Recommendations for Follow-Up After Colonoscopy and Polypectomy: A Consensus Update by the US Multi-Society Task Force on Colorectal Cancer

Enhancing colorectal cancer screening in high-risk population through fecal immunochemical test surveillance: Results from a surveillance program

BACKGROUND

Current guidelines recommend colonoscopy-based surveillance to decrease the risk of colorectal cancer (CRC) among these participants with above-average risk. The fecal immunochemical test (FIT) holds promise as a viable alternative surveillance tool, but the existing evidence regarding the use of settings remains limited. Therefore, our aim is to evaluate the CRC incidence rates in individuals with above-average CRC risk and the relationship between FIT surveillance and CRC incidence.

METHODS

The retrospective cohort study was performed based on the CRC screening program between January 2012 and December 2022, in Tianjin, China. This cohort study included 12,515 participants aged 40-74 years with above-average risk. The primary outcomes were the incidence rates of CRC and advanced colorectal neoplasia which were expressed as the number of events per 100,000 person-years. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models.

RESULTS

We included 12,515 participants aged 40-74 years, of whom 4980 received subsequent FIT surveillance during the study period. Among these participants, 51 CRC cases occurred in the non-FIT surveillance group (incidence rate, 233.88 per 100,000 person-years) and there were 29 cases of CRC in the FIT surveillance group (incidence rate, 184.85 per 100,000 person-years), resulting in an incidence rate ratio (IRR) of 0.58 (95% CI, 0.37-0.91). Meanwhile, 428 advanced colorectal neoplasia cases were reported in the non-FIT surveillance group, while 269 cases occurred in the FIT surveillance group, with significantly lower incidence of advanced colorectal neoplasia in the FIT surveillance group (IRR: 0.64; 95% CI, 0.55-0.74). Compared with the non-FIT surveillance group, the FIT surveillance group had a 54% decreased risk of developing CRC (HR, 0.46; 95% CI, 0.29-0.74) and a 45% decreased risk of developing advanced colorectal neoplasia (HR, 0.55; 95% CI, 0.47-0.64).

CONCLUSIONS

In this retrospective cohort study, above-average risk individuals who received subsequent FIT in the intervals between colonoscopies were associated with a reduction of CRC and advanced colorectal neoplasia incidence, which indicated the value and utility of FIT in the surveillance program.

Polyp size measurement during colonoscopy using a virtual scale: variability and systematic differences

BACKGROUND : Accurate polyp size measurement is important for polyp risk stratification and decision-making regarding polypectomy and surveillance. Recently, a virtual scale (VS) function has been developed that allows polyp size measurement through projection of an adaptive VS onto colorectal polyps during real-time endoscopy. We aimed to evaluate the VS in terms of variability and systematic differences. METHODS : We conducted a video-based study with 120 colorectal polyps, measured by eight dedicated colorectal gastroenterologists (experts) and nine gastroenterology residents following endoscopy training (trainees). Three endoscopic measurement methods were compared: (1) visual, (2) snare and (3) VS measurement. We evaluated the method-specific variance (as measure of variability) in polyp size measurements and systematic differences between these methods. RESULTS : Variance in polyp size measurements was significantly lower for VS measurements compared to visual and snare measurements for both experts (0.52 vs. 1.59 and 1.96, p < 0.001) and trainees (0.59 vs. 2.21 and 2.53, p < 0.001). VS measurement resulted in a higher percentage of polyps assigned to the same size category by all endoscopists compared to visual and snare measurements (experts: 69 % vs. 55 % and 59 %; trainees: 67 % vs. 51 % and 47 %) and reduced the maximum difference between individual endoscopists regarding the percentage of polyps assigned to the ≥ 10 mm size category (experts: 1.7 % vs. 10.0 % and 5.0 %; trainees: 2.5 % vs. 6.7 % and 11.7 %). Systematic differences between methods were < 0.5 mm. CONCLUSIONS : Use of the VS leads to lower polyp size measurement variability and more uniform polyp sizing by individual endoscopists compared to visual and snare measurements.

Visceral Fat Thickness, Serum Adiponectin, and Metabolic Syndrome in Patients with Colorectal Adenomas

BACKGROUND/OBJECTIVES

Most cases of colorectal cancer (CRC) arise from adenomatous polyps. Identifying risk factors for colorectal adenoma (CRA) is critical for CRC prevention. Emerging evidence suggests a link between metabolic syndrome (MetS) and an elevated risk of CRA and CRC, potentially mediated by visceral obesity and adiponectin (APN). We aimed to evaluate the association between different markers of visceral obesity, serum APN, MetS, and the presence of CRA.

METHODS

A cross-sectional study was conducted at the University Clinical Center of Vojvodina, involving 120 patients, aged 40-75 years, who underwent colonoscopy between January 2022 and January 2023. Sixty patients with CRA were compared to 60 controls with normal colonoscopy findings. Visceral fat thickness (VFT) was measured using ultrasound (US), and bioelectrical impedance analysis (BIA) was used to assess visceral fat area (VFA). Serum APN levels, anthropometric measures, and MetS components were also evaluated.

RESULTS

Patients with CRA had significantly higher VFT measured by US (p < 0.05), but no significant differences were found in VFA measured by BIA, waist circumference (WC), or waist-to-hip ratio (WHR). MetS was significantly more prevalent in the CRA group (55% vs. 31.6%, p < 0.05), and logistic regression confirmed MetS as a significant predictor of CRA presence (OR = 2.6). Serum APN levels were inversely correlated with visceral fat measurements and MetS (p < 0.01), but no significant difference in APN levels was observed between patients with and without CRA.

CONCLUSIONS

This study highlights the importance of VFT measured by US and the presence of MetS as significant factors associated with CRA.

AI support for colonoscopy quality control using CNN and transformer architectures

BACKGROUND

Construct deep learning models for colonoscopy quality control using different architectures and explore their decision-making mechanisms.

METHODS

A total of 4,189 colonoscopy images were collected from two medical centers, covering different levels of bowel cleanliness, the presence of polyps, and the cecum. Using these data, eight pre-trained models based on CNN and Transformer architectures underwent transfer learning and fine-tuning. The models' performance was evaluated using metrics such as AUC, Precision, and F1 score. Perceptual hash functions were employed to detect image changes, enabling real-time monitoring of colonoscopy withdrawal speed. Model interpretability was analyzed using techniques such as Grad-CAM and SHAP. Finally, the best-performing model was converted to ONNX format and deployed on device terminals.

RESULTS

The EfficientNetB2 model outperformed other architectures on the validation set, achieving an accuracy of 0.992. It surpassed models based on other CNN and Transformer architectures. The model's precision, recall, and F1 score were 0.991, 0.989, and 0.990, respectively. On the test set, the EfficientNetB2 model achieved an average AUC of 0.996, with a precision of 0.948 and a recall of 0.952. Interpretability analysis showed the specific image regions the model used for decision-making. The model was converted to ONNX format and deployed on device terminals, achieving an average inference speed of over 60 frames per second.

CONCLUSIONS

The AI-assisted quality system, based on the EfficientNetB2 model, integrates four key quality control indicators for colonoscopy. This integration enables medical institutions to comprehensively manage and enhance these indicators using a single model, showcasing promising potential for clinical applications.

The Recurrence Rate of Colorectal Polyps among Patients with Average Risk of Colorectal Cancer

BACKGROUND

CRC is going to be an important issue in Middle East countries. Also, the main parts of this cancer develop from benign adenomas.

AIM

To understand the recurrence rate of colorectal polyps among average-risk subjects.

METHOD

In a prospective study, the average-risk patients with colorectal adenoma were enrolled in this study based on inclusion criteria. The patients were consulted annually by an expert gastroenterologist. A control colonoscopy was programmed after three years of follow-up. It was not an obligation to follow our program, and each patient could exit the study at any time. The patient who developed one of the exclusion criteria was also withdrawn from the study by the gastroenterologist of this study.

RESULTS

237 patients were enrolled in this study. Of them, 102 patients completed their 3-year follow-up. Among these participants, 62 (60.8%) were male and 40 (39.2%) were female, with a mean age of 57.05 ± 12.87 years. Additionally, 20 (19.6%) subjects had adenomatous polyps at the end of the study. Patients with recurrent colorectal polyps tend to be raised in large ones with a tubulovillous morphology. The polyps were more commonly located in the sigmoid colon, rectum. Furthermore, high-grade dysplasia was recorded in 5 patients. Tubulovillous polyp had higher chance of recurrence than patients with tubular polyp.

CONCLUSION

We believe the colonoscopy screening needs to be set up in regions previously considered low-risk for CRC. Also, it may be valuable to control colonoscopy for less than three years in patients with dysplasia.

Performance of OC-Auto Micro 80 Fecal Immunochemical Test in an Integrated Academic-Community Health System

GOALS

We aimed to determine the performance of the OC-Auto Micro 80 fecal immunochemical test (FIT) in an average-risk population receiving care in an integrated, academic-community health system.

BACKGROUND

The FIT is the most used colorectal cancer (CRC) screening test worldwide. However, many Food and Drug Administration-cleared FIT products have not been evaluated in clinical settings.

STUDY

We performed a retrospective cohort study of patients (50 to 75 y old) in the University of Washington Medicine health care system who were screened for CRC by OC-Auto Micro 80 FIT between March 2016 and September 2021. We used electronic health records to extract patient-level and clinic-level factors, FIT use, colonoscopy, and pathology findings. The primary outcomes were the FIT positivity rate and neoplasms detected at colonoscopy. Secondary outcomes were FIT positivity by sex and safety-net versus non-safety-net clinical settings.

RESULTS

We identified 39,984 FITs completed by 26,384 patients; 2411 (6.0%) had a positive FIT result (>100 ng/mL of hemoglobin in buffer), and 1246 (51.7%) completed a follow-up colonoscopy. The FIT positive rate was 7.0% in men and 5.2% in women ( P <0.01). Among those who completed a colonoscopy after an abnormal FIT result, the positive predictive value for CRC, advanced adenoma, and advanced neoplasia was 3.0%, 20.9%, and 23.9%, respectively.

CONCLUSIONS

In a retrospective analysis of a large heterogeneous population, the OC-Auto Micro 80 FIT for CRC screening demonstrated a positivity rate of 6.0% and a positive predictive value for CRC of 3.0%.

Being Breastfed in Infancy and Risk of Colorectal Cancer and Precursor Lesions

BACKGROUND & AIMS

Emerging evidence implicates the importance of perinatal and early-life exposures in colorectal cancer (CRC) development. However, it remains unclear whether being breastfed in infancy is associated with CRC risk in adult life, particularly early adulthood.

METHODS

We prospectively investigated the association between history of being breastfed and risk of CRC and its precursor lesions among 66,634 women 46-93 years of age from the Nurses' Health Study and 92,062 women 27-68 years of age from the Nurses' Health Study II. Cox regression and logistic regression for clustered data were used to estimate hazard ratios for CRC and odds ratios for CRC precursors, respectively.

RESULTS

During 3.5 million person-years of follow-up, we identified 1490 incident cases of CRC in 2 cohorts. Having been breastfed was associated with a 23% (95% confidence interval [CI], 10% to 38%) increased risk of CRC. The risk of CRC increased with duration of being breastfed (Ptrend < .001). These findings were validated using breastfeeding information from the mothers of a subset of participants. Among younger participants from the Nurses' Health Study II, a significant association was observed between being breastfed and increased risk of high-risk adenomas under 50 years of age (odds ratio, 1.46; 95% CI, 1.16 to 1.83). Consistently, having been breastfed was associated with increased risk of CRC among participants ≤55 years of age (hazard ratio, 1.38; 95% CI, 1.06 to 1.80).

CONCLUSIONS

Being breastfed in infancy was associated with increased risk of CRC in adulthood, including among younger adults. However, further research is needed to understand the underlying biological mechanisms, as this association does not establish causation.

Systematic scoping review: Use of the faecal immunochemical test residual buffer to enhance colorectal cancer screening

BACKGROUND

The faecal immunochemical test (FIT) is an inexpensive and convenient modality to screen for colorectal cancer. However, its one-time sensitivity for detecting colorectal cancer and cancer precursors is limited. There is growing interest in using the non-haemoglobin contents of FIT residual buffer to enhance colonic neoplasia detection.

AIM

To establish from the literature a framework to catalogue candidate biomarkers within FIT residual buffer for non-invasive colorectal cancer screening.

METHODS

The search strategy evaluated PubMed, Scopus, Web of Science, Embase, and Google Scholar for publications through 25 October 2023, with search terms including FIT, buffer, OC-sensor, biomarkers, microbiome, microRNA (miR), colon, rectum, screening, neoplasm, and early detection. Studies employing home-based collection samples using quantitative FIT first processed for haemoglobin were included. One author reviewed all articles; a second author completed a 20% full-text audit to ensure adherence to eligibility criteria.

RESULTS

A broad search yielded 1669 studies and application of eligibility criteria identified 18 relevant studies. Multiple protein, DNA/RNA, and microbiome biomarkers (notably haptoglobin, miR-16, miR-27a-3p, miR-92a, miR-148a-3p, miR-223, miR-421, let-7b-5p, and Tyzzerella 4) were associated with colorectal neoplasia. Furthermore, studies highlighted the short-term stability of biomarkers for clinical use and long-term stability for research purposes.

CONCLUSIONS

This scoping review summarises the framework and progress of research on stability of biomarkers in FIT residual buffer and their associations with colorectal neoplasia to guide opportunities for further confirmatory studies to enhance colorectal cancer screening.

Exogenous Insulin Therapy Is Associated with the Risk of Advanced Colorectal Adenoma in Patients with Diabetes Mellitus

BACKGROUND/AIMS

Exogenous insulin therapy increases systemic exposure to insulin which may promote the development of colorectal neoplasia. We sought to evaluate the association between exogenous insulin therapy and the incidence of advanced adenoma in type 2 diabetes mellitus.

METHODS

A retrospective cohort study was conducted from January 1, 2007, to January 1, 2018, in a regional health system serving the United States Philadelphia metropolitan area, Central New Jersey, and South Central Pennsylvania. Study patients consisted of a random sample of patients with type 2 diabetes mellitus aged 40-80 years who had undergone two rounds of colonoscopy examinations. The exposure was cumulative duration of insulin therapy (i.e., no use, 1-365 days and > 365 days). The outcome was time to incident advanced adenoma.

RESULTS

Of the 975 eligible patients, 184 patients accumulated > 365 days of insulin therapy before the follow-up colonoscopy. The mean (standard deviation) duration between the two rounds of colonoscopy examination was 5.1 (2.9) years among the insulin users and 5.3 (3.9) years among non-users. Compared to no insulin exposure, receiving > 365 days of insulin therapy was associated with an increased incidence of advanced adenoma (adjusted hazard ratio [aHR] 4.84, 95% confidence interval [CI] 2.82-8.30), right-sided advanced adenoma (aHR 5.48, 95% CI 2.90-10.35), and 3 or more adenomas (aHR 2.61, 95% CI 1.46-4.69) at the follow-up colonoscopy examination.

CONCLUSION

Insulin therapy is associated with an increased risk of advanced adenoma and may serve as a novel risk-stratification factor to enhance the efficiency of existing colorectal cancer screening and surveillance programs.

MAFLD with central obesity is associated with increased risk of colorectal adenoma and high-risk adenoma

OBJECTIVE

To analyze the risk factors associated with colorectal adenoma and to investigate the associations of metabolism-related fatty liver disease (MAFLD) with obesity, colorectal adenoma and high-risk adenoma.

METHODS

A total of 1395 subjects were enrolled and divided into a colorectal adenoma group (593 subjects) and a control group (802 subjects) according to the inclusion and exclusion criteria. The characteristics of patients in the colorectal adenoma group and the control group were compared by the chi-square test. Univariate and multivariate logistic analyses were used to analyze independent risk factors and associations with different MAFLD subtypes. Colorectal adenoma characteristics and the proportion of patients with high-risk colorectal adenoma were also compared.

RESULTS

High-density lipoprotein (HDL-C) was significantly lower in patients in the colorectal adenoma group than in those in the control group (P < 0.001). Logistic regression analysis revealed that age, obesity status, central obesity status, hypertension status, diabetes status, fatty liver status, smoking history, BMI, waist circumference, triglyceride level, HDL-C level, fasting blood glucose level and degree of hepatic steatosis were all independent risk factors for colorectal adenoma. Notably, MAFLD was associated with a significantly increased risk of colorectal adenoma in patients with central obesity (P < 0.001). In addition, obesity, central obesity, diabetes, fatty liver and degree of hepatic steatosis were all shown to be independent risk factors for high-risk colorectal adenoma. In addition, a greater proportion of MAFLD patients with central obesity than those without central obesity had high-risk colorectal adenoma.

CONCLUSION

MAFLD and central obesity are independently associated with the development of colorectal adenoma. MAFLD with central obesity is associated with an increased risk of colorectal adenoma and high-risk adenoma.

Should we perform sigmoidoscopy for colorectal cancer screening in people under 45 years?

BACKGROUND

The strategy for preventing colorectal cancer is screening by colonoscopy, which offers a direct way for detection and removal of adenomatous polyps (APs). American College of Gastroenterology guidelines recommend that people aged ≥ 45 years should undergo colonoscopy; however, how to deal with people aged ≤ 45 years is still unknown.

AIM

To compare the prevalence of APs and high-grade neoplasia between the left and right colon in patients ≤ 45 years.

METHODS

A retrospective observational study was conducted at a single tertiary III hospital in China. This study included patients aged 18-45 years with undergoing initial colonoscopy dissection and pathological diagnosis AP or high-grade neoplasia between February 2014 and January 2021. The number of APs in the entire colon while screening and post-polypectomy surveillance in following 1-3 years were evaluated.

RESULTS

A total of 3053 cases were included. The prevalence of APs in the left and right colon was 55.0% and 41.6%, respectively (OR 1.7, 95%CI 1.6-2.4; P < 0.05). For APs with high-grade neoplasia, the prevalence was 2.7% and 0.9%, respectively (OR 3.0, 95%CI 2.0-4.6; P < 0.05). Therefore, the prevalence of APs and high-grade neoplasia in the left colon was significantly higher than in the right colon in patients aged ≤ 45 years. There were 327 patients who voluntarily participated in post-polypectomy surveillance in following 1-3 years, and APs were found in 216 cases (66.1%); 170 cases had 1-3 polyps (52.0%) and 46 cases had > 3 polyps (14.1%; OR 0.3, 95%CI 0.1-0.6; P < 0.05).

CONCLUSION

This study suggests that flexible sigmoidoscopy would be an optimal approach for initial screening in people aged ≤ 45 years and would be a more cost-effective and safe strategy.

Surveillance Colonoscopy Findings in Older Adults With a History of Colorectal Adenomas

Importance

Postpolypectomy surveillance is a common colonoscopy indication in older adults; however, guidelines provide little direction on when to stop surveillance in this population.

Objective

To estimate surveillance colonoscopy yields in older adults.

Design, Setting, and Participants

This population-based cross-sectional study included individuals 70 to 85 years of age who received surveillance colonoscopy at a large, community-based US health care system between January 1, 2017, and December 31, 2019; had an adenoma detected 12 or more months previously; and had at least 1 year of health plan enrollment before surveillance. Individuals were excluded due to prior colorectal cancer (CRC), hereditary CRC syndrome, inflammatory bowel disease, or prior colectomy or if the surveillance colonoscopy had an inadequate bowel preparation or was incomplete. Data were analyzed from September 1, 2022, to February 22, 2024.

Exposures

Age (70-74, 75-79, or 80-85 years) at surveillance colonoscopy and prior adenoma finding (ie, advanced adenoma vs nonadvanced adenoma).

Main Outcomes and Measures

The main outcomes were yields of CRC, advanced adenoma, and advanced neoplasia overall (all ages) by age group and by both age group and prior adenoma finding. Multivariable logistic regression was used to identify factors associated with advanced neoplasia detection at surveillance.

Results

Of 9740 surveillance colonoscopies among 9601 patients, 5895 (60.5%) were in men, and 5738 (58.9%), 3225 (33.1%), and 777 (8.0%) were performed in those aged 70-74, 75-79, and 80-85 years, respectively. Overall, CRC yields were found in 28 procedures (0.3%), advanced adenoma in 1141 (11.7%), and advanced neoplasia in 1169 (12.0%); yields did not differ significantly across age groups. Overall, CRC yields were higher for colonoscopies among patients with a prior advanced adenoma vs nonadvanced adenoma (12 of 2305 [0.5%] vs 16 of 7435 [0.2%]; P = .02), and the same was observed for advanced neoplasia (380 of 2305 [16.5%] vs 789 of 7435 [10.6%]; P < .001). Factors associated with advanced neoplasia at surveillance were prior advanced adenoma (adjusted odds ratio [AOR], 1.65; 95% CI, 1.44-1.88), body mass index of 30 or greater vs less than 25 (AOR, 1.21; 95% CI, 1.03-1.44), and having ever smoked tobacco (AOR, 1.14; 95% CI, 1.01-1.30). Asian or Pacific Islander race was inversely associated with advanced neoplasia (AOR, 0.81; 95% CI, 0.67-0.99).

Conclusions and Relevance

In this cross-sectional study of surveillance colonoscopy yield in older adults, CRC detection was rare regardless of prior adenoma finding, whereas the advanced neoplasia yield was 12.0% overall. Yields were higher among those with a prior advanced adenoma than among those with prior nonadvanced adenoma and did not increase significantly with age. These findings can help inform whether to continue surveillance colonoscopy in older adults.

Audit of hemostatic clip use after colorectal polyp resection in an academic endoscopy unit

Background and study aims Prophylactic closure of endoscopic resection defects reduces delayed hemorrhage after resection of non-pedunculated colorectal lesions ≥ 20 mm that are located proximal to the splenic flexure and removed by electrocautery. The risk of delayed hemorrhage after cold (without electrocautery) resection is much lower, and prophylactic clip closure after cold resection is generally unnecessary. The aim of this study was to audit clip use after colorectal polyp resection in routine outpatient colonoscopies at two outpatient centers within an academic medical center. Patients referred for resection of known lesions were excluded. Patients and methods Retrospective chart analysis was performed as part of a quality review of physician adherence to screening and post-polypectomy surveillance intervals. Results Among 3784 total lesions resected cold by 29 physicians, clips were placed after cold resection on 41.7% of 12 lesions ≥ 20 mm, 19.3% of 207 lesions 10 to 19 mm in size, and 2.8% of 3565 lesions 1 to 9 mm in size. Three physicians placed clips after cold resection of lesions 1 to 9 mm in 18.8%, 25.5%, and 45.0% of cases. These physicians accounted for 8.1% of 1- to 9-mm resections, but 69.7% of clips placed in this size range. Electrocautery was used for 3.1% of all resections. Clip placement overall after cold resection (3.9%) was much lower than after resection with electrocautery (71.1%), but 62.4% of all clips placed were after cold resection. Conclusions Audits of clip use in an endoscopy practice can reveal surprising findings, including high and variable rates of unnecessary use after cold resection. Audit can potentially reduce unnecessary costs, carbon emissions, and plastic waste.

An interpretable machine learning system for colorectal cancer diagnosis from pathology slides

Considering the profound transformation affecting pathology practice, we aimed to develop a scalable artificial intelligence (AI) system to diagnose colorectal cancer from whole-slide images (WSI). For this, we propose a deep learning (DL) system that learns from weak labels, a sampling strategy that reduces the number of training samples by a factor of six without compromising performance, an approach to leverage a small subset of fully annotated samples, and a prototype with explainable predictions, active learning features and parallelisation. Noting some problems in the literature, this study is conducted with one of the largest WSI colorectal samples dataset with approximately 10,500 WSIs. Of these samples, 900 are testing samples. Furthermore, the robustness of the proposed method is assessed with two additional external datasets (TCGA and PAIP) and a dataset of samples collected directly from the proposed prototype. Our proposed method predicts, for the patch-based tiles, a class based on the severity of the dysplasia and uses that information to classify the whole slide. It is trained with an interpretable mixed-supervision scheme to leverage the domain knowledge introduced by pathologists through spatial annotations. The mixed-supervision scheme allowed for an intelligent sampling strategy effectively evaluated in several different scenarios without compromising the performance. On the internal dataset, the method shows an accuracy of 93.44% and a sensitivity between positive (low-grade and high-grade dysplasia) and non-neoplastic samples of 0.996. On the external test samples varied with TCGA being the most challenging dataset with an overall accuracy of 84.91% and a sensitivity of 0.996.

Association of the triglyceride-glucose index with the occurrence and recurrence of colorectal adenomas: a retrospective study from China

BACKGROUND

Resection of colorectal adenoma (CRA) prevents colorectal cancer; however, recurrence is common. We aimed to assess the association of the triglyceride-glucose (TyG) index with CRA occurrence and recurrence.

METHODS

Data from 3392 participants at a hospital in China from 2020 to 2022 were analyzed. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). A restricted cubic spline was used to fit TyG index dose‒response curves to recurrent adenomas. The discriminatory power of TyG index for predicting later recurrence was assessed with the area under the receiver operating characteristic (ROC) curve in 170 patients with a TyG index at initial adenoma diagnosis.

RESULTS

One thousand five hundred ninety-six adenoma and 1465 normal participants were included in the occurrence analysis, and 179 recurrent and 152 nonrecurrent participants were included in the recurrence analysis. The TyG mutation was an independent risk factor for CRA occurrence and recurrence. After adjusting for confounders, the risk of adenoma in the participants in Q2, Q3, and Q4 groups of TyG was 1.324 (95% CI 1.020-1.718), 1.349 (95% CI 1.030-1.765), and 1.445 (95% CI 1.055-1.980) times higher than that of the Q1, respectively, and the risk of recurrence in the Q3 and Q4 groups was 2.267 (95% CI 1.096-4.691) and 2.824 (95% CI 1.199-6.648) times in Q1 group. Multiple logistic regression showed that the highest quartile of the TyG index was associated with a greater risk of advanced adenoma recurrence (OR 4.456, 95% CI 1.157-17.164), two or more adenomas (OR 5.079, 95% CI 1.136-22.714 [after removal of TyG index extreme values]), and proximal colon or both adenomas (OR 3.043, 95% CI 1.186-7.810). Subgroup analysis revealed that the association was found to be present only in participants of all age groups who were either male or without obesity, hyperglycemia, hypertension, or dyslipidemia (p < 0.05). ROC curves illustrated that the TyG index had good predictive efficacy for identifying recurrence, especially for patients with two or more adenomas (AUC 0.777, 95% CI 0.648-0.907).

CONCLUSIONS

An increase in the TyG index is associated with an increased risk of adenoma occurrence and recurrence, with a stronger association with the latter.

Boston bowel preparation scale score 6 has more missed lesions compared with 7-9

Adequate bowel preparation is an important factor in high-quality colonoscopy. It is generally accepted that a Boston Bowel Preparation Scale (BBPS) score ≥ 6 is adequate, but some reports suggest ≥ 7. Subjects who underwent colonoscopy at least twice within 3 years from August 2015 to December 2019 were included. Polyp detection rates (PDRs), adenoma detection rates (ADRs), and number of polyps including adenomas were compared stratified by baseline colonoscopy (C1) BBPS score. Among 2352 subjects, 529 had BBPS 6 (group 1) and 1823 had BBPS 7-9 (group 2) at C1. There was no significant difference in PDR or ADR at C1 and follow-up colonoscopy (C2) between the two groups. However, the numbers of polyps (1.84 vs. 1.56, P = 0.001) and adenomas (1.02 vs. 0.88, P = 0.034) at C2 were significantly higher in group 1 than group 2, respectively. Segmental BBPS score 2 in group 1 compared to group 2, especially, showed higher PDR (P = 0.001) and ADR (P = 0.007) at C2. BBPS 6 is associated with a higher number of polyps and adenomas in short-term follow-up colonoscopy than BBPS 7-9. To reduce the risk of missed polyps, a thorough examination is necessary for BBPS 6.

Causal association between telomere length and colorectal polyps: A bidirectional two-sample Mendelian randomization study

We performed a bidirectional 2-sample Mendelian randomization (MR) design to explore the causal relation between telomere length (TL) and colorectal polyps. Genome-wide association study summary data of TL and colorectal polyps were extracted from the IEU open genome-wide association study database. Single nucleotide polymorphisms were served as instrumental variables at the significance threshold of P < 5 × 10-8. The inverse variance weighted method, MR-Egger method, and weight median method were performed for causal estimation in MR. Cochran Q test, MR-Egger intercept test, and leave-one-out analyses were performed to evaluate the pleiotropy of the MR results. One hundred and twenty-four single nucleotide polymorphisms were selected as instrumental variables. We found significant casual association between TL and colorectal polyps. Long TL increased the risk of colorectal polyps using the inverse variance weighted method [ukb-a-521: odds ratio (OR): 1.004, 95% confidence interval (CI): 1.001-1.007, P = .004; ukb-d-D12: OR: 1.008, CI: 1.004-1.012, P < .001; finn-b-CD2_BENIGN_COLORECANI_EXALLC2: OR: 1.170, CI: 1.027-1.332, P = .018]. Sensitivity analyses validated that the causality between TL and colorectal polyps was robust. The study provided a causal association between TL and colorectal polyps which indicated that TL might be served as a potential biomarker of colorectal polyps for screening and prevention. Nonetheless, the conclusions need further validation.

ChatGPT on guidelines: Providing contextual knowledge to GPT allows it to provide advice on appropriate colonoscopy intervals

BACKGROUND AND AIM

Colonoscopy is commonly used in screening and surveillance for colorectal cancer. Multiple different guidelines provide recommendations on the interval between colonoscopies. This can be challenging for non-specialist healthcare providers to navigate. Large language models like ChatGPT are a potential tool for parsing patient histories and providing advice. However, the standard GPT model is not designed for medical use and can hallucinate. One way to overcome these challenges is to provide contextual information with medical guidelines to help the model respond accurately to queries. Our study compares the standard GPT4 against a contextualized model provided with relevant screening guidelines. We evaluated whether the models could provide correct advice for screening and surveillance intervals for colonoscopy.

METHODS

Relevant guidelines pertaining to colorectal cancer screening and surveillance were formulated into a knowledge base for GPT. We tested 62 example case scenarios (three times each) on standard GPT4 and on a contextualized model with the knowledge base.

RESULTS

The contextualized GPT4 model outperformed the standard GPT4 in all domains. No high-risk features were missed, and only two cases had hallucination of additional high-risk features. A correct interval to colonoscopy was provided in the majority of cases. Guidelines were appropriately cited in almost all cases.

CONCLUSIONS

A contextualized GPT4 model could identify high-risk features and quote appropriate guidelines without significant hallucination. It gave a correct interval to the next colonoscopy in the majority of cases. This provides proof of concept that ChatGPT with appropriate refinement can serve as an accurate physician assistant.

Machine Learning-Based Prediction of Responsiveness to Neoadjuvant Chemoradiotheapy in Locally Advanced Rectal Cancer Patients from Endomicroscopy

The protocol for treating locally advanced rectal cancer consists of the application of chemoradiotherapy (neoCRT) followed by surgical intervention. One issue for clinical oncologists is predicting the efficacy of neoCRT in order to adjust the dosage and avoid treatment toxicity in cases when surgery should be conducted promptly. Biomarkers may be used for this purpose along with in vivo cell-level images of the colorectal mucosa obtained by probe-based confocal laser endomicroscopy (pCLE) during colonoscopy. The aim of this article is to report our experience with Motiro, a computational framework that we developed for machine learning (ML) based analysis of pCLE videos for predicting neoCRT response in locally advanced rectal cancer patients. pCLE videos were collected from 47 patients who were diagnosed with locally advanced rectal cancer (T3/T4, or N+). The patients received neoCRT. Response to treatment by all patients was assessed by endoscopy along with biopsy and magnetic resonance imaging (MRI). Thirty-seven patients were classified as non-responsive to neoCRT because they presented a visible macroscopic neoplastic lesion, as confirmed by pCLE examination. Ten remaining patients were considered responsive to neoCRT because they presented lesions as a scar or small ulcer with negative biopsy, at post-treatment follow-up. Motiro was used for batch mode analysis of pCLE videos. It automatically characterized the tumoral region and its surroundings. That enabled classifying a patient as responsive or non-responsive to neoCRT based on pre-neoCRT pCLE videos. Motiro classified patients as responsive or non-responsive to neoCRT with an accuracy of ~ 0.62 when using images of the tumor. When using images of regions surrounding the tumor, it reached an accuracy of ~ 0.70. Feature analysis showed that spatial heterogeneity in fluorescence distribution within regions surrounding the tumor was the main contributor to predicting response to neoCRT. We developed a computational framework to predict response to neoCRT by locally advanced rectal cancer patients based on pCLE images acquired pre-neoCRT. We demonstrate that the analysis of the mucosa of the region surrounding the tumor provides stronger predictive power.

Correlation between High Incidence of Colorectal Neoplastic Polyps and High-risk Adenomas in Patients with Diabetes Mellitus: A Retrospective Study

BACKGROUND

Early detection and resection of colorectal polyps by routine colonoscopy screening can be effective in reducing the risk of colorectal cancer (CRC).

OBJECTIVE

This study aimed to determine the association between diabetes mellitus (DM) and different types of colorectal polyps in the Chinese population.

METHODS

A retrospective analysis was performed on inpatients admitted to the Gastroenterology Department of our hospital from January to December 2019. Clinical data, and colonoscopy and pathology findings of the subjects were collected. Bivariate analysis was used to assess factors associated with colorectal polyps. Significant variables from the bivariate evaluation were included in a stepwise multivariate logistic regression analysis to recognize independent predictors of neoplastic polyps and high-risk adenomas.

RESULTS

The proportion of patients with DM was significantly higher in patients with neoplastic polyps and high-risk adenomas than in patients without polyps. Age ≥ 50 years, male gender, and a first-degree relative with a history of CRC were independent risk factors for neoplastic polyps and high-risk adenomas, even in non-smokers. An independent risk factor analysis that did not include a family history of CRC showed that age, gender, and alcohol consumption were independent risk factors for neoplastic polyps and high-risk adenomas. DM was an independent risk factor for high-risk adenomas (OR = 2.902, 95% CI = 1.221-6.899; p = 0.016) after adjusting for age, gender, alcohol consumption, and body mass index. Thus, a history of DM significantly increases the risk of high-risk adenomas.

CONCLUSION

This study demonstrated that patients with DM, age ≥ 50 years, male gender, alcohol consumption, and a first-degree relative with a history of CRC should undergo regular endoscopic screening and colonic polypectomy.

Precision endoscopy in the era of climate change and sustainability

Global warming caused by increased greenhouse gas (GHG) emissions has a direct impact on human health. Gastrointestinal (GI) endoscopy contributes significantly to GHG emissions due to energy consumption, reprocessing of endoscopes and accessories, production of equipment, safe disposal of biohazardous waste, and travel by patients. Moreover, GHGs are also generated in histopathology through tissue processing and the production of biopsy specimen bottles. The reduction in unnecessary surveillance endoscopies and biopsies is a practical approach to decrease GHG emissions without affecting disease outcomes. This narrative review explores the role of precision medicine in GI endoscopy, such as image-enhanced endoscopy and artificial intelligence, with a focus on decreasing unnecessary endoscopic procedures and biopsies in the surveillance and diagnosis of premalignant lesions in the esophagus, stomach, and colon. This review offers strategies to minimize unnecessary endoscopic procedures and biopsies, decrease GHG emissions, and maintain high-quality patient care, thereby contributing to sustainable healthcare practices.

Black-White disparities in colorectal cancer outcomes: a simulation study of screening benefit

The US Black population has higher colorectal cancer (CRC) incidence rates and worse CRC survival than the US White population, as well as historically lower rates of CRC screening. The Surveillance, Epidemiology, and End Results incidence rate data in people diagnosed between the ages of 20 and 45 years, before routine CRC screening is recommended, were analyzed to estimate temporal changes in CRC risk in Black and White populations. There was a rapid rise in rectal and distal colon cancer incidence in the White population but not the Black population, and little change in proximal colon cancer incidence for both groups. In 2014-2018, CRC incidence per 100 000 was 17.5 (95% confidence interval [CI] = 15.3 to 19.9) among Black individuals aged 40-44 years and 16.6 (95% CI = 15.6 to 17.6) among White individuals aged 40-44 years; 42.3% of CRCs diagnosed in Black patients were proximal colon cancer, and 41.1% of CRCs diagnosed in White patients were rectal cancer. Analyses used a race-specific microsimulation model to project screening benefits, based on life-years gained and lifetime reduction in CRC incidence, assuming these Black-White differences in CRC risk and location. The projected benefits of screening (via either colonoscopy or fecal immunochemical testing) were greater in the Black population, suggesting that observed Black-White differences in CRC incidence are not driven by differences in risk. Projected screening benefits were sensitive to survival assumptions made for Black populations. Building racial disparities in survival into the model reduced projected screening benefits, which can bias policy decisions.

Consensus molecular subtype transition during progression of colorectal cancer

The consensus molecular subtype (CMS) classification divides colorectal cancer (CRC) into four distinct subtypes based on RNA expression profiles. The biological differences between CMSs are already present in CRC precursor lesions, but not all CMSs pose the same risk of malignant transformation. To fully understand the path to malignant transformation and to determine whether CMS is a fixed entity during progression, genomic and transcriptomic data from two regions of the same CRC lesion were compared: the precursor region and the carcinoma region. In total, 24 patients who underwent endoscopic removal of T1-2 CRC were included. Regions were subtyped for CMS and DNA mutation analysis was performed. Additionally, a set of 85 benign adenomas was CMS-subtyped. This analysis revealed that almost all benign adenomas were classified as CMS3 (91.8%). In contrast, CMS2 was the most prevalent subtype in precursor regions (66.7%), followed by CMS3 (29.2%). CMS4 was absent in precursor lesions and originated at the carcinoma stage. Importantly, CMS switching occurred in a substantial number of cases and almost all (six out of seven) CMS3 precursor regions showed a shift to a different subtype in the carcinoma part of the lesion, which in four cases was classified as CMS4. In conclusion, our data indicate that CMS3 is related to a more indolent type of precursor lesion that less likely progresses to CRC and when this occurs, it is often associated with a subtype change that includes the more aggressive mesenchymal CMS4. In contrast, an acquired CMS2 signature appeared to be rather fixed during early CRC development. Combined, our data show that subtype changes occur during progression and that CMS3 switching is related to changes in the genomic background through acquisition of a novel driver mutation (TP53) or selective expansion of a clone, but also occurred independently of such genetic changes. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Development and Validation of a Deep Learning-Based Histologic Diagnosis System for Diagnosing Colorectal Sessile Serrated Lesions

OBJECTIVES

The histopathologic diagnosis of colorectal sessile serrated lesions (SSLs) and hyperplastic polyps (HPs) is of low consistency among pathologists. This study aimed to develop and validate a deep learning (DL)-based logical anthropomorphic pathology diagnostic system (LA-SSLD) for the differential diagnosis of colorectal SSL and HP.

METHODS

The diagnosis framework of the LA-SSLD system was constructed according to the current guidelines and consisted of 4 DL models. Deep convolutional neural network (DCNN) 1 was the mucosal layer segmentation model, DCNN 2 was the muscularis mucosa segmentation model, DCNN 3 was the glandular lumen segmentation model, and DCNN 4 was the glandular lumen classification (aberrant or regular) model. A total of 175 HP and 127 SSL sections were collected from Renmin Hospital of Wuhan University during November 2016 to November 2022. The performance of the LA-SSLD system was compared to 11 pathologists with different qualifications through the human-machine contest.

RESULTS

The Dice scores of DCNNs 1, 2, and 3 were 93.66%, 58.38%, and 74.04%, respectively. The accuracy of DCNN 4 was 92.72%. In the human-machine contest, the accuracy, sensitivity, and specificity of the LA-SSLD system were 85.71%, 86.36%, and 85.00%, respectively. In comparison with experts (pathologist D: accuracy 83.33%, sensitivity 90.91%, specificity 75.00%; pathologist E: accuracy 85.71%, sensitivity 90.91%, specificity 80.00%), LA-SSLD achieved expert-level accuracy and outperformed all the senior and junior pathologists.

CONCLUSIONS

This study proposed a logical anthropomorphic diagnostic system for the differential diagnosis of colorectal SSL and HP. The diagnostic performance of the system is comparable to that of experts and has the potential to become a powerful diagnostic tool for SSL in the future. It is worth mentioning that a logical anthropomorphic system can achieve expert-level accuracy with fewer samples, providing potential ideas for the development of other artificial intelligence models.

Summary and comparison of recently updated post-polypectomy surveillance guidelines

Recently, updated guidelines for post-polypectomy surveillance have been published by the U.S. Multi-Society Task Force (USMSTF), the British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England (BSG/ACPGBI/PHE), the European Society of Gastrointestinal Endoscopy (ESGE), the Japan Gastroenterological Endoscopy Society (JGES), and the Korean Multi-Society Taskforce Committee. This review summarizes and compares the updated recommendations of these 5 guidelines. There are some differences between the guidelines for the recommended post-polypectomy surveillance intervals. In particular, there are prominent differences between the guidelines for 1-4 tubular adenomas < 10 mm with low-grade dysplasia (nonadvanced adenomas [NAAs]) and tubulovillous or villous adenomas. The USMSTF, JGES, and Korean guidelines recommend colonoscopic surveillance for patients with 1-4 NAAs and those with tubulovillous or villous adenomas, whereas the BSG/ACPGBI/PHE and ESGE guidelines do not recommend endoscopic surveillance for such patients. Surveillance recommendations for patients with serrated polyps (SPs) are limited. Although the USMSTF guidelines provide specific recommendations for patients who have undergone SPs removal, these are weak and based on very lowquality evidence. Future studies should examine this topic to better guide the surveillance recommendations for patients with SPs. For countries that do not have separate guidelines, we hope that this review article will help select the most appropriate guidelines as per each country's healthcare environment.

Performing High-Quality, Safe, Cost-Effective, and Efficient Basic Colonoscopy in 2023: Advice From Two Experts

Based on published evidence and our expert experience, we provide recommendations to maximize the efficacy, safety, efficiency, and cost-effectiveness of routine colonoscopy. High-quality colonoscopy begins with colon preparation using a split or same-day dose and preferably a low-volume regimen for optimal patient tolerance and compliance. Successful cecal intubation can be achieved by choosing the correct colonoscope and using techniques to facilitate navigation through challenges such as severe angulations and redundant colons. Safety is a primary goal, and complications such as perforation and splenic rupture can be prevented by avoiding pushing through fixed resistance and avoiding loops in proximal colon. Furthermore, barotrauma can be avoided by converting to water filling only (no gas insufflation) in every patient with a narrowed, angulated sigmoid. Optimal polyp detection relies primarily on compulsive attention to inspection as manifested by adequate inspection time, vigorous probing of the spaces between haustral folds, washing and removing residual debris, and achieving full distention. Achieving minimum recommended adenoma detection rate thresholds (30% in men and 20% in women) is mandatory, and colonoscopists should aspire to adenoma detection rate approaching 50% in screening patients. Distal attachments can improve mucosal exposure and increase detection while shortening withdrawal times. Complete resection of polyps complements polyp detection in preventing colorectal cancer. Cold resection is the preferred method for all polyps < 10 mm. For effective cold resection, an adequate rim of normal tissue should be captured in the snare. Finally, cost-effective high-quality colonoscopy requires the procedure not be overused, as demonstrated by following updated United States Multi Society Task Force on Colorectal Cancer postpolypectomy surveillance recommendations.

Clinical characteristics and risk factors related to polyposis recurrence and advanced neoplasm development among patients with non-hereditary colorectal polyposis

BACKGROUND/AIMS

Patients with more than 10 cumulative polyps might involve a greater genetic risk of colorectal neoplasia development. However, few studies have investigated the risk factors of polyposis recurrence and development of advanced neoplasms among patients with non-hereditary colorectal polyposis.

METHODS

This study included patients (n=855) with 10 or more cumulative polyps diagnosed at Severance Hospital from January 2012 to September 2021. Patients with known genetic mutations related to polyposis, known hereditary polyposis syndromes, insufficient information, total colectomy, and less than 3 years of follow-up were excluded. Finally, 169 patients were included for analysis. We collected clinical data, including colonoscopy surveillance results, and performed Cox regression analyses of risk factors for polyposis recurrence and advanced neoplasm development.

RESULTS

The 169 patients were predominantly male (84.02%), with a mean age of 64.19±9.92 years. The mean number of adenomas on index colonoscopy was 15.33±8.47. Multivariable analysis revealed history of cancer except colon cancer (hazard ratio [HR], 2.23; 95% confidence interval [CI], 1.23-4.01), current smoking (HR, 2.39; 95% CI, 1.17-4.87), and detection of many polyps (≥15) on index colonoscopy (HR, 2.05; 95% CI, 1.21-3.50) were significant risk factors for recurrence of polyposis. We found no statistically significant risk factors for advanced neoplasm development during surveillance among our cohort.

CONCLUSIONS

The presence of many polyps (≥15) on index colonoscopy, history of cancer except colon cancer, and current smoking state were significant risk factors for polyposis recurrence among patients with non-hereditary colorectal polyposis.

Development and Evaluation of a Surveillance System for Follow-Up After Colorectal Polypectomy

Importance

The adherence of physicians and patients to published colorectal postpolypectomy surveillance guidelines varies greatly, and patient follow-up is critical but time consuming.

Objectives

To evaluate the accuracy of an automatic surveillance (AS) system in identifying patients after polypectomy, assigning surveillance intervals for different risks of patients, and proactively following up with patients on time.

Design, Setting, and Participants

In this diagnostic/prognostic study, endoscopic and pathological reports of 47 544 patients undergoing colonoscopy at 3 hospitals between January 1, 2017, and June 30, 2022, were collected to develop an AS system based on natural language processing. The performance of the AS system was fully evaluated in internal and external tests according to 5 guidelines worldwide and compared with that of physicians. A multireader, multicase (MRMC) trial was conducted to evaluate use of the AS system and physician guideline adherence, and prospective data were collected to evaluate the success rate in contacting patients and the association with reduced human workload. Data analysis was conducted from July to September 2022.

Exposures

Assistance of the AS system.

Main Outcomes and Measures

The accuracy of the system in identifying patients after polypectomy, stratifying patient risk levels, and assigning surveillance intervals in internal (Renmin Hospital of Wuhan University), external 1 (Wenzhou Central Hospital), and external 2 (The First People's Hospital of Yichang) test sets; the accuracy of physicians and their time burden with and without system assistance; and the rate of successfully informed patients of the system were evaluated.

Results

Test sets for 16 106 patients undergoing colonoscopy (mean [SD] age, 51.90 [13.40] years; 7690 females [47.75%]) were evaluated. In internal, external 1, and external 2 test sets, the system had an overall accuracy of 99.91% (95% CI, 99.83%-99.95%), 99.54% (95% CI, 99.30%-99.70%), and 99.77% (95% CI, 99.41%-99.91%), respectively, for identifying types of patients and achieved an overall accuracy of at least 99.30% (95% CI, 98.67%-99.63%) in the internal test set, 98.89% (95% CI, 98.33%-99.27%) in external test set 1, and 98.56% (95% CI, 95.86%-99.51%) in external test set 2 for stratifying patient risk levels and assigning surveillance intervals according to 5 guidelines. The system was associated with increased mean (SD) accuracy among physicians vs no AS system in 105 patients (98.67% [1.28%] vs 78.10% [18.01%]; P = .04) in the MRMC trial. In a prospective trial, the AS system successfully informed 82 of 88 patients (93.18%) and was associated with reduced burden of follow-up time vs no AS system (0 vs 2.86 h).

Conclusions and Relevance

This study found that an AS system was associated with improved adherence to guidelines among physicians and reduced workload among physicians and nurses.

Elevated EVL Methylation Level in the Normal Colon Mucosa Is a Potential Risk Biomarker for Developing Recurrent Adenomas

BACKGROUND

Individuals with adenomatous colorectal polyps undergo repeated colonoscopy surveillance to identify and remove metachronous adenomas. However, many patients with adenomas do not develop recurrent adenomas. Better methods to evaluate who benefits from increased surveillance are needed. We evaluated the use of altered EVL methylation as a potential biomarker for risk of recurrent adenomas.

METHODS

Patients with ≥1 colonoscopy had EVL methylation (mEVL) measured with an ultra-accurate methylation-specific droplet digital PCR assay on normal colon mucosa. The association between EVL methylation levels and adenoma or colorectal cancer was evaluated using three case/control definitions in three models: unadjusted (model 1), adjusting for baseline characteristics (model 2), and an adjusted model excluding patients with colorectal cancer at baseline (model 3).

RESULTS

Between 2001 and 2020, 136 patients were included; 74 healthy patients and 62 patients with a history of colorectal cancer. Older age, never smoking, and baseline colorectal cancer were associated with higher levels of mEVL (P ≤ 0.05). Each log base 10 difference in mEVL was associated with an increased risk of adenoma(s) or cancer at/after baseline for model 1 [OR, 2.64; 95% confidence interval (CI), 1.09-6.36], and adenoma(s) or cancer after baseline for models 1 (OR, 2.01; 95% CI, 1.04-3.90) and model 2 (OR, 3.17; 95% CI, 1.30-7.72).

CONCLUSIONS

Our results suggest that EVL methylation level detected in the normal colon mucosa has the potential to be a biomarker for monitoring the risk for recurrent adenomas.

IMPACT

These findings support the potential utility of EVL methylation for improving the accuracy for assigning risk for recurrent colorectal adenomas and cancer.

Detecting colorectal lesions with image-enhanced endoscopy: an updated review from clinical trials

Colonoscopy plays an important role in reducing the incidence and mortality of colorectal cancer by detecting adenomas and other precancerous lesions. Image-enhanced endoscopy (IEE) increases lesion visibility by enhancing the microstructure, blood vessels, and mucosal surface color, resulting in the detection of colorectal lesions. In recent years, various IEE techniques have been used in clinical practice, each with its unique characteristics. Numerous studies have reported the effectiveness of IEE in the detection of colorectal lesions. IEEs can be divided into two broad categories according to the nature of the image: images constructed using narrowband wavelength light, such as narrowband imaging and blue laser imaging/blue light imaging, or color images based on white light, such as linked color imaging, texture and color enhancement imaging, and i-scan. Conversely, artificial intelligence (AI) systems, such as computer-aided diagnosis systems, have recently been developed to assist endoscopists in detecting colorectal lesions during colonoscopy. To better understand the features of each IEE, this review presents the effectiveness of each type of IEE and their combination with AI for colorectal lesion detection by referencing the latest research data.

Measuring the observer (Hawthorne) effect on adenoma detection rates

Background and study aims An independent observer can improve procedural quality. We evaluated the impact of the observer (Hawthorne effect) on important quality metrics during colonoscopies. Patients and Methods In a single-center comparative study, consecutive patients undergoing routine screening or diagnostic colonoscopy were prospectively enrolled. In the index group, all procedural steps and quality metrics were observed and documented, and the procedure was video recorded by an independent research assistant. In the reference group, colonoscopies were performed without independent observation. Colonoscopy quality metrics such as polyp, adenoma, serrated lesions, and advanced adenoma detection rates (PDR, ADR, SLDR, AADR) were compared. The probabilities of increased quality metrics were evaluated through regression analyses weighted by the inversed probability of observation during the procedure. Results We included 327 index individuals and 360 referents in the final analyses. The index group had significantly higher PDRs (62.4% vs. 53.1%, P =0.02) and ADRs (39.4% vs. 28.3%, P =0.002) compared with the reference group. The SLDR and AADR were not significantly increased. After adjusting for potential confounders, the ADR and SLDR were 50% (relative risk [RR] 1.51; 95%, CI 1.05-2.17) and more than twofold (RR 2.17; 95%, CI 1.05-4.47) more likely to be higher in the index group than in the reference group. Conclusions The presence of an independent observer documenting colonoscopy quality metrics and video recording the colonoscopy resulted in a significant increase in ADR and other quality metrics. The Hawthorne effect should be considered an alternative strategy to advanced devices to improve colonoscopy quality in practice.

Combined detection of SDC2/ADHFE1/PPP2R5C methylation in stool DNA for colorectal cancer screening

BACKGROUND

Colorectal cancer (CRC) is a disease of global concern, and its increasing incidence suggests the need for early and accurate diagnosis. The aim of this study was to investigate the value of combined detection of SDC2, ADHFE1 and PPP2R5C gene methylation in stool samples for early CRC screening.

METHODS

Stool samples from patients with CRC (n = 105), advanced adenoma (AA) (n = 54), non-advanced adenoma (NA) (n = 57), hyperplastic or other polyps (HOP) (n = 47) or no evidence of disease (NED) (n = 100) were collected from September 2021 to September 2022. The methylation levels of SDC2, ADHFE1 and PPP2R5C were quantified by quantitative methylation-specific polymerase chain reaction (qMSP), and faecal immunochemical testing (FIT) was performed. The diagnostic value was assessed using reporter operating characteristic (ROC) curve analysis.

RESULTS

The sensitivity of combined detection of SDC2/ADHFE1/PPP2R5C methylation in predicting CRC (0-IV) was 84.8%, the specificity was 98.0%, and the AUC was 0.930 (95% CI 0.889-0.970). Compared to FIT and serum tumour biomarkers, it showed better diagnostic performance for different stages of CRC.

CONCLUSION

The results of this study verified that the methylation levels of SDC2, ADHFE1 and PPP2R5C in stool DNA were significantly increased in CRC patients. Combined detection of SDC2/ADHFE1/PPP2R5C methylation is a potential non-invasive diagnostic method for CRC and precancerous lesion screening.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trials Registry, ChiCTR2100046662, registered on 26 May 2021, prospective registration.

Neoplasia Diagnosis After Multi-target Stool DNA Is Enhanced Among Lowest Baseline Detectors

BACKGROUND AND AIMS

Variation in colorectal neoplasia detection limits the effectiveness of screening colonoscopy. By evaluating neoplasia detection rates of individual colonoscopists, we aimed to quantify the effects of pre-procedural knowledge of a positive (+) multi-target stool DNA (mt-sDNA) on colonoscopy quality metrics.

METHODS

We retrospectively identified physicians who performed a high volume of + mt-sDNA colonoscopies; colorectal neoplasia at post-mt-sDNA colonoscopy was recorded. These colonoscopists were stratified into quartiles based on baseline adenoma detection rates. Baseline colonoscopy adenoma detection rates and sessile serrated lesion detection rates were compared to post-mt-sDNA colonoscopy neoplasia diagnosis rates among each quartile. Withdrawal times were measured from negative exams.

RESULTS

During the study period (2014-17) the highest quartile of physicians by volume of post-mt-sDNA colonoscopies were evaluated. Among thirty-five gastroenterologists, their median screening colonoscopy adenoma detection rate was 32% (IQR, 28-39%) and serrated lesion detection rate was 13% (8-15%). After + mt-sDNA, adenoma diagnosis increased to 47% (36-56%) and serrated lesion diagnosis increased to 31% (17-42%) (both p < 0.0001). Median withdrawal time increased from 10 (7-13) to 12 (10-17) minutes (p < 0.0001) and was proportionate across quartiles. After + mt-sDNA, lower baseline detectors had disproportionately higher rates of adenoma diagnosis in female versus male patients (p = 0.048) and higher serrated neoplasia diagnosis rates among all patients (p = 0.0092).

CONCLUSIONS

Knowledge of + mt-sDNA enriches neoplasia diagnosis compared to average risk screening exams. Adenomatous and serrated lesion diagnosis was magnified among those with lower adenoma detection rates. Awareness of the mt-sDNA result may increase physician attention during colonoscopy. Pre-procedure knowledge of a positive mt-sDNA test improves neoplasia diagnosis rates among colonoscopists with lower baseline adenoma detection rates, independent of withdrawal time.

Randomized Trial of Facilitated Adherence to Screening Colonoscopy vs Sequential Fecal-Based Blood Test

BACKGROUND & AIMS

Colorectal cancer (CRC) screening guidelines include screening colonoscopy and sequential high-sensitivity fecal occult blood testing (HSgFOBT), with expectation of similar effectiveness based on the assumption of similar high adherence. However, adherence to screening colonoscopy compared with sequential HSgFOBT has not been reported. In this randomized clinical trial, we assessed adherence and pathology findings for a single screening colonoscopy vs sequential and nonsequential HSgFOBTs.

METHODS

Participants aged 40-69 years were enrolled at 3 centers representing different clinical settings. Participants were randomized into a single screening colonoscopy arm vs sequential HSgFOBT arm composed of 4-7 rounds. Initial adherence to screening colonoscopy and sequential adherence to HSgFOBT, follow-up colonoscopy for positive HSgFOBT tests, crossover to colonoscopy, and detection of advanced neoplasia or large serrated lesions (ADN-SERs) were measured.

RESULTS

There were 3523 participants included in the trial; 1761 and 1762 participants were randomized to the screening colonoscopy and HSgFOBT arms, respectively. Adherence was 1473 (83.6%) for the screening colonoscopy arm vs 1288 (73.1%) for the HSgFOBT arm after 1 round (relative risk [RR], 1.14; 95% CI, 1.10-1.19; P ≤ .001), but only 674 (38.3%) over 4 sequential HSgFOBT rounds (RR, 2.19; 95% CI, 2.05-2.33). Overall adherence to any screening increased to 1558 (88.5%) in the screening colonoscopy arm during the entire study period and 1493 (84.7%) in the HSgFOBT arm (RR, 1.04; 95% CI, 1.02-1.07). Four hundred thirty-six participants (24.7%) crossed over to screening colonoscopy during the first 4 rounds. ADN-SERs were detected in 121 of the 1473 participants (8.2%) in the colonoscopy arm who were adherent to protocol in the first 12 months of the study, whereas detection of ADN-SERs among those who were not sequentially adherent (n = 709) to HSgFOBT was subpar (0.6%) (RR, 14.72; 95% CI, 5.46-39.67) compared with those who were sequentially adherent (3.3%) (n = 647) (RR, 2.52; 95% CI, 1.61-3.98) to HSgFOBT in the first 4 rounds. When including colonoscopies from HSgFOBT patients who were never positive yet crossed over (n = 1483), 5.5% of ADN-SERs were detected (RR, 1.50; 95% CI, 1.15-1.96) in the first 4 rounds.

CONCLUSIONS

Observed adherence to sequential rounds of HSgFOBT was suboptimal compared with a single screening colonoscopy. Detection of ADN-SERs was inferior when nonsequential HSgFOBT adherence was compared with sequential adherence. However, the greatest number of ADN-SERs was detected among those who crossed over to colonoscopy and opted to receive a colonoscopy. The effectiveness of an HSgFOBT screening program may be enhanced if crossover to screening colonoscopy is permitted.

CLINICALTRIALS

gov, Number: NCT00102011.

Colorectal cancer risk after removal of polyps in fecal immunochemical test based screening

Background

Colonoscopy surveillance intervals are based on the predicted risk of metachronous colorectal cancer (CRC) after polyp removal. However, risk estimation per polyp subtype is difficult due to the fact that many patients have multiple polyps. To enable risk estimation per polyp subtypes we examined the metachronous CRC risk of subgroups based on presence or absence of co-occurring findings.

Methods

Using high-quality screening colonoscopies performed after a positive fecal immunochemical test between 2014 and 2020 within the Dutch CRC screening program, we applied Cox regression analysis to evaluate the association between findings at baseline colonoscopy and metachronous CRCs. For our primary outcome, we appointed each patient to unique subgroups based on removed polyp subtypes that were present or absent at baseline colonoscopy and used the groups without polyps as reference. High-risk subgroups were individuals with high-risk serrated polyps, defined as serrated polyp ≥10 mm, sessile serrated lesions with dysplasia, or traditional serrated adenomas, as well as high-risk adenomas, defined as adenoma ≥10 mm or containing high-grade dysplasia.

Findings

In total 253,833 colonoscopies were included. Over a median follow-up of 36 months (IQR, 21-57), we identified 504 metachronous CRCs. Hazard ratios for metachronous CRC was 1.70 (95% CI, 1.07-2.69) for individuals with high-risk serrated polyps without high-risk adenomas, 1.22 (0.96-1.55) for individuals with high-risk adenomas without high-risk serrated polyps, and 2.00 (1.19-3.39) for individuals with high-risk serrated polyps and high-risk adenomas, compared to patients without polyps.

Interpretation

Accounting for co-occurring findings, we observed an increased metachronous CRC risk for individuals that had high-risk serrated polyps with the presence of high-risk adenomas, or individuals with high-risk serrated polyps without high-risk adenomas. These findings could provide more evidence to support post-polypectomy surveillance guidelines.

Funding

None.

Positive Predictive Value for Multitarget Stool DNA After Bariatric and Metabolic Surgery

BACKGROUND AND AIMS

Bariatric and metabolic surgery (BMS) may adversely affect noninvasive stool tests for colorectal cancer (CRC) screening through several mechanisms. Multitarget stool DNA (mt-sDNA) is approved for CRC screening; however, performance in post-BMS patients is unknown. As the rates of BMS are anticipated to increase with rising incidence of obesity, it is important to evaluate mt-sDNA test performance among these patients.

METHODS

In a multisite academic and community-based practice, we obtained mt-sDNA results from 10/2014 to 12/2019 through electronic records and an institutional BMS registry. Average CRC risk patients with BMS prior to a positive mt-sDNA underwent a detailed chart review. Follow-up colonoscopy findings were compared to those among BMS patients screened with colonoscopy alone and a historical cohort of patients without BMS, screened by mt-sDNA. The primary study endpoint was the positive predictive value (PPV) for advanced colorectal neoplasia.

RESULTS

Among 336 average-risk patients who had mt-sDNA after BMS, mt-sDNA was positive in 49 (14.6%), 47/49 (96%) underwent follow-up colonoscopy, and the PPV for advanced neoplasia was 12/47 (25.5%). This is similar to the PPV for advanced colorectal neoplasia (425/1542, 28%) in a historical cohort of persons without prior BMS, screened by mt-sDNA at our center (P = .86). Among those who had prior BMS, the rate of advanced neoplasia was higher after mt-sDNA compared to screening colonoscopy alone.

CONCLUSION

Despite anatomic and physiologic mechanisms that could alter blood or DNA content in stool, BMS does not appear to adversely affect the PPV of mt-sDNA.

Vitamin D Status, Cdx2 Genotype, and Colorectal Cancer Survival: Population-Based Patient Cohort

According to recent evidence, the prognostic value of Vitamin D (VitD) status for colorectal cancer (CRC) patients might be confined to patients with the GG genotype of Cdx2, a functional polymorphism of the VitD receptor gene. We aimed to validate these findings in a cohort of CRC patients. Post-operative serum 25-hydroxyvitamin D concentration was determined by mass spectrometry and Cdx2 genotyping was performed from blood or buccal swabs using standard methods. Joint associations of VitD status and Cdx2 with overall survival (OS), CRC-specific survival (CSS), recurrence-free survival (RFS), and disease-free survival (DFS) were assessed using Cox regression. For patients with GG genotype, adjusted hazard ratios (95% confidence interval) for the associations of sufficient compared with deficient VitD were 0.63 (0.50-0.78), 0.68 (0.50-0.90), 0.66 (0.51-0.86), and 0.62 (0.50-0.77) for OS, CSS, RFS, and DFS, respectively. These associations were weaker and not statistically significant for the AA/AG genotype. Interaction between VitD status and genotype did not reach statistical significance. VitD deficiency is an independent predictor of poorer survival, particularly for the GG Cdx2 carriers, suggesting a potential role of VitD supplementation according to VitD status and genotype, which should be evaluated in randomised trials.

Cost-effectiveness of Artificial Intelligence-Aided Colonoscopy for Adenoma Detection in Colon Cancer Screening

Background and Aims

Artificial intelligence-aided colonoscopy significantly improves adenoma detection. We assessed the cost-effectiveness of the GI Genius technology, an artificial intelligence-aided computer diagnosis for polyp detection (CADe), in improving colorectal cancer outcomes, adopting a Canadian health care perspective.

Methods

A Markov model with 1-year cycles and a lifetime horizon was used to estimate incremental cost-effectiveness ratio comparing CADe to conventional colonoscopy polyp detection amongst patients with a positive faecal immunochemical test. Outcomes were life years (LYs) and quality-adjusted life years (QALY) gained. The analysis applied costs associated with health care resource utilization, including procedures and follow-ups, from a provincial payer's perspective using 2022 Canadian dollars. Effectiveness and cost data were sourced from the literature and publicly available databases. Extensive probabilistic and deterministic sensitivity analyses were performed, assessing model robustness.

Results

Life years and QALY gains for the CADe and conventional colonoscopy groups were 19.144 versus 19.125 and 17.137 versus 17.113, respectively. CADe and conventional colonoscopies' overall per-case costs were $2990.74 and $3004.59, respectively. With a willingness-to-pay pre-set at $50,000/QALY, the incremental cost-effectiveness ratio was dominant for both outcomes, showing that CADe colonoscopy is cost-effective. Deterministic sensitivity analysis confirmed that the model was sensitive to the incidence risk ratio of adenoma per colonoscopy for large adenomas. Probabilistic sensitivity analysis showed that the CADe strategy was cost-effective in up to 73.4% of scenarios.

Conclusion

The addition of CADe solution to colonoscopy is a dominant, cost-effective strategy when used in faecal immunochemical test-positive patients in a Canadian health care setting.

Adherence to the World Cancer Research Fund/American Institute for Cancer Research cancer prevention recommendations throughout the life course and risk of colorectal cancer precursors

BACKGROUND

Despite the increasing incidence in colorectal cancer (CRC) among the young population, the involvement of modifiable early-life exposures is understudied.

METHODS

We prospectively investigated the association of lifestyle score, which measures adherence to the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations, in adolescence and adulthood with risk of CRC precursors in 34,509 women enrolled in the Nurses' Health Study II. Participants reported adolescent diet in 1998 and subsequently underwent at least one lower gastrointestinal endoscopy between 1999 and 2015. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariable logistic regression for clustered data.

RESULTS

During follow-up (1998-2015), 3036 women had at least one adenoma, and 2660 had at least one serrated lesion. In multivariable analysis, per unit increase in adolescent WCRF/AICR lifestyle score was not associated with risk of total adenoma or serrated lesions, in contrast to adult WCRF/AICR lifestyle score (OR = 0.92, 95% CI: 0.87-0.97, Ptrend = 0.002 for total adenoma; and OR = 0.86, 95% CI: 0.81-0.92, Ptrend < 0.001 for total serrated lesions).

CONCLUSION

Adherence to the 2018 WCRF/AICR recommendations during adulthood but not during adolescence was associated with a lower risk of CRC precursors.

The World Trade Center Health Program: Cancer screening and cancer care best practices

The events of September 11, 2001 (9/11) exposed nearly a half million persons to many carcinogenic chemicals and dusts, as well as psychological and physical stressors. Subsequent epidemiologic studies of 9/11-exposed persons have suggested elevated risks for some cancers, e.g., prostate cancer, thyroid cancer, and melanoma. To detect cancer at an early stage, the US Preventive Services Task Force recommends screening certain asymptomatic persons for lung, colorectal, cervical and breast cancer, but not for other cancers. High quality cancer diagnosis and treatment guidelines are available from the National Comprehensive Cancer Network and the National Cancer Institute. For enrolled members, the WTC Health Program provides coverage for cancer screening and diagnosis, and covers medically necessary treatment costs for all types of cancer, assuming 9/11-exposure and minimum latency requirements are met, and a Program-affiliated physician attests that 9/11 exposures were substantially likely to have been a significant factor in aggravating, contributing to, or causing the enrolled WTC member's cancer.

Computer-aided detection, mucosal exposure device, their combination, and standard colonoscopy for adenoma detection: a randomized controlled trial

BACKGROUND AND AIMS

Computer-aided detection (CADe) and a mucosal exposure device can improve adenoma detection rate (ADR). Potential benefits of combining the 2 modalities have never been studied. This study aimed to compare ADR differences among CADe alone, endocuff-assisted colonoscopy (EAC) alone, and the combination of CADe and EAC (CADe+EAC) with standard colonoscopy.

METHODS

This prospective randomized controlled study included 1245 participants who underwent screening colonoscopy. Participants were randomized to CADe, EAC, CADe+EAC, and standard colonoscopy as a control. The primary outcome was ADR. Secondary outcomes were proximal ADR (pADR), advanced ADR (AADR), and the number of adenomas per colonoscopy (APCs).

RESULTS

ADRs from the control, CADe, EAC, and CADe+EAC groups were 41.9%, 52.2%, 54.0%, and 58.8%, respectively; pADRs were 25.2%, 33.3%, 34.9%, and 37.0%, respectively; AADRs were 7.7%, 8.3%, 8.3%, and 13.6%, respectively; and APCs were .76, 1.11, 1.18, and 1.31, respectively. Significant increases in ADR and pADR were observed between the intervention and control groups (P < .05 in all comparisons). The AADR was significantly higher only in the CADe+EAC group than in the control group (P = .02). The adjusted incidence rate ratios of APCs were significantly higher in the intervention groups versus the control group (P < .01 in all comparisons).

CONCLUSIONS

CADe+EAC significantly improve ADR and AADR over standard colonoscopy. However, although CADe or EAC alone can substantially increase the detection of adenomas, they do not lead to increased detection of advanced adenomas unless used in combination. (Clinical trial registration number: TCTR20200929003.).

Can white-light endoscopy or narrow-band imaging avoid biopsy of colorectal endoscopic mucosal resection scars? A multicenter randomized single-blind crossover trial

BACKGROUND : Current guidelines suggest that routine biopsy of post-endoscopic mucosal resection (EMR) scars can be abandoned, provided that a standardized imaging protocol with virtual chromoendoscopy is used. However, few studies have examined the accuracy of advanced endoscopic imaging, such as narrow-band imaging (NBI) vs. white-light endoscopy (WLE) for prediction of histological recurrence. We aimed to assess whether NBI accuracy is superior to that of WLE and whether one or both techniques can replace biopsies. METHODS : The study was a multicenter, randomized, pathologist-blind, crossover trial, with consecutive patients undergoing first colonoscopy after EMR of lesions ≥ 20 mm. Computer-generated randomization and opaque envelope concealed allocation. Patients were randomly assigned to scar examination with NBI followed by WLE (NBI + WLE), or WLE followed by NBI (WLE + NBI). Histology was the reference method, with biopsies being performed for all tissues. RESULTS : The study included 203 scars (103 in the NBI + WLE group, 100 in the WLE + NBI group). Recurrence was confirmed histologically in 29.6 % of the scars. The diagnostic accuracy of NBI was not statistically different from that of WLE (95 % [95 %CI 92 %-98 %] vs. 94 % [95 %CI 90 %-97 %]; P = 0.48). The negative predictive values (NPVs) were 96 % (95 %CI 93 %-99 %) for NBI and 93 % (95 %CI 89 %-97 %) for WLE (P = 0.06). CONCLUSIONS : The accuracy of NBI for the diagnosis of recurrence was not superior to that of WLE. Endoscopic assessment of EMR scars with WLE and NBI achieved an NPV that would allow routine biopsy to be avoided in cases of negative optical diagnosis.

New management of surveillance in patients with baseline serrated polyps: a large single-center retrospective cohort study in China

BACKGROUND

Serrate d polyps (SP) is associated with an increased risk of colorectal cancer. Patients with SP history tend to have SP recurrence. However, the risk factors for metachronous polyps (MP) in those patients are not well established.

METHODS

Data of colonoscopy were retrospectively reviewed from October 2012 to October 2021. The pathology database, electronic medical records and telephone follow-up data were also observed.

RESULTS

A total of 906 patients were studied including 278 patients with MPs and 628 patients without. The multiplicity of polyps (OR, 13.63; 95% CI, 8.80-21.75), older age (OR, 5.71; 95% CI, 1.87-20.63), abdominal obesity (OR, 2.46; 95% CI, 0.98-6.42), current smoker (OR, 2.93; 95% CI, 1.15-7.83) and sedentary lifestyle (OR, 1.41; 95% CI, 1.22-1.65) are significantly associated with the risk of MPs. Patients with baseline SP < 10 mm were more likely to develop higher or same risk-grade polyps (HSRGP) ( P  = 0.0014). Patients with non-clinically significant SPs whether coexisted with adenoma or not were more likely to develop HSRGPs when compared to others ( P  < 0.001).

CONCLUSION

Total number of polyps, older age, sedentary behavior, abdominal obesity and smoking status contributed to the risk of MPs at surveillance colonoscopy. Patients with grade 1 SPs might require closer surveillance. SPs coexisting with conventional adenoma did not increase the risk of MPs but may increase the risk of developing HSRGPs.