Prevalence of adenomas and colorectal cancer in average risk individuals: a systematic review and meta-analysis

Age and Sex Adenoma Detection Rates in Colonoscopy and Optimization of Screening Age: A Retrospective Analysis

Background: This study aimed to contribute to the ongoing debate regarding the optimal age to initiate colorectal cancer (CRC) screening by evaluating adenoma detection rates (ADRs) across different age and sex groups and to explore whether national screening guidelines should be revised in line with international trends. Methods: In this single-center, retrospective observational study, 1216 average-risk patients who underwent colonoscopy between January and December 2024 were analyzed. The patients were stratified into three age groups: Group 1 (40-44 years), Group 2 (45-49 years), and Group 3 (50-54 years). ADR, advanced neoplasia detection rate (ADNR), ADR by sex, Boston Bowel Preparation Scale (BBPS) score, and withdrawal times were evaluated. Patients with a history of polypectomy, family history of CRC, incomplete colonoscopy, or inadequate bowel preparation (BBPS score <6) were excluded. Group comparisons were performed using Chi-square or Fisher's exact tests, with P < .05 considered statistically significant. Results: Overall ADR and ADNR were 20.8% and 2.6%, respectively. ADRs by group were 7.6%, 15.8%, and 18.9% in Groups 1, 2, and 3, respectively. A significant difference was found between Groups 1 and 2 (P = .032) but not between Groups 2 and 3 (P = .55). ADR was significantly higher in males (30.2%) than in females (13.1%; P < .001). ADNR was also higher in males (3.7%) than in females (1.8%; P = .048). All patients had withdrawal times >6 minutes. Conclusion: ADR significantly increased from age 45, supporting the potential need to lower the CRC screening age and consider sex-specific strategies. Further prospective multicenter studies are warranted.

Periendoscopic management of antithrombotic drugs: Is cold snare polypectomy the answer?

Patients undergoing colonoscopy are increasingly taking antithrombotic medication. These patients, who are generally older, also have a higher prevalence of colon polyps. Therefore, it is general practice to modify or discontinue antithrombotic treatment before colonoscopy, to reduce the risk of post-polypectomy bleeding (PPB). However, this modification increases the risk of thrombotic events. Currently, the main clinical guidelines recommend cold-snare resection for polyps smaller than 10mm because of its better safety profile, especially in reducing post-polypectomy bleeding. This reduced PPB rate could open the door to maintaining antithrombotic drugs in patients undergoing colonoscopy. This review aims to evaluate the evidence available so far that may support a modification of current guidelines on the management of antithrombotic drugs in the periendoscopic period.

Intestinal microbiota as biomarkers for different colorectal lesions based on colorectal cancer screening participants in community

Introduction

The dysregulation of intestinal microbiota has been implicated in the pathogenesis of colorectal cancer (CRC). However, the utilization of intestinal microbiota for identify the lesions in different procedures in CRC screening populations remains limited.

Methods

A total of 529 high-risk individuals who underwent CRC screening were included, comprising 13 advanced adenomas (Aade), 5 CRC, 59 non-advanced adenomas (Nade), 129 colon polyps (Pol), 99 cases of colorectal inflammatory disease (Inf), and 224 normal controls (Nor). 16S rRNA gene sequencing was used to profile the intestinal microbiota communities. The Gut Microbiota Health Index (GMHI) and average variation degree (AVD) were employed to assess the health status of the different groups.

Results

Our findings revealed that the Nor group exhibited significantly higher GMHIs and the lowest AVD compared to the four Lesion groups. The model incorporating 13 bacterial genera demonstrated optimal efficacy in distinguishing CRC and Aade from Nor, with an area under the curve (AUC) of 0.81 and a 95% confidence interval (CI) of 0.72 to 0.89. Specifically, the 55 bacterial genera combination model exhibited superior performance in differentiating CRC from Nor (AUC 0.98; 95% CI, 0.96-1), the 25 bacterial genera combination showed superior performance in distinguishing Aade from Nor (AUC 0.95). Additionally, the 27 bacterial genera combination demonstrated superior efficacy in differentiating Nade from Nor (AUC 0.82). The 13 bacterial genera combination exhibited optimal performance in distinguishing Inf from Nor (AUC 0.71).

Discussion

Our study has identified specific microbial biomarkers that can differentiate between colorectal lesions and healthy individuals. The intestinal microbiota markers identified may serve as valuable tools in community-based CRC screening programs.

Colorectal polyps in young adults: a retrospective review of colonoscopy data from Toowoomba and the Darling Downs

BACKGROUND

Polyps are the predominant precursors of colorectal cancer. In the past three decades, the incidence and mortality rates of colorectal cancer have been increasing in adults younger than 50 years.

AIMS

The aim of this clinical audit was to evaluate the prevalence, characteristics and clinical associations of polyps in adults aged 18-49 years presenting to an established private gastroenterology clinic in the Toowoomba Darling Downs region.

METHODS

The audit included data from 353 patient records held by the Toowoomba Gastroenterology Clinic. Data extracted from patient medical records through the Medical Director program software contained structured endoscopy/colonoscopy and histology reports of excised lesions of patients presenting to the clinic. The extract involved identifying all patients aged 18-49 years in the database from January 2019 to March 2022. Patients were screened based on audit inclusion and exclusion criteria. Patients were risk stratified for recommended surveillance intervals as per Australian Clinical Guidelines.

RESULTS

Of the sample population, 33.4% were identified with polyps and 22.4% were identified with neoplastic polyps (NPs). A total of 6.7% of 18- to 29-year-old patients were identified with intermediate risk for colorectal cancer (CRC) screening, and 19.8% and 19.3% of 30- to 39-year-old and 40- to 49-year-old patients identified with intermediate or high risk for CRC screening respectively. Increased age, greater size of polyps and surveillance of previous polyps were associated with increased NP prevalence.

CONCLUSIONS

Data from this audit supported the temporal trend of increasing prevalence of polyps in adults younger than 50 years. Patient cohorts aged 30-39 and 40-49 years may benefit from earlier first colonoscopies. Findings could be the impetus for future research in young adults presenting for colonoscopy.

Optimal timing of a colonoscopy screening schedule depends on adenoma detection, adenoma risk, adherence to screening and the screening objective: A microsimulation study

Colonoscopy-based screening provides protection against colorectal cancer (CRC), but the optimal starting age and time intervals of screening colonoscopies are unknown. We aimed to determine an optimal screening schedule for the US population and its dependencies on the objective of screening (life years gained or incidence, mortality, or cost reduction) and the setting in which screening is performed. We used our established open-source microsimulation model CMOST to calculate optimized colonoscopy schedules with one, two, three or four screening colonoscopies between 20 and 90 years of age. A single screening colonoscopy was most effective in reducing life years lost from CRC when performed at 55 years of age. Two, three and four screening colonoscopy schedules saved a maximum number of life years when performed between 49-64 years; 44-69 years; and 40-72 years; respectively. However, for maximum incidence and mortality reduction, screening colonoscopies needed to be scheduled 4-8 years later in life. The optimum was also influenced by adenoma detection efficiency with lower values for these parameters favoring a later starting age of screening. Low adherence to screening consistently favored a later start and an earlier end of screening. In a personalized approach, optimal screening would start earlier for high-risk patients and later for low-risk individuals. In conclusion, our microsimulation-based approach supports colonoscopy screening schedule between 45 and 75 years of age but the precise timing depends on the objective of screening, as well as assumptions regarding individual CRC risk, efficiency of adenoma detection during colonoscopy and adherence to screening.

Colon Polyp Surveillance: Separating the Wheat From the Chaff

One goal of colorectal cancer (CRC) screening is to prevent CRC incidence by removing precancerous colonic polyps, which are detected in up to 50% of screening examinations. Yet, the lifetime risk of CRC is 3.9%-4.3%, so it is clear that most of these individuals with polyps would not develop CRC in their lifetime. It is, therefore, a challenge to determine which individuals with polyps will benefit from follow-up, and at what intervals. There is some evidence that individuals with advanced polyps, based on size and histology, benefit from intensive surveillance. However, a large proportion of individuals will have small polyps without advanced histologic features (ie, "nonadvanced"), where the benefits of surveillance are uncertain and controversial. Demand for surveillance will further increase as more polyps are detected due to increased screening uptake, recent United States recommendations to expand screening to younger individuals, and emergence of polyp detection technology. We review the current understanding and clinical implications of the natural history, biology, and outcomes associated with various categories of colon polyps based on size, histology, and number. Our aims are to highlight key knowledge gaps, specifically focusing on certain categories of polyps that may not be associated with future CRC risk, and to provide insights to inform research priorities and potential management strategies. Optimization of CRC prevention programs based on updated knowledge about the future risks associated with various colon polyps is essential to ensure cost-effective screening and surveillance, wise use of resources, and inform efforts to personalize recommendations.

The Cancer Spectrum Theory

SUMMARY

Biological characteristics of tumors are heterogeneous, forming spectra in terms of several factors such as age at onset, anatomic spatial localization, tumor subtyping, and the degree of tumor aggressiveness (encompassing a neoplastic property spectrum). Instead of blindly using dichotomized approaches, the application of the multicategorical and continuous analysis approaches to detailed cancer spectrum data can contribute to a better understanding of the etiology of cancer, ultimately leading to effective prevention and precision oncology. We provide examples of cancer spectra and emphasize the importance of integrating the cancer spectrum theory into large-scale population cancer research.

Spatial-temporal pattern of colorectal cancer mortality in a Northeastern Brazilian State

Colorectal cancer (CRC) is one of the most common cancer types worldwide. Its increasing mortality trends, especially in emerging countries, are a concern. The aim of this study was to analyse mortality trends and spatial patterns of CRC in the state of Sergipe, Brazil, from 1990 to 2019. Trends were calculated using data from the Online Mortality Atlas and Joinpoint Regression Program 4.8.0.1. Spatial analyses were performed using the empirical Bayesian model and Moran indices calculated by TerraView 4.2.2 between 1990 to 1999, 2000 to 2009 and 2010 to 2019. A total of 1585 deaths were recorded during the study period, with 58.42% among females. Trends were increasing and constant for both sexes and all age groups studied. The highest mean annual percent change was 6.2 {95% Confidence interval (CI) 3.4;9.0} for males aged +65 years and 4.5 (95% CI 3.2;5.8) for females aged 50-64 years. There was positive spatial autocorrelation for both sexes in all periods studied when using the Moran index for Bayesian rates. In summary, a consistent trend of increasing colorectal cancer (CRC) mortality has been observed overall. Nevertheless, an altered spatial distribution among males has emerged over the studied period.

The association and application of sonodynamic therapy and autophagy in diseases

Sonodynamic therapy (SDT) is a new non-invasive treatment method proposed based on photodynamic therapy (PDT). It has advantages such as high precision, strong tissue penetration, minimal side effects, and good patient compliance. With the maturation of nanomedicine, the application of nanosonosensitizers has further propelled the development of SDT. In recent years, people have developed many new types of sonosensitizers and explored the mechanisms of SDT. Among them, the studies about the relationship between autophagy and SDT have attracted increasing attention. After the SDT, cells usually undergo autophagy as a self-protective mechanism to resist external stimuli and reduce cell damage, which is beneficial for the treatment of atherosclerosis (AS), diabetes, and myocardial infarction but counterproductive in cancer treatment. However, under certain treatment conditions, excessive upregulation of autophagy can also promote cell death, which is beneficial for cancer treatment. This article reviews the latest research progress on the relationship between SDT and autophagy in cancers, AS, diabetes, and myocardial infarction. We also discuss and propose the challenges and prospects in enhancing SDT efficacy by regulating autophagy, with the hope of promoting the development of this promising therapeutic approach.

Comparative Analysis of Machine Learning Models for Image Detection of Colonic Polyps vs. Resected Polyps

(1) Background: Colon polyps are common protrusions in the colon's lumen, with potential risks of developing colorectal cancer. Early detection and intervention of these polyps are vital for reducing colorectal cancer incidence and mortality rates. This research aims to evaluate and compare the performance of three machine learning image classification models' performance in detecting and classifying colon polyps. (2) Methods: The performance of three machine learning image classification models, Google Teachable Machine (GTM), Roboflow3 (RF3), and You Only Look Once version 8 (YOLOv8n), in the detection and classification of colon polyps was evaluated using the testing split for each model. The external validity of the test was analyzed using 90 images that were not used to test, train, or validate the model. The study used a dataset of colonoscopy images of normal colon, polyps, and resected polyps. The study assessed the models' ability to correctly classify the images into their respective classes using precision, recall, and F1 score generated from confusion matrix analysis and performance graphs. (3) Results: All three models successfully distinguished between normal colon, polyps, and resected polyps in colonoscopy images. GTM achieved the highest accuracies: 0.99, with consistent precision, recall, and F1 scores of 1.00 for the 'normal' class, 0.97-1.00 for 'polyps', and 0.97-1.00 for 'resected polyps'. While GTM exclusively classified images into these three categories, both YOLOv8n and RF3 were able to detect and specify the location of normal colonic tissue, polyps, and resected polyps, with YOLOv8n and RF3 achieving overall accuracies of 0.84 and 0.87, respectively. (4) Conclusions: Machine learning, particularly models like GTM, shows promising results in ensuring comprehensive detection of polyps during colonoscopies.

The role of colonoscopy in young patients with rectal bleeding: a systematic review and meta-analysis

PURPOSE

Anal bleeding is a frequent complaint in the coloproctological practice. Although usually associated with common anorectal disorders, it may represent a sign of an occult colorectal carcinoma. Our purpose was to evaluate the accuracy of the colonoscopy for detection of neoplastic lesions in patients under 50 years of age with rectal bleeding.

METHODS

This systematic review and meta-analysis searched publications in PubMed, Web of Science, and Cochrane Library databases up to August, 2023. Cross-sectional and case-control studies including patients under 50 years with rectal bleeding evaluated by colonoscopy were included. Primary outcome was prevalence of neoplastic lesions (adenomas and adenocarcinomas). Secondary outcomes were prevalence of those lesions according to age and anatomic location. The study was registered on PROSPERO (CRD42021257859) on July 5, 2021.

RESULTS

Nine studies comprising 4162 patients were analyzed. A total of 398 patients with adenomas and 40 patients with adenocarcinoma were identified. Prevalence of neoplastic lesions (adenomas and carcinomas) was 10%. In patients under 40 years, the prevalence of neoplastic lesions was 7% (6% of adenomas, 1% of carcinomas). Among patients aged 40-50 years the prevalence was 15%, 14%, and 1%, respectively. Most lesions (71%) were located distally to splenic flexure.

CONCLUSION

About 10% of patients under 50 years with anal bleeding will have a neoplastic lesion detected through colonoscopy. The greatest benefit of the procedure is observed between 40 and 50 years. Almost 30% of the neoplastic lesions were found in the proximal colon and could not be detected without the performance of a complete colonoscopy.

McKittrick-Wheelock syndrome: A rare cause of chronic diarrhea treated with endoscopic polypectomy

Chronic diarrhea is a commonly encountered complaint and a principal cause of health care utilization worldwide. Although there are various etiologies of chronic diarrhea, McKittrick-Wheelock syndrome is a rare syndrome defined as a large villous adenoma with secretory diarrhea causing severe fluid imbalances. We report a case of a patient with McKittrick-Wheelock syndrome who was successfully treated with endoscopic resection. Our case aims to add information to the current literature supporting the endoscopic management of McKittrick-Wheelock syndrome.

Analysis of the relationship between the gut microbiota enterotypes and colorectal adenoma

Introduction

The essence of enterotypes is to stratify the entire human gut microbiota, and dysregulation of gut microbiota is closely related to the development of colorectal adenoma. Enterotypes may therefore be a useful target for the prevention of colorectal adenoma. However, the relationship between gut microbiota and colorectal adenoma has not been fully elucidated. In this study, we aimed to analyze the differences in gut microbiome composition between adenoma and control populations.

Methods

We recruited 31 patients with colorectal adenoma and 71 non-adenoma controls. Patient demographics, risk factors, fecal samples from each subject were collected and metagenomic sequencing was performed. LEfSe analysis was used to reveal differences in intestinal microbiome composition. Multiple logistic regression analysis was used to determine the association between enterotypes and colorectal adenoma.

Results

The results showed that Prevotella enterotype (enterotype 4) is only present in adenoma group. Logistic regression analysis showed that Prevotella enterotype was an independent risk factor for colorectal adenoma.

Discussion

The Prevotella enterotype may increase the occurrence of colorectal adenoma through inflammatory association and interference with glucose and lipid metabolism in human body. In conclusion, the differences we observed between different enterotypes add a new potential factor to the development of colorectal adenoma.

Characteristics of adenomatous colorectal polyps among a Saudi population

Objectives

Colorectal cancer is a common cause of cancer-related mortality in KSA with a rising incidence. Although adenomatous polyps are well-recognized as precursors of colorectal cancer, local data are scarce. Therefore, in this study, we aimed to evaluate the characteristics of adenomatous colon polyps in the Saudi population.

Methods

We retrospectively reviewed the electronic databases of all patients who underwent colonoscopy for any indication between January 2015 and December 2019 at a tertiary care hospital. This study included adult patients who were found to have colorectal polyps with identified histopathology reports. We collected clinical and pathological data, including patient age, sex, and histopathological polyp characteristics. A p-value <0.05 was considered significant for descriptive and analytical statistics.

Results

A total of 184 patients with colorectal polyps with identified histopathology reports were included in the analysis. Of these, 130 (70.6%) patients were aged 50 years or older, and 135 (73.3%) were male. Among all polyps, 127 (69%) were adenomatous, 31 (16.8%) were hyperplastic, and 24 (13%) were inflammatory. For adenomatous polyps, 31 (24.4%) were observed in patients younger than 50 years, and high-grade dysplasia was observed in 23 (18%) polyps. Among patients with adenomatous polyps, the anatomical location was as follows: 27 (23%) in the cecum/ascending colon, 12 (9%) in the transverse colon, 45 (35%) in the descending/sigmoid colon, 25 (19%) in the rectum, and 18 (14%) at multiple sites. Age >50 years was significantly associated with adenomatous polyps (P = 0.03).

Conclusion

Approximately one-third of adenomatous polyps were detected proximal to the splenic flexure. Although adenomatous polyps were significantly associated with increasing age, 24% were observed in patients younger than 50 years of age. This finding supports the current recommendation to start screening at the age of 45.

Factors Predicting Malignant Occurrence and Polyp Recurrence after the Endoscopic Resection of Large Colorectal Polyps: A Single Center Experience

Background: The aim of this study was to identify risk factors contributing to the malignancy of colorectal polyps, as well as risk factors for recurrence after the successful endoscopic mucosal resection of large colorectal polyps in a referral center. Materials and Methods: This retrospective cohort study was performed in patients diagnosed with large (≥20 mm diameter) colorectal polyps and treated in the period from January 2014 to December 2019 at the University Hospital Medical Center Bezanijska Kosa, Belgrade, Serbia. Based on the endoscopic evaluation and classification of polyps, the following procedures were performed: en bloc resection, piecemeal resection or surgical treatment. Results: A total of 472 patients with large colorectal polyps were included in the study. The majority of the study population were male (62.9%), with a mean age of 65.7 ± 10.8 years. The majority of patients had one polyp (73.7%) less than 40 mm in size (74.6%) sessile morphology (46.4%), type IIA polyps (88.2%) or polyps localized in the descending colon (52.5%). The accessibility of the polyp was complicated in 17.4% of patients. En bloc resection was successfully performed in 61.0% of the patients, while the rate of piecemeal resection was 26.1%. Due to incomplete endoscopic resection, surgery was performed in 5.1% of the patients, while 7.8% of the patients were referred to surgery directly. Hematochezia (p = 0.001), type IIB polyps (p < 0.001) and complicated polyp accessibility (p = 0.002) were significant independent predictors of carcinoma presence in a multivariate logistic regression analysis. Out of the 472 patients enrolled in the study, 364 were followed after endoscopic resection for colorectal polyp recurrence, which was observed in 30 patients (8.2%) during follow-up. Piecemeal resection (p = 0.048) and incomplete resection success (p = 0.013) were significant independent predictors of polyp recurrence in the multivariate logistic regression analysis. Conclusions: Whenever an endoscopist encounters a complex colorectal lesion (i.e., a polyp with complicated accessibility), polyp size > 40 mm, the Laterally Spreading Tumor nongranular (LST-NG) morphological type, type IIB polyps or the presence of hematochezia, malignancy risk should be considered before making the decision to either resect, refer to an advanced endoscopist or perform surgery.

Computer-Aided Detection Improves Adenomas per Colonoscopy for Screening and Surveillance Colonoscopy: A Randomized Trial

BACKGROUND & AIMS

Colonoscopy for colorectal cancer screening is endoscopist dependent, and colonoscopy quality improvement programs aim to improve efficacy. This study evaluated the clinical benefit and safety of using a computer-aided detection (CADe) device in colonoscopy procedures.

METHODS

This randomized study prospectively evaluated the use of a CADe device at 5 academic and community centers by US board-certified gastroenterologists (n = 22). Participants aged ≥40 scheduled for screening or surveillance (≥3 years) colonoscopy were included; exclusion criteria included incomplete procedure, diagnostic indication, inflammatory bowel disease, and familial adenomatous polyposis. Patients were randomized by endoscopist to the standard or CADe colonoscopy arm using computer-generated, random-block method. The 2 primary endpoints were adenomas per colonoscopy (APC), the total number of adenomas resected divided by the total number of colonoscopies; and true histology rate (THR), the proportion of resections with clinically significant histology divided by the total number of polyp resections. The primary analysis used a modified intention-to-treat approach.

RESULTS

Between January and September 2021, 1440 participants were enrolled to be randomized. After exclusion of participants who did not meet the eligibility criteria, 677 in the standard arm and 682 in the CADe arm were included in a modified intention-to-treat analysis. APC increased significantly with use of the CADe device (standard vs CADe: 0.83 vs 1.05, P = .002; total number of adenomas, 562 vs 719). There was no decrease in THR with use of the CADe device (standard vs CADe: 71.7% vs 67.4%, P for noninferiority < .001; total number of non-neoplastic lesions, 284 vs 375). Adenoma detection rate was 43.9% and 47.8% in the standard and CADe arms, respectively (P = .065).

CONCLUSIONS

For experienced endoscopists performing screening and surveillance colonoscopies in the United States, the CADe device statistically improved overall adenoma detection (APC) without a concomitant increase in resection of non-neoplastic lesions (THR).

CLINICALTRIALS

gov registration: NCT04754347.

Overexpression of the miR-17-92 cluster in colorectal adenoma organoids causes a carcinoma-like gene expression signature

Gain of chromosome arm 13q is one of the most prevalent DNA copy number alterations associated with colorectal adenoma-to-carcinoma progression. The oncogenic miR-17-92 cluster, located at 13q, was found to be overexpressed in colorectal cancer and in adenomas harboring 13q gain. However, to what extent overexpression of this group of microRNAs actually drives progression to cancer remains to be resolved. Therefore, we aimed to clarify the role of miR-17-92 cluster in the progression from colorectal adenoma to carcinoma.

The miR-17-92 cluster was overexpressed in human colorectal adenoma organoids without 13q gain and downstream effects on mRNA expression were investigated, along with functional consequences in vitro and in vivo.

Comparison of mRNA sequencing results of organoids overexpressing miR-17-92 and cultures transduced with control vector revealed a miR-17-92 expression signature. This signature appeared to be enriched in an independent series of colorectal cancers and adenomas with 13q gain, confirming that miR-17-92 expression is associated with malignant progression. However, tumor-associated characteristics, such as increased proliferation rate, were not observed in miR-17-92 overexpressing adenoma organoids in vitro. In addition, subcutaneous injection of these organoids in immunodeficient mice was insufficient to cause tumor outgrowth.

In conclusion, this study showed that miR-17-92 expression contributes to 13q gain-associated adenoma-to-carcinoma progression, however, this is insufficient to cause malignancy.

Practical considerations for colorectal cancer screening in older adults

Recent guidelines recommend that colorectal cancer (CRC) screening after age 75 be considered on an individualized basis, and discourage screening for people over 85 due to competing causes of mortality. Given the heterogeneity in the health of older individuals, and lack of data within current guidelines for personalized CRC screening approaches, there remains a need for a clearer framework to inform clinical decision-making. A revision of the current approach to CRC screening in older adults is even more compelling given the improvements in CRC treatment, post-treatment survival, and increasing life expectancy in the population. In this review, we aim to examine the personalization of CRC screening cessation based on specific factors influencing life and health expectancy such as comorbidity, frailty, and cognitive status. We will also review screening modalities and endoscopic technique for minimizing risk, the risks of screening unique to older adults, and CRC treatment outcomes in older patients, in order to provide important information to aid CRC screening decisions for this age group. This review article offers a unique approach to this topic from both the gastroenterologist and geriatrician perspective by reviewing the use of specific clinical assessment tools, and addressing technical aspects of screening colonoscopy and periprocedural management to mitigate screening-related complications.

Association of demographic and health characteristics with circulating oxysterol concentrations

BACKGOUND

Circulating oxysterols, cholesterol metabolites with important signaling functions, are increasingly being recognized as candidate biomarkers for several diseases, but associations with demographic and health characteristics remain poorly described.

OBJECTIVE

This study aims to characterize associations of major circulating oxysterols with sex, age, race/ethnicity, body mass index (BMI), lifestyle factors, and use of common medications.

METHODS

We measured plasma concentrations of 27-hydroxycholesterol (27-OHC), 25-hydroxycholesterol (25-OHC), 24(S)-hydroxycholesterol (24(S)-OHC), 7ɑ-hydroxycholesterol (7ɑ-OHC), and 4β-hydroxycholesterol (4β-OHC) from 1,440 participants of a completed clinical trial for the chemoprevention of colorectal adenomas. Adjusted percent difference in means were calculated using linear regression.

RESULTS

Women had 18% (95% CI, 14%, 22%) lower 27-OHC and 21% (15%, 27%) higher 4β-OHC than men. Blacks had 15% (7%, 23%) higher 4β-OHC than Non-Hispanic Whites, and Asian or Pacific Islanders had 19% (2%, 35%) higher 7ɑ-OHC than Non-Hispanic Whites. Individuals of BMI ≥35 kg/m2 had 33% (25%, 41%) lower 4β-OHC than those <25 kg/m2. Current smokers had 15% (5%, 24%) higher 7ɑ-OHC than never smokers, and daily alcohol drinkers had 17% (10%, 24%) higher 7ɑ-OHC than never drinkers. Statin use was associated with lower concentrations of all 5 oxysterols. Differences in mean <15% were found for characteristics such as age, total dietary energy intake, physical activity, diabetes, and anti-inflammatory drug use.

CONCLUSION

Circulating oxysterols are uniquely associated with multiple demographic and health characteristics.

Risk of colonoscopic post-polypectomy bleeding in patients on single antiplatelet therapy: systematic review with meta-analysis

BACKGROUND

It was not yet fully established whether the use of antiplatelet agents (APAs) is associated with an increased risk of colorectal post-polypectomy bleeding (PPB). Temporarily, discontinuation of APAs could reduce the risk of PPB, but at the same time, it could increase the risk of cardiovascular disease recurrence. This study aimed to assess the PPB risk in patients using APAs compared to patients without APAs or anticoagulant therapy who had undergone colonoscopy with polypectomy.

METHODS

A systematic electronic search of the literature was performed using PubMed/MEDLINE, Scopus, and CENTRAL, to assess the risk of bleeding in patients who do not interrupt single antiplatelet therapy (P2Y12 inhibitors or aspirin) and undergone colonoscopy with polypectomy.

RESULTS

Of 2417 identified articles, 8 articles (all of them were non-randomized studies of interventions (NRSI); no randomized controlled trials (RCT) were available on this topic) were selected for the meta-analysis, including 1620 patients on antiplatelet therapy and 13,321 controls. Uninterrupted APAs single therapy was associated with an increased risk of PPB compared to the control group (OR 2.31; CI 1.37-3.91). Patients on P2Y12i single therapy had a higher risk of both immediate (OR 4.43; CI 1.40-14.00) and delayed PPB (OR 10.80; CI 4.63-25.16) compared to the control group, while patients on aspirin single therapy may have a little to no difference increase in the number of both immediate and delayed PPB events.

CONCLUSIONS

Uninterrupted single antiplatelet therapy may increase the risk of PPB, but the evidence is very uncertain. The risk may be higher in delayed PPB. However, in deciding to discontinue APAs before colonoscopy with polypectomy, the potential higher risk of major adverse cardiovascular events should always be assessed.

Cause, Epidemiology, and Histology of Polyps and Pathways to Colorectal Cancer

Colorectal cancer is the second leading cause of cancer-associated mortality, with a lifetime risk of approximately 4% to 5%. Colorectal cancer develops from the sequential acquisition of defined genetic mutations in the colonic epithelium. Tumorigenesis from normal tissue to cancer occurs largely through 3 pathways: the chromosomal instability pathway, the microsatellite instability pathway, and the sessile serrated pathway. Colorectal cancer incidence and mortality have decreased by approximately 35% since the beginning of screening programs in the 1990s, although other factors such as use of aspirin for coronary disease prevention and decreased smoking rates may also be important. In this review, we discuss the etiology, epidemiology, and histology of colorectal polyps and cancer.

Population-Based Prevalence of Gastrointestinal Abnormalities at Colon Capsule Endoscopy

BACKGROUND & AIMS

The population prevalence of gastrointestinal (GI) disease is unclear and difficult to assess in an asymptomatic population. The aim of this study was to determine prevalence of GI lesions in a largely asymptomatic population undergoing colon capsule endoscopy (CCE).

METHODS

Participants aged between 50-75 years were retrieved from the Rotterdam Study, a longitudinal epidemiological study, between 2017-2019. Participants received CCE with bowel preparation. Abnormalities defined as clinically relevant were Barrett segment >3cm, severe ulceration, polyp >10 mm or ≥3 polyps in small bowel (SB) or colon, and cancer.

RESULTS

Of 2800 invited subjects, 462 (16.5%) participants (mean age 66.8 years, female 53.5%) ingested the colon capsule. A total of 451 videos were analyzed, and in 94.7% the capsule reached the descending colon. At least 1 abnormal finding was seen in 448 (99.3%) participants. The prevalence of abnormalities per GI segment, and the most common type of abnormality, were as follows: Esophageal 14.8% (Barrett's esophagus <3 cm in 8.3%), gastric 27.9% (fundic gland polyps in 18.1%), SB abnormalities 33.9% (erosions in 23.8%), colon 93.3% (diverticula in 81.2%). A total of 54 participants (12%) had clinically relevant abnormalities, 3 (0.7%) in esophagus/stomach (reflux esophagitis grade D, Mallory Weiss lesion and severe gastritis), 5 (1.1%) in SB (polyps > 10 mm; n = 4, severe ulcer n = 1,) and 46 (10.2%) in colon (polyp > 10 mm or ≥3 polyps n = 46, colorectal cancer n = 1).

CONCLUSIONS

GI lesions are very common in a mostly asymptomatic Western population, and clinically relevant lesions were found in 12% at CCE. These findings provide a frame of reference for the prevalence rates of GI lesions in the general population.

Colonoscopy Following an Abnormal Fecal Test Result from an Annual Colorectal Cancer Screening Program in a Federally Qualified Health Center

OBJECTIVE

Individuals with an abnormal fecal immunochemical test (FIT) result have an elevated risk of colorectal cancer, and the risk increases if the follow-up colonoscopy is delayed. Of note, rates of follow-up colonoscopy are alarmingly low in federally qualified health centers (FQHCs), US health care settings that serve a majority racial and ethnic minority patient population. We assessed factors associated with colonoscopy after an abnormal FIT result and used chart-abstracted data to assess reasons (including process measures) for lack of follow-up as part of an annual, mailed-FIT outreach program within a large, Latino-serving FQHC.

METHODS

As part of the National Institutes of Health-funded PROMPT study, we identified patients with an abnormal FIT result and used logistic regression to assess associations between patient demographics and receipt of follow-up colonoscopy, controlling for patients' preferred language. We report on time (days) to referral and time to colonoscopy. For charts with an abnormal FIT result but no evidence of colonoscopy, we performed a manual abstraction and obtained the reason for the absence of colonoscopy. When there was no evidence of colonoscopy in a patient's electronic health record (EHR), we performed an automated query of the administrative claims database to identify colonoscopy outcomes.

RESULTS

We identified 324 patients with abnormal FIT results from July to October 2018. These patients were mostly publicly insured (Medicaid 53.1%, Medicare 14.5%), 81.8% were aged 50 to 64 years, 55.3% were female, 80.3% were Hispanic/Latino, and 67.3% preferred to speak Spanish. We found that 108/324 (33.3%) patients completed colonoscopy within 12 months, and the median time to colonoscopy was 94 days (IQR: 68-176). Common barriers to colonoscopy completion, obtained from chart-abstracted data, were: no documentation following referral to gastrointestinal (GI) specialist or GI consultation (41.6%), no referral to GI specialist following abnormal fecal test (34.2%), and absence of a valid insurance authorization (6.5%).

CONCLUSIONS

Multi-level strategies are needed to provide optimal care across the cancer continuum for FQHC patients. In order to reduce the risk of CRC and realize the return on fecal testing investment, concerted system-level efforts are urgently needed to improve rates of follow-up colonoscopy among FQHC patients and redress racial and ethnic disparities in CRC screening outcomes.

How can we better identify patients with rectal bleeding who are at high risk of colorectal cancer? An observational study

PURPOSE

Rectal bleeding is a common symptom of colorectal cancer. In this paper, we describe and evaluate the operation of a central access and triage system for patients with rectal bleeding, which uses a "high-risk"/ "low-risk" designation based on the referring doctor's subjective designation and a 10-item symptom checklist.

METHODS

A total of 1846 patients, referred between February 1, 2016, and December 31, 2018, were included. Exclusion criteria were the following: incorrect patient identification number, duplicate records, and pre-diagnosed gastrointestinal cancer. Data was obtained by chart review. Sensitivity, specificity, and positive and negative predictive values were calculated for each item on the symptom checklist.

RESULTS

Eight hundred seventy-nine (48%) patients received endoscopy, and 37 (2%) were found to have cancer. Five hundred eighty-two (32%) patients were deemed high-risk. Twenty-nine (78%) of the patients with cancer were in the high-risk group. Patients in the high-risk group had a higher incidence of cancer (5.0% vs 0.6%, p < 0.001) and shorter waits to endoscopy (201 vs 292 days). Patients designated as high-risk by the referring physician had a relative risk of 22.3 compared to those designated as low-risk. Patients deemed high-risk by the symptom checklist had a relative risk of 3.5 compared to low-risk patients.

CONCLUSION

Our system stratified 29/37 (78%) of the patients found to have cancer as high-risk. A total of 8/37 (22%) patients with cancer were deemed low-risk. Our research has identified two variables (weight loss and anemia) which have been added to our referral symptom checklist. This study helped us identify areas for refinement of our triage system. These findings are of interest to physicians who treat colorectal cancer.

Multivariable models for advanced colorectal neoplasms in screen-eligible individuals at low-to-moderate risk of colorectal cancer: towards improving colonoscopy prioritization

Background

Advanced colorectal neoplasms (ACNs), including colorectal cancers (CRC) and high-risk adenomas (HRA), are detected in less than 20% of persons aged 50 years or older who undergo colonoscopy. We sought to derive personalized predictive models of risk of harbouring ACNs to improve colonoscopy wait times for high-risk patients and allocation of colonoscopy resources.

Methods

We characterized colonoscopy indications, neoplasia risk factors and colonoscopy findings through chart review for consecutive individuals aged 50 years or older who underwent outpatient colonoscopy at The Ottawa Hospital (Ottawa, Canada) between April 1, 2008 and March 31, 2012 for non-life threatening indications. We linked patients to population-level health administrative datasets to ascertain additional historical predictor variables and derive multivariable logistic regression models for risk of harboring ACNs at colonoscopy. We assessed model discriminatory capacity and calibration and the ability of the models to improve colonoscopy specificity while maintaining excellent sensitivity for ACN capture.

Results

We modelled 17 candidate predictors in 11,724 individuals who met eligibility criteria. The final CRC model comprised 8 variables and had a c-statistic value of 0.957 and a goodness-of-fit p-value of 0.527. Application of the models to our cohort permitted 100% sensitivity for identifying persons with CRC and > 90% sensitivity for identifying persons with HRA, while improving colonoscopy specificity for ACNs by 23.8%.

Conclusions

Our multivariable models show excellent discriminatory capacity for persons with ACNs and could significantly increase colonoscopy specificity without overly sacrificing sensitivity. If validated, these models could allow more efficient allocation of colonoscopy resources, potentially reducing wait times for those at higher risk while deferring unnecessary colonoscopies in low-risk individuals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01965-5.

Artificial intelligence-assisted colonoscopy: A prospective, multicenter, randomized controlled trial of polyp detection

BACKGROUND

Artificial intelligence (AI) assistance has been considered as a promising way to improve colonoscopic polyp detection, but there are limited prospective studies on real-time use of AI systems.

METHODS

We conducted a prospective, multicenter, randomized controlled trial of patients undergoing colonoscopy at six centers. Eligible patients were randomly assigned to conventional colonoscopy (control group) or AI-assisted colonoscopy (AI group). AI assistance was our newly developed AI system for real-time colonoscopic polyp detection. Primary outcome is polyp detection rate (PDR). Secondary outcomes include polyps per positive patient (PPP), polyps per colonoscopy (PPC), and non-first polyps per colonoscopy (PPC-Plus).

RESULTS

A total of 2352 patients were included in the final analysis. Compared with the control, AI group did not show significant increment in PDR (38.8% vs. 36.2%, p = 0.183), but its PPC-Plus was significantly higher (0.5 vs. 0.4, p < 0.05). In addition, AI group detected more diminutive polyps (76.0% vs. 68.8%, p < 0.01) and flat polyps (5.9% vs. 3.3%, p < 0.05). The effects varied somewhat between centers. In further logistic regression analysis, AI assistance independently contributed to the increment of PDR, and the impact was more pronounced for male endoscopists, shorter insertion time but longer withdrawal time, and elderly patients with larger waist circumference.

CONCLUSION

The intervention of AI plays a limited role in overall polyp detection, but increases detection of easily missed polyps; ChiCTR.org.cn number, ChiCTR1800015607.

Follow-up colonoscopy after an abnormal stool-based colorectal cancer screening result: analysis of steps in the colonoscopy completion process

Background

Delays in receiving follow-up colonoscopy after an abnormal fecal immunochemical test (FIT) result are associated with increased colorectal cancer incidence and mortality. Little is known about patterns of follow-up colonoscopy completion in federally qualified health centers.

Methods

We abstracted the medical records of health center patients, aged 50–75 years, who had an abnormal FIT result between August 5, 2017 and August 4, 2018 (N = 711). We assessed one-year rates of colonoscopy referral, pre-procedure visit completion, colonoscopy completion, and time to colonoscopy; associations between these outcomes and patient characteristics; and reasons for non-completion found in the medical record.

Results

Of the 711 patients with an abnormal FIT result, 90% were referred to colonoscopy, but only 52% completed a pre-procedure visit, and 43% completed a colonoscopy within 1 year. Median time to colonoscopy was 83 days (interquartile range: 52–131 days). Pre-procedure visit and colonoscopy completion rates were relatively low in patients aged 65–75 (vs. 50–64), who were uninsured (vs. insured) or had no clinic visit in the prior year (vs. ≥ 1 clinic visit). Common reasons listed for non-completion were that the patient declined, or the provider could not reach the patient.

Discussion

Efforts to improve follow-up colonoscopy rates in health centers might focus on supporting the care transition from primary to specialty gastroenterology care and emphasize care for older uninsured patients and those having no recent clinic visits. Our findings can inform efforts to improve follow-up colonoscopy uptake, reduce time to colonoscopy receipt, and save lives from colorectal cancer.

Trial registration: National Clinical Trial (NCT) Identifier: NCT03925883.

Retrospective Review of Multitarget Stool DNA as a Screening Test for Colorectal Cancer

OBJECTIVES

To review the effectiveness of noninvasive multitarget stool DNA testing as a screening test for colorectal cancer.

METHODS

We performed a retrospective review of patients referred to 2 high volume outpatient procedural centers for colonoscopy for positive Cologuard test. Positive findings for colorectal cancer based on pathologic findings and also advanced adenomas were recorded. Positive predictive value (PPV) was assessed.

RESULTS

Of the 1585 patients evaluated and referred for colonoscopy from January 1, 2018 to November 1, 2019, for ICD-10 codes R19.5 (other fecal abnormalities) and K92.1 (melena), 84 were referred for a positive Cologuard test. Out of the 84, 6 were excluded based on family history of colon cancer in first degree relative or personal history of inflammatory bowel disease. Of the remaining 78 patients, 1 patient (1.3%) had colorectal cancer and 5 (6.4%) had advanced adenomas (>1 cm size, high grade dysplasia or villous). Postive predictive value for colorectal cancer was 1.3% and for precancerous lesions plus colorectal cancer was 7.7%. A total of 53 (68.0%) patients had either totally normal colonoscopy or hyperplastic polyps. Out of the 78 individuals in our study, 70 (89.7%) had normal findings, hyperplastic polyps, or non-advanced adenomas.

CONCLUSIONS

Multitarget stool DNA testing carries an unacceptably low PPV to be utilized as a screening test for colorectal cancer. The study fails to detect both adenomas and colon cancer at a higher rate than screening colonoscopy in selected studies. The advantage of being noninvasive has been noted to increase colorectal cancer screening in otherwise non-compliant Medicare patients.

Resting heart rate is associated with colorectal advanced adenoma

Background and aims

Resting heart rate is an independent predictor of colorectal cancer (CRC) development and CRC-related mortality. However, little is known about the relationship between resting heart rate and colorectal adenoma development. We aimed to investigate this association in a population who underwent screening colonoscopy.

Methods

Among 39,021 patients who underwent both electrocardiogram and screening colonoscopy during routine health examinations at the Seoul National University Bundang Hospital, Health Promotion Center, Korea from January 2014 to July 2019, 1,344 patients had advanced adenoma. We performed 1:1 propensity score (PS) matching to establish a control group that mitigated the confounding effects of age and sex. We performed multivariate logistic regression analyses to identify the independent risk factors of advanced adenoma development.

Results

Resting heart rate was significantly higher in the advanced adenoma group than in the control group. The prevalence of advanced polyp increased across the quartiles of resting heart rate. Patients with higher resting heart rates were more likely to be older, smokers, and have increased blood pressure and DM and less likely to engage in active exercises than those with lower resting heart rates. Patients with higher resting heart rates had higher serum glucose, triglyceride, hemoglobin A1C, and insulin levels and lower high-density lipoprotein cholesterol levels. Patients with resting heart rate in the highest quartile (≥71 bpm) still showed significantly increased odds ratio (OR) of advanced adenoma development (OR: 1.379, 95% confidence interval: 1.099–1.731, p = 0.006).

Conclusions

High resting heart rate was a meaningful independent risk factor of advanced adenoma development.

Development and validation of a risk prediction model for high-risk adenomas at the time of first screening colonoscopy among screening aged Canadians

The aim of this study was to develop a risk prediction model for high risk adenomas (HRAs) detected at screening colonoscopy based on readily available participant information. The cohort consisted of 3035 participants aged 50 to 74 years with no history of cancer who underwent a primary screening colonoscopy at a centralized colon cancer screening centre between 2008 and 2016. A multivariable logistic regression model was created using CRC risk factors identified from prior research. Model covariates were collected from a baseline questionnaire and included participant demographics (age and sex), lifestyle parameters (body mass index, alcohol, smoking, and vitamin D supplement use) and medical history (family history of CRC and diabetes). Mean participant age was 58.8 years, and 54.7% were male. 249 participants with HRAs were identified (8.2%). An adjusted c-statistic of 0.67 was calculated, and a specificity and negative predictive value of 97.2% (95% CI: 96.5-97.8) and 92.5% (95% CI: 92.2-92.8) for the detection of HRAs, respectively, were achieved using 20% predicted probability as a high-risk threshold. However, only a sensitivity of 12.1% (95% CI: 8.3-16.8) was achieved. Our model has moderate predictive ability, with strengths in being able to rule out those with an absence of HRAs on screening colonoscopy. Maximizing screening efficiency through improved risk prediction can enhance resource allocation. Ultimately, this model has the potential to improve patient care by reducing unnecessary colonoscopies, limiting this invasive procedure to those most likely to have significant findings.

Automatic colonic polyp detection using integration of modified deep residual convolutional neural network and ensemble learning approaches

BACKGROUND AND OBJECTIVE

The increased incidence of colorectal cancer (CRC) and its mortality rate have attracted interest in the use of artificial intelligence (AI) based computer-aided diagnosis (CAD) tools to detect polyps at an early stage. Although these CAD tools have thus far achieved a good accuracy level to detect polyps, they still have room to improve further (e.g. sensitivity). Therefore, a new CAD tool is developed in this study to detect colonic polyps accurately.

METHODS

In this paper, we propose a novel approach to distinguish colonic polyps by integrating several techniques, including a modified deep residual network, principal component analysis and AdaBoost ensemble learning. A powerful deep residual network architecture, ResNet-50, was investigated to reduce the computational time by altering its architecture. To keep the interference to a minimum, median filter, image thresholding, contrast enhancement, and normalisation techniques were exploited on the endoscopic images to train the classification model. Three publicly available datasets, i.e., Kvasir, ETIS-LaribPolypDB, and CVC-ClinicDB, were merged to train the model, which included images with and without polyps.

RESULTS

The proposed approach trained with a combination of three datasets achieved Matthews Correlation Coefficient (MCC) of 0.9819 with accuracy, sensitivity, precision, and specificity of 99.10%, 98.82%, 99.37%, and 99.38%, respectively.

CONCLUSIONS

These results show that our method could repeatedly classify endoscopic images automatically and could be used to effectively develop computer-aided diagnostic tools for early CRC detection.

The Prognostic Significance of c-Met and p53 Immunohistochemical Expression in Gastric and Colorectal Carcinomas

BACKGROUND: Colorectal and gastric carcinomas are the most common and deadly gastrointestinal (GIT) malignancies. AIM: This study aimed to evaluate the expression of c-Met and p53 in gastric and colorectal carcinomas (CRCs) as well as colorectal adenomas using immunohistochemistry. MATERIALS AND METHODS: c-Met and p53 immunohistochemical expression was conducted on 66 cases of gastric adenocarcinomas and total of 60 colonic cases (36 CRCs and 24 colorectal adenomas). RESULTS: In this study, c-Met was positively expressed in 54.5% of gastric carcinomas and 50% of CRCs. In addition, p53 was positively expressed in 56.1% of gastric carcinomas and 72.2% of CRCs. Moreover, higher expression of both c-Met (p = 0.001) and p53 expression (p < 0.001) was reported in CRCs compared to colorectal adenomas. In the same context, c-Met and p53 expressions were positively correlated with intestinal type gastric adenocarcinoma (p < 0.001 and p = 0.03, respectively). Moreover, c-Met was correlated with non-mucinous adenocarcinomas (p = 0.008) and lower grades (p < 0.001) of gastric carcinomas. As regard survival analysis in gastric carcinomas, median overall survival (OS) was better in p53 positive patients (p = 0.05), patients with negative lymph node metastasis (p = 0.03), and patients with better response to neoadjuvant chemotherapy (p = 0.04). In contrast, c-Met did not exhibit significant correlation with OS (p > 0.05). Both c-Met and p53 did not reveal significant correlation with tumor stage and site in both CRCs and gastric carcinomas (p > 0.05). CONCLUSION: We concluded that c-Met and p53 are expressed in the most common GIT malignancies addressing them as potential biomarkers. In addition, c- Met and p53 may have a potential role in colorectal cancer development as they showed higher positivity in CRCs compared to adenomas.

Referrals for surgical removal of polyps since the introduction of a colorectal cancer screening programme

AIM

Implementation of the Dutch national bowel screening programme in 2014 led to an increased rate of detection of polyps. In general, polyps should be removed endoscopically. However, if the size and location of the polyp make endoscopic removal technically difficult, or if there is a suspicion for early (T1) cancer, surgery is the preferred method for removal. An increasing number of these patients are being treated with minimally invasive surgical procedures instead of segmental resection. The aim of this study was to assess the number of referrals for surgery and the type of surgery for polyps since the introduction of the Dutch national bowel screening programme.

METHOD

A retrospective cohort study was performed. Patients who underwent surgery for colorectal polyps between January 2012 and December 2017 were included. Patients with histologically proven carcinoma prior to surgery were excluded. Primary outcomes were the number and type of surgical procedures for polyps.

RESULTS

A total of 164 patients were included. An annual increase in procedures for colorectal polyps was observed, from 18 patients in 2012 to 36 patients in 2017. All the procedures before implementation of the screening programme were segmental resections, and 58.8% of the patients underwent organ-preserving surgery after implementation of the screening. The overall complication rate of organ-preserving surgery was 16.3%, compared with 44.3% for segmental resections (P = 0.001). Overall, invasive colorectal cancer was encountered in 23.8% of cases.

CONCLUSION

The number of referrals for surgical resection of colorectal polyps has doubled since the introduction of the Dutch national bowel screening programme with a substantial shift towards organ-preserving techniques.

Histopathological and epidemiological findings of colonoscopy screening in a population with an average risk of colorectal cancer in Kuwait

BACKGROUND

Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men worldwide, with a significantly rising incidence in the Middle East region over the last few decades. This study investigates the histopathological and epidemiological characteristics of colonoscopic findings in a population with an average risk of CRC in Kuwait.

METHODS

In this study, 1,005 asymptomatic average-risk Kuwaiti adults aged over 40 years had their first colonoscopy screening during the 2015-2018 period. Data on lifestyle behaviors (cigarette smoking, alcohol consumption, and physical activity), body mass index (BMI), and comorbidities were routinely collected from these individuals. All colorectal polyps or masses were assessed for their site, size, and number and then resected and sent for histopathological examination.

RESULTS

The mean age of the participants was 54 years, and 52.2% were women. In screened individuals, the polyp detection rate, adenoma detection rate, and carcinoma detection rate were 43.8%, 27.7%, and 1.2%, respectively. Tubular, tubulovillous, and villous types of adenoma constituted 17.3%, 2.8%, and 1.3% of all screened participants. Neoplastic lesions, particularly in the proximal colon, were more common among men aged 40-49 years. Age of 70 years and older (OR: 9.6; 95% CI: 4.7-19.9; P < 0.001), male gender (OR: 1.6; 95% CI: 1.1-2.3; P = 0.011), increased BMI (OR: 1.05; 95% CI: 1.02-1.08; P = 0.001), and smoking (OR: 3.5; 95% CI: 2.3-5.4; P < 0.001) were the most significant independent risk factors for colorectal neoplasia.

CONCLUSIONS

The high adenoma detection rate (ADR) in Kuwaiti population calls for the establishment of a national programe for CRC screening. The higher ADR in those younger than 50 years calls for assessment of the threshold age at which to start screening.

Young-onset colorectal cancer risk among individuals with iron-deficiency anaemia and haematochezia

OBJECTIVE

Young-onset colorectal cancer (YCRC) incidence is rising. Scant data exist on YCRC risk after presentation with concerning symptoms such as iron-deficiency anaemia (IDA) or haematochezia. We examined the association between IDA and YCRC, and haematochezia and YCRC.

DESIGN

Cohort study of US Veterans aged 18-49 years receiving Veterans Health Administration (VHA) care 1999-2016. IDA analytic cohort was created matching individuals without incident IDA to those with IDA 4:1 based on sex, birth year and first VHA visit date (n=239 000). We used this approach to also create a distinct haematochezia analytic cohort (n=653 740). Incident YCRC was ascertained via linkage to cancer registry and/or cause-specific mortality data. We computed cumulative incidence, risk difference (RD) and HRs using Cox models in each cohort.

RESULTS

Five-year YCRC cumulative incidence was 0.45% among individuals with IDA versus 0.05% without IDA (RD: 0.39%, 95% CI: 0.33%-0.46%), corresponding to an HR of 10.81 (95% CI: 8.15-14.33). Comparing IDA versus no IDA, RD was 0.78% for men (95% CI: 0.64%-0.92%) and 0.08% for women (95% CI: 0.03%-0.13%), and RD increased by age from 0.14% for <30 years to 0.53% for 40-49 years. YCRC cumulative incidence was 0.33% among individuals with haematochezia versus 0.03% without haematochezia (RD: 0.30%, 95% CI: 0.26%-0.33%), corresponding to an HR of 10.66 (95% CI: 8.76-12.97). Comparing haematochezia versus no haematochezia, RD increased by age from 0.04% for <30 years to 0.43% for 40-49 years.

CONCLUSION

Colonoscopy should be strongly considered in adults aged <50 years with IDA or haematochezia without a clinically confirmed alternate source.

Risk prediction rule for advanced neoplasia on screening colonoscopy for average-risk individuals

BACKGROUND

In resource-limited countries, risk stratification can be used to optimize colorectal cancer screening. Few prospective risk prediction models exist for advanced neoplasia (AN) in true average-risk individuals.

AIM

To create and internally validate a risk prediction model for detection of AN in average-risk individuals.

METHODS

Prospective study of asymptomatic individuals undergoing first screening colonoscopy. Detailed characteristics including diet, exercise and medications were collected. Multivariate logistic regression was used to elucidate risk factors for AN (adenoma ≥1 cm, villous histology, high-grade dysplasia or carcinoma). The model was validated through bootstrapping, and discrimination and calibration of the model were assessed.

RESULTS

980 consecutive individuals (51% F; 49% M) were enrolled. Adenoma and AN detection rates were 36.6% (F 29%: M 45%; P < 0.001) and 5.1% (F 3.8%; M 6.5%) respectively. On multivariate analysis, predictors of AN [OR (95%CI)] were age [1.036 (1.00-1.07); P = 0.048], BMI [overweight 2.21 (0.98-5.00); obese 3.54 (1.48-8.50); P = 0.018], smoking [< 40 pack-years 2.01 (1.01-4.01); ≥ 40 pack-years 3.96 (1.86-8.42); P = 0.002], and daily red meat consumption [2.02 (0.92-4.42) P = 0.079]. Nomograms of AN risk were developed in terms of risk factors and age separately for normal, overweight and obese individuals. The model had good discrimination and calibration.

CONCLUSION

The prevalence of adenoma and AN in average-risk Lebanese individuals is similar to the West. Age, smoking, and BMI are important predictors of AN, with obesity being particularly powerful. Though external validation is needed, this model provides an important platform for improved risk-stratification for screening programs in regions where universal screening is not currently employed.

ACE (Angiotensin-Converting Enzyme) Inhibitors/Angiotensin Receptor Blockers Are Associated With Lower Colorectal Cancer Risk: A Territory-Wide Study With Propensity Score Analysis

Whether ACE (angiotensin-converting enzyme) inhibitors and angiotensin receptor blockers modify colorectal cancer risk remains controversial. We aimed to determine association between their use and colorectal cancer risk after a negative baseline colonoscopy. This is a territory-wide retrospective cohort study recruiting patients aged ≥40 who had undergone colonoscopy between 2005 and 2013. Exclusion criteria included colorectal cancer detected <6 months of index colonoscopy, prior colorectal cancer, inflammatory bowel disease, and prior colectomy. The primary outcome was colorectal cancer diagnosed between 6 and 36 months after index colonoscopy. Sites of colorectal cancer were categorized as proximal (proximal to splenic flexure) and distal cancer. The adjusted hazard ratio of colorectal cancer with ACE inhibitor/angiotensin receptor blocker use (≥180-day use within 5 years before index colonoscopy) was derived by propensity score regression adjustment of 23 covariates (including patient's factors, concurrent medication use, and endoscopy center's performance). Of 187 897 eligible patients, 30 856 (16.4%) were ACE inhibitors/angiotensin receptor blocker users. Eight hundred fifty-four (0.45%) developed colorectal cancer between 6 and 36 months after index colonoscopy (proximal cancer: 147 [17.2%]). These drugs were associated with lower risk of colorectal cancer that developed <3 years after index colonoscopy (adjusted hazard ratio, 0.78 [95% CI, 0.64-0.96]), but not colorectal cancer that developed >3years (adjusted hazard ratio, 1.18 [95% CI, 0.88-1.57]); every single year increase in the drug use was associated with 5% reduction in adjusted hazard ratio risk. ACE inhibitors/angiotensin receptor blocker were associated with a lower colorectal cancer risk in a duration-response manner.

Endoscopic Management of a Tubulovillous Adenoma Within a Diverticulum: Report of a Case and Review of Literature

Adenomas or adenocarcinomas located within a colonic diverticulum are considered a rare phenomenon that has been described in the literature. These lesions are technically difficult to manage endoscopically and usually require surgical intervention for removal. There is also an increased risk of perforation upon endoscopic resection owing to the lack of a muscular layer within the diverticulum. We report a case and include a literature review to evaluate different endoscopic techniques and propose the most effective for management of adenomas within a diverticulum. This technique is potentially comprised of employing a combined approach using a suction banding device, an over-the-scope clip (OTSC; Ovesco Endoscopy AG, Tübingen, Germany) , and hyperthemic snare to successfully remove the polyp, ensure tissue retrieval, and reduce risk of iatrogenic colonic perforation.

A Retrospective Analysis of Gender-Based Difference in Adherence to Initial Colon Cancer Screening Recommendations

Background: Colorectal cancer (CRC) is the fourth leading cause of cancer-related death in the United States, despite being largely preventable and treatable. Improving overall screening rates among both men and women is considered an important and effective strategy toward reducing morbidity and mortality from CRC. In order to optimize screening strategies, factors associated with decreased compliance need to be understood. This study aimed to compare initial CRC screening rates between males and females in a population of patients who presented for an annual physical examination. Methods: A retrospective chart review study of 380 patients designed to compare rates of initial CRC screening between males and females was conducted. Patients who were seen at our institution for an annual physical examination and were between 51 and 60 years of age were included. Results: There was no evidence of a difference in the rate of initial colon cancer screening between females (83.0%) and males (80.9%) in either unadjusted analysis (odds ratio = 1.16, P = .59) or in multivariable analysis adjusting for potential confounding variables (odds ratio = 1.16, P = .61). Conclusions: There was no significant difference in the rate of initial CRC screening between males and females who presented for an annual physical examination. This suggests that designing interventions to improve screening specific to gender may not be needed in a population of patients who attend routine preventive health examinations. Further study is needed in the general population to examine for gender-based differences in initial CRC screening among patients who do not regularly follow up for preventive examinations.

Recurrence with malignancy after endoscopic resection of large colon polyps with high-grade dysplasia: incidence and risk factors

BACKGROUND

In the West, piecemeal endoscopic resection remains the primary treatment for large colon polyps (LCP), as most recurrences are believed to be benign and resectable with follow-up endoscopy. However, invasive malignancy at the site of prior piecemeal endoscopic mucosal resection has been reported in the Asian literature. This study aims to identify the incidence of and the risk factors for local recurrence with malignancy after endoscopic resection of LCP with high-grade dysplasia (HGD).

METHODS

In this retrospective cohort study, we identified patients undergoing complete endoscopic resection of LCPs (≥ 20 mm) with HGD at the Cleveland Clinic between January 2000 and December 2016. Demographic, endoscopic, and pathologic data were collected. All subsequent endoscopic and pathology reports were reviewed to identify recurrence. The cumulative incidence of malignancy at the polypectomy site was determined and univariate analysis was performed to assess risk factors.

RESULTS

A total of 254 LCPs with HGD were resected in 229 patients. Mean polyp size was 29.2 mm. There were 138 lesions resected in piecemeal fashion and 116 en-bloc. After a median follow-up of 28.7 months for the entire cohort, local recurrence with malignancy was diagnosed in six cases. Median time to malignancy diagnosis was 28.5 months. All malignant cases occurred after piecemeal resection and none after en-bloc resection (HR 11.4; 95% CI 0.48-273).

CONCLUSION

Malignancy after endoscopic resection of LCPs with HGD is uncommon and may be associated with piecemeal resection. When possible, en-bloc resection should be the goal for the management of LCPs.

Hospital Prevalence of Colorectal Cancer among Colonoscopy Recipients Attending a Tertiary Hospital in Oman: A Cross-Sectional Study

Purpose

Evidence from industrialized/developed countries showed that colorectal cancer (CRC) incidence rates have significantly dropped due to the widespread use of colonoscopy. In Arab countries, however, the CRC had been reported to have increased. Despite the concerted effort in the primary prevention and widespread use of colonoscopy, to our knowledge, there have been no reports of the prevalence rate of CRC among colonoscopy recipients from Oman. This study aims to explore the CRC prevalence estimates over selected sociodemographic characteristics among colonoscopy-recipients at a tertiary hospital in Oman over five years of follow-up. The regional variations in Oman were also examined in this study.

Methods

This hospital-based cross-sectional study reviewed reports of colonoscopies performed over 5-years of retrospective follow-up at a tertiary hospital in Oman. CRC prevalence estimates were calculated over age, gender, governorate, and time of follow-up.

Results

A total of 442 CRC cases were enumerated among 3701 colonoscopies, with an overall CRC prevalence estimate of 11.9 per 100 colonoscopies (95% CI: 10.9, 13.0). Gender-specific CRC prevalence was higher among males compared with females (13.3 vs. 10.5). Age-specific CRC prevalence increased with advancing age, from 2.8 among those less than 40 years of age to 26.5 among aged 70 years or more. Regional CRC prevalence was highest among residents in Batinah Governorate. Over the 5-years of follow-up, there was a slow rise in CRC prevalence with an annual increment of 0.59%.

Conclusion

The study provides supportive evidence for a steady increase in CRC prevalence over age categories and years of follow-up and depicted the variations of gender-specific CRC prevalence estimates over increasing age categories. The study calls for timely formulation and adoption of national CRC screening programs centered on the colonoscopy use as primary prevention and maximizing its utilization and efficiency.

Nonsteroidal anti-inflammatory drugs but not aspirin are associated with a lower risk of post-colonoscopy colorectal cancer

BACKGROUND

Although nonsteroidal anti-inflammatory drugs (NSAIDs) reduce colorectal cancer (CRC) risk, their role in preventing post-colonoscopy CRC (PCCRC) remains undetermined.

AIMS

To investigate whether NSAIDs reduce PCCRC risk after a negative baseline colonoscopy METHODS: This is a retrospective cohort study based on a territory-wide healthcare database of Hong Kong. All patients (aged 40 or above) who underwent colonoscopies between 2005 and 2013 were identified. Exclusion criteria included CRC detected within 6 months of index colonoscopy, prior CRC, inflammatory bowel disease and prior colectomy. The primary outcome was PCCRC-3y diagnosed between 6 and 36 months after index colonoscopy. Sites of CRC were categorised as proximal (proximal to splenic flexure) and distal. The adjusted hazards ratio (aHR) of PCCRC-3y with NSAID and aspirin use (defined as cumulative use for ≥90 days within 5 years before index colonoscopy) was derived by propensity score (PS) regression adjustment of 22 covariates (including patient factors, concurrent medication use and endoscopy centre's performance).

RESULTS

Of 187 897 eligible patients, 21 757 (11.6%) were NSAID users. 854 (0.45%) developed PCCRC-3y (proximal cancer: 147 [17.2%]). NSAIDs were associated with a lower PCCRC-3y risk (aHR: 0.54, 95% CI: 0.41-0.70), but not CRC that developed >3 years (aHR: 0.78, 95% CI 0.56-1.09). The aHR was 0.48 (95% CI: 0.24-0.95) for proximal and 0.55 (95% CI: 0.40-0.74) for distal cancer. A duration- and frequency response relationship was observed (P_trend  < 0.001). For aspirin, the aHR was 1.01 (95% CI: 0.80-1.28).

CONCLUSIONS

Non-aspirin NSAIDs were associated with lower PCCRC risk after a negative baseline colonoscopy.

Prevalence and risk factors for colorectal polyps in a Chinese population: a retrospective study

The incidence of colorectal polyps is rising. Certain types of polyps are considered to be the precursor lesions for colorectal cancers. To investigate the prevalence and related factors of colorectal polyps in Chinese subjects, we first performed a cross-sectional study. A total of 3066 subjects were documented, and the prevalence of colorectal polyps was 18.1%. Then we evaluated the incidence and risk factors of polyps via a retrospective cohort study in the same population. 561 subjects who received at least twice surveillance colonoscopies with available reports during the study period and had no polyp at the first endoscopy were included in the retrospective cohort study, of whom 19.1% developed colorectal polyps. Regular smoking was independently associated with the presence and development of colorectal polyps. Further analyses indicated that polyps were associated with smoking status, daily cigarette consumption, and drinking habit. Moreover, smoking tends to be more relavent to rectal, small and single polyp. In conclusion, colorectal polyp is a common disease in China. Exploring the epidemiology and risk factors may improve the prevention of colorectal polyps, even colorectal cancer.

The two-week rule colorectal cancer pathway: an update on recent practice, the unsustainable burden on diagnostics and the role of faecal immunochemical testing

INTRODUCTION

Survival for colorectal cancer is improved by earlier detection. Rapid assessment and diagnostic demand have created a surge in two-week rule referrals and have subsequently placed a greater burden on endoscopy services. Between 2009 and 2014, a mean of 709 patients annually were referred to Royal Surrey County Hospital with a detection rate of 53 cancers per year giving a positive predictive value for these patients of 7.5%. We aimed to assess what impact the 2015 changes in National Institute for Health and Care Excellence referral criteria had on local cancer detection rate and endoscopy services.

METHODS

A prospectively maintained database of patients referred under the two-week rule pathway for April 2017-2018 was sub-analysed and the data cross-referenced with all diagnostic reports.

FINDINGS

There were 1,414 referrals, which is double the number of previous years; 80.6% underwent endoscopy as primary investigation and 62 cancers were identified, 51 being of colorectal and anal origin (positive predictive value 3.6%). A total of 88 patients were diagnosed, with other significant colorectal disease defined as high-risk adenomas, colitis and benign ulcers. Overall, a total of 10.6% of our two-week rule patients had a significant finding.Since the 2015 referral criteria, despite a dramatic rise in two-week rule referrals, there has been no increase in cancer detection. It has placed significant pressure on diagnostic services. This highlights the need for a less invasive, cheaper yet sensitive test to rule out cancer such as faecal immunochemical testing that can enable clinicians to triage and reduce referral to endoscopy in symptomatic patients.

Global Prevalence of Colorectal Neoplasia: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Most colorectal cancers (CRC) arise from colorectal adenomas, yet there is not enough information on global prevalence to inform health care policy. We examined the prevalence of any type of adenomas, advanced adenomas (AADs), and CRC according to age, sex, ethnicity, geographic regions, and anatomic location (proximal vs distal).

METHODS

MEDLINE and Embase were searched from their inception through May 1, 2018, to identify population-based, observational studies that reported the prevalence of colorectal neoplasia. Studies on participants 15 years or older, with a sample size of 500 persons or more, were included. Metaprop (College Station, TX) was used to model within-study variability by binomial distribution and Freeman-Tukey Double Arcsine Transformation to stabilize the variances. The prevalence figures were presented by proportions and their 95% CIs using random-effects models.

RESULTS

Our meta-analysis included 70 studies involving 637,414 individuals. The overall prevalence rates of adenoma (23.9%; 95% CI, 22.2%-25.8%), AAD (4.6%; 95% CI, 3.8%-5.5%), and CRC (0.4%, 95% CI, 0.3%-0.5%) were calculated. Subgroup analysis indicated that prevalence values (adenomas, AADs, and CRCs) were higher among men (29.7%, 6.5%, and 0.8%, respectively) than women (19.3%, 3.8% and 0.4%, respectively), among older adults (25.9%, 5.2%, and 0.6%, respectively) than younger adults (14.6%, 1.6%, and 0.1%, respectively), among Caucasians (23.7%, 6.6%, and 0.5%, respectively) than other ethnicities, in European countries (25.9%, 8.4%, and 0.8%, respectively) than other countries, and among patients with proximal (25.9%, 5.3%, and 0.1%, respectively) vs distal neoplasia.

CONCLUSIONS

In a systematic review and meta-analysis, we found a high prevalence of colorectal neoplasia among some populations. This indicates a need to expand CRC screening programs for these groups. The pooled prevalence estimates can be used as quality indicators for established CRC screening programs.