Age-Based Comparative Analysis of Colorectal Cancer Colonoscopy Screening Findings

Background and Objectives: Colorectal cancer (CRC) incidence is rapidly emerging among individuals <50 years, termed as early-onset colorectal cancer (EOCRC). This study aimed to probe variations in tumorigenic pathology and relevant manifestations (polyp and adenoma incidence) between suspected cases of EOCRC and late-onset CRC (LOCRC; ≥50 years of age). Materials and Methods: Between September 2022 and February 2023, colonoscopy-based screening data from 1653 patients were included in this study. All eligible participants were divided into two groups, depending upon patient age, where Group 1 consisted of 1021 patients aged <50 years while Group 2 consisted of 632 patients aged ≥ 50 years. Polyp samples were collected when identified peri-procedurally and characterized according to World Health Organization criteria. Results: Polyp detection rate was 42% for the <50-year age group, while this was 76% for the ≥50-year age group. Additionally, the <50-year age group predominated in hyperplastic polyp manifestation, particularly within the rectum and sigmoid colon. In addition, the ≥50-year age group had increased prevalence of serrated polyps and differing adenoma manifestations. Conclusions: This investigation served to highlight the importance of age stratification for CRC colonoscopy-based screening effectiveness, with particular reference to evaluations that are based on polyp localization within differing colon regions.

The Impact of Artificial Intelligence in Improving Polyp and Adenoma Detection Rate During Colonoscopy: Systematic-Review and Meta-Analysis

INTRODUCTION

Colonoscopy may detect colorectal polyp and facilitate its removal in order to prevent colorectal cancer. However, substantial miss rate for colorectal adenomas detection still occurred during screening colonoscopy procedure. Nowadays, artificial intelligence (AI) have been employed in trials to improve polyp detection rate (PDR) and adenoma detection rate (ADR). Therefore, we would like to determine the impact of AI in increasing PDR and ADR.

METHODS

The present study adhered to the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-analyses 2020 (PRISMA 2020) statement. To identify relevant literature, comprehensive searches were conducted on major scientific databases, including Pubmed, EBSCO-host, and Proquest. The search was limited to articles published up to November 30, 2022. Inclusion criteria for the study encompassed full-text accessibility, articles written in the English language, and randomized controlled trials (RCTs) that reported both ADR and PDR values, comparing conventional diagnostic methods with AI-aided approaches. To synthesize the data, we computed the combined pooled odds ratio (OR) using a random-effects model. This model was chosen due to the expectation of considerable heterogeneity among the selected studies. To evaluate potential publication bias, the Begg's funnel diagram was employed.

RESULTS

A total of 13 studies were included in this study. Colonoscopy with AI had significantly higher PDR compared to without AI (pooled OR 1.46, 95% CI 1.13-1.89, p = 0.003) and higher ADR (pooled OR 1.58, 95% CI 1.37-1.82, p < 0.00001). PDR analysis showed moderate heterogeneity between included studies (p = 0.004; I2=63%). Furthermore, ADR analysis showed moderate heterogeneity (p < 0.007; I2 = 57%). Additionally, the funnels plot of ADR and PDR analysis showed an asymmetry plot and low publication bias.

CONCLUSION

AI may improve colonoscopy result quality through improving PDR and ADR.

Advancing Colorectal Cancer Screening: A Comprehensive Systematic Review of Artificial Intelligence (AI)-Assisted Versus Routine Colonoscopy

Colorectal cancer (CRC) is a rapidly escalating public health concern, which underlines the significance of its early detection and the need for the refinement of current screening methods. In this systematic review, we aimed to analyze the potential advantages and limitations of artificial intelligence (AI)-based computer-aided detection (CADe) systems as compared to routine colonoscopy. This review begins by shedding light on the global prevalence and mortality rates of CRC, highlighting the urgent need for effective screening techniques and early detection of this cancer type. It addresses the problems associated with undetected adenomas and polyps and the subsequent risk of interval CRC following colonoscopy. The incorporation of AI into diagnostics has been studied, specifically the use of CADe systems which are powered by deep learning. The review summarizes the findings from 13 randomized controlled trials (RCTs) (2019-2023), evaluating the impact of CADe on polyp and adenoma detection. The findings from the studies consistently show that CADe is superior to conventional colonoscopy procedures in terms of adenoma detection rate (ADR) and polyp detection rate (PDR), particularly with regard to small and flat lesions which are easily overlooked. The review acknowledges certain limitations of the included studies, such as potential performance bias and geographic limitations. The review ultimately concludes that AI-assisted colonoscopy can reduce missed lesion rates and improve CRC diagnosis. Collaboration between experts and clinicians is key for successful implementation. In summary, this review analyzes recent RCTs on AI-assisted colonoscopy for polyp and adenoma detection. It describes the likely benefits, limitations, and future implications of AI in enhancing colonoscopy procedures and lowering the incidence of CRC. More double-blinded trials and studies among diverse populations from different countries must be conducted to substantiate and expand upon the findings of this review.

Exploring the Influence of Age, Gender and Body Mass Index on Colorectal Cancer Location

Background and objectives: The global burden of non-communicable diseases like obesity and cancer, particularly colorectal cancer (CRC), is increasing. The present study aimed to investigate the association between CRC location (proximal vs. distal) and patient demographic factors including age, sex, and BMI, as well as cancer stage at diagnosis. Materials and Methods: In this cross-sectional study, data from 830 patients diagnosed with CRC were analyzed. The variables included age, sex, weight, height, BMI, cancer location, and cancer stage at diagnosis. Patients were stratified into three age groups and three BMI categories, and we analyzed the association between cancer location and these variables using Chi-squared tests and multivariate logistic regression. Results: The rectum and ascending colon were the most common locations of malignant neoplasms. No statistically significant differences in cancer location across age groups were observed. Significant differences were found in the BMI across age groups, particularly in the normal weight and overweight categories. Normal weight and obese patients had a higher proportion of Stage 3 and Stage 4 cancers. Obesity emerged as a significant predictor for rectal cancer in a multivariate logistic regression analysis, with an odds ratio of 1.56. However, no significant associations were found between cancer location and other factors like age, gender, or cancer stage. Conclusions: Our study revealed that normal weight and obese patients had a higher proportion of Stage 3 and Stage 4 cancers, with obesity emerging as a significant predictor for rectal cancer. It is important to note that while obesity was found to be a significant predictor for rectal cancer, the development and location of colorectal cancer is likely influenced by various factors beyond those studied here. Therefore, further research is needed to investigate the roles of other potential risk factors, like loss of SIRT6 and adipose tissue homeostasis. Additionally, inflammation associated with microbiota in the colorectal mucosa, systemic gene expression, and visceral obesity may also play important roles in the development and progression of colorectal cancer. Understanding these intricate relationships is crucial for better screening, disease prognosis, and management strategies.

Eye tracking technology in endoscopy: Looking to the future

The visual patterns of an endoscopist, that is, what the endoscopist is looking at during luminal endoscopy, is an interesting area with an evolving evidence base. The tools required for gaze analysis have become cheaper and more easily accessible. A comprehensive literature search was undertaken identifying 19 relevant papers. Gaze analysis has been used to identify certain visual patterns associated with higher polyp detection rates. There have also been increasing applications of gaze analysis as an objective study tool to compare the effectiveness of endoscopic imaging technologies. Gaze analysis also has the potential to be incorporated into endoscopic training. Eye movements have been used to control and steer a robotic endoscope. This review presents the current evidence available in this novel and evolving field of endoscopic research.

Negative effect of prolonged cecal intubation time on adenoma detection in female patients

Background and Aim

Withdrawal time of the colonoscope is associated with adenoma detection. However, the association between cecal intubation time and adenoma detection remains unclear. This study aimed to evaluate the association between cecal intubation time and adenoma detection.

Methods

This retrospective study analyzed prospectively collected data from a randomized controlled trial on female patients who underwent colonoscopy in an academic hospital. The primary outcome was the mean number of all adenomas detected per patient. Secondary outcomes included the mean number of advanced, diminutive, small/large, right-sided colonic, and left-sided colonic adenomas detected per patient. Furthermore, the detection rates of all categories of adenoma were evaluated.

Results

The analysis included 216 female patients aged ≥20 years. The correlation analysis did not reveal a significant relationship (P = 0.473) between cecal intubation and withdrawal times. The mean number of all adenomas detected per patient declined by approximately 30% (1.05-0.70) from the fastest to the slowest insertion time quartile. Adjusted regression analysis showed a significant decrease in the mean number of all adenomas detected per patient with increased intubation time (relative risk, RR = 0.87; 95% confidence interval, 0.76-0.99, P = 0.045), whereas the mean number of other categories of adenomas detected per patient and the detection rates of all categories of adenoma were not associated with the cecal intubation time.

Conclusions

This study showed a significant association between prolonged cecal intubation time and decreased adenoma detection. The cecal intubation time may be a significant quality indicator for colonoscopy.

High Adenoma Detection Rates in Fecal Immunochemical Test-Based Colorectal Cancer Screening: Interim Results of the National Bowel Cancer Screening Program in Qatar

INTRODUCTION

Colorectal cancer is one of the most common cancers globally. Recent reductions in mortality rates have been primarily attributed to screening programs. The State of Qatar established a national bowel cancer screening program in 2016.

METHODOLOGY

Fecal immunochemical testing (FIT) was used for average-risk individuals aged 50 to 74 years. Fecal immunochemical testing -positive participants were referred for total colonoscopy to detect polyps and cancers.

RESULTS

Among 32,751 FIT invitees, 11,130 took the test, and 758 (6%) of those were FIT positive. Of these, 375 (56.13%) participants underwent a colonoscopy, and polyps were detected in 198 (52.8%) and cancers in 19 (5.1%) participants. The adenoma detection rate exceeded 40%.

DISCUSSION AND CONCLUSION

The high yield of polyps and cancers in the screening program justifies an active, resource-intensive, and organized bowel cancer screening effort. The high adenoma detection rate in a FIT-based program warrants recalibration of target adenoma detection rates in screening programs.

Factors associated with lesion detection in colonoscopy among different indications

BACKGROUND AND OBJECTIVE

Different factors may influence colonoscopy performance measures. We aimed to analyze procedure- and endoscopist-related factors associated with detection of colorectal lesions and whether these factors have a similar influence in the context of different colonoscopy indications: positive fecal immunochemical test (+FIT) and post-polypectomy surveillance colonoscopies.

METHODS

This multicenter cross-sectional study included adults aged 40-80 years. Endoscopists (N = 96) who had performed ≥50 examinations were assessed for physician-related factors. Adenoma detection rate (ADR), adenomas per colonoscopy rate (APCR), advanced ADR, serrated polyp detection (SDR), and serrated polyps per colonoscopy rate (SPPCR) were calculated.

RESULTS

We included 12,932 procedures, with 4810 carried out after a positive FIT and 1967 for surveillance. Of the 96 endoscopists evaluated, 43.8% were women, and the mean age was 41.9 years. The ADR, advanced ADR, and SDR were 39.7%, 17.7%, and 12.8%, respectively. Adenoma detection rate was higher in colonoscopies after a +FIT (50.3%) with a more than doubled advanced ADR compared to non-FIT procedures (27.6% vs. 13.0%) and similar results in serrated lesions (14.7% vs. 13.5%). Among all the detection indicators analyzed, withdrawal time was the only factor independently related to improvement (p < 0.001). Regarding FIT-positive and surveillance procedures, for both indications, withdrawal time was also the only factor associated with a higher detection of adenomas and serrated polyps (p < 0.001). Endoscopist-related factors (i.e., weekly hours dedicated to endoscopy, annual colonoscopy volume and lifetime number of colonoscopies performed) had also impact on lesion detection (APCR, advanced ADR and SPPCR).

CONCLUSIONS

Withdrawal time was the factor most commonly associated with improved detection of colonic lesions globally and in endoscopies for + FIT and post-polypectomy surveillance. Physician-related factors may help to address strategies to support training and service provision. Our results can be used for establishing future benchmarking and quality improvement in different colonoscopy indications.

Yield of Post-Acute Diverticulitis Colonoscopy for Ruling Out Colorectal Cancer

BACKGROUND AND AIMS

Colonoscopy is recommended post-acute diverticulitis (AD) to exclude underlying adenocarcinoma (CRC). However, post-AD colonoscopy utility remains controversial. We aimed to examine yield of post-AD colonoscopy in our majority-Hispanic patient population.

METHODS

Patients undergoing post-AD colonoscopy between 11/1/2015-7/31/2021 were identified from a prospectively maintained endoscopic database. AD cases without computed tomography confirmation were excluded. Pertinent data, including complicated vs uncomplicated AD, fecal immunochemical test (FIT) result post-AD/pre-colonoscopy, and number/type/location of non-advanced adenomas, advanced adenomas, and CRC, were abstracted. Analyses were conducted using two-sample Wilcoxon rank-sum and Fisher's exact tests.

RESULTS

208 patients were included, of whom 62.0% had uncomplicated AD. Median age was 53, 54.3% were female, and 77.4% were Hispanic. Ninety non-advanced adenomas were detected in 45 patients (21.6%), in addition to advanced adenoma in eight patients (3.8%). Two patients (1.0%) had CRC, both of whom had complicated AD in the same location seen on imaging, and one of whom was FIT+ (the other had not undergone FIT). Patients with uncomplicated versus complicated AD had similarly low rates of advanced adenomas (4.7% vs. 2.5%, p=0.713). FIT data were available in 51 patients and positive in three (5.9%); non-advanced adenomas were found in all three FIT+ patients. No FIT- patient had an advanced adenoma or CRC.

CONCLUSION

Colonoscopy post-AD is generally low yield, with CRC being rare and found only in those with complicated AD. Colonoscopy post-complicated AD appears advisable, whereas less invasive testing (e.g. FIT) may be considered post-uncomplicated AD to inform the need for colonoscopy.

Conventional Colonoscopy for Polyp and Adenoma Detection: A Systematic Review of 7 Discordant Meta-Analyses

Objectives: Multiple meta-analyses which investigated the comparative efficacy and safety of artificial intelligence (AI)-aid colonoscopy (AIC) vs. conventional colonoscopy (CC) in the detection of polyp and adenoma have been published. However, a definitive conclusion has not yet been generated. This systematic review selected from discordant meta-analyses to draw a definitive conclusion about whether AIC is better than CC for the detection of polyp and adenoma. Methods: We comprehensively searched potentially eligible literature in PubMed, Embase, Cochrane library, and China National Knowledgement Infrastructure (CNKI) databases from their inceptions until to April 2021. Assessment of Multiple Systematic Reviews (AMSTAR) instrument was used to assess the methodological quality. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was used to assess the reporting quality. Two investigators independently used the Jadad decision algorithm to select high-quality meta-analyses which summarized the best available evidence. Results: Seven meta-analyses met our selection criteria finally. AMSTAR score ranged from 8 to 10, and PRISMA score ranged from 23 to 26. According to the Jadad decision algorithm, two high-quality meta-analyses were selected. These two meta-analyses suggested that AIC was superior to CC for colonoscopy outcomes, especially for polyp detection rate (PDR) and adenoma detection rate (ADR). Conclusion: Based on the best available evidence, we conclude that AIC should be preferentially selected for the route screening of colorectal lesions because it has potential value of increasing the polyp and adenoma detection. However, the continued improvement of AIC in differentiating the shape and pathology of colorectal lesions is needed.

Gastrointestinal endoscopy nurse assistance during colonoscopy and polyp detection: A PRISMA-compliant meta-analysis of randomized control trials

BACKGROUND

Previous studies showed difference results about the effect of nurse in improvement of the colonoscopy detection rate. This meta-analysis aims to investigate whether nurse participation during colonoscopy can help in improving the detection rate of polyps and adenomas.

METHODS

Original studies in English were searched from the MEDLINE database, PubMed, Web of Science, and the Cochrane Library database. Randomized control trials (RCT) comparing colonoscopy with and without nurse participation for the detection of colorectal polyps and adenomas were identified. A meta-analysis was performed using Revman 5.3 software.

RESULTS

A total of 2268 patients from 4 RCTs were included in this meta-analysis. Outcomes of colonoscopy with nurse participation were compared with those of colonoscopy without nurse participation. The results showed that nurses' participation during colonoscopy could significantly increase both, polyp detection rate and adenoma detection rate.

CONCLUSION

Nurse assistance during colonoscopy can help improve the rate of detection of polyps and adenomas.

Improved adenoma detection with linked color imaging technology compared to white-light colonoscopy

OBJECTIVES

Linked color imaging (LCI) is a new endoscopic technology that may increase colorectal adenoma detection rate (ADR) and polyp detection rate (PDR) by virtual chromoendoscopy. Aim of the present study was to evaluate the effectiveness of LCI in ADR and PDR compared to the HD white-light colonoscopy (WLC) technique.

MATERIALS AND METHODS

Between October 2016 and June 2018, we enrolled consecutive outpatients prospectively. Eligible patients allocated randomly to undergo HD WLC or LCI colonoscopy technique during instrument withdrawal. Each colonoscopy was performed in a single center by the same three expert endoscopists (with expertise more than 5000 colonoscopies).

RESULTS

A total of 1278 patients underwent colonoscopy in the study period. ADR and PDR were significantly higher in the LCI group compared to the WLC group (34.4% vs. 26.8%; p = .007; and 53.3% vs 46.4%; p = .023, respectively). Similarly, the mean number of adenomas per patient (MAP) was significantly higher with the LCI than WLC (0.64 vs 0.44, respectively; p = .002). The mean age of patients at the time of colonoscopy was 51.95 years (SD = 13.861) in the LCI group and 51.96 years (SD = 14.028) in the WLC group. No significant differences observed in patient demographic characteristics (there was no difference in gender and age distribution, p = .986), quality of colonoscopy preparation and withdrawal times (WT) between the two groups (WLC and the LCI groups, 493.9 (SD: 143.5) and 514.0 (SD: 139.5) sec, respectively).

CONCLUSIONS

According to our results, LCI virtual chromoendoscopic technology was superior compared to conventional HD WLC in detecting colorectal polyps and adenomas.

Impact of cuff-assisted colonoscopy for adenoma detection: A protocol of systematic review and meta-analysis

BACKGROUND

Previous studies have reported that cuff-assisted colonoscopy (CAC) can be used for detection of adenoma (DA). However, there are inconsistent results regarding the CAC for DA. Thus, this study will systematically explore the impact of CAC for DA.

METHODS

In order to retrieve potential eligible articles, this study will identify the following electronic databases from their inceptions to present: MEDLINE, EMBASE, Cochrane Library, PSYCINFO, Web of Science, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure. All electronic databases will be searched without any language limitation. We will consider case-controlled studies that focused on exploring the impacts of CAC for DA. Two authors will perform study selection, information collection and risk of bias assessment, respectively. Any discrepancies between 2 authors will be resolved through discussion with a third author.

RESULTS

This study will summarize the most recent evidence to assess the impact of CAC for DA.

CONCLUSION

The findings of this study will provide evidence of CAC for DA in clinical practice.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202040042.

Providing data for serrated polyp detection rate benchmarks: an analysis of the New Hampshire Colonoscopy Registry

BACKGROUND AND AIMS

Similar to achieving adenoma detection rate (ADR) benchmarks to prevent colorectal cancer (CRC), achieving adequate serrated polyp detection rates (SDRs) may be essential to the prevention of CRC associated with the serrated pathway. Previous studies have been based on data from high-volume endoscopists at single academic centers. Based on a hypothesis that ADR is correlated with SDR, we stratified a large, diverse group of endoscopists (n = 77 practicing at 28 centers) into high performers and low performers, based on ADR, to provide data for corresponding target SDR benchmarks.

METHODS

By using colonoscopies in adults aged ≥50 years (4/09-12/14), we stratified endoscopists by high and low ADRs (<15%, 15%-<25%, 25%-<35%, ≥35%) to determine corresponding SDRs by using 2 SDR measures, for screening and surveillance colonoscopies separately: (1) Clinically significant SDR (CSSDR), meaning colonoscopies with any sessile serrated adenoma/polyp (SSA/P), traditional serrated adenoma (TSA), or hyperplastic polyp (HP) >1 cm anywhere in the colon or HP >5 mm in the proximal colon only divided by the total number of screening and surveillance colonoscopies, respectively. (2) Proximal SDR (PSDR) meaning colonoscopies with any serrated polyp (SSA/P, HP, TSA) of any size proximal to the sigmoid colon divided by the total number of screening and surveillance colonoscopies, respectively.

RESULTS

A total of 45,996 (29,960 screening) colonoscopies by 77 endoscopists (28 facilities) were included. Moderately strong positive correlation coefficients were observed for screening ADR/CSSDR (P = .69) and ADR/PSDR (P = .79) and a strong positive correlation (P = .82) for CSSDR/PSDR (P < .0001 for all) was observed. For ADR ≥25%, endoscopists' median (interquartile range) screening CSSDR was 6.8% (4.3%-8.6%) and PSDR was 10.8% (8.6%-16.1%).

CONCLUSIONS

Derived from ADR, the primary colonoscopy quality indicator, our results suggest potential SDR benchmarks (CSSDR = 7% and PSDR = 11%) that may guide adequate serrated polyp detection. Because CSSDR and PSDR are strongly correlated, endoscopists could use the simpler PSDR calculation to assess quality.

Antispasmodic drugs in colonoscopy: a review of their pharmacology, safety and efficacy in improving polyp detection and related outcomes

Antispasmodic drugs are cheap, effective and generally safe. They may improve outcomes in colonoscopy, however their use has not been consistent or widespread. This manuscript reviews the three most commonly used antispasmodics in colonoscopy, namely, hyoscine butylbromide (and related ammonium compounds), glucagon and peppermint oil. The pharmacology, action and safety of the agents, as well as the evidence for them improving colonoscopic outcomes will be discussed. In addition to polyp detection, other colonoscopic outcome endpoints of interest include cecal and ileal intubation, and patient comfort. The drugs studied were all found to be effective gastrointestinal antispasmodics with good safety profiles. There is insufficient evidence to conclude whether antispasmodics improve cecal intubation rate, predominantly because the baseline rates are already high. Antispasmodics probably have efficacy in reducing cecal intubation time especially in those with marked colonic spasm. Antispasmodics do not offer significant benefit in polyp detection or improving patient comfort during colonoscopy. Future studies should focus on inexperienced colonoscopists as well as those with marked colonic spasm, in whom the greatest benefit seems to lie.

Adenoma Detection Rates for Screening Colonoscopies in Smokers and Obese Adults: Data From the New Hampshire Colonoscopy Registry

GOAL

To examine screening adenoma detection rates (ADR) and serrated detection rates (SDR) among smokers and obese adults in the New Hampshire Colonoscopy Registry.

BACKGROUND

ADR, a quality measure for screening colonoscopies, is associated with protection from interval colorectal cancer. Currently, only sex-specific ADR benchmarks are reported. However, obesity and smoking ≥20 pack-years are strong predictors for colorectal neoplasia, as highlighted by the 2009 American College of Gastroenterology CRC Screening Guidelines. Data comparing ADR in smokers and obese adults to those without these risks are limited.

STUDY

We calculated ADR, SDR, and 95% confidence intervals for screening colonoscopies in participants ≥50 years. Sex-specific and sex-age-specific rates were compared by smoking exposure (never vs. <20 vs. ≥20 pack-years) and body mass index (<30 vs. ≥30).

RESULTS

A total of 21,539 screening colonoscopies were performed by 77 endoscopists at 20 facilities (April 2009 to September 2013). The difference in ADR between nonsmokers and smokers with ≥20 pack-years was 8.8% (P<0.0001) and between obesity groups 5.0% (P<0.0001). Significant sex-specific and sex-age-specific increases in ADR and SDR were found among smokers and obese participants.

CONCLUSIONS

ADR and SDR for smokers and obese adults were significantly higher than their counterparts without those risks. Endoscopists should consider the prevalence of these risks within their screening population when comparing their rates to established benchmarks. Calculating sex-specific or sex-age-specific ADR and SDR based on smoking and obesity may provide optimal protection for populations with a particularly high prevalence of smokers and obese adults.

The endoscopy evolution: 'the superscope era'

Developments to the design of the flexible endoscope are transforming the field of gastroenterology. There is a drive to improve colonic adenoma detection rates leading to advancements in the design of the colonoscope. Novel endoscopes now allow increased visualisation of colonic mucosa, including behind colonic folds, and aim to reduce pain associated with the procedure. In addition, a shift in surgical paradigm towards minimally invasive endoluminal surgery has meant innovations in flexible platforms are being sought. There are a number of limitations of the basic endoscope. These include a lack of stability and triangulation of instruments. Modifications to the flexible endoscope design form the basis of a number of newly developed and research platforms, some of which are discussed in this review.

Good is better than excellent: bowel preparation quality and adenoma detection rates

BACKGROUND

Inadequate bowel cleansing is associated with missed lesions, yet whether polyp and adenoma detection rates (PDR, ADR) increase at the highest levels of bowel cleanliness is unknown.

OBJECTIVE

To evaluate the association between bowel preparation quality by using the Boston Bowel Preparation Scale (BBPS) and PDR and ADR among colonoscopies with adequate preparation.

DESIGN

Cross-sectional analysis.

SETTING

Boston Medical Center (BMC) and the Clinical Outcomes Research Initiative (CORI).

PATIENTS

Average-risk ambulatory patients attending screening colonoscopy with adequate bowel preparation defined as BBPS score ≥6.

INTERVENTIONS

Colonoscopy.

MAIN OUTCOME MEASUREMENTS

PDR and ADR stratified by BBPS score.

RESULTS

Among the 3713 colonoscopies at BMC performed by 19 endoscopists, the PDR, ADR, and advanced ADR were 49.8%, 37.7%, and 6.0%, respectively. Among the 5532 colonoscopies in CORI performed by 85 endoscopists at 41 different sites, the PDR was 44.5%, and the PDR for polyps >9 mm (surrogate for advanced ADR) was 6.2%. The PDR associated with total BBPS scores of 6, 7, and 8 were higher than those associated with a BBPS score of 9 at BMC (BBPS 6, 51%; BBPS 7, 53%; BBPS 8, 52% vs BBPS 9, 46%; P = .002) and CORI (BBPS 6, 51%; BBPS 7, 48%; BBPS 8, 45% vs BBPS 9, 40%; P < .0001). This trend persisted after we adjusted for age, sex, and race and/or ethnicity and was observed for ADR and advanced ADR. PDR was higher among good compared with excellent preparations at BMC (odds ratio [OR] 1.3; 95% confidence interval [CI], 1.0-1.5) and CORI (OR 4.7; 95% CI, 3.1-7.1).

LIMITATIONS

Retrospective study.

CONCLUSION

The PDR and ADR decreased at the highest levels of bowel cleanliness. Endoscopists finding a pristine bowel preparation should avoid a sense of overconfidence for polyp detection during the inspection phase of screening colonoscopy and still perform a careful evaluation for polyps. Furthermore, endoscopists expending additional effort to maximize cleansing of the bowel should never sacrifice on their inspection technique or inspection time.

Adenoma detection rates decline with increasing procedural hours in an endoscopist's workload

BACKGROUND

Operator fatigue may negatively influence adenoma detection (AD) during screening colonoscopy.

OBJECTIVE

To better characterize factors affecting AD, including the number of hours worked, and the number and type of procedures performed before an index screening colonoscopy.

METHODS

A retrospective cohort study was conducted involving individuals undergoing a screening colonoscopy at a major tertiary care hospital in Montreal, Quebec. Individuals were identified using an endoscopic reporting database; AD was identified by an electronic chart review. A hierarchical logistic regression analysis was performed to determine the association between patient- and endoscopist-related variables and AD.

RESULTS

A total of 430 consecutive colonoscopies performed by 10 gastroenterologists and two surgeons were included. Patient mean (± SD) age was 63.4±10.9 years, 56.3% were males, 27.7% had undergone a previous colonoscopy and the cecal intubation rate was 95.7%. The overall AD rate was 25.7%. Age was associated with AD (OR 1.06 [95% CI 1.03 to 1.08]), while female sex (OR 0.44 [95% CI 0.25 to 0.75]), an indication for average-risk screening (OR 0.47 [95% CI 0.27 to 0.80]) and an increase in the number of hours during which endoscopies were performed before the index colonoscopy (OR 0.87 [95% CI 0.76 to 0.99]) were associated with lower AD rates. On exploratory univariable analysis, a threshold of 3 h of endoscopy time performed before the index colonoscopy was associated with decreased AD.

CONCLUSION

The number of hours devoted to endoscopies before the index colonoscopy was inversely associated with AD rate, with decreased performance possibly as early as within 3 h. This metric should be confirmed in future studies and considered when optimizing scheduling practices.

Emerging technological advancements in colonoscopy: Third Eye® Retroscope® and Third Eye® Panoramic(TM) , Fuse® Full Spectrum Endoscopy® colonoscopy platform, Extra-Wide-Angle-View colonoscope, and NaviAid(TM) G-EYE(TM) balloon colonoscope

Colonoscopy is the criterion standard for detecting colorectal adenomas and cancers. However, multiple studies have reported a significant percentage of adenomas are missed during standard, forward-viewing colonoscopy. Missed adenomas can lead to interval colorectal cancers. Aside from inadequate colon preparation, incomplete examinations (e.g. failure to intubate the cecum), short withdrawal times, and patient-related factors, the primary reason for missing colorectal adenomas and early cancers is poor visualization of the proximal aspect of colonic folds, at anatomical flexures, and in the ileocecal valve area. These anatomical sites tend to be hidden from the standard forward-viewing colonoscope (170-degree angle of view) and can often only be seen through manipulation of the colonoscope by the endoscopist. Thus, there is mounting evidence supporting the need to reduce the adenoma 'miss rate' of standard forward-viewing colonoscopy by improving upon current colonoscope technology and its current visualization/optics limitations. Recently, there are a number of emerging technologies that may help revolutionize how colonoscopy is carried out and that will significantly reduce adenoma miss rates. These include the Third Eye® Retroscope® and Third Eye® Panoramic(TM) (Avantis Medical Systems, Sunnyvale, CA, USA); Fuse® Full Spectrum Endoscopy® colonoscopy platform (EndoChoice Inc., Alpharetta, GA, USA); Extra-Wide-Angle-View colonoscope (Olympus, Tokyo, Japan), and the NaviAid(TM) G-EYE(TM) balloon colonoscope (SMART Medical Systems Ltd, Ra'anana, Israel).

Progress in digestive endoscopy: Flexible Spectral Imaging Colour Enhancement (FICE)-technical review

Background. A substantial advance in digestive endoscopy that has been made during the last decade is represented by digital chromoendoscopy, which was developed as a quicker and sometimes better alternative to the gold standard of dye spraying. Fujifilm developed a virtual coloration technique called Flexible spectral Imaging Color Enhancement (FICE). FICE provides a better detection of lesions of "minimal" esophagitis, of dysplasia in Barrett's esophagus and of squamous cell esophageal cancer. The use of FICE resulted in an improvement in the visualization of the early gastric cancer, being less invasive, and time consuming than the classic dye methods. Current evidence does not support FICE for screening purposes in colon cancer but it definitely improves characterization of colonic lesions. Its use in inflammatory bowel disease is still controversial and in video capsule endoscopy is considered a substantial progress. Conclusions. The use of FICE endoscopy in routine clinical practice can increase the diagnostic yield and can provide a better characterization of lesions. Future studies to validate its use, the good choice of channels, and the "perfect indications" and to provide common definitions and classifications are necessary.

Indigocarmine added to the water exchange method enhances adenoma detection - a RCT

PURPOSE

Chromoendoscopy with dye spray and the water method both increase adenoma detection.

HYPOTHESIS

Adding indigocarmine to the water method will enhance further the effectiveness of the latter in adenoma detection.

METHODS

Screening colonoscopy was performed with the water method (control) or with 0.008% indigocarmine added (study) by two endoscopists. Randomization was based on computer-generated codes contained in blocks of pre-arranged opaque sealed envelopes. High resolution colonoscopes were used. Upon insertion into the rectum, air was suctioned. With the air pump turned off, water was infused using a blunt needle adaptor connected to the scope channel and a foot pump to facilitate scope insertion until the cecum was reached. Residual stool causing cloudiness was suctioned followed by infusion of clear or colored water (water exchange) to facilitate scope passage with minimal distention of the colonic lumen. Upon seeing the appendix opening under water, water was suctioned and air was insufflated to facilitate inspection on scope withdrawal.

STATISTICS

Sample size calculation revealed 168 patients (84/group) needed to be randomized. Study was IRB-approved and registered (NCT01383265).

RESULTS

There were no significant differences in mean age, gender distribution, BMI, and family history of colon cancer. Cecal intubation success rate was 100% in both groups. The overall adenoma detection rate was 44% (water only) versus 62% (water with indigocarmine), respectively (p=0.03). One cancer was detected in each group.

CONCLUSION

In a RCT, indigocarmine at 0.008% concentration, added to the water method, significantly enhanced further the effectiveness of the latter in detecting adenomas.

The stool DNA test is more accurate than the plasma septin 9 test in detecting colorectal neoplasia

BACKGROUND & AIMS

Several noninvasive tests have been developed for colorectal cancer (CRC) screening. We compared the sensitivities of a multimarker test for stool DNA (sDNA) and a plasma test for methylated septin 9 (SEPT9) in identifying patients with large adenomas or CRC.

METHODS

We analyzed paired stool and plasma samples from 30 patients with CRC and 22 with large adenomas from Mayo Clinic archives. Stool (n = 46) and plasma (n = 49) samples from age- and sex-matched patients with normal colonoscopy results were used as controls. The sDNA test is an assay for methylated BMP3, NDRG4, vimentin, and TFPI2; mutant KRAS; the β-actin gene, and quantity of hemoglobin (by the porphyrin method). It was performed blindly at Exact Sciences (Madison, Wisconsin); the test for SEPT9 was performed at ARUP Laboratories (Salt Lake City, Utah). Results were considered positive based on the manufacturer's specificity cutoff values of 90% and 89%, respectively.

RESULTS

The sDNA test detected adenomas (median, 2 cm; range, 1-5 cm) with 82% sensitivity (95% confidence interval [CI], 60%-95%); SEPT9 had 14% sensitivity (95% CI, 3%-35%; P = .0001). The sDNA test identified patients with CRC with 87% sensitivity (95% CI, 69%-96%); SEPT9 had 60% sensitivity (95% CI, 41%-77%; P = .046). The sDNA test identified patients with stage I-III CRC with 91% sensitivity (95% CI, 71%-99%); SEPT9 had 50% sensitivity (95% CI, 28%-72%; P = .013); for stage IV CRC, sensitivity values were 75% (95% CI, 35%-97%) and 88% (95% CI, 47%-100%), respectively (P = .56). False positive rates were 7% for the sDNA test and 27% for SEPT9.

CONCLUSIONS

Based on analyses of paired samples, the sDNA test detects nonmetastatic CRC and large adenomas with significantly greater levels of sensitivity than the SEPT9 test. These findings might be used to modify approaches for CRC prevention and early detection.

Unsedated colonoscopy: is it feasible?

Unsedated colonoscopy has been an evolving subject ever since its initial description four decades ago. Failure in unsedated diagnostic cases due to patient pain led to the introduction of sedation. Extension to screening cases, albeit logical, created a sedation-related barrier to colonoscopy screening. In recent years a water method has been developed to combat the pain during unsedated colonoscopy in the US. In randomized controlled trials the water method decreases pain, increases cecal intubation success, and enhances the proportion of patients who complete unsedated colonoscopy. The salvage cleansing of suboptimal bowel preparation by the water method serendipitously may have increased the detection of adenoma in both unsedated and sedated patients. The state-of-the-art lecture concludes that unsedated colonoscopy is feasible. The hypothesis is that recent advances, such as the development of the water method, may contribute to reviving unsedated colonoscopy as a potentially attractive option for colon cancer screening and deserves to be tested.