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

Low-Dose Aspirin and Prevention of Colorectal Cancer: Evidence From a Nationwide Registry-Based Cohort in Norway

INTRODUCTION

To examine the association between low-dose aspirin use and risk of colorectal cancer (CRC).

METHODS

In this nationwide cohort study, we identified individuals aged 50 years or older residing for 6 months or more in Norway in 2004-2018 and obtained data from national registers on drug prescriptions, cancer occurrence, and sociodemographic factors. Multivariable Cox regression models were used to estimate the association between low-dose aspirin use and CRC risk. In addition, we calculated the number of CRC potentially averted by low-dose aspirin use.

RESULTS

We included 2,186,390 individuals. During the median follow-up of 10.9 years, 579,196 (26.5%) used low-dose aspirin, and 38,577 (1.8%) were diagnosed with CRC. Current use of aspirin vs never use was associated with lower CRC risk (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.84-0.90). The association was more pronounced for metastatic CRC (HR 0.79; 95% CI 0.74-0.84) than regionally advanced (HR 0.89; 95% CI 0.85-0.92) and localized CRC (HR 0.93; 95% CI 0.87-1.00; P heterogeneity = 0.001). A significant trend was found between duration of current use and CRC risk: HR 0.91 (95% CI 0.86-0.95) for <3 years, HR 0.85 (0.80-0.91) for ≥3 and <5 years, and HR 0.84 (0.80-0.88) for ≥5 years of use vs never use ( P trend < 0.001). For past use, HR were 0.89 (95% CI 0.84-0.94) for <3 years, 0.90 (0.83-0.99) for ≥3 and <5 years, and 0.98 (0.91-1.06) for ≥5 years since last use vs never use ( P -trend < 0.001). We estimated that aspirin use averted 1,073 cases of CRC (95% CI 818-1,338) in the study period.

DISCUSSION

In this nationwide cohort, use of low-dose aspirin was associated with a lower risk of CRC.

Fecal Occult Blood Screening before Cardiac Surgery

BACKGROUND

Concerns of gastrointestinal (GI) bleeding after cardiac surgery are increasing with increased use of antiplatelets and anticoagulants. We investigated the roles of preoperative screening for fecal occult blood by fecal immunochemical test (FIT) widely used to detect GI bleeding and cancer.

METHODS

A retrospective review was done in 1,663 consecutive patients undergoing FIT before cardiac surgery between years 2012 and 2020. One or two rounds of FIT were performed 2 to 3 weeks before surgery, when antiplatelets and anticoagulants were not suspended yet.

RESULTS

Positive FIT (> 30 μg of hemoglobin/g of feces) was observed in 227 patients (13.7%). Preoperative risk factors for positive FIT included age > 70 years, anticoagulants, and chronic kidney disease. Of those with positive FIT, 180 patients (79%) received preoperative endoscopy, including gastroscopy (n = 139), colonoscopy (n = 9), and both (n = 32), with no findings of bleeding. The most common finding of gastroscopy was atrophic gastritis (36%) while early gastric cancer was detected in 2 patients. The most common finding of colonoscopy was colon polyps (42%) while colorectal cancer was detected in 5 patients. Of 180 FIT-positive patients receiving endoscopy, 8 (4.4%) underwent preoperative GI treatment, while postoperative GI events were documented in 28 (15.6%). Of 1,436 with negative FIT, 21 (1.5%) presented GI complications after surgery.

CONCLUSION

Preoperative FIT, which is influenced by anticoagulant use, has little impacts on identification of GI bleeding sites. However, it may be useful to detect GI malignant lesions, potentially impacting operative risks, surgical strategies, and postoperative management.

Effect of aspirin, warfarin, and proton-pump inhibitors on performance of fecal immunochemical test in colorectal cancer screening: a systematic review and meta-analysis

This study aims to investigate the impact of antithrombotic agents and proton-pump inhibitors (PPIs) on fecal immunochemical test (FIT). PubMed, EMBASE, Web of Science, Cochrane Central, and Google Scholar were searched from inception until September 3, 2023. Studies comparing the diagnostic performance of FIT between medicine users and non-users in average-risk colorectal cancer screening populations were included. Pooled sensitivity, specificity, and positive predictive values (PPVs) for advanced neoplasia (AN) of FIT were compared by reporting pooled odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects model. Twenty-two studies enrolling 5,572,367 individuals were included. For aspirin, pooled sensitivity and specificity for AN were 57.2% and 88.4% in users versus 60.2% and 93.2% in non-users; while pooled ORs were 1.49 (95% CI 0.89-2.48, P = 0.13) and 0.72 (95% CI 0.62-0.83, P < 0.001), respectively. In subgroup analysis, there was no difference in sensitivity and specificity between the two groups at the cutoff of 20 μg Hb/g (P = 0.57 and 0.29, respectively) but a significantly lower specificity in users compared with non-users at lower cutoffs (P < 0.001). Moreover, a significantly lower PPVAN in users compared with non-users was observed after matching age and sex confounders (P = 0.001). Warfarin had no significant influence on PPVAN of FIT (P = 0.43). PPIs were associated with a significantly lower PPVAN in users (P < 0.001). Aspirin use was associated with lower specificity and PPV of FIT. Aspirin discontinuation before FIT to reduce false-positive results should be interpreted with caution given concerns about cardiovascular events. Increasing cutoff values of FIT in aspirin users may be another possible approach. Additionally, warfarin withdrawal before FIT is unnecessary but PPIs withdrawal before FIT is recommended to reduce false-positive results.

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.

Association between use of low-dose aspirin and detection of colorectal polyps and cancer in a screening setting

BACKGROUND

The possible protective effect of aspirin on risk of colorectal cancer (CRC) is still highly debated.

METHODS

We used data from Bowel Cancer Screening in Norway, a trial randomizing individuals from general population, aged 50-74 years, to flexible sigmoidoscopy or faecal immunochemical test (FIT), to study the association between aspirin use and detection of CRC and two CRC precursors: adenomas and advanced serrated lesions (ASL). Prescriptions of low-dose aspirin were obtained from Norwegian prescription database. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among 64,889 screening participants (24,159 sigmoidoscopy, 40,730 FIT), 314 (0.5%) had CRC, 6,208 (9.6%) adenoma and 659 (1.0%) ASL. Overall and short-term use (<3 years) of low-dose aspirin, versus no use, were not associated with any colorectal lesion. Long-term use (≥3 years) was associated with lower detection of CRC (overall OR 0.66, 95%CI 0.46-0.93; sigmoidoscopy: 0.56, 0.33-0.97; FIT: 0.72, 0.45-1.15), adenomas in sigmoidoscopy arm (overall OR 0.95, 95%CI 0.87-1.03; sigmoidoscopy: 0.89, 0.80-0.99; FIT: 1.03, 0.89-1.18), but not ASLs. We did not observe significant differences in the effect of aspirin according to the location of colorectal lesions.

CONCLUSION

Our results suggest that long-term use of aspirin might have a protective effect against adenomas and colorectal cancer, but not ASLs.

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.

Impact of antithrombotic drugs on the accuracy of fecal occult blood testing for advanced colorectal neoplasia screening: a meta-analysis and systematic review

BACKGROUND

The current meta-analysis was conducted to determine whether antithrombotic drug use would affect the diagnostic accuracy of fecal occult blood testing for advanced colorectal neoplasia.

METHODS

Articles published between 2000 and 2019 were systematically retrieved and screened according to the inclusion and exclusion criteria by two reviewers independently. Pooled analyses were conducted with a fixed-effect model if no apparent heterogeneity (I² ≥ 50%) was found between studies; otherwise, the random effects model would be used. Sensitivity analysis and subgroup analysis were also conducted using Review Manager 5.3.

RESULTS

Pooled analysis revealed that aspirin and nonsteroidal anti-inflammatory drugs were associated with a decrease in the positive predictive value of fecal occult blood testing for advanced colorectal neoplasia screening, with a RR of 0.89 (95% CI: 0.84-0.94) and 0.88 (95% CI: 0.84-0.93, p<0.001) respectively. Subgroup analysis based on data limited to high-quality studies, fecal immunochemical testing, or in Caucasians also showed that the use of aspirin/NSAID drugs decreased the accuracy for advanced colorectal neoplasia screening.

CONCLUSION

Aspirin/NSAIDs and direct oral anticoagulants rather than warfarin may decrease the diagnostic accuracy of fecal occult blood testing for advanced colorectal neoplasia screening.

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.

The effect of antithrombotic treatment on the fecal immunochemical test for colorectal cancer screening: a nationwide cross-sectional study

BACKGROUND : Screening for colorectal cancer (CRC) using the fecal immunochemical test (FIT) has been widely adopted. The use of antithrombotic treatment is increasing in the Western world. This study aimed to assess the effects of antithrombotic treatment on the FIT-based Danish national screening program for CRC. METHODS : This was a cross-sectional study of all individuals returning a FIT from 2014 until 2016. The effect of antithrombotic treatment on FIT positivity and the positive predictive value (PPV) were assessed using proportions and multivariable Poisson regression. RESULTS : Of 884 036 invited individuals, we identified 551 570 participants. A positive FIT was observed in 9052 of 77 007 individuals (11.8 %) receiving antithrombotic treatment compared with 28 387 of 474 587 individuals (6.0 %) receiving no treatment. The adjusted relative risk (RR) for a positive FIT was 1.59 (95 %CI 1.56-1.63) for any treatment. Nonvitamin K oral anticoagulants (NOACs) were associated with the largest increase in FIT positivity (adjusted RR 2.40, 95 %CI 2.48-2.54). The proportion of CRC detected at colonoscopy was slightly lower among patients on antithrombotic treatment (6.0 %, 95 %CI 5.5 %-6.6 %) than among treatment-naïve patients (6.4 %, 95 %CI 6.1 %-6.7 %). The PPV for CRC or high risk adenomas was decreased nearly twofold in patients treated with NOAC (adjusted RR 0.58, 95 %CI 0.51-0.66]). CONCLUSION : Antithrombotic treatment was associated with a decreased PPV in FIT-based CRC screening.

Colorectal cancer chemoprevention: is aspirin still in the game?

Screening strategies have demonstrated their potential for decreasing the incidence and mortality of cancers, particularly that of colorectal cancer (CRC). Another strategy that has been developed to reduce CRC occurrence is the use of chemoprevention agents. Among them, aspirin is the most promising. Aspirin acts in colorectal tumourigenesis through several mechanisms, either directly in tumor cells or in their microenvironment, such as through its anti-inflammatory activity or its effect on the modulation of platelet function. Many retrospective studies, as well as follow-up of large cohorts from trials with primary cardiovascular end points, have shown that long-term treatment with daily low-dose aspirin decreases the incidence of adenomas and colorectal cancers. Therefore, aspirin is currently recommended by the United States Preventive Services Task Force (USPSTF) for primary prevention of CRC in all patients aged 50 to 59 with a 10-y risk of cardiovascular events greater than 10%. Furthermore, several studies have also reported that long-term aspirin treatment taking after CRC resection decreases recurrence risk and increases overall survival, especially in patients with PIK3CA-mutated tumors. This review summarizes current knowledge on the pathophysiological mechanisms of aspirin chemoprevention, discusses the primary clinical results on CRC prevention and highlights the potential biomarkers identified to predict aspirin efficacy.

Screening for Colorectal Cancer

Colorectal cancer (CRC) is the second-leading cause of cancer death in the United States. Screening reduces CRC incidence and mortality. 2021 US Preventive Service Task Force (USPSTF) guidelines and available evidence support routine screening from ages 45 to 75, and individualized consideration of screening ages 76 to 85. USPSTF guidelines recommend annual guaiac fecal occult blood testing, annual fecal immunochemical testing (FIT), annual to every 3-year multitarget stool DNA-FIT, every 5-year sigmoidoscopy, every 10-year sigmoidoscopy with annual FIT, every 5-year computed tomographic colonography, and every 10-year colonoscopy as options for screening. The "best test is the one that gets done."

Impact of antiplatelet agents and anticoagulants on the performance of fecal immunochemical tests: a systematic review and meta-analysis

BACKGROUND

Antithrombotic agents may increase the bleeding tendency and affect the performance of fecal immunochemical test (FIT). We aimed to evaluate the impact of antithrombotic agents on the performance of FIT through a systematic review and meta-analysis.

METHODS

All relevant studies published between January 1980 and September 2020 that examined the diagnostic performance of FIT were searched through MEDLINE, EMBASE, and Cochrane Library databases. We performed a meta-analysis for the positive predictive value (PPV) of FIT for detecting advanced colorectal neoplasia (ACRN) or colorectal cancer (CRC) according to the administration of antithrombotic agents including aspirin, antiplatelet agents, and oral anticoagulants (OACs).

RESULTS

Thirteen studies with 27,518 patients were included. Of these, 11 studies with data required for the calculation of pooled PPV were included in the meta-analysis. The pooled PPV of FIT for detecting ACRN was significantly lower in antithrombotic agent users than in non-users (odds ratio [OR] [95% confidence interval [CI]]: aspirin, 0.82 [0.68-0.99]; antiplatelet agents, 0.82 [0.69-0.96]; OACs, 0.66 [0.52-0.84]). For detecting CRC, antithrombotic agent use tended to be associated with a reduced PPV (aspirin, 0.76 [0.51-1.14]; antiplatelet agents, 0.73 [0.52-1.02]; OACs, 0.60 [0.25-1.44]). In the subgroup analysis, a FIT cutoff value of 15 μg Hb/g feces tended to be associated with lower PPVs compared to a value of 20 μg Hb/g feces in antithrombotic agent users.

CONCLUSIONS

Aspirin, antiplatelet agents, and OACs significantly lowered the PPV of FIT for detecting ACRN. These drugs may increase the false-positive of FIT.

Challenges and Opportunities Associated With Platelets in Pancreatic Cancer

Pancreatic cancer is one of the most common malignant tumors in the digestive system with a poor prognosis. Accordingly, better understanding of the molecular mechanisms and innovative therapies are warranted to improve the prognosis of this patient population. In addition to playing a crucial role in coagulation, platelets reportedly contribute to the growth, invasion and metastasis of various tumors, including pancreatic cancer. This narrative review brings together currently available evidence on the impact of platelets on pancreatic cancer, including the platelet-related molecular mechanisms of cancer promotion, pancreatic cancer fibrosis, immune evasion, drug resistance mechanisms, thrombosis, targeted platelet therapy, combined radiotherapy and chemotherapy treatment, platelet combined with nanotechnology treatment and potential applications of pancreatic cancer organoids. A refined understanding of the role of platelets in pancreatic cancer provides the foothold for identifying new therapeutic targets.

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.

Noninvasive fecal testing for colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) is the third most common malignancy worldwide, with the second highest mortality rate among all malignancies. In this review, we describe the current utility of stool diagnostic biomarkers for CRC.

METHODS

We reviewed stool-related tests and biomarker candidates for the diagnosis of CRC. The guaiac-based fecal occult blood test (gFOBT), fecal immunochemical test (FIT), and multitarget stool DNA test (MT-sDNA) have been used as clinical CRC screening tools. Although microRNAs, protein biomarkers, and microbiota have not yet been used in clinical CRC screening, there is growing evidence that they have the potential to function as CRC screening tools.

RESULTS

According to the literature, the sensitivity of MT-sDNA for detecting CRC was 87.0-100%, 32.7-82.0% for advanced adenomas, and the specificity was 86.1-95.2%. The sensitivity of individual biomarkers of fecal microRNAs for detecting CRC was 34.2-88.2%, 73.0% for advanced adenomas, and the specificity was 68-100%. The sensitivity of fecal protein markers for detecting CRC was 63.6-93.0%, 47.7-69.4% for advanced adenomas, and the specificity was 38.3-97.5%. The sensitivity of fecal microbiota for detecting CRC was 54.0-100.0%, 32.0-48.3% for advanced adenomas, and the specificity was 61.3-90.0%.

CONCLUSION

MT-sDNA is the most sensitive CRC screening test, and its sensitivity is the highest for advanced adenomas; however, its detection cost is high. MT-sDNA was more sensitive to CRC and advanced precancerous lesions than FIT, but compared to three years of MT-sDNA, annual FIT as the first non-invasive screening test for CRC seemed to be more effective.

Single, Dual, and Triple Antithrombotic Therapy in Cancer Patients with Coronary Artery Disease: Searching for Evidence and Personalized Approaches

Improvement in life expectancy of patients suffering from oncohematologic disorders has turned cancer from an acute into a chronic condition, making the management of comorbidities problematic, especially when it comes to both acute and chronic cardiovascular diseases. Treatment-related adverse events and drug-drug interactions often influence the therapeutic approach of patients with active malignancies and cardiovascular disease. Furthermore, tumor cells and platelets maintain a complex crosstalk that on one hand enhances tumor dissemination and on the other hand induces hemostasis abnormalities. Hence, clinicians should move carefully in the intricate land mines established by patients with active cancer under antithrombotic therapy. To date, there is no consensus on the antithrombotic treatment of patients with cardiovascular diseases and concomitant malignancies. The aim of this review is to collect the available scientific evidence, including the latest clinical trials and guidelines, in order to provide guidance on the management of antithrombotic treatment (both antiplatelet and anticoagulant therapy) in cancer patients with either pre-existent or new-onset coronary artery disease. Randomized-controlled trials on antithrombotic treatment in oncologic populations, which by far have thus far been excluded, have to be promoted to supply recommendations in the oncohematologic setting.

Risk of lower gastrointestinal bleeding and colorectal neoplasms following initiation of low-dose aspirin: a Danish population-based cohort study

OBJECTIVE

Aspirin may increase the risk of lower gastrointestinal bleeding (LGIB) from precursors of colorectal cancer (CRC). We investigated whether use of low-dose aspirin, through initiation of LGIB, may lead patients to undergo colonoscopy and polypectomy before manifest CRC.

DESIGN

We conducted a historical cohort study (2005-2013) of all Danish residents who initiated low-dose aspirin treatment (n=412 202) in a setting without screening for CRC. Each new aspirin user was matched with three non-users (n=1 236 560) by age, sex and region of residence on the date of their matched new user's first-time aspirin prescription (index date). We computed absolute risks (ARs), risk differences and relative risks (RRs) of LGIB, lower gastrointestinal endoscopy, colorectal polyps and CRC, comparing aspirin users with non-users.

RESULTS

The ARs were higher for new users than non-users for LGIB, lower gastrointestinal endoscopy, colorectal polyps and CRC within 3 months after index. Comparing new users with non-users, the RRs were 2.79 (95% CI 2.40 to 3.24) for LGIB, 1.73 (95% CI 1.63 to 1.84) for lower gastrointestinal endoscopy, 1.56 (95% CI 1.42 to 1.72) for colorectal polyps and 1.73 (95% CI 1.51 to 1.98) for CRC. The RRs remained elevated for more than 12 months after the index date, with the exception of CRC where the RRs were slightly decreased during the 3-5 years (RR 0.90, 95% CI 0.83 to 0.98) and more than 5 years (RR 0.91, 95% CI 0.82 to 1.00) following the index date.

CONCLUSION

These findings indicate that aspirin may contribute to reduce CRC risk by causing premalignant polyps to bleed, thereby expediting colonoscopy and polypectomy before CRC development.

Use of Antiplatelet Agents Decreases the Positive Predictive Value of Fecal Immunochemical Tests for Colorectal Cancer but Does Not Affect Their Sensitivity

Previous studies have evaluated the effects of antithrombotic agents on the performance of fecal immunochemical tests (FITs) for the detection of colorectal cancer (CRC), but the results were inconsistent and based on small sample sizes. We studied this topic using a large-scale population-based database. Using the Korean National Cancer Screening Program Database, we compared the performance of FITs for CRC detection between users and non-users of antiplatelet agents and warfarin. Non-users were matched according to age and sex. Among 5,426,469 eligible participants, 768,733 used antiplatelet agents (mono/dual/triple therapy, n = 701,683/63,211/3839), and 19,569 used warfarin, while 4,638,167 were non-users. Among antiplatelet agents, aspirin, clopidogrel, and cilostazol ranked first, second, and third, respectively, in terms of prescription rates. Users of antiplatelet agents (3.62% vs. 4.45%; relative risk (RR): 0.83; 95% confidence interval (CI): 0.78–0.88), aspirin (3.66% vs. 4.13%; RR: 0.90; 95% CI: 0.83–0.97), and clopidogrel (3.48% vs. 4.88%; RR: 0.72; 95% CI: 0.61–0.86) had lower positive predictive values (PPVs) for CRC detection than non-users. However, there were no significant differences in PPV between cilostazol vs. non-users and warfarin users vs. non-users. For PPV, the RR (users vs. non-users) for antiplatelet monotherapy was 0.86, while the RRs for dual and triple antiplatelet therapies (excluding cilostazol) were 0.67 and 0.22, respectively. For all antithrombotic agents, the sensitivity for CRC detection was not different between users and non-users. Use of antiplatelet agents, except cilostazol, may increase the false positives without improving the sensitivity of FITs for CRC detection.

Development and user-testing of a brief decision aid for aspirin as a preventive approach alongside colorectal cancer screening

BACKGROUND

Several epidemiological and cohort studies suggest that regular low-dose aspirin use independently reduces the long-term incidence and risk of colorectal cancer deaths by approximately 20%. However, there are also risks to aspirin use, mainly gastrointestinal bleeding and haemorrhagic stroke. Making informed decisions depends on the ability to understand and weigh up benefits and risks of available options. A decision aid to support people to consider aspirin therapy alongside participation in the NHS bowel cancer screening programme may have an additional impact on colorectal cancer prevention. This study aims to develop and user-test a brief decision aid about aspirin to enable informed decision-making for colorectal screening-eligible members of the public.

METHODS

We undertook a qualitative study to develop an aspirin decision aid leaflet to support bowel screening responders in deciding whether to take aspirin to reduce their risk of colorectal cancer. The iterative development process involved two focus groups with public members aged 60-74 years (n = 14) and interviews with clinicians (n = 10). Interviews (n = 11) were used to evaluate its utility for decision-making. Analysis was conducted using a framework approach.

RESULTS

Overall, participants found the decision aid acceptable and useful to facilitate decision-making. They expressed a need for individualised risk information, more detail about the potential risks of aspirin, and preferred risk information presented in pictograms when offered different options. Implementation pathways were discussed, including the possibility of involving different clinicians in the process such as GPs and/or community pharmacists. A range of potentially effective timepoints for sending out the decision aid were identified.

CONCLUSION

An acceptable and usable decision aid was developed to support decisions about aspirin use to prevent colorectal cancer.

Effects of antithrombotic drugs on the results of fecal immunochemical test in colorectal neoplasms screening

Fecal immunochemical test (FIT) is widely used as a colorectal cancer screening tool. Antithrombotic drugs may affect the screening performance of FIT for colorectal tumors. The aim of this study was to clarify the effect of antithrombotic agents on FIT accuracy in screening for colorectal neoplasms. This retrospective study enrolled a total of 758 patients who underwent both FIT and total colonoscopy. The effect of antithrombotic drugs on FIT accuracy in detecting colorectal neoplasms (CN), including colorectal cancer (CRC), advanced adenoma (AA), and non-advanced adenoma (NAA), was examined. Of the 758 patients, 144 (19%) received antithrombotic drugs (administration group). In administration group, 61/144 (42%) cases had CN [CRC:14, AA:15, NAA:32] and 217/614 (35%) cases had CN (CRC:43, AA:56, NAA:118) in non-administration group. The prevalence of CN was not significantly different between the two groups (p = 0.1157). There was no significant difference in sensitivity or specificity of the detection of all types of CN with or without taking antithrombotic drugs. Neither the positive predictive value nor negative predictive value of FIT was affected by antithrombotic drug administration. Taking antithrombotic drugs may not have a large impact on sensitivity, specificity, positive predictive value, or negative predictive value of FIT in screening for CN.

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.

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.

Automatic detection of blood content in capsule endoscopy images based on a deep convolutional neural network

BACKGROUND AND AIM

Detecting blood content in the gastrointestinal tract is one of the crucial applications of capsule endoscopy (CE). The suspected blood indicator (SBI) is a conventional tool used to automatically tag images depicting possible bleeding in the reading system. We aim to develop a deep learning-based system to detect blood content in images and compare its performance with that of the SBI.

METHODS

We trained a deep convolutional neural network (CNN) system, using 27 847 CE images (6503 images depicting blood content from 29 patients and 21 344 images of normal mucosa from 12 patients). We assessed its performance by calculating the area under the receiver operating characteristic curve (ROC-AUC) and its sensitivity, specificity, and accuracy, using an independent test set of 10 208 small-bowel images (208 images depicting blood content and 10 000 images of normal mucosa). The performance of the CNN was compared with that of the SBI, in individual image analysis, using the same test set.

RESULTS

The AUC for the detection of blood content was 0.9998. The sensitivity, specificity, and accuracy of the CNN were 96.63%, 99.96%, and 99.89%, respectively, at a cut-off value of 0.5 for the probability score, which were significantly higher than those of the SBI (76.92%, 99.82%, and 99.35%, respectively). The trained CNN required 250 s to evaluate 10 208 test images.

CONCLUSIONS

We developed and tested the CNN-based detection system for blood content in CE images. This system has the potential to outperform the SBI system, and the patient-level analyses on larger studies are required.

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.