Colorectal Cancer Screening: Recommendations for Physicians and Patients From the U.S. Multi-Society Task Force on Colorectal Cancer

Summary of The Third Capsule Endoscopy Global Summit

In order to emphasize the epidemic prevention during capsule endoscopy examinations, exhibit the latest achievements of capsule endoscopy, and strengthen international exchanges and cooperation in capsule endoscopy products, quality control, R&D, clinical applications, and talents, The Third Capsule Endoscopy Global Summit was held in Chongqing, China. The summit invited foreign experts to live online and remotely broadcast special academic speeches. The invited domestic experts brought the latest academic reports on the spot. A total of 17 medical experts presented a number of latest technologies and academic achievements in the field of capsule endoscopy from five levels. Professor Xue-Liang Jiang, President of the World Chinese Digestive Society and Editor-in-Chief of the World Chinese Journal of Digestology, was invited to give a report on the clinical application of capsule endoscopy.

[Application of artificial intelligence for detection and classification of colon polyps]

Colorectal cancer is one of the most common cancers worldwide, and colonoscopy has proven to be a preferable modality for screening and surveillance of colorectal cancer. This review discusses the clinical application of artificial intelligence (AI) and computer-aided diagnosis for automated colonoscopic detection and diagnosis of colorectal polyps for better understanding of the application of AI-based computer-aided diagnosis systems especially in terms of machine learning, deep learning and convolutional neural network for screening and surveillance of colorectal cancer.

Machine Learning-based Differentiation of Benign and Premalignant Colorectal Polyps Detected with CT Colonography in an Asymptomatic Screening Population: A Proof-of-Concept Study

Background CT colonography does not enable definite differentiation between benign and premalignant colorectal polyps. Purpose To perform machine learning-based differentiation of benign and premalignant colorectal polyps detected with CT colonography in an average-risk asymptomatic colorectal cancer screening sample with external validation using radiomics. Materials and Methods In this secondary analysis of a prospective trial, colorectal polyps of all size categories and morphologies were manually segmented on CT colonographic images and were classified as benign (hyperplastic polyp or regular mucosa) or premalignant (adenoma) according to the histopathologic reference standard. Quantitative image features characterizing shape (n = 14), gray level histogram statistics (n = 18), and image texture (n = 68) were extracted from segmentations after applying 22 image filters, resulting in 1906 feature-filter combinations. Based on these features, a random forest classification algorithm was trained to predict the individual polyp character. Diagnostic performance was validated in an external test set. Results The random forest model was fitted using a training set consisting of 107 colorectal polyps in 63 patients (mean age, 63 years ± 8 [standard deviation]; 40 men) comprising 169 segmentations on CT colonographic images. The external test set included 77 polyps in 59 patients comprising 118 segmentations. Random forest analysis yielded an area under the receiver operating characteristic curve of 0.91 (95% CI: 0.85, 0.96), a sensitivity of 82% (65 of 79) (95% CI: 74%, 91%), and a specificity of 85% (33 of 39) (95% CI: 72%, 95%) in the external test set. In two subgroup analyses of the external test set, the area under the receiver operating characteristic curve was 0.87 in the size category of 6-9 mm and 0.90 in the size category of 10 mm or larger. The most important image feature for decision making (relative importance of 3.7%) was quantifying first-order gray level histogram statistics. Conclusion In this proof-of-concept study, machine learning-based image analysis enabled noninvasive differentiation of benign and premalignant colorectal polyps with CT colonography. © RSNA, 2021 Online supplemental material is available for this article.

A Safety and Efficacy Comparison of a New Sulfate-Based Tablet Bowel Preparation Versus a PEG and Ascorbate Comparator in Adult Subjects Undergoing Colonoscopy

INTRODUCTION

A new tablet-based bowel prep for colonoscopy has been developed containing poorly absorbed sulfate salts which act to retain water within the intestinal lumen resulting in a copious diarrhea, thereby cleansing the bowel. This study evaluated the safety and efficacy of these oral sulfate tablets (OST) compared with a US FDA-approved bowel prep solution containing PEG3350, electrolytes, and ascorbate (polyethylene glycol and ascorbate [PEG-EA]).

METHODS

Five hundred fifteen adult patients (mean 57y) were enrolled in this single-blind, multicenter, noninferiority study. Subjects were assigned either PEG-EA or OST to be administered in a split-dose regimen starting the evening before colonoscopy. PEG-EA was taken according to its approved labeling (1 L of prep solution with 16 oz. of additional water) in the evening and again in the morning. OST patients took a total of 24 tablets. OST patients were administered 12 tablets in the evening, and the following morning. Patients consumed 16 ounces of water with each dose of 12 tablets and drank an additional 32 oz. of water with each dose. Colonoscopies were performed by blinded investigators. Cleansing efficacy was evaluated globally and segmentally using a 4-point scale (Excellent-no more than small bits of feces/fluid which can be suctioned easily; achieves clear visualization of the entire colonic mucosa. Good-feces and fluid requiring washing and suctioning, but still achieves clear visualization of the entire colonic mucosa. Fair-enough feces even after washing and suctioning to prevent clear visualization of the entire colonic mucosa. Poor-large amounts of fecal residue and additional bowel preparation required). Scores of Good or Excellent were considered to be a success. Safety was assessed by spontaneously reported adverse events, solicited ratings of expected prep symptoms, and laboratory testing.

RESULTS

A high rate of cleansing success was seen with OST (92%), which was noninferior to PEG-EA (89%). Only a small proportion of subjects rated their expected gastrointestinal symptoms as severe (<5% for both preps). No clinically significant differences were seen between preps for chemistry and hematology parameters. No serious adverse experiences were reported with OST.

DISCUSSION

Sulfate tablets achieved a high level of cleansing in the study, comparable with US FDA-approved preps. OST was noninferior to PEG-EA in this study and achieved significantly more Excellent preps overall and in the proximal colon. The OST prep was well-tolerated, with a similar rate of spontaneously reported adverse experiences to PEG-EA and a low rate of severe expected gastrointestinal symptoms.

Long-Term Incidence and Mortality of Colorectal Cancer After Endoscopic Biopsy With Normal Mucosa: A Swedish-Matched Cohort Study

INTRODUCTION

Endoscopic screening reduces colorectal cancer (CRC) incidence and mortality. Individuals with a negative result are recommended to undergo rescreening within a 10-year interval, but evidence supporting this advice is limited.

METHODS

We performed a matched cohort study using prospectively collected data from 88,798 individuals in Sweden with normal mucosa at the first colorectal biopsy (aged ≥50 years) in the nationwide gastrointestinal epidemiology strengthened by histopathology reports (ESPRESSO) (1965-2016) and 424,150 matched reference individuals from the general population. Cox proportional hazards regression estimated multivariable hazard ratios and 95% confidence intervals (CIs) of CRC incidence and mortality of incident CRCs up to 44 years of follow-up.

RESULTS

In the normal biopsy and reference groups, respectively, the 20-year incidences of CRC were 3.03% and 4.53% and the 20-year mortalities of incident CRC were 0.89% and 1.54%. The multivariable hazard ratio comparing the normal biopsy and reference groups was 0.62 for CRC incidence (95% CI = 0.58-0.66, P < 0.001) and 0.56 for mortality of incident CRC (95% CI = 0.49-0.64, P < 0.001). When assessed by time interval after biopsy, lower CRC incidence and mortality were observed throughout the follow-up. The association seemed weaker for proximal colon cancer than for rectal and distal colon cancer.

DISCUSSION

A normal colorectal biopsy was associated with lower CRC incidence and mortality for at least 20 years after the examination. Our findings confirm previous data and suggest that the screening intervals after a normal colonoscopy could be longer than the commonly recommended 10 years. It may be time to open the discussion for a revision of the international guidelines.

KCNQ5 and C9orf50 Methylation in Stool DNA for Early Detection of Colorectal Cancer

Background

Aberrant DNA methylation has emerged as a class of promising biomarkers for early colorectal cancer (CRC) detection, but the performance of methylated C9orf50 and methylated KCNQ5 in stool DNA has never been evaluated.

Methods

Methylation specific quantitative PCR (qPCR) assays for methylated C9orf50 and methylated KCNQ5 were developed. The methylation levels of C9orf50 and KCNQ5 in 198 CRC patients, 20 advanced adenoma (AA) patients, 101 small polyp (SP) patients, and 141 no evidence of disease (NED) subjects were analyzed.

Results

The methylation levels of both KCNQ5 and C9orf50 genes were significantly higher in CRC and AA groups than those in SP and NED groups, but showed no significant difference among different stages of CRC. The sensitivities of methylated KCNQ5 and methylated C9orf50 for CRC detection were 77.3% (95% CI: 70.7–82.8%) and 85.9% (95% CI: 80.0–90.2%) with specificities of 91.5% (95% CI: 85.3–95.3%) and 95.0% (95% CI: 89.7–97.8%), respectively. When C9orf50 and methylated KCNQ5 were combined, the clinical performance for CRC detection was similar to that of methylated C9orf50 alone.

Conclusions

Stool DNA based methylated C9orf50 test has the potential to become an alternative approach for CRC screening and prevention.

Advanced adenomas may be a red flag for hereditary cancer syndromes

Background

16–25% of colorectal cancers (CRCs) diagnosed under age 50 are associated with hereditary cancer syndromes. Advanced adenomas are considered precursors to CRC. Although polyp removal prevents cancer, polypectomy does not change underlying genetic risk. Patients with isolated advanced polyps do not currently qualify for genetic testing unless they have a personal or family history of cancer.

Aim

Describe the prevalence of hereditary cancer syndromes among patients with advanced colorectal polyps.

Methods

We performed a single center retrospective review from 2015 to 2019 of patients who underwent germline genetic testing with indication for testing listed as colorectal polyp. We excluded patients with a personal history of CRC and those with ≥10 cumulative polyps. We collected patient demographics, polyp characteristics, family history data and genetic testing results from the medical record. Discrete variables were reported as frequency and percentages and continuous variables reported as mean with range.

Results

A total of 42 patients underwent genetic testing due to a personal history of advanced adenoma. 17% of patients met current genetic testing criteria. All patients underwent multi-gene panel testing. Two patients (4.8%) had a germline pathogenic mutation (one in MLH1 and one in CHEK2). The patient with an MLH1 mutation met current criteria for genetic testing (PREMM5 score 5.8), however the patient with the CHEK2 mutation did not. Both mutation carriers had a personal history of synchronous or metachronous advanced adenomas. 38% had a variant of uncertain significance.

Conclusions

5% of patients with advanced adenomas in our retrospective series had a pathogenic germline mutation in a cancer predisposition gene. Though the patient with a pathogenic mutation in MLH1 met current clinical criteria for genetic testing, this was not recognized prior to referral; he was referred based on a personal history of advanced adenoma. Advanced polyps may be a red flag to identify patients who are at risk for hereditary cancer syndromes.

Adoption of Multi-society Guidelines Facilitates Value-Based Reduction in Screening and Surveillance Colonoscopy Volume During COVID-19 Pandemic

BACKGROUND

COVID-19 has caused a backlog of endoscopic procedures; colonoscopy must now be prioritized to those who would benefit most. We determined the proportion of screening and surveillance colonoscopies appropriate for rescheduling to a future year through strict adoption of US Multi-Society Task Force (USMSTF) guidelines.

METHODS

We conducted a single-center observational study of patients scheduled for "open-access colonoscopy"-ordered by a primary care provider without being seen in gastroenterology clinic-over a 6-week period during the COVID-19 pandemic. Each chart was reviewed to appropriately assign a surveillance year per USMSTF guidelines including demographics, colonoscopy history and family history. When guidelines recommended a range of colonoscopy intervals, both a "conservative" and "liberal" guideline adherence were assessed.

RESULTS

We delayed 769 "open-access" screening or surveillance colonoscopies due to COVID-19. Between 14.8% (conservative) and 20.7% (liberal), colonoscopies were appropriate for rescheduling to a future year. Conversely, 415 (54.0%) patients were overdue for colonoscopy. Family history of CRC was associated with being scheduled too early for both screening (OR 3.9; CI 1.9-8.2) and surveillance colonoscopy (OR 2.6, CI 1.0-6.5). The most common reasons a colonoscopy was inappropriately scheduled this year were failure to use new surveillance colonoscopy intervals (28.9%), incorrectly applied family history guidelines (27.2%) and recommending early surveillance colonoscopy after recent normal colonoscopy (19.3%).

CONCLUSION

Up to one-fifth of patients scheduled for "open-access" colonoscopy can be rescheduled into a future year based on USMSTF guidelines. Rigorously applying guidelines could judiciously allocate colonoscopy resources as we recover from the COVID-19 pandemic.

A Meta-Analysis of Proteomic Blood Markers of Colorectal Cancer

BACKGROUND

Early diagnosis will significantly improve the survival rate of colorectal cancer (CRC); however, the existing methods for CRC screening were either invasive or inefficient. There is an emergency need for novel markers in CRC's early diagnosis. Serum proteomics has gained great potential in discovering novel markers, providing markers that reflect the early stage of cancer and prognosis prediction of CRC. In this paper, the results of proteomics of CRC studies were summarized through a meta-analysis in order to obtain the diagnostic efficiency of novel markers.

METHODS

A systematic search on bibliographic databases was performed to collect the studies that explore blood-based markers for CRC applying proteomics. The detection and validation methods, as well as the specificity and sensitivity of the biomarkers in these studies, were evaluated. Newcastle- Ottawa Scale (NOS) case-control studies version was used for quality assessment of included studies.

RESULTS

Thirty-four studies were selected from 751 studies, in which markers detected by proteomics were summarized. In total, fifty-nine proteins were classified according to their biological function. The sensitivity, specificity, or AUC varied among these markers. Among them, Mammalian STE20-like protein kinase 1/ Serine threonine kinase 4 (MST1/STK4), S100 calcium-binding protein A9 (S100A9), and Tissue inhibitor of metalloproteinases 1 (TIMP1) were suitable for effect sizes merging, and their diagnostic efficiencies were recalculated after merging. MST1/STK4 obtained a sensitivity of 68% and a specificity of 78%. S100A9 achieved a sensitivity of 72%, a specificity of 83%, and an AUC of 0.88. TIMP1 obtained a sensitivity of 42%, a specificity of 88%, and an AUC of 0.71.

CONCLUSION

MST1/STK4, S100A9, and TIMP1 showed excellent performance for CRC detection. Several other markers also presented optimized diagnostic efficacy for CRC early detection, but further verification is still needed before they are suitable for clinical use. The discovering of more efficient markers will benefit CRC treatment.

Artificial Intelligence in Colorectal Polyp Detection and Characterization

BACKGROUND

Over the past 20 years, the advancement of artificial intelligence (AI) and deep learning (DL) has allowed for fast sorting and analysis of large sets of data. In the field of gastroenterology, colorectal screening procedures produces an abundance of data through video and imaging. With AI and DL, this information can be used to create systems where automatic polyp detection and characterization is possible. Convoluted Neural Networks (CNNs) have proven to be an effective way to increase polyp detection and ultimately adenoma detection rates. Different methods of polyp characterization of being hyperplastic vs. adenomatous or non-neoplastic vs. neoplastic has also been investigated showing promising results.

FINDINGS

The rate of missed polyps on colonoscopy can be as high as 25%. At the beginning of the 2000s, hand-crafted machine learning (ML) algorithms were created and trained retrospectively on colonoscopy images and videos, achieving high sensitivity, specificity, and accuracy of over 90% in many of the studies. Over time, the advancement of DL and CNNs has allowed algorithms to be trained on non-medical images and applied retrospectively to colonoscopy videos and images with similar results. Within the past few years, these algorithms have been applied in real-time colonoscopies and has shown mixed results, one showing no difference while others showing increased polyp detection.Various methods of polyp characterization have also been investigated. Through AI, DL, and CNNs polyps can be identified has hyperplastic/adenomatous or non-neoplastic/neoplastic with high sensitivity, specificity, and accuracy. One of the research areas in polyp characterization is how to capture the polyp image. This paper looks at different modalities of characterizing polyps such as magnifying narrow band imaging (NBI), endocytoscopy, laser-induced florescent spectroscopy, auto-florescent endoscopy, and white-light endoscopy.

CONCLUSIONS

Overall, much progress has been made in automatic detection and characterization of polyps in real time. Barring ethical or mass adoption setbacks, it is inevitable that AI will be involved in the field of GI, especially in colorectal polyp detection and identification.

The Role of Fecal Fusobacterium nucleatum and pks+ Escherichia coli as Early Diagnostic Markers of Colorectal Cancer

BACKGROUND

Accurate analysis of intestinal microbiota will facilitate establishment of an evaluating system for assessing colorectal cancer (CRC) risk and prognosis. This study evaluates the potential role of Fusobacterium nucleatum (F. nucleatum) and Escherichia coli with a pks gene (pks⁺ E. coli) in early CRC diagnosis.

METHODS

We recruited 139 patients, including CRC (n = 60), colorectal adenomatous polyposis (CAP) (n = 37), and healthy individuals (n = 42) based on their colonoscopy examinations. We collected stool and serum samples from the participants and measured the relative abundance of F. nucleatum and pks⁺ E. coli in fecal samples by quantitative PCR. Receiver operating characteristic curve (ROC) analyses were used to analyze the diagnostic value of single or combined biomarkers.

RESULTS

Fecal F. nucleatum and pks⁺ E. coli levels were higher in the CRC group in either the CAP group or healthy controls (P = 0.02; 0.01). There was no statistical difference in the distribution of F. nucleatum and pks⁺ E. coli in patients with different tumor sites (P > 0.05). The combination of F. nucleatum+pks⁺ E. coli+CEA+CA19-9+FOBT was chosen as the optimal panel in differentiating both CRC and CAP from the controls. The combination of F. nucleatum, pks⁺ E. coli, and FOBT improved diagnostic efficiency. However, there was difficulty in differentiating CRC from CAP.

CONCLUSION

Our results suggested that combining bacterial markers with conventional tumor markers improves the diagnostic efficiency for noninvasive diagnosis of CRC.

Estimating the impact of differential adherence on the comparative effectiveness of stool-based colorectal cancer screening using the CRC-AIM microsimulation model

BACKGROUND

Real-world adherence to colorectal cancer (CRC) screening strategies is imperfect. The CRC-AIM microsimulation model was used to estimate the impact of imperfect adherence on the relative benefits and burdens of guideline-endorsed, stool-based screening strategies.

METHODS

Predicted outcomes of multi-target stool DNA (mt-sDNA), fecal immunochemical tests (FIT), and high-sensitivity guaiac-based fecal occult blood tests (HSgFOBT) were simulated for 40-year-olds free of diagnosed CRC. For robustness, imperfect adherence was incorporated in multiple ways and with extensive sensitivity analysis. Analysis 1 assumed adherence from 0%-100%, in 10% increments. Analysis 2 longitudinally applied real-world first-round differential adherence rates (base-case imperfect rates = 40% annual FIT vs 34% annual HSgFOBT vs 70% triennial mt-sDNA). Analysis 3 randomly assigned individuals to receive 1, 5, or 9 lifetime (9 = 100% adherence) mt-sDNA tests and 1, 5, or 9 to 26 (26 = 100% adherence) FIT tests. Outcomes are reported per 1000 individuals compared with no screening.

RESULTS

Each screening strategy decreased CRC incidence and mortality versus no screening. In individuals screened between ages 50-75 and adherence ranging from 10%a-100%, the life-years gained (LYG) for triennial mt-sDNA ranged from 133.1-300.0, for annual FIT from 96.3-318.1, and for annual HSgFOBT from 99.8-320.6. At base-case imperfect adherence rates, mt-sDNA resulted in 19.1% more LYG versus FIT, 25.4% more LYG versus HSgFOBT, and generally had preferable efficiency ratios while offering the most LYG. Completion of at least 21 FIT tests is needed to reach approximately the same LYG achieved with 9 mt-sDNA tests.

CONCLUSIONS

Adherence assumptions affect the conclusions of CRC screening microsimulations that are used to inform CRC screening guidelines. LYG from FIT and HSgFOBT are more sensitive to changes in adherence assumptions than mt-sDNA because they require more tests be completed for equivalent benefit. At imperfect adherence rates, mt-sDNA provides more LYG than FIT or HSgFOBT at an acceptable tradeoff in screening burden.

Split-Dose Regimen With Bisacodyl Increases the Quality of Bowel Preparation for Colonoscopy

The aim of the present study was to compare 2 different bowel preparations procedures (split-dose with PicoPrep and bisacodyl vs. same-day preparation with PicoPrep) in patients undergoing colonoscopy with regard to quality of bowel preparation, compliance, and willingness to repeat. A retrospective quasi-experimental investigation was conducted. Adults with outpatient diagnostic and surveillance colonoscopies were included. A total of 540 patients participated: group 'split-dose with bisacodyl' (n = 293) and group 'same-day' (n = 247). Patients in group 'split-dose with bisacodyl' had a higher chance for having an excellent quality of bowel preparation (21.2%; 95% CI [13.5, 28.9]) and a reduced risk of an incomplete colonoscopy (4.1%; 95% CI [1.2, 7.0]). Group 'split-dose with bisacodyl' drank more fluid, had more nightly visits to the bathroom, and had more bathroom stops on the way to the endoscopic site. No differences were found between groups regarding adenoma detection rate, withdrawal time, overall time of colonoscopy, well-being during cleansing, patient satisfaction, the professional's assessment of the patient's tolerability of colonoscopy, and willingness to repeat the bowel preparation process. The split-dose regimen with PicoPrep and bisacodyl is now the standard bowel preparation procedure for patients undergoing elective colonoscopy as it is superior to the same-day regimen with PicoPrep regarding colon cleansing and incomplete colonoscopy. Hence, the written and verbal information at our institution regarding the bowel preparation procedure was altered according to the split-dose regimen, emphasizing the importance of adequate oral fluid intake and complete intake of the solution in order to ensure a safe and effective procedure.

Development and validation of prognostic nomograms for early-onset locally advanced colon cancer

BACKGROUND

The incidence of colorectal cancer in patients younger than 50 years has been increasing in recent years.

OBJECTIVE

Develop and validate prognostic nomograms predicting overall survival (OS) and cancer-specific survival (CSS) for early-onset locally advanced colon cancer (EOLACC) based on the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

The entire cohort comprised 13,755 patients with EOLACC. The nomogram predicting OS for EOLACC displayed that T stage contributed the most to prognosis, followed by N stage, regional nodes examined (RNE) and surgery. The nomogram predicting CSS for EOLACC demonstrated similar results. Various methods identified the discriminating superiority of the nomograms. X-tile software was used to classify patients into high-risk, medium-risk, and low-risk according to the risk score of the nomograms. The risk stratification effectively avoided the survival paradox.

CONCLUSIONS

We established and validated nomograms for predicting OS and CSS based on a national cohort of almost 13,000 EOLACC patients. The nomograms could effectively solve the issue of survival paradox of the AJCC staging system and be an excellent tool to integrate the clinical characteristics to guide the therapeutic choice for EOLACC patients.

METHODS

Nomograms were constructed based on the SEER database and the Cox regression model.

The efficacy and safety of colonoscopy in nonagenarians: A multicenter study

INTRODUCTION

The number of colonoscopy (CS) for the elderly is increasing. There are only a few reports focusing on CS among the very elderly aged ≥ 90-y. We aimed to analyze the efficacy of CS and of colorectal cancer (CRC) for patients aged ≥ 90-y.

METHODS

We retrospectively analyzed consecutive patients aged ≥ 90-y receiving CS at eight institutions from October 2016 to September 2017. Bowel preparation, complications, and endoscopic diagnosis were analyzed. The non-elderly group aged between 50-y and 64-y and elderly group aged between 65-y and 79-y were compared to very-elderly group aged ≥ 90-y. Through propensity score matching of sex and CS indications (symptomatic or asymptomatic), the number of CRC and the treatment in each group were analyzed.

RESULTS

We analyzed 125 patients receiving 154 colonoscopies (0.9%) in the very-elderly group from among 16,968 cases. Among 92 cases who received bowel-cleansing solution, good preparations were achieved in 94.5%. The rate of CS-related complications was 1.3% (2/154). The rate of CRC in the very-elderly group was 27.2% (34/125), higher than the non-elderly group (7.2%, 9/125, p < 0.01) and elderly group (8.8%, 11/125, p < 0.01). Therapeutic interventions for CRC in the very-elderly group were performed in 73.5% (24/34) patients. The mean survival of 12 patients with CRC resection was 788 days.

CONCLUSIONS

CS could be performed safely for the very elderly aged ≥ 90-y with careful considerations. CRC was confirmed to be more frequent in this group with over 70% of patients receiving appropriate therapeutic intervention.

Biomarkers for Early Detection of Colorectal Cancer: The Early Detection Research Network, a Framework for Clinical Translation

Early detection by screening significantly reduces mortality from colorectal cancer, but 40% of guideline-eligible patients are not screened as recommended in the United States. Novel strategies to improve screening uptake overall and efforts to deploy best practices to underserved populations are a high priority for health care. This review focuses on existing biomarkers in practice and those in development with clinical relevance to early detection of colorectal neoplasia, with an emphasis on those developed by investigators of the NCI's Early Detection Research Network. Aberrantly methylated DNA markers (blood and stool), stool-based markers (including fecal immunochemical test-DNA), and a variety of blood-based marker assays in development (protein markers, glycoproteins including mucins, and cell-free DNA tests) are reviewed. Individual markers and biomarker panels, sample resources, and barriers to translating biomarkers to clinical practice are discussed.See all articles in this CEBP Focus section, "NCI Early Detection Research Network: Making Cancer Detection Possible."

Effects of the vibrating capsule on colonic circadian rhythm and bowel symptoms in chronic idiopathic constipation

BACKGROUND

Constipated patients remain dissatisfied with current treatments suggesting a need for alternative therapies.

AIM

Evaluate the mechanistic effects of oral vibrating capsule in chronic idiopathic constipation (CIC) by examining the temporal relationships between the onset of vibrations, complete spontaneous bowel movements (CSBM), and circadian rhythm.

METHODS

In post hoc analyses of two double-blind studies, CIC patients (Rome III) were randomized to receive 5 active or sham capsules/week for 8 weeks. The capsules were programmed for single vibration (study 1) or two vibration sessions with two modes, 8 hours apart (study 2). Daily electronic diaries assessed stool habit and percentage of CSBMs associated with vibrations. Responders were patients with ≥ 1 CSBM per week over baseline.

RESULTS

250 patients were enrolled (active = 133, sham = 117). During and within 3 hours of vibration, there were significantly more % CSBMs in the active vs. sham group (50% vs. 42%; P = .0018). In study 2, there were two CSBM peaks associated with vibration sessions. Significantly more % CSBMs occurred in active mode 1 (21.5%) vs. sham (11.5%); (P = .0357). Responder rates did not differ in study 1 (active vs. sham: 26.9% vs. 35.9%, P = .19) or study 2 (mode 1 vs. sham: 50% vs. 31.8%, P = .24; mode 2 vs. sham: 38.1% vs. 31.8%, P = .75). Device was well-tolerated barring mild vibration sensation.

CONCLUSIONS

Vibrating capsule may increase CSBMs possibly by enhancing the physiologic effects of waking and meals, and augmenting circadian rhythm, although responder rate was not different from sham. Two vibration sessions were associated with more CSBMs.

Early Screening of African Americans (45-50 Years Old) in a Fecal Immunochemical Test-Based Colorectal Cancer Screening Program

BACKGROUND & AIMS

Some guidelines recommend starting colorectal cancer (CRC) screening before age 50 years for African Americans, but there are few data on screening uptake and yield in this population.

METHODS

We performed a prospective study of fecal immunochemical test (FIT) screening among African American members of the Kaiser Permanente Northern California health plan. We compared data from African American members screened when they were 45-50 years old (early screening group) in 2018 with data from previously unscreened African American, white, Hispanic, and Asian/Pacific Islander health plan members who were 51-56 years old. Screening outreach was performed with mailed FIT kits. Logistic regression models, adjusted for sex, were used to evaluate differences among groups in screening uptake, colonoscopy follow-up of abnormal test results, and test yield.

RESULTS

Among 10,232 African Americans in the early screening group who were mailed a FIT, screening was completed by 33.1%. Among the 4% with positive test results, 85.3% completed a follow-up colonoscopy: 57.8% had any adenoma, 33.6% had an advanced adenoma (adenoma with advanced histology or polyp ≥10 mm), and 2.6% were diagnosed with CRC. African Americans in the early screening group were modestly more likely to have completed screening than previously unscreened African Americans, whites, and Hispanics 51-56 years old. The groups did not differ significantly in positive results from the FIT (range, 3.8%-4.6%) and more than 74% received a follow-up colonoscopy after a positive test result. The test yields for any adenoma (range, 56.7%-70.7%), advanced adenoma (range, 20.0%-33.6%), and CRC (range, 0%-7.1%) were similar.

CONCLUSIONS

Proportions of African Americans who participated in early (aged 45-50 years) FIT screening and test yield were comparable to those of previously unscreened African Americans, whites, Hispanics, and Asian/Pacific Islanders who were 51-56 years old.

Use of Polygenic Risk Scores to Select Screening Intervals After Negative Findings From Colonoscopy

BACKGROUND & AIMS

Polygenic risk scores (PRSs) could help to define starting ages for colorectal cancer (CRC) screening. However, the role of PRS in determining the length of screening interval after negative findings from colonoscopies is unclear. We aimed to evaluate CRC risk according to PRS and time since last negative colonoscopy.

METHODS

We collected data from 3827 cases and 2641 CRC-free controls in a population-based case-control study in Germany. We constructed a polygenic risk scoring system, based on 90 single-nucleotide polymorphisms, associated with risk of CRC in people of European descent. Participants were classified as having low, medium, or high genetic risk according to tertiles of PRSs among controls. Multiple logistic regression models were used to assess CRC risk according to PRS and time since last negative colonoscopy.

RESULTS

Compared to individuals without colonoscopy in the low PRS category, a 42%-85% lower risk of CRC was observed for individuals who had a negative finding from colonoscopy within 10 years. Beyond 10 years after a negative finding from colonoscopy, significantly lower risk only persisted for the low and medium PRS groups, but not for the high PRS group. Adjusted odds ratios were 0.44 (95% CI, 0.29-0.68), 0.51 (95% CI, 0.34-0.77), and 0.85 (95% CI, 0.58-1.23) in the low, medium, and high PRS group, respectively. Within any time interval, risks were lower for distal than for proximal CRCs.

CONCLUSIONS

Based on findings from a population-based case-control study, the recommended 10-year screening interval for colonoscopy may not need to be shortened among people with high PRSs, but could potentially be prolonged for people with low and medium PRSs. Studies are needed to address personalized time intervals for repeat colonoscopies in average-risk screening cohorts.

Robust performance of a novel stool DNA test of methylated SDC2 for colorectal cancer detection: a multicenter clinical study

BACKGROUND AND AIMS

Stool DNA testing is an emerging and attractive option for colorectal cancer (CRC) screening. We previously evaluated the feasibility of a stool DNA (sDNA) test of methylated SDC2 for CRC detection. The aim of this study was to assess its performance in a multicenter clinical trial setting.

METHODS

Each participant was required to undergo a sDNA test and a reference colonoscopy. The sDNA test consists of quantitative assessment of methylation status of SDC2 promoter. Results of real-time quantitative methylation-specific PCR were dichotomized as positive and negative, and the main evaluation indexes were sensitivity, specificity, and kappa value. All sDNA tests were performed and analyzed independently of colonoscopy.

RESULTS

Among the 1110 participants from three clinical sites analyzed, 359 and 38 were diagnosed, respectively, with CRC and advanced adenomas by colonoscopy. The sensitivity of the sDNA test was 301/359 (83.8%) for CRC, 16/38 (42.1%) for advanced adenomas, and 134/154 (87.0%) for early stage CRC (stage I-II). Detection rate did not vary significantly according to age, tumor location, differentiation, and TNM stage, except for gender. The follow-up testing of 40 postoperative patients with CRC returned negative results as their tumors had been surgically removed. The specificity of the sDNA test was 699/713 (98.0%), and unrelated cancers and diseases did not seem to interfere with the testing. The kappa value was 0.84, implying an excellent diagnostic consistency between the sDNA test and colonoscopy.

CONCLUSION

Noninvasive sDNA test using methylated SDC2 as the exclusive biomarker is a clinically viable and accurate CRC detection method.

CHINESE CLINICAL TRIAL REGISTRY

Chi-CTR-TRC-1900026409, retrospectively registered on October 8, 2019; http://www.chictr.org.cn/edit.aspx?pid=43888&htm=4 .

CILP2 overexpression correlates with tumor progression and poor prognosis in patients with colorectal cancer in The Cancer Genome Atlas (TCGA) study

Background

Genetic alterations play an important role in the progression of colorectal cancer (CRC). Identifying new biomarkers to assess the prognosis of patients with CRC is critical. Cartilage intermediate layer protein 2 (CILP2) gene, screened from TCGA database by bioinformatics, may be closely related to the progression of CRC. CILP2 was barely reported with clinical features of tumors.

Materials and methods

Clinical information and RNA-seq data were derived from TCGA colorectal carcinoma cohort. CILP2 expression at mRNA level was estimated by bioinformatical analysis of TCGA cases. Tissue microarray (TMA) was constructed containing paraffin-embedded 64 pairs of CRC and matched adjacent normal tissues. The expression at the protein level was detected in 64 pairs of CRC and matched adjacent normal tissues by immunohistochemical analysis. CILP2 expression level and its clinical value were estimated by bioinformatical analysis with linear and logistic regression. Survival analysis was performed between high and low groups of CILP2 expression by Cox regression analysis, and the P value was calculated by the log-rank test. The Kaplan-Meier curves were tested by the log-rank test.

Results

CILP2 was statistically significantly higher expressed in the CRC tissues when compared with paired adjacent normal tissues in TCGA cohort (P < 0.001) and in the TMA cohort (P = 0.001). Also, CILP2 high expression was strongly correlated with T3/4 stage (P = 0.001), N1/2/3 stage (P = 0.005), M1 stage (P = 0.048), and higher clinical stage (UICC 2010 stage) (P < 0.001) in TCGA cohort, and also positively associated with T3/4 stage (P = 0.022) and higher clinical stage (UICC 2010 stage) (P = 0.03) in TMA cohort. Furthermore, CILP2 overexpression predicted poor prognosis and could be an independent prognostic factor (P = 0.003).

Conclusion

We revealed that CILP2 is associated with advanced stages and could play a role as an independent predictor of poor survival in CRC.

Geographic and intra-racial disparities in early-onset colorectal cancer in the SEER 18 registries of the United States

Background

Although early‐onset colorectal cancer (EOCRC) incidence rates (IRs) are increasing, geographic and intra‐racial IR disparities are not well defined.

Methods

2000‐2015 Surveillance, Epidemiology, and End Results (SEER) program CRC IR Analysis (170,434 cases) was performed from ages 30 to 60 in four US regions, 18 individual registries, metropolitan and nonmetropolitan locations and stratified by race. Analyses were conducted in 1‐year and 5‐year age increments.

Results

Wide US regional EOCRC IR variations exist: For example, age 45 IRs in the south are 26.8/100,000, 36.0% higher than the West, 19.7/100,000 (p < 0.0001). Disparities magnify between individual registries: EOCRC IRs in highest risk registries were 177‐348% (Alaska Natives), 75‐200% (Hawaii), 76‐128% (Louisiana), and 61‐125% (Kentucky) higher than lowest risk registries depending on age. EOCRC IRs are 18.2%‐25.6% higher in nonmetropolitan versus metropolitan settings. Wide geographic intra‐racial disparities exist. Within the White population, the greatest IR difference (78.8%) was between Kentucky (5.9/100,000) and Los Angeles (3.3/100,000) in 30‐ to 34‐year‐olds (p < .0001). Within the Black population, the greatest difference (136.2%) was between rural Georgia (30.7/100,000) and California excluding San Francisco‐Oakland/San Jose‐Monterey/Los Angeles (13/100,000) in 40‐ to 44‐year‐olds (p = 0003).

Conclusion

Marked geographic EOCRC disparities exist with disproportionately high IRs in Alaska Natives, Hawaii, and southern registries. Geographic intra‐racial disparities are present within White and Black populations. In Blacks, there are disproportionately high EOCRC IRs in rural Georgia. Although vigilance is required in all populations, attention must be paid to these higher risk populations. Potential interventions include assuring early investigation of symptoms, targeting modifiable risk factors and utilizing earlier age 45 screening options supported by some guidelines.

Faecal immunochemical test to triage patients with abdominal symptoms for suspected colorectal cancer in primary care: review of international use and guidelines

BACKGROUND

Recently, faecal immunochemical tests (FITs) have been introduced for investigation of primary care patients with low-risk symptoms of colorectal cancer (CRC), but recommendations vary across the world. This systematic review of clinical practice guidelines aimed to determine how FITs are used in symptomatic primary care patients and the underpinning evidence for these guidelines.

METHODS

MEDLINE, Embase and TRIP databases were systematically searched, from 1 November 2008 to 1 November 2018 for guidelines on the assessment of patients with symptoms suggestive of CRC. Known guideline databases, websites and references of related literature were searched. The following questions were addressed: (i) which countries use FIT for symptomatic primary care patients; (ii) in which populations is FIT used; (iii) what is the cut-off level used for haemoglobin in the faeces (FIT) and (iv) on what evidence are FIT recommendations based.

RESULTS

The search yielded 2433 publications; 25 covered initial diagnostic assessment of patients with symptoms of CRC in 15 countries (Asia, n = 1; Europe, n = 13; Oceania, n = 4; North America, n = 5; and South America, n = 2). In three countries (Australia, Spain and the UK), FIT was recommended for patients with abdominal symptoms, unexplained weight loss, change in bowel habit or anaemia despite a low level of evidence in the symptomatic primary care patient population.

CONCLUSIONS

Few countries recommend FITs in symptomatic patients in primary care either because of limited evidence or because symptomatic patients are directly referred to secondary care without triage. These results demonstrate a clear need for research on FIT in the symptomatic primary care population.

Relationship between serum gamma-glutamyl transferase level and colorectal adenoma

Background and aims

Cost-effective serology tests may increase the predictive accuracy of colonoscopy for colorectal cancer screening. Reportedly, gamma-glutamyl transferase (GGT) is associated with oxidative stress and carcinogenesis and has been found to be elevated in the serum of cancer patients and colorectal adenoma tissue. We aimed to investigate the association between serum GGT levels and colorectal adenoma.

Methods

This single-center, health examination-based cohort enrolled 2475 subjects from 2006 to 2015. Baseline characteristics, laboratory data, bidirectional gastrointestinal endoscopy, and transabdominal ultrasonography were used to evaluate the severity of fatty liver.

Results

We found an elevated median GGT level in subjects with tubular adenoma compared with those without (23 IU/L and 20 IU/L, p<0.001). A GGT cutoff of ≥20 IU/L reached a maximal Youden index in receiver operating curve (ROC) analyses. Subsequent regression analyses showed an odds ratio of 1.46 (95% CI 1.17–1.82, p<0.001) for age, body mass index, diabetes diagnosis, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and positive Helicobacter pylori urease test, all being associated with an increased incidence of colon adenoma. Subgroup analysis showed that the odds ratio (OR 1.27, 95% CI 1.15–1.68, p<0.001) is only significant and highest in patients with a negative or mild fatty liver and an ALT level of ≤40 IU/L.

Conclusions

The results suggested a positive correlation of GGT with colon adenoma incidence and a predictive value with a cutoff point of >20 IU/L, which is within the normal range. The effect may be most prominent for those without steatohepatitis.

Self-Reported Lower Gastrointestinal Endoscopy Use and Changes in Colorectal Cancer Mortality Rates in European Countries

To quantify the association of self-reported lower gastrointestinal endoscopy use measured in 2004/05 with colorectal cancer (CRC) mortality changes over 2004–2015 in Europe.

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.

Increasing Incidence of Left-Sided Colorectal Cancer in the Young: Age Is Not the Only Factor

BACKGROUND

Recent single-institution studies have shown that colorectal cancer (CRC) in patients < 50 is predominantly left-sided. The aims of this study were to 1 compare the incidence of left-sided CRC in patients under and over 50, 2 investigate this trend over time, and 3 examine whether racial differences exist in the anatomical distribution of CRC.

METHODS

We used the Nationwide Inpatient Sample to identify all patients with colon or rectal cancer who underwent a resection from 2000 to 2014. Logistic regression models were used to determine the odds of a patient having a left-sided CRC based on age and race.

RESULTS

A total of 1,547,589 patients underwent resection, with a mean age of 68.6. Overall, 65.1% of patients < 50 had a left-sided CRC compared with 47.2% of patients ≥ 50 (OR = 2.1; 95% CI 2.0, 2.1). The difference was greater as patients became older with 39.9% of patients > 70 having a left-sided CRC (< 50 vs ≥ 70; OR = 2.8; 95% CI 2.7, 2.9). The incidence of CRC in those under 50 increased over the study period due to an increase in left-sided tumors. The distribution of CRC varied with race, with African-Americans having a lower odds for left-sided CRC (OR = 0.89; 95% CI 0.87, 0.91) and Asians/Pacific Islanders having a higher odds (OR = 1.8; 95% CI 1.7, 1.9).

CONCLUSION

In the < 50 age group, the incidence of CRC is increasing, with majority of these tumors left-sided. Tumor location varies with both age and race.

Select group of patients might benefit from early colonoscopic screening for colorectal cancer

BACKGROUND

Recently, the American Cancer Society made a qualified recommendation to start colorectal cancer (CRC) screening at 45 years of age in all average-risk individuals. In this study, our primary aim is to calculate the prevalence and also evaluate the predictors of increased prevalence of detected adenomas in the 40-49-year-old individuals undergoing colonoscopy.

METHODS

A retrospective cross-sectional study was performed using our endoscopy database. Study subjects included all 40-49-year-old patients undergoing their first colonoscopy at our institution from January 1, 2010 to September 30, 2017. Exclusion criteria included patients who underwent colonoscopy for overt gastrointestinal bleeding, inflammatory bowel disease, a history of familial adenomatous polyposis, hereditary non-polyposis CRC. Univariate analysis and multivariate analysis were performed to identify factors associated with increased adenoma detection rate (ADR).

RESULTS

A total of 2059 patients were included in the study, and 317 of these patients had family history (FH) of CRC. Patients with FH of CRC had significantly higher ADR (27.8% vs. 19.7%, p = 0.001) as compared to those without FH of CRC. There was no significant difference in ADR in patients between 40-44 years and 45-49 years of age (17.7% vs. 21.4%, p = 0.058). On a multivariate analysis while adjusting for multiple patient and procedural variables, FH of CRC, male sex, BMI > 30 kg/m², chronic kidney disease, and age were associated with high ADR.

CONCLUSIONS

Our study shows that in addition to FH of CRC, age, male sex, BMI, and CKD are independent predictors of increased ADR in patients between 40 and 49 years of age.

Effect of successive endoscopic procedures in polyp and adenoma detection rates: Too early is not always too good

BACKGROUND AND AIMS: There is conflicting evidence regarding the impact of hypothetical cumulative fatigue after performing too many endoscopic procedures on both polyp and adenoma detection rates (PDR, and ADR, respectively). The aim of this study is to evaluate the effect of successive endoscopic procedures on PDR and ADR.

METHODS

A retrospective cross-sectional study was undertaken among consecutive patients on whom colonoscopy and/or esophagogastroduodenoscopy were performed between January 2012 and August 2014. Data regarding polyp and adenoma detection, cecal intubation, and bowel cleansing quality as well as demographical data of subjects were extracted. Endoscopic procedures were classified according to the time slots of the procedures throughout the endoscopy session in three groups: from the 1st to 4th endoscopy study (round 1), from the 5th to the 8th study (round 2), above the 9th study (round 3). We compared PDR and ADR among rounds.

RESULTS

Overall, 3388 patients were enrolled. Median age was 50 years (range 18-95) and 52.39% were female. There was a significant difference in terms of PDR among rounds (36.83%, 41.24%, and 43.38%, respectively, p = 0.007) and a non-significant numerical difference when ADR was compared (23.2%, 25.71%, and 26.78%, p = 0.07). On multivariate analysis, ADR was significantly associated with age (odds ratio [OR] 1.02 [1.01-1.03]), and male sex (OR 1.64 [1.38-1.94]).

CONCLUSION

Theoretical endoscopist's fatigue due to cumulative performance of endoscopies does not diminish colonoscopy quality. Both PDR and ADR seem to improve after endoscopist's cumulative rounds of performed endoscopies. This could be due to a "warm-up" effect.

Higher risk of advanced histology in adenoma less than 10 mm in fecal immunochemical test screening: Implication for management

BACKGROUND AND AIM

Whether diminutive or small adenomas detected by fecal immunochemical tests (FITs) are associated with a higher risk of advanced histology remains unknown. We investigated the prevalence of advanced histology in diminutive and small adenomas detected by FIT and compared with that detected by colonoscopy screening.

METHODS

We prospectively compared 1860 FIT-positive patients (FIT-positive cohort) and 6691 average-risk patients (screening colonoscopy cohort). Both groups underwent colonoscopies and were shown to have neoplastic lesions. The prevalence of advanced histology was determined, as was the associations with size and FIT positivity.

RESULTS

We analyzed 3920 neoplastic lesions from the FIT-positive cohort and 9789 neoplastic lesions from the screening colonoscopy cohort. Eighty (4.3%) diminutive lesions in FIT-positive cohort had advanced histology but without any invasive cancer. Twenty-one patients in the FIT-positive cohort and 49 in the screening colonoscopy cohort with diminutive adenomas displayed advanced histology (3.5% vs 1.2%; adjusted odds ratio [aOR] = 2.99, 95% confidence interval [CI]: 1.77-5.06). Sixteen patients in the FIT-positive cohort (2.7%) with diminutive adenomas might have changed the surveillance interval if a resect-and-discard strategy was applied, with a higher likelihood compared with the screening colonoscopy cohort (aOR = 2.76, 95% CI: 1.53-4.99).

CONCLUSIONS

Fecal immunochemical test screening detected more diminutive and small adenomas with advanced histology compared with colonoscopy screening. Its impact on current management of diminutive polyp is limited.

Prevalence of a First-Degree Relative With Colorectal Cancer and Uptake of Screening Among Persons 40 to 54 Years Old

BACKGROUND & AIMS

People with a first-degree relative with colorectal cancer (CRC) are recommended to start CRC screening at age 40. However, there is limited information on how many people in different age groups have a known family history of CRC and how many of them have had a colonoscopy.

METHODS

We set up a multicenter, cross-sectional, population-based study in Germany to determine what proportions of persons in age groups from 40 to 54 years old have a known family history of CRC. We invited 160,000 persons to participate in an online survey from 2015 through 2016. We investigated what proportions of persons in each age group reported a family history of CRC and what proportions of persons underwent a colonoscopy examination using descriptive statistics and multiple logistic regression models.

RESULTS

Of 28,711 responders to the online questionnaire (8428 were age 40-44 years, 9879 were age 45-49 years, and 10,404 were age 50-54 years), 2705 stated that they had a first-degree relative with CRC (9.4%). The prevalence of a first-degree relative with CRC increased with age: 7.5%, 9.6%, and 10.9% for people 40 to 44 years old, 45 to 49 years old, and 50 to 54 years old, respectively. The prevalence of a first-degree relative who received a diagnosis of CRC at age 70 years or older increased steadily with each age group. Although a greater proportion of people with a family history of CRC had undergone a colonoscopy examination (54.5%) than people without a family history of CRC (25.7%; P < .0001), large proportions of people within this risk group were not in compliance with the guidelines (54.8%, 47.6%, and 38.6% for ages 40-44 y, 45-49 y, and 50-54 y, respectively).

CONCLUSIONS

One in 10 persons in Germany age 40 to 54 years old has a first-degree relative with CRC. Guidelines recommend initiation of screening at ages 40 to 45 years for people with a family history, yet at this age many people do not have a family history of CRC yet, and almost half of persons 40 to 54 years old with a family history of CRC have not yet received a screening colonoscopy.

Efficacy of different dose of dexmedetomidine combined with remifentanil in colonoscopy: a randomized controlled trial

Background

Dexmedetomidine has advantages during colonoscopy as it allows the patient to cooperate during the procedure. Few studies examined the dexmedetomidine-remifentanil combination. This study was to evaluate the effects of different doses of the dexmedetomidine-remifentanil combination in colonoscopy.

Methods

This was a prospective trial carried out at the Fourth Hospital of Hebei Medical University between 02/2018 and 10/2018. The patients were randomized: group I (dexmedetomidine 0.2 μg·kg^− 1), group II (dexmedetomidine 0.3 μg·kg^− 1), and group III (dexmedetomidine 0.4 μg·kg^− 1), all combined with remifentanil. The primary outcomes were the patient’s body movements during the procedure and adverse events.

Results

Compared with at admission (T₀), the SBP, HR, and RR at immediately after giving DEX (T₁), at the beginning of the examination (T₂), 5 min after the beginning of the examination (T₃), 10 min after the beginning of the examination (T₄), and at the end of the examination (T₅) in the three groups were all reduced (all P < 0.05), but all were within the clinically normal range. SpO₂ remained > 98% in all patients during the examination. Compared with T₀, the BIS values of the three groups were decreased at T₁ and T₂ (all P < 0.05). There were no significant differences in BIS among the three groups (all P > 0.05). The minimum BIS value in group III was lower than in groups I and II (P < 0.05). The degree of satisfaction with the anesthesia effect was higher in groups II and III that in group I (P < 0.05). No hypotension occurred, seven patients had bradycardia, and four patients had nausea/vomiting.

Conclusions

Dexmedetomidine 0.3 μg·kg^− 1 combined with remifentanil was effective for colonoscopy and had few adverse reactions.

Chinese Clinical Trial Registry: ChiCTR2000029105, Registered 13 January 2020 - Retrospectively registered.

Poor Knowledge of Personal and Familial Colorectal Cancer Risk and Screening Recommendations Associated with Advanced Colorectal Polyps

BACKGROUND AND AIMS

Advanced colorectal polyps (adenoma or sessile serrated polyp ≥ 1 cm, adenoma with villous features, adenoma with high-grade dysplasia, or any sessile serrated polyps with dysplasia) are associated with an increased risk of future advanced colorectal neoplasia and confer an increased risk of advanced neoplasia to first-degree family members. Professional societies therefore recommend more intensive surveillance of these polyps and earlier screening for first-degree relatives. The aim of this study was to assess knowledge of personal and familial risk and recommendations among patients with advanced colorectal polyps and identify predictors of knowledge.

METHODS

An online survey was designed to assess the domains of knowledge and risk perception regarding personal and familial colorectal cancer risk and screening recommendations. After expert review and pilot testing, the 37-item survey was electronically sent to all patients diagnosed with an advanced colon or rectal polyp under the age of 60. Patient report of polyp findings was compared to documented findings in the medical record. Univariable and multivariable regressions were performed to evaluate predictors of knowledge.

RESULTS

One hundred thirty-seven out of 344 (39.8%) eligible patients responded to the survey. 28.5% of participants reported that the polyp they had removed was precancerous. 54.8% of participants reported that they have a higher risk of CRC, and 65.2% reported that they should be undergoing colonoscopy surveillance in 3 years or less. 40.1% reported that their first-degree family members are at increased CRC risk, and 38.0% reported that first-degree family members should get earlier screening. Participants reported their endoscopists as their top source of information about risk and recommendations, though only 7.3% of endoscopists made recommendations for family members. Female gender and higher income were predictors of accurate knowledge, as endoscopist was the main source of knowledge.

CONCLUSIONS

Patients with advanced colorectal polyps have poor knowledge of personal and familial CRC risk and recommendations. Endoscopists who remove advanced polyps are in an ideal position to educate their patients about their personal risk and the risk and recommendations for first-degree family members.

Primary Care Clinician Decision-Making Around Surveillance Colonoscopies in Older Adults with Prior Adenomas

INTRODUCTION

While guidelines recommend against routine colorectal cancer screening in adults >75 years and/or those with limited life expectancies, there is no clear guidance on when surveillance colonoscopies following prior adenoma detection should stop. How primary care clinicians weigh the potential risks and benefits of surveillance colonoscopies in older adults with prior adenomas is unknown.

METHODS

We conducted semistructured in-person interviews with 30 primary care clinicians from 21 clinics in Maryland. We asked how clinicians decided whether to continue or stop surveillance colonoscopies in older adults (65+ years) with prior adenomas. Interview transcripts were independently coded by 2 investigators using qualitative content analysis.

RESULTS

Participants described a range of decision-making approaches. Some deferred to specialists because they did not feel confident making decisions about stopping surveillance in light of the higher cancer risk involved. Some took a more active role and discussed the decision with patients and/or specialists. Other clinicians felt comfortable stopping surveillance colonoscopies and made these decisions based on patient age, comorbidities, or life expectancy.

DISCUSSION

We found a range of decision-making approaches among primary care clinicians on whether to continue surveillance colonoscopies in older adults with prior adenomas. Separate bodies of evidence currently exist on how prior adenoma characteristics influence colorectal cancer risk and on how older age and declining health influence the benefit/harm balance of screening. Information is lacking on the benefits and harms of surveillance in older adults with prior adenomas. Developing the evidence to address this knowledge gap is critically needed to inform clinical decision making.

Elevated Risk for Sessile Serrated Polyps in African Americans with Endometrial Polyps

BACKGROUND

Colorectal and endometrial lesions increase with age. It is not known if these two precursor lesions in sporadic cases associate with each other.

AIM

To determine the association between colorectal polyps and endometrial polyps (EP) in African Americans.

METHODS

We reviewed records of patients referred to gynecology clinics and had colonoscopy at Howard University Hospital from January 2004 to December 2015. We defined cases as all patients who had EP and underwent colonoscopy. For controls, we used EP-free patients who underwent colonoscopy. Logistic regression analysis was used to assess the association between colon polyps and EP.

RESULTS

The median age was 60 years in 118 Cases and 57 years in 664 Controls. The overall colorectal polyps prevalence in the two groups was not statistically different (54% in controls vs. 52% in cases, P = 0.60). Sessile serrated adenoma/polyps (SSPs) were more frequent in cases (8% vs. 2% in controls, P = 0.003). Sigmoid and rectal locations were more prevalent in controls than cases. In multivariate analysis and after adjusting for age, diabetes mellitus (DM), and BMI, SSPs were associated with EP occurrence with an odds ratio of 4.6 (CI 1.2-16.7, P = 0.022).

CONCLUSION

Colorectal polyp prevalence was similar in EP patients compared to EP-free controls. However, we observed a significant association between higher-risk SSPs in patients with EP. The prevalence of smoking and DM was higher in these patients. Females with EP might benefit from a screening for colonic lesions in an age-independent manner.

High incidence of prolonged rectal bleeding and advanced stage cancer in early-onset colorectal cancer patients

Background: We examined characteristics of early-onset colorectal cancer (CRC) patients to identified factors, which may lead to earlier diagnosis. Materials & methods: This is a retrospective study with inclusion criteria: CRC diagnosed between 2012 and 2018 and age at diagnosis <50 years. Results: A total of 209 patients were included (mean age 41.8 years). Of those patients 42.5% had rectal cancer and 37.8% were stage IV at initial diagnosis. Of patients with data available for rectal bleeding history (n = 173), 50.8% presented with rectal bleeding and median time from onset of bleeding to diagnosis was 180 days (interquartile range 60–365), with longer duration noted in advanced cancer. Conclusion: Prolonged rectal bleeding history was noted in a significant proportion of early-onset CRC patients, with longer duration of rectal bleeding noted in stage IV patients. Patients and primary care physicians should be made aware of this finding in order to facilitate timely referral for diagnostic workup.

Yield of Random Biopsies During Colonoscopies in Inflammatory Bowel Disease Patients Undergoing Dysplasia Surveillance

BACKGROUND

The development of chromoendoscopy (CE) and high definition endoscopy (HDE) has improved detection of subtle colonic dysplasia in patients with inflammatory bowel diseases (IBDs). The role of random biopsies for dysplasia surveillance is unclear.

METHODS

We reviewed patients with IBD who underwent a CE or HDE colonoscopy and had colonic dysplasia detected. Detection of dysplasia was classified as either visible or random and graded as low grade dysplasia (LGD), high grade dysplasia (HGD), or indefinite for dysplasia. Multivariable regression adjusted for relevant confounders examined the predictors of dysplasia detectable on random biopsies alone.

RESULTS

The study included 300 patients (203 ulcerative colitis, 97 Crohn's disease with colonic involvement) contributing 442 colonoscopies; the mean disease duration was 24.5 years; 7.2% had primary sclerosing cholangitis (PSC). Three hundred sixty-two colonoscopies (82%) had only visible dysplasia, 52 (12%) had only random dysplasia, and 28 (6%) had both visible and random dysplasia. Longer disease duration (odds ratio, 1.04; 95% CI, 1.01-1.07), active inflammation (odds ratio, 2.89; 95% CI, 1.26-6.67), and concomitant PSC (odds ratio, 3.66; 95% CI, 1.21-11.08) were associated with detecting dysplasia on random biopsies compared with visible lesions. Patients with random dysplasia (21%) or both random and visible dysplasia (21%) were more likely to undergo surgical resection compared with those with only visible dysplasia (5%; P < 0.001) and have subsequent development of colorectal cancer (15%, 7%, 1%, respectively; P < 0.0001).

CONCLUSION

Nearly one fifth of dysplasia detected in patients with IBD was found on random biopsies. Patients with high risk characteristics may benefit from continuing the practice of random biopsies during surveillance examinations.

New Ultra Low Volume Bowel Preparation and Overview of Existing Bowel Preparations

BACKGROUND

Adequate bowel cleansing is essential in achieving a good quality colonoscopy. However, one of the barriers to achieving high-quality bowel cleansing is the patient's tolerability. Different bowel preparations have been developed to improve tolerability while maintaining adequate bowel cleansing.

OBJECTIVES

We aim to explore the pros and cons of commonly used bowel preparations, particularly highlighting the new ultra-low volume bowel preparation.

METHODS

Extensive literature search was carried out on various databases to evaluate the effectiveness and side effects of different bowel cleansing agents, including findings of recent clinical trials on ultra-low bowel preparation.

RESULTS

Polyethylene glycol (PEG) has been commonly used as a bowel prep. Due to its high volume required to ingest to achieve an adequate effect, it has been combined with various adjuncts to reduce the volume to make it more tolerable. Magnesium and phosphate-based preps can achieve low volume, but they can be associated with multiple side effects, mainly electrolyte disturbances. Ultra low volume prep (NER1006) was achieved by combing PEG with ascorbic acid, and its efficacy and side effects were demonstrated in three noninferiority studies.

CONCLUSION

It is important to consider patient preferences, co-morbidities and tolerability, and efficacy and side effect profiles when choosing bowel prep for patients undergoing colonoscopy. New ultra-low bowel prep showed promising results in initial clinical trials, but further real-world post-marketing data will inform its value in clinical practice.

Multitarget stool DNA testing for the prevention of colon cancer: outcomes in a large integrated healthcare system

BACKGROUND AND AIMS

Multitarget stool DNA (MT-sDNA) testing is used in primary care as a screening test for colon cancer. Test effectiveness and patient compliance were examined in clinical practice.

METHODS

We assessed outcomes of MT-sDNA testing in a cohort study conducted in a large integrated healthcare system comprising 15 hospitals and 150 outpatient clinics using advanced electronic data capture (Clarity2 [Epic, Verona, Wisc, USA] and REDCap [Encinitas, Calif, USA]) followed by manual chart review to confirm MT-sDNA test results and to monitor the outcomes of subsequent colonoscopy.

RESULTS

A total of 6835 MT-sDNA tests were performed over 1 year between 2017 and 2018. Of 1242 patients (18%) who tested positive, 1109 (89%) were referred for colonoscopy, and 905 of them (73%) underwent colonoscopy. Eleven patients (<1%) with a positive test had colorectal cancer, 215 (17%) had advanced adenomas, 110 (9%) had serrated adenomas, and 546 (60%) patients had an adenoma. Of the 6835 patients tested, adenoma or cancer was found in 557 patients (8%). An advanced adenoma or cancer was found in 226 of 1242 patients with a positive test (18%). Nonadherence with colonoscopy after a positive test was high (21%), and the cost to detect 1 advanced adenoma or cancer was $38,849.

CONCLUSIONS

The frequency of adenoma detection by an MT-sDNA screening strategy is low, and many positive tests are not associated with significant findings at colonoscopy. Failure to follow a positive test with colonoscopy is a significant problem that needs to be considered when this screening strategy is adopted.

Comparison of Tissue-Based Molecular Markers in Younger versus Older Patients with Colorectal Neoplasia

BACKGROUND

Emerging colorectal cancer trends demonstrate increased incidence and mortality in younger populations, prompting consideration of average-risk colorectal cancer screening initiation at age 45 versus 50 years. However, screening test performance characteristics in adults 45-49 years have been minimally described. To inform the biologic rationale for multi-target stool DNA (mt-sDNA) screening in younger patients, we analyzed and compared tissue levels of methylation (BMP3, NDRG4) and mutation (KRAS) markers included in the FDA-approved, mt-sDNA assay (Cologuard; Exact Sciences Corporation).

METHODS

Within 40-44, 45-49, and 50-64 year age groups, archived colorectal tissue specimens were identified for 211 sporadic colorectal cancer cases, 123 advanced precancerous lesions (APLs; adenomas >1 cm, high-grade dysplasia, ≥25% villous morphology, or sessile serrated polyp; 45-49 and 50-64 age groups only), and 204 histologically normal controls. Following DNA extraction, KRAS, BMP3, and NDRG4 were quantified using QuARTS assays, relative to ACTB (reference gene).

RESULTS

None of the molecular marker concentrations were significantly associated with age (P > 0.05 for all comparisons), with the exception of NDRG4 concentration in APL samples (higher in older vs. younger cases; P = 0.008). However, NDRG4 levels were also statistically higher in APL case versus normal control samples in both the 45-49 (P < 0.0001) and 50-64 (P < 0.0001) year age groups.

CONCLUSIONS

Overall, these findings support the potential for earlier onset of average-risk colorectal cancer screening with the mt-sDNA assay.

IMPACT

These novel data address an identified knowledge gap and strengthen the biologic basis for earlier-onset, average-risk screening with the mt-sDNA assay.

Afro-Caribbeans Have a Lower Prevalence of Advanced Colon Neoplasia than African-Americans

BACKGROUND/AIMS

The black population in the USA is a heterogeneous group composed of smaller subgroups from different origins. The definition of black in many colorectal cancer (CRC) risk studies is vague, and differences in CRC risk comparing black subpopulations have not been evaluated. The aim of the study is to compare advanced colorectal neoplasia (ACN) between two subgroups of black populations: African-American (AA) and Afro-Caribbean (AC). A secondary aim was to determine whether there are differences in prevalence of adenomas.

METHODS

This was a retrospective study of 3797 AA and AC patients undergoing first time screening colonoscopy in two different institutions in the USA.

RESULTS

Overall adenoma prevalence was 29.3% for the entire population with 29.5% in AAs and 29.0% in AC with no statistically significant difference between the study groups (AOR: 1.02; 95% CI 0.88-1.18, P = 0.751). However, ACN was significantly higher in the AA group (11.8%) compared to AC (9.0%) (AOR: 1.30, 95% CI 1.02-1.66, P = 0.034). It was observed that AAs had ACN at a higher BMI than AC. After adjusting for BMI/ethnicity interactions, the difference in ACN between both groups became more significant (AOR: 1.93, 95% CI 1.16-3.23, P = 0.012).

CONCLUSIONS

AAs have a higher risk of ACN than AC. Current recommendations to start screening in average-risk AAs at an earlier age may not apply to other black subgroups.

Factors Associated with Participation in Stool Based Colorectal Screening in Brunei Darussalam

Introduction:

Colorectal cancers (CRC) continues to increase worldwide and is associated with significant morbidity and mortality. CRC can be prevented through early detection using several modalities. However, like any screening program participation remains suboptimal. This study assessed the factors associated with participation in a stool based CRC screening that was carried out as part of an Integrated Health Screening Survey for civil servants.

Materials and Methods:

Civil servants who participated in a health survey (N=10,756, mean age 48.08 ± 5.26 years old) were studied. Demographic factors (gender, age groups, marital status, employment status, body mass index [BMI] categories, smoking status, personal and family history of cancers) were analyzed to assess for features associated with willingness to participate in this fecal immunohistochemistry test (FIT) screening for CRC. Comorbid conditions studied were cardiac disease, diabetes mellitus, dyslipidemia, hypertension and stroke. Multivariate analysis was performed to evaluate variables associated with participation in CRC screening programme.

Results:

Of the invited 10,756 participants, 7,360 returned a stool specimen giving a participation rate of 68.4%. Those who participated were significantly older (<40 [41.3%], 40-44 [64.6%], 45-49 [68.8%], 50-54 years [70.6%], 55-59 years [72.4%] and >60 years [77.8%], p<0.001 for trend), being of professional employment (p=0.010) and presence of comorbid conditions (p=0.003). There were no significant differences between gender, race, marital status, BMI categories, personal history of cancer, family history of cancer, and smoking status (all p values >0.05). Multivariate analyses showed that older age (45-49, 50-54, 55-59 and >60) and employment status (professional) remained significant factors associated with participation in a stool based CRC screening.

Conclusions:

Our study showed that older age and professional employment status were significantly associated with willingness to participate in a stool based CRC screening.

Impact of the COVID-19 pandemic on Gastroenterology Divisions in Italy: A national survey

BACKGROUND

In Italy, the spread of the COVID-19 pandemic has stressed the entire healthcare system and required a huge re-organization of many Divisions, including those of Gastroenterology.

AIMS

to assess the impact of COVID-19 pandemic on Gastroenterology Divisions across Italy.

METHODS

All members of the Italian Society of Gastroenterology (SIGE) were invited to answer a web-based survey.

RESULTS

Data of 121 hospitals from all 20 Italian regions were analyzed. Overall, 10.7% Gastroenterology Divisions have been converted to Covid Units. Outpatients consultations, endoscopic and ultrasound procedures were limited to urgencies and oncology indications in 85.1%, 96.2% and 72.2% of Units, respectively, and 46.7% of them suspended the screening for colorectal cancer. Moreover, 72.2% of the staff received a training for use of personal protective equipment, although 45.5% did not have sufficient devices for adequate replacement. Overall, 132 healthcare workers in 41 Gastroenterology Divisions were found to be infected.

CONCLUSION

This is the first study to evaluate, at a country level, the impact of COVID-19 outbreak on Gastroenterology Divisions. Substantial changes of practice and reduction of procedures have been recorded in the entire country. The long-term impact of such modifications is difficult to estimate but potentially very risky for many digestive diseases.

A Transparent and Adaptable Method to Extract Colonoscopy and Pathology Data Using Natural Language Processing

Key variables recorded as text in colonoscopy and pathology reports have been extracted using natural language processing (NLP) tools that were not easily adaptable to new settings. We aimed to develop a reliable NLP tool with broad adaptability. During 1996-2016, Kaiser Permanente Northern California performed 401,566 colonoscopies with linked pathology. We randomly sampled 1000 linked reports into a Training Set and developed an NLP tool using SAS® PERL regular expressions. The NLP tool captured five colonoscopy and pathology variables: type, size, and location of polyps; extent of procedure; and quality of bowel preparation. We used a Validation Set (N = 3000) to confirm the variables' classifications using manual chart review as the reference. Performance of the NLP tool was assessed using the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and Cohen's κ. Cohen's κ ranged from 93 to 99%. The sensitivity and specificity ranged from 95 to 100% across all categories. For categories with prevalence exceeding 10%, the PPV ranged from 97% to 100% except for adequate quality of preparation (prevalence 92%), for which the PPV was 65%. For categories with prevalence below 10%, the PPVs ranged from 62% to 100%. NPVs ranged from 94% to 100% except for the "complete" extent of procedure, for which the NPV was 73%. Using information from a large community-based population, we developed a transparent and adaptable NLP tool for extracting five colonoscopy and pathology variables. The tool can be readily tested in other healthcare settings.