A pooled analysis of advanced colorectal neoplasia diagnoses after colonoscopic polypectomy

Dynamic adenoma detection rate influences the risk of metachronous advanced neoplasia after removal of low-risk findings in screening colonoscopy

BACKGROUND

Endoscopists' adenoma detection rate (ADR) may change over time and dynamic ADR has been identified as a predictor for post-screening colorectal cancer. However, whether low-risk findings removed by an endoscopist with a lower dynamic ADR benefit from a shorter duration of follow-up requires further research.

METHODS

We conducted a two-center retrospective study of individuals who had low-risk findings removed and underwent subsequent surveillance colonoscopy. Endoscopists' dynamic ADR was the ADR of the previous 100 screening colonoscopies performed by the same endoscopist. A Cox-regression model and Kaplan-Meier survival analysis were used to explore the relationship between dynamic ADR and metachronous advanced colorectal neoplasia (ACRN).

RESULTS

Totally, 3471 individuals who had low-risk findings removed in baseline colonoscopy were included in analysis. Decreasing endoscopists' dynamic ADR was independently associated with metachronous ACRN. A 3.97-, 2.21-, and 2.67-fold increased risk for metachronous ACRN was observed in individuals of which baseline colonoscopy was performed by an endoscopist with a dynamic ADR of < 15%, 15-19%, and 20-24%, respectively, compared with those with the highest dynamic ADR (≥ 25%). The cumulative incidence of metachronous ACRN reached the 5% threshold at 4.5 years, 7.3 years, and 6.2 years in the dynamic ADR < 15%, 15-19%, and 20-24% group, respectively.

CONCLUSION

Endoscopists' dynamic ADR influences the risk of metachronous ACRN after removal of low-risk findings in screening colonoscopy. Individuals undergoing removal of low-risk findings in screening colonoscopy by an endoscopist with a dynamic ADR < 25% may benefit from a shorter duration of follow-up interval.

Construction and validation of machine learning-based predictive model for colorectal polyp recurrence one year after endoscopic mucosal resection

BACKGROUND

Colorectal polyps are precancerous diseases of colorectal cancer. Early detection and resection of colorectal polyps can effectively reduce the mortality of colorectal cancer. Endoscopic mucosal resection (EMR) is a common polypectomy procedure in clinical practice, but it has a high postoperative recurrence rate. Currently, there is no predictive model for the recurrence of colorectal polyps after EMR.

AIM

To construct and validate a machine learning (ML) model for predicting the risk of colorectal polyp recurrence one year after EMR.

METHODS

This study retrospectively collected data from 1694 patients at three medical centers in Xuzhou. Additionally, a total of 166 patients were collected to form a prospective validation set. Feature variable screening was conducted using univariate and multivariate logistic regression analyses, and five ML algorithms were used to construct the predictive models. The optimal models were evaluated based on different performance metrics. Decision curve analysis (DCA) and SHapley Additive exPlanation (SHAP) analysis were performed to assess clinical applicability and predictor importance.

RESULTS

Multivariate logistic regression analysis identified 8 independent risk factors for colorectal polyp recurrence one year after EMR (P < 0.05). Among the models, eXtreme Gradient Boosting (XGBoost) demonstrated the highest area under the curve (AUC) in the training set, internal validation set, and prospective validation set, with AUCs of 0.909 (95%CI: 0.89-0.92), 0.921 (95%CI: 0.90-0.94), and 0.963 (95%CI: 0.94-0.99), respectively. DCA indicated favorable clinical utility for the XGBoost model. SHAP analysis identified smoking history, family history, and age as the top three most important predictors in the model.

CONCLUSION

The XGBoost model has the best predictive performance and can assist clinicians in providing individualized colonoscopy follow-up recommendations.

Identification of Genetic Factors Related With Nonhereditary Colorectal Polyposis and Its Recurrence Through Genome-Wide Association Study

BACKGROUND

Many patients with colorectal polyposis demonstrate negative results in germline mutation test. This study aimed to uncover genetic variants associated with nonhereditary colorectal polyposis using a genome-wide association study (GWAS).

METHODS

At a single referral university hospital, between January 2012 and September 2021, 638 patients with ≥ 10 biopsy-proven cumulative polyps on colonoscopy without germline mutations related to hereditary colorectal cancer or polyposis were included. The control group comprised 1863 individuals from the Korea Medical Institute, each having undergone at least two colonoscopies, all of which were normal. This study utilized GWAS to identify susceptibility loci for nonhereditary colorectal polyposis. Genetic differences between patients with and without ≥ 10 polyp recurrences were analyzed using Cox proportional hazards models.

RESULTS

GWAS revealed 71 novel risk single-nucleotide polymorphisms (SNPs) not seen in previous colorectal cancer and polyp GWAS. Five genes (UPF3A, BICRA, CBWD6, PDE4DIP, and ABCC4) overlapping seven SNPs (rs566295755, rs2770288, rs1012003, rs201270202, rs71264659, rs1699813, and rs149368557), previously linked to colorectal cancer, were identified as significant risk factors for nonhereditary colorectal polyposis. Two novel genes (CNTN4 and CNTNAP3B), not previously associated with colorectal diseases, were identified. Three SNPs (rs149368557, rs12438834, and rs9707935) were significantly associated with higher risk of recurrence of polyposis. The gene overlapping with rs149368557 was ABCC4, which was also significantly associated with an increased risk of nonhereditary colorectal polyposis.

CONCLUSION

This study identified 71 novel risk variants for nonhereditary colorectal polyposis, with three SNPs (rs149368557, rs12438834, and rs9707935) indicating significant associations with increased risk of polyposis recurrence.

Negative predictive value of fecal immunochemical testing in significant bowel disease screening: a systematic review and meta-analysis

OBJECTIVES

General practitioners (GPs) must assess significant bowel disease (SBD) in patients with lower bowel symptoms during primary care. Studies have evaluated the efficacy of fecal immunochemical testing (FIT) for SBD screening. However, the effectiveness of FIT remains controversial. This study aimed to investigate the value of FIT in SBD screening.

METHODS

PubMed, the Cochrane Database, and EMBASE were systematically searched. Studies that estimated FIT values in screening for SBD among patients with lower bowel symptoms were included. Sensitivity, specificity, negative likelihood ratio (NLR), positive likelihood ratio (PLR), diagnostic odds ratio (DOR), and negative predictive value (NPV) were calculated. Additionally, the pooled area under the summary receiver operating characteristic (SROC) curve was analyzed.

RESULTS

A total of 8615 patients with lower bowel symptoms who underwent FIT and colonoscopy to screen for SBD were enrolled and assessed in this meta-analysis; of these, 1226 patients were ultimately diagnosed with SBD. The pooled sensitivity, specificity, PLR, NLR, DOR, and NPV of FIT in SBD screening were 0.65 (95% CI: 0.50-0.78), 0.85 (95% CI: 0.72-0.92), 4.2 (95% CI: 2.60-6.90), 0.41 (95% CI: 0.29-0.58), 10 (95% CI: 6-17), and 0.90 (95% CI: 0.87-0.94), respectively. Besides, the pooled SROC was 0.82 (95% CI: 0.78-0.85).

CONCLUSIONS

This study indicates that the FIT provides a favorable NPV for SBD screening and could be a valuable technique for GPs to rule out SBD in primary care. At the same time, GPs need to remain vigilant and refer patients to gastroenterologists when necessary.

Proximal Polyps Are Associated With Higher Incidence of Colorectal Cancer: Analysis of the Minnesota Colon Cancer Control Study

INTRODUCTION

Despite reports indicating that polyps proximal to the splenic flexure have higher rates of metachronous colorectal adenocarcinoma (CRC), the role of adenoma location on surveillance recommendations remains unclear. This study aimed to analyze the association between index polyp location and postcolonoscopy CRC among participants of the Minnesota Colon Cancer Control Study.

METHODS

The Minnesota Colon Cancer Control Study randomized 46,551 patients 50-80 years to usual care, annual, or biennial screening with fecal occult-blood testing. Screening was performed between 1976 and 1992. Positive fecal occult-blood testing was followed by colonoscopy. We analyzed participants whose colonoscopy revealed at least 1 adenoma. Patients were divided into those with at least 1 lesion proximal to the splenic flexure and those without.

RESULTS

Of 2,295 patients, 815 had proximal adenomas. The majority were men; mean age = 62 years at randomization, and 69 years at index polyp. There was a high rate of advanced adenomas: 44% ≥ 1 polyp ≥1 cm, 35% with villous histology, and 5% high-grade dysplasia. At 20 years, 87 patients had a CRC diagnosis, and the estimated cumulative incidence of CRC was 4.3%. Proximal adenomas had a higher risk of developing a postcolonoscopy CRC (subdistribution hazard ratio = 1.63, 95% confidence interval = 1.05-2.53, P = 0.03), which was attenuated after adjusting for polyp multiplicity in sensitivity analyses (subdistribution hazard ratio = 1.56, 95% confidence interval = 0.96-2.53, P = 0.07).

DISCUSSION

Although patients with proximal adenomas were found to have higher hazards of postcolonoscopy CRC, adjusting for polyp multiplicity attenuated the strength of association. Further research is warranted to determine whether polyp location should be factored in the determination of appropriate surveillance intervals.

Projected Impact and Cost-Effectiveness of Novel Molecular Blood-Based or Stool-Based Screening Tests for Colorectal Cancer

BACKGROUND

Cell-free DNA blood tests (cf-bDNA) and next-generation stool tests could change colorectal cancer (CRC) screening.

OBJECTIVE

To estimate the clinical and economic impacts of novel CRC screening tests.

DESIGN

Cost-effectiveness analysis using MOSAIC (Model of Screening and Surveillance for Colorectal Cancer).

DATA SOURCES

Published data.

TARGET POPULATION

Average-risk persons.

TIME HORIZON

Ages 45 to 100 years.

PERSPECTIVE

Health sector.

INTERVENTION

Novel versus established CRC screening tests.

OUTCOME MEASURES

Incidence and mortality of CRC, quality-adjusted life-years (QALYs), costs.

RESULTS OF BASE-CASE ANALYSIS

For colonoscopy every 10 years, annual fecal immunochemical test (FIT), and triennial next-generation multitarget stool DNA, FIT-RNA, cf-bDNA (Guardant Shield), or cf-bDNA (Freenome), the relative rates (RRs) and 95% uncertainty intervals (UIs) versus no screening for CRC incidence were 0.21 (0.19 to 0.22), 0.29 (0.27 to 0.31), 0.33 (0.32 to 0.36), 0.32 (0.30 to 0.34), 0.58 (0.55 to 0.61) and 0.58 (0.55 to 0.60), respectively; the RRs for CRC death were 0.19 (0.17 to 0.20), 0.25 (0.23 to 0.27), 0.28 (0.27 to 0.30), 0.28 (0.26 to 0.30), 0.44 (0.42 to 0.47), and 0.46 (0.44 to 0.49), respectively. The cf-bDNA test (Shield; list price $1495) cost $89 600 ($74 800 to $102 300) per QALY gained versus no screening; alternatives were less costly and more effective.

RESULTS OF SENSITIVITY ANALYSIS

Incremental costs exceeded incremental benefits when novel test intervals were shortened to 2 or 1 years. The cf-bDNA test matched FIT's impact on CRC mortality at 1.35 (1.30 to 1.40)-fold FIT's uptake rate, assuming equal colonoscopy follow-up. If persons who accept colonoscopy or stool tests shifted to cf-bDNA, CRC deaths increased. This adverse effect was overcome if every 3 such substitutions were counterbalanced by cf-bDNA uptake by 2 or more persons refusing alternatives, assuming equal colonoscopy follow-up.

LIMITATION

Longitudinal test-specific participation patterns are unknown.

CONCLUSION

First-generation cf-bDNA tests may deliver net benefit or harm, depending on the balance between achieving screening in persons who decline alternatives versus substituting cf-bDNA for more effective alternatives.

PRIMARY FUNDING SOURCE

The Gorrindo Family Fund.

Early-onset Colorectal Cancer Patients Do Not Require Shorter Intervals for Post-surgical Surveillance Colonoscopy

BACKGROUND & AIMS

Early-onset colorectal cancer (EO-CRC), diagnosed before age 50, is rising in incidence worldwide. Although post-surgical colonoscopy surveillance strategies exist, appropriate intervals in EO-CRC remain elusive, as long-term surveillance outcomes remain scant. We sought to compare findings of surveillance colonoscopies of EO-CRC with patients with average onset colorectal cancer (AO-CRC) to help define surveillance outcomes in these groups.

METHODS

Single-institution retrospective chart review identified EO-CRC and AO-CRC patients with colonoscopy and no evidence of disease. Surveillance intervals and time to development of advanced neoplasia (CRC and advanced polyps [adenoma/sessile serrated]) were examined. For each group, 3 serial surveillance colonoscopies were evaluated. Statistical analyses were performed utilizing log-ranked Kaplan-Meier method and Cox proportional hazards.

RESULTS

A total of 1259 patients with CRC were identified, with 612 and 647 patients in the EO-CRC and AO-CRC groups, respectively. Compared with patients with AO-CRC, patients with EO-CRC had a 29% decreased risk of developing advanced neoplasia from time of initial surgery to first surveillance colonoscopy (hazard ratio, 0.71; 95% confidence interval, 0.52-1.0). Average follow-up time from surgical resection to first surveillance colonoscopy was 12.6 months for both cohorts. Overall surveillance findings differed between cohorts (P = .003), and patients with EO-CRC were found to have less advanced neoplasia compared with their counterparts with AO-CRC (12.4% vs 16.0%, respectively). Subsequent colonoscopies found that, while patients with EO-CRC returned for follow-up surveillance colonoscopy earlier than patients with AO-CRC, the EO-CRC cohort did not have more advanced neoplasia nor non-advanced adenomas.

CONCLUSIONS

Patients with EO-CRC do not have an increased risk of advanced neoplasia compared with patients with AO-CRC and therefore do not require more frequent colonoscopy surveillance than current guidelines recommend.

Prediction of metachronous advanced colorectal neoplasia by KRAS mutation in polyps

BACKGROUND

The potential of molecular markers in the removed polys as reliable predictors of metachronous lesions is still uncertain.

AIM

Our aim was to evaluate the role of somatic mutations in KRAS in polyps of patients with high-risk adenomas to predict the risk of advanced polyps or colorectal cancer (CRC) within 3 years.

METHODS

A total of 518 patients were prospectively enrolled. The included patients had adenomas ≥10 mm, high-grade dysplasia, villous component or ≥3 more adenomas at baseline and were scheduled to undergo surveillance colonoscopy at 3 years ± 6 months. Somatic KRAS mutation was performed on 1189 polyps collected from these patients. At surveillance, advanced lesions were defined as adenomas with a size of ≥10 mm. High-grade dysplasia or villous component, serrated polyps ≥10 mm or with dysplasia or CRC.

RESULTS

At baseline, 81 patients (15.6%) had KRAS mutations in at least one polyp. Patients with KRAS mutated polyps had more frequent villous histological lesions and size ≥20 mm. In the multivariate analysis, adjusted for age and sex, only age (odds ratios [OR], 1.06; 95% confidence interval [CI], 1.02-1.09; p < 0.001), ≥5 adenomas (OR, 3.92; 95% CI, 1.96-7.82), and KRAS mutation (OR, 2.54; 95% CI, 1.48-4.34; p < 0.01) were independently associated with the development of advanced lesions at surveillance.

CONCLUSIONS

Our results show that, in patients with high-risk adenomas, the presence of somatic mutations in KRAS is an independent risk factor for the development of advanced metachronous polyps.

Risk factors for advanced colorectal neoplasia and colorectal cancer detected at surveillance: a nationwide study in the modern era

AIM

Recommendations for surveillance after colonoscopy are based on risk factors for metachronous advanced colorectal neoplasia (AN) and colorectal cancer (CRC). The value of these risk factors remains unclear in populations enriched by individuals with a positive faecal immunochemical test and were investigated in a modern setting.

METHODS AND RESULTS

This population-based cohort study included all individuals in the Netherlands of ≥55 years old with a first adenoma diagnosis in 2015. A total of 22,471 patients were included. Data were retrieved from the Dutch Nationwide Pathology Databank (Palga). Primary outcomes were metachronous AN and CRC. Patient and polyp characteristics were evaluated by multivariable Cox regression analyses. During follow-up, 2416 (10.8%) patients were diagnosed with AN, of which 557 (2.5% from the total population) were CRC. Adenomas with high-grade dysplasia (hazard ratio [HR] 1.60, 95% confidence interval [CI] 1.40-1.83), villous histology (HR 1.91, 95% CI 1.59-2.28), size ≥10 mm (HR 1.12, 95% CI 1.02-1.23), proximal location (HR 1.12, 95% CI 1.02-1.23), two or more adenomas (HR 1.28, 95% CI 1.16-1.41), and serrated polyps ≥10 mm (HR 1.67, 95% CI 1.42-1.97) were independent risk factors for metachronous AN. In contrast, only adenomas with high-grade dysplasia (HR 2.49, 95% CI 1.92-3.24) were an independent risk factor for metachronous CRC.

CONCLUSIONS

Risk factors for metachronous AN and CRC were identified for populations with access to a faecal immunochemical test (FIT)-based screening programme. If only risk factors for metachronous CRC are considered, a reduction in criteria for surveillance seems reasonable.

Chinese national clinical practice guidelines on prevention, diagnosis and treatment of early colorectal cancer

BACKGROUND

The incidence and mortality of colorectal cancer (CRC) in China are increasing in recent years. The clarified pathogenesis and detectable precancerous lesions of CRC make it possible to prevent, screen, and diagnose CRC at an early stage. With the development of endoscopic and surgical techniques, the choice of treatment for early CRC is also worth further discussion, and accordingly, a standard follow-up program after treatment needs to be established.

METHODS

This clinical practice guideline (CPG) was developed following the recommended process of the World Health Organization, adopting Grading of Recommendations Assessment, Development and Evaluation (GRADE) in assessing evidence quality, and using the Evidence to Decision framework to formulate clinical recommendations, thereby minimizing bias and increasing transparency of the CPG development process. We used the Reporting Items for practice Guidelines in HealThcare (RIGHT) statement and Appraisal of Guidelines for Research and Evaluation II (AGREE II) as reporting and conduct guides to ensure the guideline's completeness and transparency.

RESULTS

This CPG comprises 46 recommendations concerning prevention, screening, diagnosis, treatment, and surveillance of CRC. In these recommendations, we have indicated protective and risk factors for CRC and made recommendations for chemoprevention. We proposed a suitable screening program for CRC based on the Chinese context. We also provided normative statements for the diagnosis, treatment, and surveillance of CRC based on existing clinical evidence and guidelines.

CONCLUSIONS

The 46 recommendations in this CPG are formed with consideration for stakeholders' values and preferences, feasibility, and acceptability. Recommendations are generalizable to resource-limited settings with similar CRC epidemiology pattern as China.

Dysbiosis promotes recurrence of adenomatous polyps in the distal colorectum

BACKGROUND

Colorectal polyps, which are characterized by a high recurrence rate, represent preneoplastic conditions of the intestine. Due to unclear mechanisms of pathogenesis, first-line therapies for non-hereditary recurrent colorectal polyps are limited to endoscopic resection. Although recent studies suggest a mechanistic link between intestinal dysbiosis and polyps, the exact compositions and roles of bacteria in the mucosa around the lesions, rather than feces, remain unsettled.

AIM

To clarify the composition and diversity of bacteria in the mucosa surrounding or 10 cm distal to recurrent intestinal polyps.

METHODS

Mucosal samples were collected from four patients consistently with adenomatous polyps (Ade), seven consistently with non-Ade (Pol), ten with current Pol but previous Ade, and six healthy individuals, and bacterial patterns were evaluated by 16S rDNA sequencing. Linear discriminant analysis and Student's t-tests were used to identify the genus-level bacteria differences between groups with different colorectal polyp phenotypes. Pearson's correlation coefficients were used to evaluate the correlation between intestinal bacteria at the genus level and clinical indicators.

RESULTS

The results confirmed a decreased level of probiotics and an enrichment of pathogenic bacteria in patients with all types of polyps compared to healthy individuals. These changes were not restricted to the mucosa within 0.5 cm adjacent to the polyps, but also existed in histologically normal tissue 10 cm distal from the lesions. Significant differences in bacterial diversity were observed in the mucosa from individuals with normal conditions, Pol, and Ade. Increased abundance of Gram-negative bacteria, including Klebsiella, Plesiomonas, and Cronobacter, was observed in Pol group and Ade group, suggesting that resistance to antibiotics may be one risk factor for bacterium-related harmful environment. Meanwhile, age and gender were linked to bacteria changes, indicating the potential involvement of sex hormones.

CONCLUSION

These preliminary results support intestinal dysbiosis as an important risk factor for recurrent polyps, especially adenoma. Targeting specific pathogenic bacteria may attenuate the recurrence of polyps.

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.

Predicting Risk of Colorectal Cancer After Adenoma Removal in a Large Community-Based Setting

INTRODUCTION

Colonoscopy surveillance guidelines categorize individuals as high or low risk for future colorectal cancer (CRC) based primarily on their prior polyp characteristics, but this approach is imprecise, and consideration of other risk factors may improve postpolypectomy risk stratification.

METHODS

Among patients who underwent a baseline colonoscopy with removal of a conventional adenoma in 2004-2016, we compared the performance for postpolypectomy CRC risk prediction (through 2020) of a comprehensive model featuring patient age, diabetes diagnosis, and baseline colonoscopy indication and prior polyp findings (i.e., adenoma with advanced histology, polyp size ≥10 mm, and sessile serrated adenoma or traditional serrated adenoma) with a polyp model featuring only polyp findings. Models were developed using Cox regression. Performance was assessed using area under the receiver operating characteristic curve (AUC) and calibration by the Hosmer-Lemeshow goodness-of-fit test.

RESULTS

Among 95,001 patients randomly divided 70:30 into model development (n = 66,500) and internal validation cohorts (n = 28,501), 495 CRC were subsequently diagnosed; 354 in the development cohort and 141 in the validation cohort. Models demonstrated adequate calibration, and the comprehensive model demonstrated superior predictive performance to the polyp model in the development cohort (AUC 0.71, 95% confidence interval [CI] 0.68-0.74 vs AUC 0.61, 95% CI 0.58-0.64, respectively) and validation cohort (AUC 0.70, 95% CI 0.65-0.75 vs AUC 0.62, 95% CI 0.57-0.67, respectively).

DISCUSSION

A comprehensive CRC risk prediction model featuring patient age, diabetes diagnosis, and baseline colonoscopy indication and polyp findings was more accurate at predicting postpolypectomy CRC diagnosis than a model based on polyp findings alone.

Comparative Effectiveness and Cost-Effectiveness of Colorectal Cancer Screening With Blood-Based Biomarkers (Liquid Biopsy) vs Fecal Tests or Colonoscopy

BACKGROUND & AIMS

Colorectal cancer (CRC) screening is highly effective but underused. Blood-based biomarkers (liquid biopsy) could improve screening participation.

METHODS

Using our established Markov model, screening every 3 years with a blood-based test that meets minimum Centers for Medicare & Medicaid Services' thresholds (CMSmin) (CRC sensitivity 74%, specificity 90%) was compared with established alternatives. Test attributes were varied in sensitivity analyses.

RESULTS

CMSmin reduced CRC incidence by 40% and CRC mortality by 52% vs no screening. These reductions were less profound than the 68%-79% and 73%-81%, respectively, achieved with multi-target stool DNA (Cologuard; Exact Sciences) every 3 years, annual fecal immunochemical testing (FIT), or colonoscopy every 10 years. Assuming the same cost as multi-target stool DNA, CMSmin cost $28,500/quality-adjusted life-year gained vs no screening, but FIT, colonoscopy, and multi-target stool DNA were less costly and more effective. CMSmin would match FIT's clinical outcomes if it achieved 1.4- to 1.8-fold FIT's participation rate. Advanced precancerous lesion (APL) sensitivity was a key determinant of a test's effectiveness. A paradigm-changing blood-based test (sensitivity >90% for CRC and 80% for APL; 90% specificity; cost ≤$120-$140) would be cost-effective vs FIT at comparable participation.

CONCLUSIONS

CMSmin could contribute to CRC control by achieving screening in those who will not use established methods. Substituting blood-based testing for established effective CRC screening methods will require higher CRC and APL sensitivities that deliver programmatic benefits matching those of FIT. High APL sensitivity, which can result in CRC prevention, should be a top priority for screening test developers. APL detection should not be penalized by a definition of test specificity that focuses on CRC only.

Risk of advanced neoplasia after removal of colorectal adenomas with high-grade dysplasia

BACKGROUND

Many studies reported the presence of adenomas with high-grade dysplasia (HGD) at index colonoscopy increased the incidence of advanced neoplasia (AN) and colorectal cancer (CRC) following. However, the conclusion remains obscure due to lack of studies on the specific population of adenomas with HGD. This study aimed to assess the long-term risk of AN and CRC after removal of adenomas with HGD.

METHODS

A total of 814 patients who underwent adenomas with HGD removal between 2010 and 2019 were retrospectively analyzed. The outcomes were the incidences of AN and CRC during surveillance colonoscopy. Cox proportional hazards models were utilized to identify risk factors associated with AN and CRC.

RESULTS

During more than 2000 person-years of follow-up, we found that AN and CRC incidence densities were 44.3 and 4.4 per 1000 person-years, respectively. The 10-year cumulative incidence of AN and CRC were 39.1% and 5.5%, respectively. In the multivariate model, synchronous low-risk polyps (HR 1.80, 95% CI 1.10-2.93) and synchronous high-risk polyps (HR 3.99, 95% CI 2.37-6.72) were risk factors for AN, whereas participation in surveillance colonoscopy visits (HR 0.56, 95% CI 0.36-0.88 for 1 visit; HR 0.10, 95% CI 0.06-0.19 for ≥ 2 visits) were associated with decreased AN incidence. Additionally, elevated baseline carcinoembryonic antigen (CEA) level (HR 10.19, 95% CI 1.77-58.59) was a risk factor for CRC, while participation in ≥ 2 surveillance colonoscopy visits (HR 0.11, 95% CI 0.02-0.56) were associated with decreased CRC incidence. Interestingly, for 11 patients who developed CRC after removal of adenomas with HGD, immunohistochemistry revealed that 8 cases (73%) were deficient mismatch repair CRCs.

CONCLUSIONS

Patients who have undergone adenoma with HGD removal are at higher risk of developing AN and CRC, while surveillance colonoscopy can reduce the risk. Patients with synchronous polyps, or with elevated baseline CEA level are considered high-risk populations and require more frequent surveillance.

Exploring the Role of the Gut Microbiota in Colorectal Cancer Development

Colorectal cancer is currently a public health concern due to its high incidence, morbidity, and mortality rates. Researchers have identified the intestinal microbiome as a crucial factor in the development of this disease. Currently, specialized literature data support the role of the microbiota in both the development of colorectal cancer and resistance to oncological therapies. Therefore, studying the composition of the gut microbiome can aid in creating risk assessment tools to identify specific populations that would benefit from tailored screening approaches. Also, manipulation of the intestinal microbiome can be useful in improving the response to chemotherapy or immunotherapy. Identifying the pathogenic mechanisms responsible for this causal link can aid in the discovery of novel treatment targets. This article will provide the latest information regarding the influence of the intestinal microbiota on the development and progression of colorectal cancer.

The Innate Immune System Surveillance Biomarker p87 in African Americans and Caucasians with Small High-Grade Dysplastic Adenoma [SHiGDA] and Right-Sided JAK3 Colon Mutations May Explain the Presence of Multiple Cancers Revealing an Important Minority of Patients with JAK3 Mutations and Colorectal Neoplasia

Colorectal cancer (CRC) outcomes in terms of incidence and mortality are significantly worse in African Americans than other Americans. While differences in primary preventions for neoplasia (diet, obesity remediation, aspirin prophylaxis) are being elucidated, genetic mutations affecting premalignant lesions and immune response mechanisms may possibly also explain the increased incidence and mortality, particularly from right-sided disease.

OBJECTIVE

Our team therefore examined colonic segments seeking to test the hypothesis that the immune response and somatic genetic profiles of the colonic anatomic segments may vary and thus account for variations in neoplasia risk among the various colonic segments revealing an antigenic relationship with precancerous lesions. The p87 antigenic field effect is recognized via Adnab-9 antibody immunohistochemistry to be significantly less in the right colon in African Americans, particularly in the cecum.

METHOD

Since small high-grade dysplastic adenomas (SHiGDA) likely missed by CRC screening may progress to cancer, we used Ion Torrent™ sequencing of DNA extracted from four normal colonic segments (two left-sided and two right) of patients with SHiGDAs. We also contrasted unique mutational fields in one patient with a large HiGDA (APC with unique mutations) and one patient who prospectively developed a SHiGDA (JAK3).

RESULT

The SHiGDA (small high-grade dysplastic polyp) patient was p87 negative for any extracted stool, saliva, or colonic effluent via ELISA (enzyme linked immunoadsorbant assay). Furthermore, mean values of expression in segments from the right colon were reduced with respect to the means obtained from the left segments in 233 patients evaluated for a p87 field effect. This has recently been shown to be the case in a large cohort of AA and Caucasian 2294 patients, possibly explaining the right-sided CRC disparity in African Americans and the subsequent increase in mortality. This field effect disparity is also true for two cancers contracted by the SHiGDa patient (lung and prostate).

CONCLUSION

Thus, this pilot study suggests that the reduction in p87 in the right colon is possibly correlated with JAK3 mutations. If confirmed, JAK3 mutations, known to be associated with immune aberrations, may provide a mechanistic explanation for the lack of a p87 (protein 87 kilodaltons) field in some patients with HGD polyps who might benefit from possible intervention such as more intensive screening. Limited microbiome studies were also performed on two patients with familial cancer syndromes and these compared favorably with controls available from the literature.

Endoscopist adenomas-per-colonoscopy detection rates and risk for postcolonoscopy colorectal cancer: data from the New Hampshire Colonoscopy Registry

BACKGROUND AND AIMS

Adenomas per colonoscopy (APC) may be a better measure of colonoscopy quality than adenoma detection rate (ADR) because it credits endoscopists for each detected adenoma. There are few data examining the association between APC and postcolonoscopy colorectal cancer (PCCRC) incidence. We used data from the New Hampshire Colonoscopy Registry to examine APC and PCCRC risk.

METHODS

We included New Hampshire Colonoscopy Registry patients with an index examination and at least 1 follow-up event, either a colonoscopy or a colorectal cancer (CRC) diagnosis. Our outcome was PCCRC defined as any CRC diagnosed ≥6 months after an index examination. The exposure variable was endoscopist-specific APC quintiles of .25, .40, .50, and .70. Cox regression was used to model the hazard of PCCRC on APC, controlled for age, sex, year of index examination, index findings, bowel preparation, and having more than 1 surveillance examination.

RESULTS

In 32,535 patients, a lower hazard for PCCRC (n = 178) was observed for higher APCs as compared to APCs of <.25 (reference): .25 to <.40: hazard ratio (HR), .35; 95% confidence interval (CI), .22-.56; .40 to <.50: HR, .31; 95% CI, .20-.49; .50 to <.70: HR, .20; 95% CI, .11-.36; and ≥.70: HR, .19; 95% CI, .09-.37. When examining endoscopists with an ADR of at least 25%, an APC of <.50 was associated with a significantly higher hazard than an APC of ≥.50 (HR, 1.65; 95% CI, 1.06-2.56). A large proportion of endoscopists-one-fifth (32 of 152; 21.1%)-had an ADR of ≥25% but an APC of <.50.

CONCLUSIONS

Our novel data demonstrating lower PCCRC risk in examinations performed by endoscopists with higher APCs suggest that APC could be a useful quality measure. Quality improvement programs may identify important deficiencies in endoscopist detection performance by measuring APC for endoscopists with an ADR of ≥25%.

Surveillance colonoscopy findings in asymptomatic participants over 75 years of age

Background and Aim

Surveillance colonoscopy for colorectal cancer (CRC) is generally not recommended beyond 75 years of age. The study determined incidence and predictors of advanced adenoma and CRC in older individuals undergoing surveillance colonoscopy.

Methods

This was a retrospective cohort study of asymptomatic older participants (≥75 years), enrolled in a South Australian CRC surveillance program who underwent colonoscopy (2015-2020). Clinical records were extracted for demographics, personal or family history of CRC, comorbidities, polypharmacy, and colonoscopy findings. The associations between clinical variables and advanced adenoma or CRC at surveillance were assessed with multivariable Poisson regression analysis.

Results

Totally 698 surveillance colonoscopies were analyzed from 574 participants aged 75-91 years (55.6% male). The incidence of CRC was 1.6% (11/698), while 37.9% (260/698) of procedures had advanced adenoma detected. Previous CRC (incidence rate ratio [IRR] 5.9, 95% CI 1.5-22.5), age ≥85 years (IRR 5.8, 95% CI 1.6-20.1) and active smoking (IRR 4.9, 95% CI 1.0-24.4) were independently associated with CRC diagnosis, while advanced adenoma at immediately preceding colonoscopy (IRR 1.6, 95% CI 1.3-2.0) and polypharmacy (IRR 1.2, 95% CI 1.0-1.5) were associated with advanced adenoma at surveillance colonoscopy in asymptomatic older participants (≥75 years).

Conclusion

Advanced neoplasia was found in more than one third of the surveillance procedures completed in this cohort. Continuation of surveillance beyond age 75 yeasrs may be considered in participants who have previous CRC or are active smokers (provided they are fit to undergo colonoscopy). In other cases, such as past advanced adenoma only, the need for ongoing surveillance should be considered alongside participant preference and health status.

Colon Polyp Surveillance: Separating the Wheat From the Chaff

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

Prevalence of neoplasia at colonoscopy among testicular cancer survivors treated with platinum-based chemotherapy

Testicular cancer survivors (TCS) treated with platinum-based chemotherapy have an increased risk of colorectal cancer (CRC). We determined the yield of colonoscopy in TCS to assess its potential in reducing CRC incidence and mortality. We conducted a colonoscopy screening study among TCS in four Dutch hospitals to assess the yield of colorectal neoplasia. Neoplasia was defined as adenomas, serrated polyps (SPs), advanced adenomas (AAs: ≥10 mm diameter, high-grade dysplasia or ≥25% villous component), advanced serrated polyps (ASPs: ≥10 mm diameter or dysplasia) or CRC. Advanced neoplasia (AN) was defined as AA, ASP or CRC. Colonoscopy yield was compared to average-risk American males who underwent screening colonoscopy (n = 24,193) using a propensity score matched analysis, adjusted for age, smoking status, alcohol consumption and body mass index. A total of 137 TCS underwent colonoscopy. Median age was 50 years among TCS (IQR 43-57) vs 55 years (IQR 51-62) among American controls. A total of 126 TCS were matched to 602 controls. The prevalence of AN was higher in TCS than in controls (8.7% vs 1.7%; P = .0002). Nonadvanced adenomas and SPs were detected in 45.2% of TCS vs 5.5% of controls (P < .0001). No lesions were detected in 46.0% of TCS vs 92.9% of controls (P < .0001). TCS treated with platinum-based chemotherapy have a higher prevalence of neoplasia and AN than matched controls. These results support our hypothesis that platinum-based chemotherapy increases the risk of colorectal neoplasia in TCS. Cost-effectiveness studies are warranted to ascertain the threshold of AN prevalence that justifies the recommendation of colonoscopy for TCS.

The Relationship Between Serum Lipids and the Formation of Colorectal Polyps

BACKGROUND AND AIMS

Obesity, metabolic syndrome, and hyperlipidemia are known as risk factors for colorectal tumors. Colorectal polyps are accepted as potential precursors of colorectal cancer (CRC). This study was designed to clarify the association between the levels of serum lipids and the presence of colorectal polyps.

METHODS

This study was conducted at Basaksehir Cam and Sakura City Hospital, Gastroenterological Surgery Clinic, Istanbul, Turkey. We retrospectively analyzed patients who underwent colonoscopy with serum lipid profile within one month for a one-year period. Groups were analyzed in terms of the correlation between hyperlipidemia and the formation of polyps. The study group was also evaluated in terms of the polyp type, localization, and number.

RESULTS

Among 453 patients, females were 248 and males were 211, with a mean age of 56.7. The study and control groups involved 259 and 194 patients, respectively. The age and serum levels of low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), and triglyceride (TG) were found to be statistically significant in terms of polyp presence and number (p < 0.05).

CONCLUSION

Colorectal polyps are well-known precursors of CRC. We found that the combination of elevated serum levels of low-density lipoprotein cholesterol, total cholesterol, and triglycerides may be a risk predictor for the presence of colorectal polyps, which can be advantageous in cancer screening.

Endoscopic resection of large non-pedunculated colorectal polyps: current standards of treatment

Colorectal cancer is a significant public health concern, and large non-pedunculated colorectal polyps pose a substantial risk for malignancy and incomplete resection, which may lead to interval cancer. The choice of resection technique is influenced by various factors, including polyp size, morphology, location, submucosal invasion depth and endoscopist expertise. For non-cancerous superficial large non-pedunculated polyps, conventional hot or cold snare polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection are common techniques for non-surgical therapeutic endoscopic resection of these polyps. This manuscript provides a comprehensive review of literature on current endoscopic resection techniques for large non-pedunculated colorectal polyps, emphasising indications, advantages, limitations and outcomes.

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.

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.

Preventive effects of chemical drugs on recurrence of colorectal adenomas: systematic review and Bayesian network meta-analysis

BACKGROUND

The onset of colorectal adenomas (CRAs) is significantly associated with colorectal cancer. The preventive effects of chemical drugs on the recurrence of CRAs have been evaluated in a large number of randomized controlled trials (RCTs). However, there are still uncertainties about the relative effectiveness of such chemical drugs.

METHODS

We searched relevant RCTs published in six databases up to February 2023. The quality of the included studies was assessed by using the Cochrane risk of bias assessment tool and Review Manager 5.4. Pairwise comparison and network meta-analysis (NMA) were conducted using RStudio to compare the effects of chemical drugs on the recurrence of CRAs.

RESULTS

Forty-five high-quality RCTs were included. A total of 35 590 (test group: 20 822; control group: 14 768) subjects with a history of CRAs have been enrolled and randomized to receive placebo treatment or one of 24 interventions. Based on surface under the cumulative ranking values and NMA results, difluoromethylornithine (DFMO) + Sulindac significantly reduced the recurrence of CRAs, followed by berberine and nonsteroidal antiinflammatory drugs.

CONCLUSION

DFMO + Sulindac is more effective in reducing the recurrence of CRAs but has a high risk of adverse events. Considering drug safety, tolerance, and compliance, berberine has a brighter prospect of clinical development. However, further studies are needed to verify our findings.

Recurrence rates of advanced colorectal neoplasia (ACN) in subjects with baseline ACN followed up at different surveillance intervals

BACKGROUND

Current clinical guidelines recommend that a baseline finding of advanced colorectal neoplasia (ACN) should be followed-up within 1-3 years.

AIM

We compared the recurrence rate of ACN at 1 year vs. 3 years among individuals with ACN detected and polypectomised at baseline colonoscopy.

METHODS

We extracted data from eligible patients in a Chinese population database from 2008 to 2018. The outcome variables included recurrence of advanced adenoma and advanced neoplasia, respectively, at follow-up colonoscopy. Binary logistic regression modeling was constructed to examine the association between length of surveillance and the outcome variables, controlling for risk factors of colorectal cancer, including age, gender, smoking, alcohol drinking, body mass index and chronic diseases.

RESULTS

We included 147,270 subjects who have received a baseline colonoscopy from our dataset. They were aged 69.3 years and 59.7% of them were male subjects. The crude 1-year and 3-year recurrence rate of ACN was 7.57% and 7.74%. From a binary logistic regression model, individuals with surveillance colonoscopy performed at 3 years did not have significantly higher recurrence rate of ACN than those followed-up at 1 year.

CONCLUSIONS

No statistically significantly difference in recurrence of ACN between individuals who received workup at 1vs. 3 years. These findings support a 3-year surveillance period after baseline ACN was polypectomised.

Risk of recurrent advanced colorectal neoplasia in individuals with baseline non-advanced neoplasia followed up at 5 vs 7-10 years

BACKGROUND AND AIM

Colorectal cancer (CRC) is one of the commonest cancers, especially among the Asian populations. We compared the recurrence rate of advanced colorectal neoplasia (ACN) at 5 year vs 7-10 years among individuals with non-advanced adenoma (NAA) detected and polypectomized at baseline colonoscopy in a large Chinese population.

METHODS

We extracted data of a large Chinese population with NAA polypectomized who received surveillance colonoscopy after 5 or 7-10 years from a large database (2008-2018). The outcome variable included recurrence of ACN at surveillance colonoscopy. We examined the association between length of surveillance and the outcome variable, whilst controlling for risk factors of colorectal cancer.

RESULTS

We include 109 768 subjects who have received a baseline colonoscopy from our dataset. They were aged 67.35 (SD 9.84) years, and 60.9% of them were male subjects. The crude 5-year and 10-year recurrence rate of ACN was 1.50% and 2.42%, respectively (crude odds ratio = 1.629, 95% CI 1.362 to 1.949, P < 0.001). From the binary logistic regression model, individuals with surveillance colonoscopy performed at 10 years had a statistically higher recurrence rate of ACN than those followed-up at 5 year (adjusted odds ratio [aOR] = 1.544, 95% CI 1.266 to 1.877, P < 0.001), but the effect size of aOR is small.

CONCLUSIONS

There is a small difference in recurrence of ACN between individuals who received colonoscopy workup at 5 years vs 7-10 years. These findings support a 7-10 years surveillance period after baseline NAA was polypectomized.

Weighing the benefits of lymphadenectomy in early-stage colorectal cancer

Recent advancements in endoscopic procedures have resulted in a growing diagnosis of early colorectal cancer (CRC) cases, where classical en bloc lymph node (LN) dissection is not performed and treatment is terminated with the removal of the main cancer lesion by endoscopy without pathologic LN staging. Although many studies report noninferior outcomes of endoscopic resection in comparison to surgical resection, a cautious approach to completing treatment with endoscopic resection alone is recommended because LN metastases may be present even in early-stage CRC. In most countries, including the United States, Europe, and South Korea, the guidelines for additional surgery after endoscopic resection are very similar. If LN metastasis is suspected, even in T1 stage or lower lesions, further surgery is an essential treatment modality, but confirmation of the presence of LN metastasis is perhaps the most difficult part of this process. Another paradoxical recent trend is the expansion of more extensive and complete surgical lymphadenectomy for CRC. The success rate of surgery has improved dramatically over the past decade with the introduction of surgical devices and minimally invasive surgery, and the associated risks have been significantly reduced. While the burden of surgery on patients is understandable, the indications for surgery in early colon cancer need to be carefully reviewed to improve cure rates. In this process, we believe that an integrated decision-making process with surgeons, radiologists, and pathologists, in addition to the opinions of endoscopists, will be an important process to improve the cure rate.

Effectiveness of switching endoscopists for repeat surveillance colonoscopy: a retrospective study

BACKGROUND

Surveillance colonoscopy decreases colorectal cancer mortality; however, lesions are occasionally missed. Although an appropriate surveillance interval is indicated, variations may occur in the methods used, such as scope manipulation or observation. Therefore, individual endoscopists may miss certain areas. This study aimed to verify the effectiveness of performing repeat colonoscopies with a different endoscopist from the initial procedure.

METHODS

We retrospectively reviewed a database of 8093 consecutive colonoscopies performed in the Omori Red Cross Hospital from January 1st 2018 to June 30th 2021. Data from repeat total colonoscopies performed within three months were collected to assess missed lesions. The patients were divided into two groups according to whether the two examinations were performed by different endoscopists (group D) or the same endoscopist (group S). The primary outcome in both groups was the missed lesion detection rate (MLDR).

RESULTS

Overall, 205 eligible patients were analyzed. In total, 102 and 103 patients were enrolled in groups D and S, respectively. The MLDR was significantly higher in group D (61.8% vs. 31.1%, P < 0.0001). Multivariate logistic regression analysis for the detection of missed lesions identified performance by the different endoscopists (odds ratio, 3.38; 95% CI, 1.81-6.30), and sufficient withdrawal time (> 6 min) (odds ratio, 3.10; 95% CI, 1.12-8.61) as significant variables.

CONCLUSIONS

Overall, our study showed a significant improvement in the detection of missed lesions when performed by different endoscopists. When performing repeat colonoscopy, it is desirable that a different endoscopist perform the second colonoscopy.

TRIAL REGISTRATION

This study was approved by the Institutional Review Board of the Omori Red Cross Hospital on November 28, 2022 (approval number:22-43).

Surveillance after colorectal polyp resection

Post-polypectomy surveillance has proven to reduce colorectal cancer (CRC) incidence in patients with high-risk polyps, but it implies a major burden on colonoscopy units. Therefore, it should be targeted to individuals with a higher risk. Different societies have published guidelines on surveillance after resection of polyps, with notable discrepancies among them, and many recommendations come from low-quality evidence based on surrogate measures, such as risk of advanced adenoma, and not CRC risk. In this review, we aimed to summarize the evidence supporting post-polypectomy surveillance, compare the recently updated major guidelines, and discuss the existing discrepancies on this topic. Briefly, patients with adenomas ≥10 mm or high-grade dysplasia and patients with serrated polyps ≥10 mm or dysplasia are generally considered to have an increased risk of metachronous CRC and require surveillance, whereas the indication of surveillance is not clearly established in patients without these high-risk features.

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.

The 2023 Impact of Inflammatory Bowel Disease in Canada: Cancer and IBD

Cancer is a major cause of morbidity and mortality among people with inflammatory bowel disease (IBD). Intestinal cancers may arise as a complication of IBD itself, while extra-intestinal cancers may arise due to some of the immunosuppressive therapies used to treat IBD. Colorectal cancer (CRC) and small bowel cancer risks remain elevated among persons with IBD as compared to age-and sex-matched members of the general population, and the lifetime risk of these cancers is strongly correlated to cumulative intestinal inflammatory burden. However, the cumulative risk of cancer, even among those with IBD is still low. Some studies suggest that IBD-CRC incidence has declined over the years, possibly owing to improved treatment standards and improved detection and management of early neoplastic lesions. Across studies of extra-intestinal cancers, there are generally higher incidences of melanoma, hepatobiliary cancer, and lung cancer and no higher incidences of breast cancer or prostate cancer, with equivocal risk of cervical cancer, among persons with IBD. While the relative risks of some extra-intestinal cancers are increased with treatment, the absolute risks of these cancers remain low and the decision to forego treatment in light of these risks should be carefully weighed against the increased risks of intestinal cancers and other disease-related complications with undertreated inflammatory disease. Quality improvement efforts should focus on optimized surveillance of cancers for which surveillance strategies exist (colorectal cancer, hepatobiliary cancer, cervical cancers, and skin cancers) and the development of cost-effective surveillance strategies for less common cancers associated with IBD.

Large serrated polyps indicate a greater risk of advanced metachronous colorectal neoplasia than high-grade adenomas

Background and study aims The risk of developing total metachronous advanced neoplasia (TMAN) in patients with index serrated lesions (SL) or adenoma with high-grade dysplasia (HGD) is unknown. We evaluated this risk in patients with either HGD, SL < 10 mm or SL ≥ 10 mm at index colonoscopy, who underwent surveillance colonoscopies. Patients and methods This retrospective cohort study evaluated all consecutive patients (n = 2477) diagnosed between 2010 and 2019 with colorectal HGD, SLs < 10 mm or SLs ≥ 10 mm. We excluded patients aged < 45 or > 75 years or those who had inflammatory bowel disease, hereditary colorectal cancer (CRC) syndromes, previous or synchronous CRC, or no follow-up colonoscopy. Descriptive variables were compared using analysis of variance or Pearson chi-squared tests. Multivariate Cox regressions were used to compare the risk of TMAN between the HGD, SL < 10 mm and SL ≥ 10 mm groups. Results Overall, 585 patients (mean age 63 years; 55% male; mean follow-up 3.67 years) were included (226 with SLs < 10 mm, 204 with SLs ≥ 10 mm, 155 with HGD). Compared with SLs < 10 mm, patients with HGD did not have a significantly different rate of TMAN (HR=0.75 [0.39-1.44]) and patients with SLs ≥ 10 mm had a higher rate of TMAN (HR=2.08 [1.38-3.15]). Compared with HGD, patients with SLs ≥ 10 mm had a higher rate of TMAN (HR=1.87 [1.04-3.36]). Conclusions The risk for TMAN was higher for patients with SLs ≥ 10 mm than with HGD or SLs < 10 mm. This risk should be considered when planning surveillance intervals for patients diagnosed with large SLs.

Risk stratification for the detection of metachronous polyps after bowel screening polypectomy: clinical outcomes from the Integrated Technologies for Improved Polyp Surveillance (INCISE) study cohort

BACKGROUND

After colorectal polypectomy, 20-50 per cent of patients develop metachronous polyps and some have increased colorectal cancer risk. British Society of Gastroenterology (BSG) 2020 guidelines recommend surveillance colonoscopy for high-risk patients based on index pathology. The aim of this study was to evaluate metachronous lesion outcome using BSG 2020 criteria.

METHODS

A retrospective, multicentred study was conducted including patients who had polypectomy during screening colonoscopy (2009-2016) followed by surveillance. Demographics, index pathology, and BSG 2020 risk criteria were compared with regard to metachronous lesion pathology (non-advanced versus advanced lesions) and timing of detection (early versus late). Advanced lesions were defined as adenomas/serrated polyps greater than or equal to 10 mm, high-grade dysplasia, serrated polyps with dysplasia, or colorectal cancer, and late lesions those detected greater than 2 years after the index procedure.

RESULTS

Of 3090 eligible patients, 2643 were included. Among these, retrospective BSG 2020 application would have excluded 51.5 per cent from surveillance. After a median of 36 months, the advanced polyp/colorectal cancer rate in BSG 2020 high-risk patients was 16.3 versus 13.0 per cent in low-risk patients. Older age (P = 0.008) correlated with advanced metachronous lesions. Male sex, greater than five polyps, and BSG 2020 high-risk criteria correlated with non-advanced and advanced lesions (P < 0.001). Older age (P < 0.001), villous features (P = 0.006), advanced index polyp (P = 0.020), and greater than five polyps (P < 0.001) correlated with early metachronous lesions. Male sex and BSG 2020 high-risk criteria correlated with early and late lesions (P < 0.001). On multivariable regression, increased polyp number (odds ratio (OR) 1.15 (95 per cent c.i. 1.07 to 1.25); P < 0.001) and villous features (OR 1.49 (95 per cent c.i. 1.05 to 2.10); P = 0.025) independently correlated with early advanced lesions. The rate of non-advanced and advanced metachronous polyps was higher in BSG 2020 high- versus low-risk patients (44.4 versus 35.4 per cent for non-advanced and 15.7 versus 11.8 per cent for advanced; P < 0.001), but the colorectal cancer rate was similar (0.6 versus 1.2 per cent). However, when examining only lesions detected greater than 2 years after the index colonoscopy in high- versus low-risk patients, no significant differences were observed (P = 0.140).

CONCLUSION

BSG 2020 criteria correlated with metachronous polyps, but did not differentiate advanced and non-advanced lesions and were not predictive of late lesions.

Phase IIa Clinical Biomarker Trial of Dietary Arginine Restriction and Aspirin in Colorectal Cancer Patients

After potentially curative treatment, colorectal cancer (CRC) patients remain at high risk for recurrence, second primary CRC, and high-risk adenomas. In combination with existing data, our previous findings provide a rationale for reducing tissue polyamines as tertiary prevention in non-metastatic CRC patients. The goal of this study was to demonstrate rectal tissue polyamine reduction in optimally treated stage I-III CRC patients after intervention with daily oral aspirin + dietary arginine restriction. A single-institution phase IIa clinical trial was conducted. Patients were treated with aspirin 325 mg/day and an individualized dietary regimen designed to reduce arginine intake by ≥30% over a 12-week study period. Dietary intake, endoscopy with rectal biopsies, and phlebotomy were performed pre- and post-intervention. The primary endpoint was to demonstrate ≥50% decrease in rectal tissue putrescine levels from baseline as a measure of polyamine reduction in the target tissue. Twenty eligible patients completed the study. After study intervention, mean dietary arginine intake decreased from 3.7 g/day ± 1.3 SD to 2.6 g/day ± 1.2 SD (29.7% decrease, p < 0.02 by Sign test). Mean plasma arginine levels decreased from 46.0 ng/mL ± 31.5 SD at baseline to 35 ng/mL ± 21.7 SD (p < 0.001). Rectal tissue putrescine levels were 0.90 nMol/mg-protein pre-intervention and 0.99 nMol/mg-protein post-intervention (p < 0.64, NS). No significant differences were observed for the other tissue polyamines investigated: spermidine (p < 0.13), spermine (p < 0.21), spermidine:spermine ratio (p < 0.71). Among CRC survivors, treatment with daily oral aspirin and an individualized dietary arginine restriction intervention resulted in lower calculated dietary arginine intake and plasma arginine levels but did not affect rectal tissue polyamine levels.

Risk Factors for Metachronous Colorectal Cancer or Advanced Adenomas After Endoscopic Resection of High-risk Adenomas

BACKGROUND & AIMS

Among the characteristics of high-risk adenomas (HRAs), some may predict a higher risk of metachronous advanced lesions. Our aim was to assess which HRA characteristics are associated with high risk of metachronous colorectal cancer (CRC) or advanced adenomas (AAs).

METHODS

We systematically searched Pubmed, EMBASE, and Cochrane for cohort studies and clinical trials of CRC or AA incidence at surveillance stratified by baseline lesion size, histology, and multiplicity. We calculated pooled relative risks (RRs) using a random-effects model. Heterogeneity was assessed with the I² statistic.

RESULTS

Fifty-five studies were included, with 936,540 patients with mean follow-up 5.4 ± 2.9 years. CRC incidence per 1000 person-years was 2.6 (2.1-3.0) for adenomas ≥20 mm, 2.7 (2.2-3.2) for high-grade dysplasia (HGD), 2.0 (1.8-2.3) for villous component, 0.8 (0.1-1.4) for ≥5 adenomas, 1.0 (0.7-1.2) for ≥3 adenomas. Metachronous CRC risk was higher in adenomas ≥20 mm vs 10 to 19 mm (RR, 2.08; 95% confidence interval [CI], 1.20-3.61), HGD vs low-grade dysplasia (RR, 2.89; 95% CI, 1.88-4.44), villous vs tubular (RR, 1.75; 95% CI, 1.33-2.31). No significant differences in CRC risk were found in ≥3 adenomas vs 1 to 2 (RR, 1.24; 95% CI, 0.84-1.83), nor in ≥5 adenomas vs 3 to 4 (RR, 0.79; 95% CI, 0.30-2.11). Compared with normal colonoscopy, RR for CRC risk was 2.61 (95% CI, 2.06-3.32) for ≥10mm, 6.62 (95% CI, 4.60-9.52) for HGD, 3.58 (95% CI, 2.24-5.73) for villous component, and 2.03 (95% CI, 1.40-2.94) for ≥3 adenomas. Similar trends were seen for metachronous AAs.

CONCLUSION

Metachronous CRC risk is highest in patients with baseline adenomas with ≥20 mm or HGD. Multiplicity does not seem to be associated with substantially higher CRC risk in the near term.

The Surface Morphology of Large Nonpedunculated Colonic Polyps Predicts Synchronous Large Lesions

BACKGROUND & AIMS

Large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) may have synchronous LNPCPs in up to 18% of cases. The nature of this relationship has not been investigated. We aimed to examine the relationship between individual LNPCP characteristics and synchronous colonic LNPCPs.

METHODS

Consecutive patients referred for resection of LNPCPs over 130 months until March 2022 were enrolled. Serrated lesions and mixed granularity LNPCPs were excluded from analysis. Patients with multiple LNPCPs resected were identified, and the largest was labelled as dominant. The primary outcome was the identification of individual lesion characteristics associated with the presence of synchronous LNPCPs.

RESULTS

There were 3149 of 3381 patients (93.1%) who had a single LNPCP. In 232 (6.9%) a synchronous lesion was detected. Solitary lesions had a median size of 35 mm with a predominant Paris 0-IIa morphology (42.9%) and right colon location (59.5%). In patients with ≥2 LNPCPs, the dominant lesion had a median size of 40 mm, Paris 0-IIa (47.6%) morphology, and right colon location (65.9%). In this group, 35.8% of dominant LNPCPs were non-granular compared with 18.7% in the solitary LNPCP cohort. Non-granular (NG)-LNPCPs were more likely to demonstrate synchronous disease, with left colon NG-LNPCPs demonstrating greater risk (odds ratio, 4.78; 95% confidence interval, 2.95-7.73) than right colon NG-LNPCPs (odds ratio, 1.99; 95% confidence interval, 1.39-2.86).

CONCLUSIONS

We found that 6.9% of LNPCPs have synchronous disease, with NG-LNPCPs demonstrating a greater than 4-fold increased risk. With post-colonoscopy interval cancers exceeding 5%, endoscopists must be cognizant of an individual's LNPCP phenotype when examining the colon at both index procedure and surveillance.

CLINICALTRIALS

gov, NCT01368289; NCT02000141; NCT02198729.

Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 revised edition

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: adenoma ≥10 mm in size; 3 to 5 (or more) adenomas; tubulovillous or villous adenoma; adenoma containing high-grade dysplasia; traditional serrated adenoma; sessile serrated lesion containing any grade of dysplasia; serrated polyp of at least 10 mm in size; and 3 to 5 (or more) sessile serrated lesions. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Korean guidelines for postpolypectomy colonoscopic surveillance: 2022 revised edition

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for the management of advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: (1) adenoma ≥10 mm in size; (2) 3 to 5 (or more) adenomas; (3) tubulovillous or villous adenoma; (4) adenoma containing high-grade dysplasia; (5) traditional serrated adenoma; (6) sessile serrated lesion (SSL) containing any grade of dysplasia; (7) serrated polyp of at least 10 mm in size; and (8) 3 to 5 (or more) SSLs. More studies are needed to fully comprehend the patients most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Long-term Outcomes After Endoscopic Submucosal Dissection for Large Colorectal Epithelial Neoplasms: A Prospective, Multicenter, Cohort Trial From Japan

BACKGROUND & AIMS

To determine the long-term outcomes after colorectal endoscopic submucosal dissection (ESD), we conducted a large, multicenter, prospective cohort trial with a 5-year observation period.

METHODS

Between February 2013 and January 2015, we consecutively enrolled 1740 patients with 1814 colorectal epithelial neoplasms ≥20 mm who underwent ESD. Patients with noncurative resection (non-CR) lesions underwent additional radical surgery, as needed. After the initial treatment, intensive 5-year follow-up with planned multiple colonoscopies was conducted to identify metastatic and/or local recurrences. Primary outcomes were overall survival, disease-specific survival, and intestinal preservation rates. The rates of local recurrence and metachronous invasive cancer were evaluated as the secondary outcomes.

RESULTS

The 5-year overall survival, disease-specific survival, and intestinal preservation rates were 93.6%, 99.6%, and 88.6%, respectively. Patients with CR lesions had no metastatic occurrence, and patients with non-CR lesions had 4 metastatic occurrences. Kaplan-Meier curves revealed that overall survival and disease-specific survival rates were significantly higher in patients with CR lesions than in those with non-CR lesions (P > .001 and P = .009, respectively). Local recurrence occurred in only 8 lesions (0.5%), which were successfully resected by subsequent endoscopic treatment. Multiple logistic regression analyses revealed that piecemeal resection (hazard ratio, 8.19; 95% CI, 1.47-45.7; P = .02) and margin-positive resection (hazard ratio, 8.06; 95% CI, 1.76-37.0; P = .007) were significant independent predictors of local recurrence after colorectal ESD. Fifteen metachronous invasive cancers (1.0%) were identified during surveillance colonoscopy, most of which required surgical resection.

CONCLUSIONS

A favorable long-term prognosis indicates that ESD can be the standard treatment for large colorectal epithelial neoplasms.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000010136.

Risk of adenoma recurrence after polypectomy in patients younger than 50 years vs. 50 years old and over with diminutive or small adenomas

Background and aims

Current studies have shown that polyp recurrence occurs after colonic adenomas polypectomy (AP), but the difference in recurrence risk between patients in patients older than 50 years and younger than 50 years has not been clearly studied.

Methods

490 patients after AP were enrolled in the study. The patients were classified according to age (&lt;50 years old or ≥50 years old), and then further categorized according to the baseline adenoma characteristics: Group 1: 1–2 non-advanced adenomas (NAAs) 1–5 mm in size; Group 2: ≥3 NAAs, 1–5 mm; Group 3: 1–2 NAAs, 6–9 mm; Group 4: ≥3 NAAs, 6–9 mm; and Group 5: advanced adenomas.

Results

During a mean follow-up interval of 2.52 years (2.51 years for ≥50 years old and 2.55 years for patients &lt;50 years old), NAA recurrence was detected in 147 patients (30.0%). Overall, the hazard ratio (HR) for NAA recurrence after AP was higher in patients ≥50 years old than that in patients &lt;50 years old (HR, 1.774, P = 0.003). For patients &lt;50 years old, HRs (Group 2-5 vs. G1, respectively) for NAA recurrence were 0.744 (P = 0.773), 3.885 (P = 0.007), 5.337 (P = 0.003), and 3.334 (P = 0.015). For patients ≥50 years old, HRs (Group 2-5 vs. G1, respectively) for NAA recurrence were 1.033 (P = 0.965), 1.250 (P = 0.405), 2.252 (P = 0.015), and 1.887 (P = 0.009). For G1, the risk of NAA recurrence was significantly higher in patients ≥50 years old (HR, 2.932, P = 0.011) than that in patients &lt;50 years old; for G2–G5, the risk was similar in the two age groups (P &gt; 0.05).

Conclusions

For patients &lt;50 years old with less than 3 NAAs that are 1–5 mm in size, the recurrence rate of NAA is less than that of patients ≥50 years old with the same index colonoscopy findings. When the adenomas are ≥5 mm, or their number exceeds 3, they have similar recurrence risk as that for patients ≥50 years old.

Adenoma Detection Rate and Clinical Characteristics Influence Advanced Neoplasia Risk After Colorectal Polypectomy

BACKGROUND AND AIMS

Postpolypectomy risk stratification for subsequent metachronous advanced neoplasia (MAN) is imprecise and does not account for colonoscopist adenoma detection rate (ADR). Our aim was to assess association of ADR with MAN and create a prediction model for postpolypectomy risk stratification incorporating ADR and other factors.

METHODS

We conducted a retrospective cohort study of individuals with baseline polypectomy and subsequent surveillance colonoscopy from 2004 to 2016 within the U.S. Department of Veterans Affairs (VA). Clinical factors, polyp findings, and baseline colonoscopist ADR were considered for the model. Model performance (sensitivity, specificity, and area under the curve) for identifying individuals with MAN was compared with 2020 U.S. Multi-Society Task Force on Colorectal Cancer (USMSTF) surveillance recommendations.

RESULTS

A total of 30,897 individuals were randomly assigned 2:1 into independent model training and validation sets. Increasing age, male sex, diabetes, current smoking, adenoma number, polyp location, adenoma ≥10 mm or with tubulovillous/villous features, and decreasing colonoscopist ADR were independently associated with MAN. A range of 1.48- to 1.66-fold increased risk for MAN was observed for ADR in the lowest 3 quintiles (ADR <19.7%-39.3%) vs the highest quintile (ADR >47.0%). When the final model selected based on the training set was applied to the validation set, improved sensitivity and specificity over 2020 USMSTF risk stratification were achieved (P = .001), with an area under the curve of 0.62 (95% confidence interval, 0.60-0.64).

CONCLUSIONS

Colonoscopist ADR is associated with MAN. Combining clinical factors and ADR for risk stratification has potential to improve postpolypectomy risk stratification. Improving ADR is likely to improve postpolypectomy outcomes.

[Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 Revised Edition]

Colonoscopic polypectomy is effective in decreasing the incidence and mortality of colorectal cancer (CRC). Premalignant polyps discovered during colonoscopy are associated with the risk of metachronous advanced neoplasia. Postpolypectomy surveillance is the most important method for managing advanced metachronous neoplasia. A more efficient and evidence-based guideline for postpolypectomy surveillance is required because of the limited medical resources and concerns regarding colonoscopy complications. In these consensus guidelines, an analytic approach was used to address all reliable evidence to interpret the predictors of CRC or advanced neoplasia during surveillance colonoscopy. The key recommendations state that the high-risk findings for metachronous CRC following polypectomy are as follows: 1) adenoma ≥10 mm in size; 2) 3-5 (or more) adenomas; 3) tubulovillous or villous adenoma; 4) adenoma containing high-grade dysplasia; 5) traditional serrated adenoma; 6) sessile serrated lesion (SSL) containing any grade of dysplasia; 7) serrated polyp of at least 10 mm in size; and 8) 3-5 (or more) SSLs. More studies are needed to fully comprehend the patients who are most likely to benefit from surveillance colonoscopy and the ideal surveillance interval to prevent metachronous CRC.

Risk of Colorectal Cancer and Advanced Polyps One Year After Excision of High-Risk Adenomas

BACKGROUND

Patients with multiple or large adenomas are considered to be high-risk for metachronous colorectal cancer.

OBJECTIVE

Evaluate the risks of detecting colorectal cancer, advanced adenoma, and advanced serrated polyps at 1-year surveillance colonoscopy in patients with >5 adenomas or adenomas >20 mm.

DESIGN

Descriptive, retrospective, multicentric, cohort study. We calculated the absolute risk of developing colorectal cancer, advanced adenomas, and advanced serrated polyps at the 1-year surveillance colonoscopy. Potential risk factors for advanced neoplasia at follow-up were evaluated with univariable and multivariable logistic regression analyses.

SETTINGS

This study included data from a multicenter cohort colorectal cancer screening program, conducted from January 2014 to December 2015, based on fecal immunochemical tests in Spain.

PATIENTS

We included 2119 participants with at least 1 adenoma ≥20 mm or ≥5 adenomas of any size.

MAIN OUTCOME MEASURES

We calculated the absolute risk of developing colorectal cancer, advanced adenomas, and advanced serrated polyps at the 1-year surveillance colonoscopy. Potential risk factors for advanced neoplasia at follow-up were evaluated with univariable and multivariable logistic regression analyses.

RESULTS

At 1 year, participants displayed 6 colorectal cancers (0.3%), 228 advanced adenomas (10.5%), and 58 advanced serrated polyps (2.7%). The adjusted analysis identified 2 factors associated with advanced neoplasia: >5 adenomas (odds ratio 1.53; 95% CI: 1.15-2.03; p = 0.004) and polyps in a proximal location (OR 1.52; 95% CI: 1.15-2.02; p = 0.004).

LIMITATIONS

First, the sample size was relatively small compared to other studies with similar aims. Another limitation was the lack of a comparison group, which could have provided more practical results in terms of surveillance recommendations.

CONCLUSIONS

The colorectal cancer detection rate at a 1-year colonoscopy surveillance was low among patients classified at high risk of advanced neoplasia. The risk factors for advanced neoplasia were ≥5 adenomas and proximal polyps at baseline. See Video Abstract at http://links.lww.com/DCR/B820 .

RIESGO DE CNCER COLORRECTAL Y DE PLIPOS AVANZADOS UN AO DESPUS DE LA RESECCIN DE ADENOMAS DE ALTO RIESGO

ANTECEDENTES:Los pacientes con adenomas múltiples o grandes se consideran de alto riesgo para desarrollar cáncer colorrectal metacrónico.OBJETIVO:Evaluar los riesgos de detectar cáncer colorrectal, adenoma avanzado y pólipos serrados avanzados en la colonoscopia de seguimiento al año, en pacientes con un número mayor o igual a 5 adenomas o adenomas de 20 mm o más.DISEÑO:Estudio descriptivo, retrospectivo, multicéntrico, de cohortes. Calculamos el riesgo absoluto de desarrollar cáncer colorrectal, adenomas avanzados y pólipos serrados avanzados en la colonoscopia de vigilancia al año. Los factores de riesgo potenciales para el desarrollo de una neoplasia avanzada en el seguimiento, fueron evaluados mediante un análisis de regresión logística univariable y multivariable.AJUSTES:Este estudio incluyó datos de un programa de cribado de cáncer colorrectal de cohorte multicéntrico, realizado entre enero de 2014 y diciembre de 2015, con base en pruebas inmunoquímicas de materia fecal, en España.PACIENTES:Incluimos 2119 participantes con al menos un adenoma ≥20 mm o con cinco o más adenomas de cualquier tamaño.PRINCIPALES MEDIDAS DE RESULTADO:Calculamos el riesgo absoluto de desarrollar cáncer colorrectal, adenomas avanzados y pólipos serrados avanzados en la colonoscopia de vigilancia al año. Los potenciales factores de riesgo para desarrollar una neoplasia avanzada en el seguimiento, se evaluaron mediante un análisis de regresión logística univariable y multivariable.RESULTADOS:Al año se encontraron en los pacientes participantes, 6 cánceres colorrectales (0,3%), 228 adenomas avanzados (10,5%) y 58 pólipos serrados avanzados (2,7%). Mediante el análisis ajustado se identificaron dos factores asociados con el desarrollo de neoplasia avanzada: un número igual o mayor a 5 adenomas (razón de probabilidades 1,53; IC del 95%: 1,15-2,03; p = 0,004) y la presencia de pólipos en una ubicación proximal (razón de probabilidades 1,52; IC del 95%: 1,15-2,02; p = 0,004).LIMITACIONES:Primero, el tamaño de la muestra fue relativamente pequeño en comparación con otros estudios con objetivos similares. Otra limitación fue la falta de un grupo comparativo, que podría haber proporcionado resultados más prácticos, en términos de recomendaciones de vigilancia.CONCLUSIÓNES:La tasa de detección de cáncer colorrectal mediante una colonoscopia de vigilancia al año, fue baja entre los pacientes clasificados como de alto riesgo de neoplasia avanzada. Los factores de riesgo para desarrollar una neoplasia avanzada fueron; un número igual o mayor a 5 adenomas y la presencia de pólipos proximales en la colonoscopia inicial de base. Consulte Video Resumen en http://links.lww.com/DCR/B820 . ( Traducción-Eduardo Londoño-Schimmer ).

Compliance with follow-up guidelines after high-risk colorectal polyp removal: a population-based study

BACKGROUND AND AIMS

After high-risk colorectal adenoma removal, colorectal cancer risk remains higher than that in the general population. Depending on polyp characteristics, a 3-month or 3-year follow-up colonoscopy is recommended, and clear follow-up instructions must be given to the patient. Our primary aim was to evaluate compliance with French follow-up recommendations. Second, we evaluated the impact of how the information was given and if patients actually underwent their control colonoscopy according to the instructions given.

METHODS

We collected data from the Burgundy polyp population-based registry and medical records from the endoscopy centers of the area. Between June 30, 2014 and July 1, 2015, 405 patients were included in this study.

RESULTS

Written follow-up instructions were provided to 345 patients (85.2%), and 184 of them (53.3%) complied with guidelines. For 29.9% the interval to follow-up colonoscopy was longer than recommended, and for 6.4% the interval was shorter. Among the 303 patients who had clear follow-up instructions, 42.2% had their control colonoscopy and 83.6% respected the stipulated interval. Follow-up instructions were found in the colonoscopy report in at least 49% of cases.

CONCLUSIONS

Compliance with follow-up guidelines was poor: Inappropriate intervals were often longer than recommended. Patients with written follow-up instructions and those who underwent follow-up colonoscopy mostly followed these instructions. Ensuring compliance with guidelines and giving written instructions to patients should be primary goals to achieve effective follow-up. Gastroenterologist training should be improved in this way.

Yield of Surveillance Colonoscopy in Older Adults with a History of Polyps: A Systematic Review and Meta-Analysis

BACKGROUND

The benefit of surveillance colonoscopy in older adults is not well described.

AIMS

To quantify the detection of colorectal cancer (CRC) and advanced polyps during surveillance colonoscopy in older adults with a history of colon polyps.

METHODS

We conducted a systematic review (MEDLINE, Cochrane Library, Web of Science, and Embase) for all published studies through May 2020 in adults age > 70 undergoing surveillance colonoscopy. The main outcome was CRC and advanced polyps detection. We performed meta-analysis to pool results by age (>70 vs. 50-70).

RESULTS

The search identified 6239 studies, of which 569 underwent full-text review and 64 data abstraction, of which 19 were included. The risk of detecting CRC (N = 11) was higher in those >70 compared to 50-70 (risk ratio 1.5 (95% CI 1.1-2.2); risk difference 0.8% (95% CI -0.2%-1.8%)). Similarly, the risk of detecting advanced polyps (N = 8) was higher in those >70 compared to 50-70 (risk ratio 1.3 (95% CI 1.2-1.3), risk difference 2.7% (95% CI 1.3%-4.0%)). Most studies did not stratify results by baseline polyp risk.

CONCLUSIONS

The detection of CRC and advanced polyps during surveillance colonoscopy in older individuals was higher than in younger controls; however, the absolute risk increase for both was small. These differences must be weighed against competing medical problems and limited life expectancy in older adults when making decisions about surveillance colonoscopy. More primary data on the risks of CRC and advanced polyps accounting for number of past colonoscopies, prior polyp risk, and duration of time since last polyp are needed.