Risk Factors of Advanced Adenoma in Small and Diminutive Colorectal Polyp

Increased risk of colorectal adenoma and benign colorectal polyp associated with Helicobacter pylori infection: a systematic review and meta-analysis

Background

Although the association between Helicobacter pylori (H. pylori) infection and the risk of colorectal adenomas (CRAs) is suggested, specific analysis of the histological subtype of CRA is limited. The aim of the study was to conduct a meta-analysis on the risk of histological classifications of CRA as benign colorectal polyp (BCP), CRA, and advanced CRA to investigate the effects of H. pylori.

Methods

A comprehensive literature searches of the PubMed, Embase, and Cochrane databases through January 2024. Meta-regression analysis was conducted to identify potential moderators (e.g., histological subtype and ethnic groups).

Results

Among the 503,365 participants across 40 studies, H. pylori was consistently associated with increased probabilities of BCP, CRA, and advanced CRA. In BCP, H. pylori positive was found to be associated with an increase [odds ratio (OR), 1.430; 95% confidence interval (CI): 1.292-1.583]. In CRA and advanced CRA, H. pylori positive was found to be associated with an increase (OR, 1.711; 95% CI: 1.408-2.080). In subgroup analysis by ethnicity, Western group had lower OR compared to Asian, with a statistically significant difference observed (Western OR, 1.369; 95% CI: 1.222-1.535 vs. Asian OR, 1.990; 95% CI: 1.416-2.796, P=0.04).

Conclusions

This systematic review and meta-analysis findings revealed a significant association between H. pylori infection and BCP, CRA, and advanced CRA. In particular, meta-regression analysis confirmed that ethnicity acts as a risk factor in both BCP and CRA.

Comparison of traction vs. snare as rescue methods for challenging colorectal endoscopic submucosal dissection: Propensity score-matched study

Background and study aims

To address the challenges of difficult colorectal endoscopic submucosal dissection (ESD), conversion to snare resection (rescue-snare ESD: rSnare), a variant of hybrid ESD, is commonly proposed. However, rSnare is associated with a lower en bloc resection rate compared with conventional ESD. Traction-assisted ESD has emerged as a technique to facilitate dissection, but its effectiveness as a rescue method remains unclear. This study was the first to compare the effectiveness of rSnare and rescue-traction-assisted ESD (rTraction).

Patients and methods

This retrospective study involved 1464 consecutive lesions from 1372 patients with superficial colorectal neoplasms across eight institutions. Among these, 162 lesions required rescue methods of rSnare or rTraction. After propensity score matching, 88 lesions treated with either rSnare or rTraction were analyzed.

Results

The rTraction group exhibited significantly higher en bloc resection and R0 resection rates (93.2% and 77.3%, respectively) compared with the rSnare group (45.5% and 38.6%, respectively). However, average procedure time was significantly longer in the rTraction group (122.3 ± 72.5 min) compared with the rSnare group (92.2 ± 54.2 min). In the rTraction group, univariable and multivariable analyses identified traction initiation time > 75 minutes as the only independent predictor of procedure durations exceeding 120 minutes.

Conclusions

Utilizing a traction device as a rescue technique in difficult colorectal ESD resulted in higher en bloc and R0 resection rates compared with conversion to snare resection. Initiating traction within 75 minutes may contribute to reducing overall procedure time for challenging colorectal ESD cases.

A comprehensive RCT in screening, surveillance, and diagnostic AI-assisted colonoscopies (ACCENDO-Colo study)

BACKGROUND AND AIMS

Adenoma detection rate (ADR) serves as a primary quality metric in colonoscopy. Various computer-aided detection (CADe) tools have emerged, yielding diverse impacts on ADR across different demographic cohorts. This study aims to evaluate a new CADe system in patients undergoing colonoscopy.

METHODS

This is an Italian multicenter randomized control trial (RCT) that included patients aged 40-85 scheduled for screening, surveillance or diagnostic colonoscopy randomly assigned to CADe or standard colonoscopy (SC). Patients with a Boston Bowel Preparation Scale < 2 in any segment were excluded. The primary outcome was ADR in both groups. Secondary outcomes included adenoma per colonoscopy (APC), polyp per colonoscopy (PPC) and sessile serrated lesion detection rate (SSLDR).

RESULTS

1228 patients were enrolled of whom 70 were excluded for inadequate bowel cleansing or missed cecal intubation. Therefore, 1158 subjects (578 CADe vs 580 SC) were included in the final analysis. ADR was significantly higher in CADe than in the control group (50.2 % vs 40.5 %, p = 0.001). CADe also significantly increased PPC and APC (1.64 ± 2.03 vs 1.23 ± 1.72, p < 0.001; 1.16 ± 1.82 vs 0.80 ± 1.46 p < 0.001; respectively). No significant differences were found in SSLDR between CADe and SC (12.1 % vs 11.0 %, p = 0.631).

CONCLUSIONS

The results of this RCT indicate that AI-assisted colonoscopy significantly improved ADR in a non-selected population undergoing colonoscopy without causing any significant delay in procedure time or increasing the detection of nonneoplastic lesions. (Ethical committee approval: NCT05862948).

The absolute number of small and diminutive adenomas with high-grade dysplasia is substantially higher compared with large adenomas: a retrospective pooled study

Introduction

The risk that a large polyp (≥10 mm) evolves into high-grade dysplasia (HGD) is relatively high compared with that of a small/diminutive polyp (<10 mm). Recently, the detection of small and diminutive polyps has been substantially improved with the advancement of endoscopy. However, further research is needed on the role of the incidence of HGD caused by the co-occurrence of small and diminutive polyps in the progression of HGD. In this study, we aim to investigate whether and how the small and diminutive polyps correlate with the incidence of HGD in the population.

Methods

The pooled data were deeply analyzed from four published randomized controlled trials (RCTs) regarding colon polyp detection. All polyps detected were examined and confirmed by pathologists. The primary outcome was the composition ratio of the HGD polyps in each polyp size category.

Results

Among a total of 3,179 patients with 2,730 polyps identified, there were 83 HGD polyps confirmed, and 68 patients had at least one polyp with HGD. The risk of development of HGD was lower for a single small and diminutive polyp than for one large polyp (2.18% vs. 22.22%, P < 0.0001). On the contrary, the composition ratio for HGD from small and diminutive polyps was significantly higher than that from the large ones (68.67% vs. 31.33%, P < 0.0001). The combined number of HGD presented a trend negatively correlated to size.

Conclusions

Our data demonstrated that the absolute number of HGD significantly derives more from small and diminutive polyps than from the large ones, and the collective number of small and diminutive polyps per patient is indicative of his/her HGD exposure. These findings positively provide novel perspectives on the management of polyps and may further optimize the prevention of colorectal cancer.

Systematic Review Registration

http://www.chictr.org.cn, identifier ChiCTR1900025235, ChiCTR1800017675, ChiCTR1800018058, and ChiCTR1900023086.

Artificial intelligence for colorectal neoplasia detection during colonoscopy: a systematic review and meta-analysis of randomized clinical trials

BACKGROUND

The use of artificial intelligence (AI) in detecting colorectal neoplasia during colonoscopy holds the potential to enhance adenoma detection rates (ADRs) and reduce adenoma miss rates (AMRs). However, varied outcomes have been observed across studies. Thus, this study aimed to evaluate the potential advantages and disadvantages of employing AI-aided systems during colonoscopy.

METHODS

Using Medical Subject Headings (MeSH) terms and keywords, a comprehensive electronic literature search was performed of the Embase, Medline, and the Cochrane Library databases from the inception of each database until October 04, 2023, in order to identify randomized controlled trials (RCTs) comparing AI-assisted with standard colonoscopy for detecting colorectal neoplasia. Primary outcomes included AMR, ADR, and adenomas detected per colonoscopy (APC). Secondary outcomes comprised the poly missed detection rate (PMR), poly detection rate (PDR), and poly detected per colonoscopy (PPC). We utilized random-effects meta-analyses with Hartung-Knapp adjustment to consolidate results. The prediction interval (PI) and I2 statistics were utilized to quantify between-study heterogeneity. Moreover, meta-regression and subgroup analyses were performed to investigate the potential sources of heterogeneity. This systematic review and meta-analysis is registered with PROSPERO (CRD42023428658).

FINDINGS

This study encompassed 33 trials involving 27,404 patients. Those undergoing AI-aided colonoscopy experienced a significant decrease in PMR (RR, 0.475; 95% CI, 0.294-0.768; I2 = 87.49%) and AMR (RR, 0.495; 95% CI, 0.390-0.627; I2 = 48.76%). Additionally, a significant increase in PDR (RR, 1.238; 95% CI, 1.158-1.323; I2 = 81.67%) and ADR (RR, 1.242; 95% CI, 1.159-1.332; I2 = 78.87%), along with a significant increase in the rates of PPC (IRR, 1.388; 95% CI, 1.270-1.517; I2 = 91.99%) and APC (IRR, 1.390; 95% CI, 1.277-1.513; I2 = 86.24%), was observed. This resulted in 0.271 more PPCs (95% CI, 0.144-0.259; I2 = 65.61%) and 0.202 more APCs (95% CI, 0.144-0.259; I2 = 68.15%).

INTERPRETATION

AI-aided colonoscopy significantly enhanced the detection of colorectal neoplasia detection, likely by reducing the miss rate. However, future studies should focus on evaluating the cost-effectiveness and long-term benefits of AI-aided colonoscopy in reducing cancer incidence.

FUNDING

This work was supported by the Heilongjiang Provincial Natural Science Foundation of China (LH2023H096), the Postdoctoral research project in Heilongjiang Province (LBH-Z22210), the National Natural Science Foundation of China's General Program (82072640) and the Outstanding Youth Project of Heilongjiang Natural Science Foundation (YQ2021H023).

The incremental yield of adenoma detection with I-Scan versus high-definition white light colonoscopy-a systematic review and meta-analysis of randomized studies

INTRODUCTION

The incremental yield of I-Scan virtual chromoendoscopy compared to high-definition white light endoscopy (HD-WLE) in detection of colorectal adenomas has not been thoroughly elucidated.

METHODS

A systematic search from inception to April 2023 was conducted to identify randomized controlled trials (RCTs) comparing I-Scan to HD-WLE for detection of adenomas. A random effects model was used to compute risk difference (RD) with corresponding 95% confidence intervals in adenoma detection rate (ADR). Influence analysis was done to assess robustness of findings. The number needed to diagnose was computed. Heterogeneity was assessed using the I2 statistic and explored further by subgroup analyses defined a priori. Certainty in effect estimates was assessed using the GRADE approach.

RESULTS

We identified four studies (I-Scan n = 730, HD-WLE n = 765). I-Scan increased adenoma detection by 9% (risk difference (RD), 0.09; 0.04, 0.14; I2 02%; certainty, low). Influence analysis revealed that the gain in yield remained statistically significant with exclusion of all but one study. The number needed to capture one additional adenomatous polyp with I-Scan use was 11.2. I-Scan 1 use was associated with a statistically significant gain in ADR, whereas no significant difference in ADR was noted with I-Scan use on subgroup analysis.

DISCUSSION

In conclusion, I-Scan increases the yield of adenoma detection by 9% compared to HD-WLE, with low certainty in the estimate of this effect. Data on the gain in yield of detecting large polyps, sessile serrated lesions, and on the impact of formally training endoscopists and trainees in I-Scan use and similar technology on adenoma detection rate are needed.

Effect of computer-aided colonoscopy on adenoma miss rates and polyp detection: A systematic review and meta-analysis

BACKGROUND AND AIM

Multiple computer-aided techniques utilizing artificial intelligence (AI) have been created to improve the detection of polyps during colonoscopy and thereby reduce the incidence of colorectal cancer. While adenoma detection rates (ADR) and polyp detection rates (PDR) are important colonoscopy quality indicators, adenoma miss rates (AMR) may better quantify missed lesions, which can ultimately lead to interval colorectal cancer. The purpose of this systematic review and meta-analysis was to determine the efficacy of computer-aided colonoscopy (CAC) with respect to AMR, ADR, and PDR in randomized controlled trials.

METHODS

A comprehensive, systematic literature search was performed across multiple databases in September of 2022 to identify randomized, controlled trials that compared CAC with traditional colonoscopy. Primary outcomes were AMR, ADR, and PDR.

RESULTS

Fourteen studies totaling 10 928 patients were included in the final analysis. There was a 65% reduction in the adenoma miss rate with CAC (OR, 0.35; 95% CI, 0.25-0.49, P < 0.001, I²  = 50%). There was a 78% reduction in the sessile serrated lesion miss rate with CAC (OR, 0.22; 95% CI, 0.08-0.65, P < 0.01, I²  = 0%). There was a 52% increase in ADR in the CAC group compared with the control group (OR, 1.52; 95% CI, 1.39-1.67, P = 0.04, I²  = 47%). There was 93% increase in the number of adenomas > 10 mm detected per colonoscopy with CAC (OR 1.93; 95% CI, 1.18-3.16, P < 0.01, I²  = 0%).

CONCLUSIONS

The results of the present study demonstrate the promise of CAC in improving AMR, ADR, PDR across a spectrum of size and morphological lesion characteristics.

Detection of Colorectal Polyps from Colonoscopy Using Machine Learning: A Survey on Modern Techniques

Given the increased interest in utilizing artificial intelligence as an assistive tool in the medical sector, colorectal polyp detection and classification using deep learning techniques has been an active area of research in recent years. The motivation for researching this topic is that physicians miss polyps from time to time due to fatigue and lack of experience carrying out the procedure. Unidentified polyps can cause further complications and ultimately lead to colorectal cancer (CRC), one of the leading causes of cancer mortality. Although various techniques have been presented recently, several key issues, such as the lack of enough training data, white light reflection, and blur affect the performance of such methods. This paper presents a survey on recently proposed methods for detecting polyps from colonoscopy. The survey covers benchmark dataset analysis, evaluation metrics, common challenges, standard methods of building polyp detectors and a review of the latest work in the literature. We conclude this paper by providing a precise analysis of the gaps and trends discovered in the reviewed literature for future work.

Analysis of Patients Undergoing Colonoscopies and the Importance of Exam Quality for Colorectal Cancer Screening

Objective To determine the impact of the quality of colonoscopy examination for colorectal cancer screening.

Methods Retrospective observational study of medical records from patients treated at the endoscopy and colonoscopy service of Hospital Universitário Evangélico Mackenzie (Curitiba, PR, Brazil) from January 2019 to January 2020.

Results The analysis was based on 337 medical records from patients with adenomas identified during colonoscopy, and 1,385 medical records from patients without adenomas. The estimated occurrence rate of diagnosis of adenoma during colonoscopy in the target population of the study was of 19.6%, with a 95% confidence interval ranging from 17.7 to 21.5%. Of the 337 patients with adenoma, 136 (40.4%) presented the advanced form. Statistical analysis indicated a significant association between the quality of colonoscopy preparation and test completion.

Conclusion The quality of colonoscopy images is a critical factor for colorectal cancer screening, as it leads to higher rates of adenoma detection and test completion.

Risk Factors for High-Risk Adenoma on the First Lifetime Colonoscopy Using Decision Tree Method: A Cross-Sectional Study in 6,047 Asymptomatic Koreans

Background/Aims: As risk of colorectal neoplasm is varied even in persons with “average-risk,” risk evaluation and tailored screening are needed. This study aimed to evaluate the risk factors of high-risk adenoma (HRA) in healthy individuals and determine the characteristics of advanced neoplasia (AN) among individual polyps.

Methods: Asymptomatic adults who underwent the first lifetime screening colonoscopy at the Seoul National University Hospital Healthcare System Gangnam Center (SNUH GC) were recruited from 2004 to 2007 as SNUH GC Cohort and were followed for 10 years. Demographic and clinical characteristics were compared between the subjects with and without AN (≥10 mm in size, villous component, and/or high-grade dysplasia and/or cancer) or HRA (AN and/or 3 or more adenomas). For individual polyps, correlations between clinical or endoscopic features and histologic grades were evaluated using a decision tree method.

Results: A total of 6,047 subjects were included and 5,621 polyps were found in 2,604 (43%) subjects. Advanced age, male sex, and current smoking status were statistically significant with regards to AN and HRA. A lower incidence of AN was observed in subjects taking aspirin. In the decision tree model, the location, shape, and size of the polyp, and sex of the subject were key predictors of the pathologic type. A weak but significant association was observed between the prediction of the final tree and the histological grouping (Kendall's tau-c = 0.142, p < 0001).

Conclusions: Advanced neoplasia and HRA can be predicted using several individual characteristics and decision tree models.

Water Exchange Produces Significantly Higher Adenoma Detection Rate Than Water Immersion: Pooled Data From 2 Multisite Randomized Controlled Trials

GOALS

To test the hypothesis that water exchange (WE) significantly increases adenoma detection rates (ADR) compared with water immersion (WI).

BACKGROUND

Low ADR was linked to increased risk for interval colorectal cancers and related deaths. Two recent randomized controlled trials of head-to-head comparison of WE, WI, and traditional air insufflation (AI) each showed that WE achieved significantly higher ADR than AI, but not WI. The data were pooled from these 2 studies to test the above hypothesis.

STUDY

Two trials (5 sites, 14 colonoscopists) that randomized 1875 patients 1:1:1 to AI, WI, or WE were pooled and analyzed with ADR as the primary outcome.

RESULTS

The ADR of AI (39.5%) and WI (42.4%) were comparable, significantly lower than that of WE (49.6%) (vs. AI P=0.001; vs. WI P=0.033). WE insertion time was 3 minutes longer than that of AI (P<0.001). WE showed significantly higher detection rate (vs. AI) of the >10 mm advanced adenomas. Right colon combined advanced and sessile serrated ADR of AI (3.4%) and WI (5%) were comparable and were significantly lower than that of WE (8.5%) (vs. AI P<0.001; vs. WI P=0.039).

CONCLUSIONS

Compared with AI and WI, the superior ADR of WE offsets the drawback of a significantly longer insertion time. For quality improvement focused on increasing adenoma detection, WE is preferred over WI. The hypothesis that WE could lower the risk of interval colorectal cancers and related deaths should be tested.

Risk of Metachronous Advanced Neoplasia in Patients With Multiple Diminutive Adenomas

OBJECTIVES

Individuals with advanced adenomas or three or more adenomas have a higher risk of metachronous advanced neoplasia (AN) and are recommended to undergo surveillance colonoscopy at shorter intervals. However, it is questionable whether patients with multiple (three or more) non-advanced diminutive adenomas should be considered as high-risk.

METHODS

We analyzed 5482 patients diagnosed with one or more adenomas during their first colonoscopy screening and who underwent a follow-up colonoscopy. Patients were categorized into four groups based on adenoma characteristics at baseline: Group 1, 1-2 non-advanced adenomas; Group 2, ≥3 non-advanced, diminutive (1 to 5 mm) adenomas; Group 3, ≥3 non-advanced, small (6-9 mm) adenomas; and Group 4, advanced adenomas.

RESULTS

During a median follow-up of 38 months, the incidence of metachronous AN at surveillance colonoscopy was 5.6%. The incidence of AN was 3.9% in group 1, 5.9% in group 2, 10.6% in group 3, and 22.1% in group 4. The adjusted hazard ratios (HRs) [95% confidence intervals (CIs)] for metachronous AN between group 2, group 3, and group 4, and low risk group 1 were 1.71 (0.99-2.94), 2.76 (1.72-4.44), and 5.23 (3.57-7.68), respectively. Compared with group 4, the adjusted HRs (95% CIs) for group 1, group 2, and group 3 were 0.19 (0.13-0.28), 0.32 (0.18-0.59), and 0.52 (0.31-0.89), respectively.

CONCLUSIONS

We found that patients with three or more non-advanced diminutive adenomas had a borderline increased risk of metachronous AN compared with patients with low risk adenomas.

Colonoscopy conversion after flexible sigmoidoscopy screening: results from the UK Bowel Scope Screening Programme

AIM

In the UK Bowel Scope Screening Programme (BSSP), patients progress to colonoscopy based on high-risk features on flexible sigmoidoscopy (FS). We aim to assess the practice of colonoscopy conversion and predictors of detection of additional adenomas on colonoscopy.

METHOD

The Bowel Cancer Screening database was interrogated and collated with endoscopic and histological findings from patients undergoing colonoscopy following FS between August 2013 and August 2016. Multivariate analysis was performed to identify predictors of new adenomas.

RESULTS

FS was performed on 11 711 patients, with an adenoma detection rate (ADR) of 8.5% and conversion to colonoscopy in 421 (3.6%). The additional ADR at colonoscopy was 35.2%, with one additional malignant diagnosis (0.26%). The adenoma miss rate was 3.6%. On multivariate analysis, a polyp ≥ 10 mm was the only high-risk indication associated with additional ADR at colonoscopy (OR 3.68, 95% CI 1.51-3.65, P < 0.001), in addition to male gender (OR 2.36, 95% CI 1.46-3.83, P < 0.001). Predictors of detection of a new adenoma ≥ 10 mm included: villous adenoma (P = 0.002), polyp ≥ 10 mm (P = 0.007) and male gender (P = 0.039). The presence of any conversion criterion was associated with the detection of any proximal adenoma (P < 0.001) and adenoma ≥ 10 mm (P = 0.031).

CONCLUSION

Male gender, polyps ≥ 10 mm and villous-preponderant histology at FS were predictors of adenomas < 10 mm and ≥ 10 mm at colonoscopy. Further data are required to assess the role for gender-based stratification of conversion criteria.