnostic test is prone to false positives and false negatives, not to mention misuse and misinterpretation of results. In this study, we aimed to compare relevant findings among three diagnostic tests: a fecal occult blood test, an esophagogastroduodenoscopy, and histopathology. Methods This study used a retrospective analysis of 74 patients' electronic medical records from September 2021 to September 2022 at the Human Clinic and Gastroenterology Specialized Clinic in Riyadh, Saudi Arabia. Symptomatic adult Saudi patients who underwent a fecal occult blood test, esophagogastroduodenoscopy, and histopathology were included in the study. Results A total of 74 patients with a mean age of 43.76 ± 15.1 years were analyzed. More than half of the patients were men (63.5%). Eighteen (18) individuals tested positive through a fecal occult blood test, and 49 individuals showed a positive finding under esophagogastroduodenoscopy. Furthermore, statistical analyses revealed a significant correlation between fecal occult blood test outcomes and histopathological outcomes (p = 0.001). Conclusion A significant proportion of the sample population presented a false negative result under the fecal occult blood test. This emphasizes the importance of confirmatory endoscopic procedures and subsequent histopathology in the diagnosis of abnormalities in the upper gastrointestinal tract.

Risk Scoring Systems for Predicting the Presence of Colorectal Neoplasia by Fecal Immunochemical Test Results in Chinese Population

INTRODUCTION

Adherence to colonoscopy screening for colorectal cancer (CRC) is low in general populations, including those tested positive in the fecal immunochemical test (FIT). Developing tailored risk scoring systems by FIT results may allow for more accurate identification of individuals for colonoscopy.

METHODS

Among 807,109 participants who completed the primary tests in the first-round Shanghai CRC screening program, 71,023 attended recommended colonoscopy. Predictors for colorectal neoplasia were used to develop respective scoring systems for FIT-positive or FIT-negative populations using logistic regression and artificial neural network methods.

RESULTS

Age, sex, area of residence, history of mucus or bloody stool, and CRC in first-degree relatives were identified as predictors for CRC in FIT-positive subjects, while a history of chronic diarrhea and prior cancer were additionally included for FIT-negative subjects. With an area under the receiver operating characteristic curve of more than 0.800 in predicting CRC, the logistic regression-based systems outperformed the artificial neural network-based ones and had a sensitivity of 68.9%, a specificity of 82.6%, and a detection rate of 0.24% by identifying 17.6% subjects at high risk. We also reported an area under the receiver operating characteristic curve of about 0.660 for the systems predicting CRC and adenoma, with a sensitivity of 57.8%, a specificity of 64.6%, and a detection rate of 6.87% through classifying 38.1% subjects as high-risk individuals. The performance of the scoring systems for CRC was superior to the currently used method in Mainland, China, and comparable with the scoring systems incorporating the FIT results.

DISCUSSION

The tailored risk scoring systems may better identify high-risk individuals of colorectal neoplasia and facilitate colonoscopy follow-up. External validation is warranted for widespread use of the scoring systems.

Strategies to minimise the current disadvantages experienced by women in faecal immunochemical test-based colorectal cancer screening

Currently, women are disadvantaged compared to men in colorectal cancer (CRC) screening, particularly in programmes that use faecal immunochemical tests for haemoglobin (FIT) followed by colonoscopy. Although there is no single cause for all the known disadvantages, many can be attributed to the ubiquitous finding that women have lower faecal haemoglobin concentrations (f-Hb) than men; there are many plausible reasons for this. Generally, a single f-Hb threshold is used in CRC screening programmes, leading to lower positivity for women than men, which causes poorer outcomes for women, including lower CRC detection rate, higher interval cancer (IC) proportion, and higher CRC mortality. Many of the now widely advocated risk scoring strategies do include factors taking account of sex, but these have not been extensively piloted or introduced. Using different f-Hb thresholds for the sexes seems advantageous, but there are difficulties, including deciding which characteristic should be selected to achieve equivalency, for example, positivity, IC proportions, or specificity. Moreover, additional colonoscopy resources, often constrained, would be required. Governments and their agencies should be encouraged to prioritise the allocation of resources to put simple strategies into practice, such as different f-Hb thresholds to create equal positivity in both sexes.

Urinary MicroRNA Sensing Using Electrochemical Biosensor to Evaluate Colorectal Cancer Progression

Research in cancer diagnostics has recently established its footing and significance in the biosensor sphere, emphasizing the idea of a unique probe design used as a sensor and actuator, to identify the presence of protein, DNA, RNA, or miRNA. The fluorescein isothiocyanate (FITC) probe and biotinylated probe are designed for a two-pronged approach to the detection of the urinary miR-21 and miR-141, both of which have demonstrated significance in the development and progression of colorectal cancer, a leading cause of mortality and morbidity. The remainder of the apparatus is composed of a modified screen-printed carbon electrode (SPCE), to which the probes adhere, that transduces signals via the redox reaction between H2O2 and HRP, measured with chronoamperometry and cyclic voltammetry. The precise nature of our ultra-non-invasive biosensor makes for a highly sensitive and practical cancer detector, concluded by the significance when establishing disease presence (miR-21 p-value = 0.0176, miR-141 p-value = 0.0032), disease follow-up (miR-21 p-value = 0.00154, miR141 p-value < 0.0005), and even disease severity. This article hopes to emphasize the potential of an additional clinical tool for the management of colorectal cancer.

Faecal immunochemical tests safely enhance rational use of resources during the assessment of suspected symptomatic colorectal cancer in primary care: systematic review and meta-analysis

OBJECTIVE

Implementation of faecal immunochemical tests (FIT) as a triage test in primary healthcare may improve the efficiency of referrals without missing cases of colorectal cancer (CRC). We aim to summarise the performance characteristics of FITs for CRC in symptomatic patients presenting to primary healthcare.

DESIGN

We performed a systematic literature review of Medline and EMBASE databases from May 2018 to November 2020. Previous related systematic searches were also adapted to this aim and completed with reference screening. We identified studies performed on adult patients consulting for abdominal symptoms in primary care which reported data such that the FIT diagnostic performance parameters for CRC could be obtained. Bivariate models were used to synthesise available evidence. Meta-regression analysis was performed to evaluate the causes of heterogeneity.

RESULTS

Twenty-three studies (69 536 participants) were included (CRC prevalence 0.3%-6.2%). Six studies (n=34 691) assessed FIT as rule in test (threshold of ≥150 µg Hb/g faeces) showing a sensitivity of 64.1% (95% CI 57.8% to 69.9%) and a specificity of 95.0% (95% CI 91.2% to 97.2%). A threshold of 10 µg/g (15 studies; n=48 872) resulted in a sensitivity of 87.2% (95% CI 81.0% to 91.6%) and a specificity of 84.4% (95% CI 79.4% to 88.3%) for CRC. At a 20 µg Hb/g faeces threshold (five studies; n=24 187) less than one additional CRC would be missed per 1000 patients investigated compared with 10 µg Hb/g faeces threshold (CRC prevalence 2%).

CONCLUSION

FIT is the test of choice to evaluate patients with new-onset lower gastrointestinal symptoms in primary healthcare.

Alternative diagnoses and demographics associated with a raised quantitative faecal immunochemical test in symptomatic patients

Background

The faecal immunochemical test (FIT) has proven utility for colorectal cancer detection in symptomatic patients. However, most patients with a raised faecal haemoglobin (f-Hb) do not have colorectal cancer. We investigated alternative diagnoses and demographics associated with a raised f-Hb in symptomatic patients.

Methods

A retrospective, observational study was performed of patients with FIT submitted between August 2018 to January 2019 in NHS Greater Glasgow and Clyde followed by colonoscopy. Colonoscopy/pathology reports were searched for alternative diagnoses. Covariables were compared using the χ² test. Multivariate binary logistic regression identified independent predictors of a raised f-Hb.

Results

1272 patients were included. In addition to colorectal cancer (odds ratio (OR), 9.27 (95% confidence interval (CI): 3.61–23.83; p < 0.001)), older age (OR, 1.52 (95% CI: 1.00–2.32; p = 0.05)), deprivation (OR, 1.54 (95% CI: 1.21–1.94; p < 0.001)), oral anticoagulants (OR, 1.78 (95% CI: 1.01–3.15; p = 0.046)), rectal bleeding (OR, 1.47 (95% CI: 1.15–1.88; p = 0.002)), advanced adenoma (OR, 7.52 (95% CI: 3.90–14.49; p < 0.001)), non-advanced polyps (OR, 1.78 (95% CI: 1.33–2.38; p < 0.001)) and inflammatory bowel disease (IBD) (OR, 4.19 (95% CI: 2.17–8.07; p < 0.001)) independently predicted raised f-Hb. Deprivation (Scottish Index of Multiple Deprivation (SIMD) 1-2: OR, 2.13 (95% CI: 1.38–3.29; p = 0.001)) independently predicted a raised f-Hb in patients with no pathology found at colonoscopy.

Conclusions

An elevated f-Hb is independently associated with older age, deprivation, anticoagulants, rectal bleeding, advanced adenoma, non-advanced polyps and IBD in symptomatic patients. Deprivation is associated with a raised f-Hb in the absence of pathology. This must be considered when utilising FIT in symptomatic patients.

Predictive Modeling of Colonoscopic Findings in a Fecal Immunochemical Test-Based Colorectal Cancer Screening Program

BACKGROUND

The fecal immunochemical test (FIT) is the primary modality used by the Los Angeles County Department of Health Services (LADHS) for colorectal cancer (CRC) screening in average-risk patients. Some patients referred for FIT-positive diagnostic colonoscopy have neither adenomas nor more advanced pathology. We aimed to identify predictors of false-positive FIT (FP-FIT) results in our largely disenfranchised, low socioeconomic status population.

METHODS

We conducted a retrospective study of 596 patients who underwent diagnostic colonoscopy following a positive screening FIT. Colonoscopies showing adenomas (or more advanced pathology) were considered positive. We employed multiple logistic and linear regression as well as machine learning models (MLMs) to identify clinical predictors of FP-FIT (primary outcome) and the presence of advanced adenomas (secondary outcome).

RESULTS

Overall, 268 patients (45.0%) had a FP-FIT. Female sex and hemorrhoids (odds ratios [ORs] 1.59 and 1.89, respectively) were associated with increased odds of FP-FIT and fewer advanced adenomas (β = - 0.658 and  - 0.516, respectively). Conversely, increasing age and BMI (ORs 0.94 and 0.96, respectively) were associated with decreased odds of FP-FIT and a greater number of advanced adenomas (β = 0.073 and 0.041, respectively). MLMs predicted FP-FIT with high specificity (93.8%) and presence of advanced adenoma with high sensitivity (94.4%).

CONCLUSION

Increasing age and BMI are associated with lower odds of FP-FIT and greater number of advanced adenomas, while female sex and hemorrhoids are associated with higher odds of FP-FIT and fewer advanced adenomas. The presence of the aforementioned predictors may inform the decision to proceed with diagnostic colonoscopy in FIT-positive patients.

A user-friendly objective prediction model in predicting colorectal cancer based on 234 044 Asian adults in a prospective cohort

BACKGROUND

Prediction models of colorectal cancer (CRC) had limited application for not being user-friendly. Whether fecal immunochemical tests (FITs) can help predict CRC has been overlooked.

PATIENTS AND METHODS

With 1972 CRCs identified, 234 044 adults aged ≥40 years were successively enrolled between 1994 and 2008. Prediction models were developed by questionnaire/medical screening and quantitative FIT. NNS (number needed to scope to find one cancer) is time dependent, spanning entire study period. Significant 'risk factors' were family history, body mass index, smoking, drinking, inactivity, hypertension, diabetes, carcinoembryonic antigen, and C-reactive protein.

RESULTS

Positive FIT (≥20 μg/g hemoglobin/feces) had cancer risk 10-fold larger than negative FIT, and within each age group, another 10-fold difference. The C statistic of FIT (0.81) with age and sex alone was superior to the 'common risk-factors' model (0.73). NNS, stratified by age and by FIT values, demonstrated a scorecard of cancer risks, like 1/15 or 1/25, in 5 years. When FIT was negative, cancer risk was small (1/750-1/3000 annually). The larger the FIT, the sooner the appearance of CRC. For every 80-μg/g increase of FIT, there were 1.5-year earlier development of CRC incidence and 1-year earlier development of CRC mortality, respectively. Given the same FIT value, CRC events appeared in the proximal colon sooner than the distal colon.

CONCLUSIONS

A simple user-friendly model based on a single FIT value to predict CRC risk was developed. When positive, NNS offered a simple quantitative value, with a better precision than most risk factors, even combined. When FIT is negative, risk is very small, but requiring a repeat every other year to rule out false negative. FIT values correlated well with CRC prognosis, with worst for proximal CRC.

A fecal-based test for the detection of advanced adenoma and colorectal cancer: a case-control and screening cohort study

BACKGROUND

Colorectal cancer (CRC) is the leading cause of cancer death worldwide. Screening is a confirmed way to reduce the incidence and mortality rates of CRC. This study aimed to identify a fecal-based, noninvasive, and accurate method for detection of colorectal cancer (CRC) and advanced adenoma (AA).

METHODS

Through detection in tissue (n = 96) and fecal samples (n = 88) and tested in an independent group of fecal samples (n = 294), the methylated DNA marker ITGA4 and bacterial markers Fusobacterium nucleatum (Fn) and Pepetostreptococcusanaerobius (Pa) were identified from the candidate biomarkers for CRC and AA detection. A prediction score (pd-score) was constructed using the selected markers and fecal immunochemical test (FIT) for distinguishing AA and CRC from healthy subjects by logistic regression method. The diagnostic performance of the pd-score was compared with FIT and validated in the external validation cohort (n = 117) and in a large CRC screening cohort.

RESULTS

The pd-score accurately identified AA and CRC from healthy subjects with an area under the curve (AUC) of 0.958, at a specificity of 91.37%; the pd-score showed sensitivities of 95.38% for CRC and 70.83% for AA, respectively. In the external validation cohort, the sensitivities of the pd-score for CRC and AA detection were 94.03% and 80.00%, respectively. When applied in screening, the pd-score identified 100% (11/11) of CRC and 70.83% (17/24) of AA in participants with both colonoscopy results and qualified fecal samples, showing an improvement by 41.19% compared to FIT.

CONCLUSIONS

The current study developed a noninvasive and well-validated approach for AA and CRC detection, which could be applied widely as a diagnostic and screening test.

Significant decrease in interval colorectal cancer incidence after implementing immunochemical testing in a multiple-round guaiac-based screening programme

BACKGROUND AND AIMS

We aimed to evaluate the effects of switching to faecal immunochemical testing (FIT) on the cumulative 2-year incidence rate of interval cancers, interval cancer rate and test sensitivity within a mature population-based colorectal cancer screening programme consisting of six rounds of biennial guaiac faecal occult blood testing (gFOBT).

METHODS

The FIT results were compared with those of gFOBT used in each of the previous two rounds. For the three rounds analysed, 279,041 tests were performed by 156,186 individuals. Logistic regression analysis was used to determine interval cancer risk factors (Poisson regression) and to compare the sensitivity of FIT to gFOBT.

RESULTS

There were 612 cases of screen-detected cancers and 209 cases of interval cancers. The sex- and age-adjusted cumulative 2-year incidence rates of interval cancers were 55.7 (95% CI, 45.3-68.5), 42.4 (95% CI, 32.6-55.2) and 15.8 (95% CI, 10.9-22.8) per 100,000 person-years after the last two rounds of gFOBT and FIT, respectively. The FIT/gFOBT incidence rate ratio was 0.38 [95% CI, 0.27-0.54] (P < 0.001). Sex- and age-adjusted sensitivity was significantly higher with FIT than with gFOBT (OR = 6.70 [95% CI, 4.48-10.01], P < 0.0001).

CONCLUSIONS

This population-based study revealed a dramatic decrease in the cumulative incidence rates of interval cancers after switching from gFOBT to FIT. These data provide an additional incentive for countries still using gFOBT to switch to FIT.

False-positive fecal immunochemical test results in colorectal cancer screening and gastrointestinal drug use

PURPOSE

The study aimed to determine the influence of drug treatments (proton pump inhibitors [PPIs] combined with other drugs) on the false-positive (FP) rate in the fecal immunochemical test (FIT).

METHODS

Patients undergoing colonoscopy in the setting of a CRC screening program due to a positive FIT result were included prospectively. Demographic data and drug intake of PPIs, antiplatelet therapy (APA), anticoagulants, selective serotonin reuptake inhibitors (SSRIs), and nonsteroidal anti-inflammatory drugs (NSAIDs) were collected. An FP FIT result was considered normal colonoscopy or with nonneoplastic pathology (NNP). Logistic regression models were used to evaluate the effect of these drugs on the rate of FP FIT results.

RESULTS

We included 515 patients, and 59% (304/515) were males. The rate of FP FIT results was 48% (249/515). Study drug use was higher in patients > 60 years old and females than in those < 60 years old and males (p < 0.001 and p = 0.049, respectively). Multivariate logistic regression revealed that female sex (OR = 2.7 95% CI 1.9-3.9), NNP (OR = 1.5 95% CI 1.1-2.2), and the use of any of the study drugs (OR = 1.4 95% CI 0.9-2.0) were independent risk factors for FP FIT results. The risk of FP FIT results was significantly higher in PPI users than in nonusers (OR = 1.8 95% CI 1.1-2.9), specifically when PPIs were combined with other drugs (OR = 2.01 95% CI 1.1-3.6) only in men.

CONCLUSION

Female sex, NNP, and PPIs combined with other drugs in males were identified as independent risk factors for FP FIT results.

The Case of the Lime-green Stool: A Case Report and Review of Occult Blood Testing in the Emergency Department

Introduction

Food dyes mimicking gastrointestinal (GI) hemorrhage have been described in literature. However, reports of food additives causing melanotic stools and falsely positive fecal occult blood tests (FOBT) are uncommon in literature.

Case Report

We present a case of a 93-year-old with FOBT positive melanotic stool, felt to be falsely positive due to food additives.

Conclusion

Evaluation for GI bleeding accounts for 0.3% of yearly visits to the emergency department (ED).1 While FOBT is commonly used, its clinical validity in the ED is not supported by guidelines. We showcase the limitations of the FOBT and review the causes of false positive FOBT.

Optimal cut-off value for detecting colorectal cancer with fecal immunochemical tests according to age and sex

In the fecal immunological test, a suitable cut-off value may be selected to classify results as either positive or negative. Our aim is to estimate the optimal cut-off value for detecting colorectal cancer in different age and sex groups. This is a multicentric retrospective cohort study of participants in CRC screening programs with FIT between 2006 and 2012. A total of 545,505 participations were analyzed. Cancers diagnosed outside of the program were identified after a negative test result (IC_test) up until 2014. The Wilcoxon test was used to compare fecal hemoglobin levels. ROC curves were used to identify the optimal cut-off value for each age and sex group. Screening program results were estimated for different cut-off values. The results show that the Hb concentration was higher in colorectal cancer (average = 179.6μg/g) vs. false positives (average = 55.2μg/g), in IC_test (average = 3.1μg/g) vs. true negatives (average = 0μg/g), and in men (average = 166.2μg/g) vs. women (average = 140.2μg/g) with colorectal cancer. The optimal cut-off values for women were 18.3μg/g (50-59y) and 14.6μg/g (60-69y), and 16.8μg/g (50-59y) and 19.9μg/g (60-69y) for men. Using different cut-off values for each age and sex group lead to a decrease in the IC_test rate compared to the 20μg/g cut-off value (from 0.40‰ to 0.37‰) and an increase in the false positive rate (from 6.45% to 6.99%). Moreover, test sensitivity improved (90.7%), especially in men and women aged 50-59y (89.4%; 90%) and women aged 60-69y (90.2%). In conclusion, the optimal cut-off value varies for different sex and age groups and the use of an optimal cut-off value for each group improves sensitivity and leads to a small decrease in IC_tests, but also to a larger increase in false positives.

Performance of the faecal immunochemical test for the detection of colorectal neoplasms and the role of proton pump inhibitors in their diagnostic accuracy

AIM

The faecal immunochemical test (FIT) is currently utilized in both symptomatic and screening populations, but little is known about factors that affect its performance. For example, proton pump inhibitor (PPI) therapy has been purported to increase false negative rates. This has significant implications given the extent of PPI prescriptions. The aim of this work was to evaluate the performance of the FIT for the detection of colorectal neoplasms and the impact of PPI therapy on its diagnostic accuracy.

METHOD

Symptomatic patients referred on the suspected cancer pathway and those on polyp surveillance between 2015 and 2019 were approached to participate. Estimates of the accuracy of FIT at different cut-off levels in diagnosing colorectal neoplasms were made. Logistic regression was used to assess the effect of PPIs on the FIT results.

RESULTS

A total of 667 participants were eligible for the final analysis. At a cut-off of 10 μg/g faeces, the overall sensitivity and specificity of FIT for the detection of colorectal cancer (CRC) was 0.85 (95% CI 0.71-0.94) and 0.81 (95% CI 0.78-0.84), respectively. For the detection of advanced neoplasia, the sensitivity was 0.70 (95% CI 0.58-0.79) and the specificity was 0.83 (95% CI 0.80-0.86). At higher thresholds, the sensitivity steadily declined whilst specificity increased. PPI therapy did not have a significant effect on performance of the FIT.

CONCLUSION

FIT is a good rule-out test for the detection of CRC and advanced neoplasia at lower thresholds. PPI therapy does not appear to have an effect on its diagnostic performance.

Systematic review with meta-analysis: volatile organic compound analysis to improve faecal immunochemical testing in the detection of colorectal cancer

BACKGROUND

Faecal immunochemical test (FIT) is emerging as a valid test to rule-out the presence of colorectal cancer (CRC). However, the accuracy of FIT is dependent on the cut-off applied. An additional low-cost test could improve further detection of CRC.

AIMS

To evaluate the efficacy of combined FIT and volatile organic compounds (VOC) in the detection of CRC within symptomatic populations.

METHODS

Systematic reviews on the diagnostic accuracy of FIT and VOC, for the detection of CRC, were updated. Meta-analyses were performed adopting a bivariate model for sensitivity and specificity. Clinical utility of combined FIT and VOC was estimated using Fagan's nomogram. Post-test probability of FIT negatives was used as a pre-test probability for VOC.

RESULTS

The pooled sensitivity and specificity of FIT at 10 µg/g faeces, for the detection of CRC, were 0.914 (95% confidence interval [CI] = 0.894-0.936) and 0.783 (CI = 0.850-0.696), respectively. For VOC, the sensitivity was 0.837 (CI = 0.781-0.881) and the specificity was 0.803 (CI = 0.870-0.712). The area under the curve for FIT and VOC were 0.926 and 0.885, respectively. In a population with 5% CRC prevalence, the estimated probability of having CRC following a negative FIT was 0.5% and following both negative FIT and VOC was 0.1%.

CONCLUSIONS

In a FIT-negative symptomatic population, VOC can be a good test to rule-out the presence of CRC. The estimated probability reduction by 0.4% when both tests being negative offers adequate safety netting in primary care for the exclusion of CRC. The number needed to colonoscope to identify one CRC is eight if either FIT or VOC positive. Cost-effectiveness and clinical accuracy of this approach will need further evaluation.

Age, male sex, smoking and metabolic syndrome as risk factors of advanced colorectal neoplasia for fecal immunochemical test negative patients

BACKGROUND

Fecal immunochemical test (FIT) is worldwide strategy for colorectal cancer screening. The subjects with negative FIT still have the risk of an advanced colorectal neoplasia (AN), including adenoma with villous histology, high grade dysplasia or larger than 1 cm in size, or adenocarcinoma. The study determined the risk factors associated with AN in FIT-negative subjects.

METHODS

The study included asymptomatic subjects who received health checkup colonoscopy and have provided FIT study within 6 months prior to colonoscopy. The risk factors to have AN in cases with negative FIT were analyzed. The numbers of colonoscopies needed to detect one AN were calculated for the subjects with different risk factors.

RESULTS

There were 1411 cases, 85 with positive FIT and 1326 with negative FIT within 6 months before colonoscopy. In FIT positive and FIT negative cases, 45.9% and 34.6% were found to have colorectal adenoma, while 20.2% and 4.6% had AN, respectively. The univariate and multivariate logistic regression analyses showed that age more than 50 years old, male sex, smoking history and metabolic syndrome were the significant risk factors to have AN in the FIT negative cases. For cases with negative FIT to have these risk factors, the number of colonoscopies needed to detect one AN was 3.7, lower than 4.5 of the cases with positive FIT.

CONCLUSION

For the cases with negative FIT, colonoscopy screening should be considered for those male patients over 50 years old, with a history of smoking and metabolic syndrome to detect AN.

Screening of chronic radiation proctitis and colorectal cancer using periodic total colonoscopy after external beam radiation therapy for prostate cancer

OBJECTIVE

To investigate the incidence of colorectal cancer and chronic radiation proctitis after prostate radiotherapy using periodic total colonoscopy screening.

METHODS

From February 2013 to January 2018, 270 patients who underwent external beam radiation therapy for prostate cancer were advised to receive periodic total colonoscopy screening annually. We evaluated the incidence and characteristics of colorectal cancer and chronic radiation proctitis.

RESULTS

First, second, third, fourth and fifth total colonoscopy were performed in 256 (95%), 151 (56%), 60 (22%), 23 (8.5%) and 7 (2.6%) patients at a median of 14, 31, 42, 54 and 72 months after radiotherapy, respectively. The prevalence proportion of colorectal cancer in the first colonoscopy since radiotherapy was 3.9%. Twelve (4.4%) patients were diagnosed with colorectal cancer, including four invasive cancers, during a follow-up period. Eight of these 12 patients had not experienced rectal bleeding. The median time to diagnosis of colorectal cancer was 21 months. Chronic radiation proctitis was observed in 136 (50%) patients, including 67 (25%) patients with symptomatic bleeding.

CONCLUSIONS

The high detection rate of asymptomatic radiation proctitis suggests the utility of total colonoscopy to screen for early-stage colorectal cancer prior to or following radiotherapy for prostate cancer. Considering the longevity after localized prostate cancer treatment, the awareness of chronic radiation-induced proctitis and the risk of colorectal cancer masked by bleeding is needed in treatment decision -making.

The Roadmap of Colorectal Cancer Screening

Colorectal cancer (CRC) is the third most common form of cancer in terms of incidence and the second in terms of mortality worldwide. CRC develops over several years, thus highlighting the importance of early diagnosis. National screening programs based on fecal occult blood tests and subsequent colonoscopy have reduced the incidence and mortality, however improvements are needed since the participation rate remains low and the tests present a high number of false positive results. This review provides an overview of the CRC screening globally and the state of the art in approaches aimed at improving accuracy and participation in CRC screening, also considering the need for gender and age differentiation. New fecal tests and biomarkers such as DNA methylation, mutation or integrity, proteins and microRNAs are explored, including recent investigations into fecal microbiota. Liquid biopsy approaches, involving novel biomarkers and panels, such as circulating mRNA, micro- and long-non-coding RNA, DNA, proteins and extracellular vesicles are discussed. The approaches reported are based on quantitative PCR methods that could be easily applied to routine screening, or arrays and sequencing assays that should be better exploited to describe and identify candidate biomarkers in blood samples.

Noninvasive strategies for colorectal cancer screening: opportunities and limitations

PURPOSE OF REVIEW

In the United States, only 67% of patients are up to date with colorectal cancer (CRC) screening. While colonoscopy is highly sensitive and specific for CRC and precursor lesion detection and removal, it is invasive, expensive and resource heavy. Hence, there is an unfulfilled need for multiple modality CRC screening that can improve current CRC screening rates and may be resource effective strategies when used in conjunction with a colonoscopy program. Our review highlights the complementary, often underutilized, noninvasive CRC screening methods with a focus on performance, risks, benefits, and recent updates.

RECENT FINDINGS

Studies demonstrate that fecal immunochemical testing (FIT) is superior to guaiac-based fecal occult blood tests for CRC screening. Studies show superiority of multitarget stool DNA test to FIT in sensitivity, though with concern for decreased specificity in setting of one-time tests. Technical advances continue to improve accuracy of colon capsule endoscopy. There are ongoing studies to characterize often difficult-to-detect high-risk lesions in computed tomography colonography. Septin 9 continues to have suboptimal accuracy for CRC screening, but has been shown to be associated with more advanced, invasive CRC stages.

SUMMARY

There are ongoing advances in noninvasive screening modalities for CRC; these should be considered as alternatives to colonoscopy in specific patient populations.

Proton-pump inhibitors are associated with a high false-positivity rate in faecal immunochemical testing

BACKGROUND

False-positivity rates in faecal immunochemical test (FIT) can be affected by drug exposure. We aimed to assess the association between proton pump inhibitors (PPI) consumption and false positive (FP) results in a colorectal cancer (CRC) screening programme using electronic prescription records.

METHODS

A retrospective cohort study within a population-based screening program for CRC from 2010 to 2016 was performed. Participants with a conclusive FIT result and with prescription electronic data were included. An FP result was defined as having a positive FIT (≥ 20 µg haemoglobin/g faeces) and a follow-up colonoscopy without intermediate or high-risk lesions or CRC. Screening data were anonymously linked to the public data analysis program for health research and innovation (PADRIS) database that recorded patient diseases history and reimbursed medication. PPI exposure was defined as having retrieved at least one dispensation of PPI three months prior to the FIT.

RESULTS

A total of 89,199 tests (of 46,783 participants) were analysed, 4824 (5.4%) tested positive and the proportion of FP was 53.5%. Overall, 17,544 participants (19.7%) were PPI users prior to FIT performance. PPI exposure increased the probability of obtaining an FP FIT result from 50.4 to 63.3% (adjusted OR 1.39; 95% CI 1.18-1.65). Nonsteroidal anti-inflammatory drugs, acetylsalicylic acid, antibiotics, and laxatives were also associated with an FP result. The effect of PPI was independent and showed a synergistic interaction with nonsteroidal anti-inflammatory drugs.

CONCLUSION

PPIs increase FIT positivity at the expense of FP results. The recommendation to avoid their use before FIT performance could reduce up to 3% of colonoscopies and 9% of FP results.

Cancer Prevention and Screening for Older Adults: Part 1. Lung, Colorectal, Bladder, and Kidney Cancer

The incidence of most cancers increases with age. Cancer is the second most common cause of death in older adults after cardiovascular disease. Many common cancers in older adults can be prevented from occurring or can be identified at an early stage and treated effectively. The prevention and identification of cancer in its early stages, in an attempt to reduce discomfort and disability associated with advanced cancer and cancer treatment, is also a priority. Overscreening for cancer in older adults can lead to unnecessary diagnostic testing and unnecessary treatment. Both older adults and their healthcare providers need guidance on the appropriate use of cancer prevention and screening interventions. This first of a two-part review addresses special considerations regarding cancer prevention for adults aged 65 and older. Screening decisions and the impact of limited life expectancy and an older adult's ability to tolerate cancer treatment are also addressed. Guidance is provided regarding the prevention and early identification of lung, colorectal, bladder, and kidney cancer in older adults. The prevention of breast, prostate, and female urogenital cancers are addressed in Part 2. J Am Geriatr Soc 68:2399-2406, 2020.

Fecal Immunochemical Test: The World's Colorectal Cancer Screening Test

The fecal immunochemical test (FIT) is a tool used for colorectal cancer screening and its use is growing rapidly. FIT, applied as a qualitative or quantitative test, has far better sensitivity for hemoglobin than older, guaiac fecal occult blood tests. This translates into several advantages of FIT, including ability to screen using only 1 stool sample per cycle. This article reviews current understanding of FIT performance as a 1-time test and when applied programmatically. It outlines how to apply the test at the patient level and track performance at the program level. Future prospects for FIT application are highlighted.

Thrombocytosis helps to stratify risk of colorectal cancer in patients referred on a 2-week-wait pathway

PURPOSE

Primary care studies suggest that thrombocytosis (platelet counts > 400 × 109/L) is associated with an increased risk of colorectal cancer (CRC). We aimed to establish whether this marker has significant stratification value in patients seen in secondary care.

METHODS

A retrospective review of 2991 patients referred to our colorectal 2-week-wait (2WW) pathway between August 2014 and August 2017. Patient demographics were recorded prospectively, and local electronic records systems were used to retrieve full blood counts (FBC) and cancer diagnoses. Patients with no recent platelet count at the time of referral or incomplete records were excluded.

RESULTS

2236 patients were included in this evaluation. There was no significant difference in the age distribution of those with thrombocytosis and those without. There were significantly more females in the thrombocytosis group (72.1% vs 53.9%, chi-squared 24.63, p < 0.0001). 130 CRCs were detected (5.8%) and patients with thrombocytosis were more likely to have CRC (OR 2.62, 95% CI 1.60-4.30). The CRC diagnosis rate was significantly higher in females with thrombocytosis (10.3% vs 2.9%, chi-squared 19.41, p < 0.0001) and males with thrombocytosis (16.1% vs 7.9%, chi-squared 4.62, p = 0.032).

CONCLUSION

Thrombocytosis appears to have stratification value in the 2WW population. Further evaluation of its value alone or in combination with other stratification tests is required.

Predictors of adherence to positive airway pressure therapy in children: a systematic review and meta-analysis

BACKGROUND

While positive airway pressure (PAP) is effective for treating sleep-disordered breathing (SDB) in children, adherence is poor. Studies evaluating predictors of PAP adherence have inconsistent findings, and no rigorous reviews have been conducted. This systematic review aims to summarize the literature on predictors of PAP therapy adherence in children.

METHODS

Studies evaluating baseline predictors of PAP therapy adherence in children (≤20 years) with SDB were included. We searched MEDLINE, Embase, CENTRAL, CINAHL, Clinicaltrials.gov, and the last four years of conference abstracts. Results were described narratively, with random-effects meta-analyses performed where feasible. Risk of bias and confidence in the evidence were assessed.

RESULTS

We identified 50 factors evaluated across 28 studies (21 full text articles, seven abstracts). The highest rates of PAP therapy adherence were most consistently found with female sex, younger age, Caucasian race, higher maternal education, greater baseline apnea-hypopnea index (AHI), and presence of developmental delay. Pooled estimates included odds ratios of 1.48 (95%CI: 0.75-2.93) favoring female sex, 1.26 (95%CI: 0.68-2.36) favoring Caucasian race, and a mean difference in AHI of 4.32 (95%CI: -0.61-9.26) events/hour between adherent and non-adherent groups. There was low quality evidence to suggest that psychosocial factors like health cognitions and family environment may predict adherence.

CONCLUSION

In this novel systematic review, we identified several factors associated with increased odds of PAP therapy adherence in children. These findings may help guide clinicians to identify and support children less likely to adhere to PAP therapy and should be considered when developing interventions to improve adherence.

Optimizing the Quality of Colorectal Cancer Screening Worldwide

Screening, followed by colonoscopic polypectomy (or surgery for malignant lesions), prevents incident colorectal cancer and mortality. However, there are variations in effective application of nearly every aspect of the screening process. Screening is a multistep process, and failure in any single step could result in unnecessary morbidity and mortality. Awareness of variations in operator- and system-dependent performance has led to detailed, comprehensive recommendations in the United States and Europe on how colonoscopy screening should be performed and measured. Likewise, guidance has been provided on quality assurance for nonprimary colonoscopy-based screening programs, including strategies to maximize adherence. Quality improvement is now a validated science, and there is clear evidence that higher quality prevents incident cancer and cancer death. Quality must be addressed at the levels of the system, provider, and individuals, to maximize the benefits of screening for any population. We review the important aspects of measuring and improving the quality of colorectal cancer screening.

Effects of Oral Anticoagulants and Aspirin on Performance of Fecal Immunochemical Tests in Colorectal Cancer Screening

BACKGROUND & AIMS

The fecal immunochemical test (FIT) is the tool most frequently used for colorectal cancer (CRC) screening worldwide. It is unclear how the use of aspirin and oral anticoagulants in the screening population affects the diagnostic performance of FIT.

METHODS

We performed a cross-sectional study in an ongoing CRC screening trial in Norway. Participants aged 50-74 years with a positive result from an FIT (>15 μg hemoglobin/g feces) and subsequent colonoscopy (reference standard) were included. Those who used regular aspirin, warfarin, or direct-acting oral anticoagulants (DOACs) were defined as users. Non-users were matched according to age, sex, screening center, and screening round. The primary outcomes were the positive predictive value (PPV) for CRC and advanced adenoma.

RESULTS

Among 4908 eligible participants, 1008 used aspirin, 147 used warfarin, 212 used DOACs, and 3541 were non-users. CRCs were found in 234 individuals and advanced adenomas in 1305 individuals. The PPV for CRC was 3.8% for aspirin users vs 6.4% for matched non-users (P = .006), The PPV for advanced adenoma in aspirin users was 27.2% vs 32.6% for matched non-users (P = .011). For DOAC, the PPV for CRC was 0.9% in users vs 6.8% in matched non-users (P = .001). The PPV for advanced adenoma in DOAC users was 20.5% vs 32.4% in matched non-users (P = .002). There was no significant difference in PPV for CRC or advanced adenoma in warfarin users compared to non-users.

CONCLUSIONS

In a large screening cohort in Norway, regular use of aspirin and particularly DOACs, were associated with lower PPV of FIT for detection of CRCs and advanced adenomas. ClinicalTrials.gov ID NCT01538550.

Learning to be More Positive About FIT

Systematic application of the fecal immunochemical test (FIT) as a screen for colorectal cancer has been shown to meaningfully impact colorectal cancer incidence and mortality. However, there is room for improvement. FIT performance is impacted by a host of patient level factors such as sex and medication use. Meta-analysis has defined those factors most likely to result in a false positive or false negative test. Further work determining how best to gather information on important factors and incorporate them into the FIT result will further enhance the accuracy and outcomes accomplished with this valuable screening test.