Long-term Risk of Colorectal Cancer After Removal of Conventional Adenomas and Serrated Polyps

Demographic and Clinicopathologic Risk Factors for Colorectal Adenoma Recurrence: A Large-Scale Surveillance Cohort Study of 59,667 Adults

Background

Current colorectal surveillance guidelines emphasize adenoma characteristics but overlook temporal, racial, and sex-based heterogeneity in recurrence risk- an gap that limits equitable and personalized care. To evaluate the associations of demographic factors, obesity, and adenoma features with recurrence risk over time in a large longitudinal surveillance cohort.

Methods

This retrospective cohort study included 59,667 adults who underwent their first colonoscopic polypectomy between January 1990 and July 2024 at a tertiary medical center. Median follow-up was 4 years. Demographic variables included race and ethnicity (non-Hispanic White [NHW], non-Hispanic Black [NHB], Hispanic, Asian or Pacific Islander [API]), sex, obesity (BMI >30), family history of colorectal cancer (CRC) or polyps, and age at adenoma onset (<50 vs ≥50 years). Adenoma features included histology, size, number, and dysplasia. The primary outcome was recurrence-free survival, defined as time from initial polypectomy to histologically confirmed recurrence. Cox proportional hazards models estimated associations adjusted for confounders, with stratified analyses over 5-, 10-, and >10-year follow-up intervals.

Findings

Among 59,667 patients, 17,596 (29.5%) experienced recurrence within 5 years, revealing substantial temporal heterogeneity. Early recurrence was associated with male sex (adjusted hazard ratio [aHR], 1.10; 95% CI, 1.06-1.14), obesity (aHR, 1.18; 95% CI, 1.13-1.23), early-onset adenomas (aHR, 1.17; 95% CI, 1.11-1.23), and family history of CRC (aHR, 1.24; 95% CI, 1.18-1.31). Compared with NHW patients, NHB individuals had lower early recurrence risk (aHR, 0.89; 95% CI, 0.83-0.96) but higher late recurrence (>10 years; aHR, 1.26; 95% CI, 1.06-1.50). API patients had a similar shift, with lower early risk (aHR, 0.80; 95% CI, 0.67- 0.96) and elevated mid-term risk (5-10 years; aHR, 1.40; 95% CI, 1.08-1.81). High-grade dysplasia (aHR 2.86; 95% CI, 2.54-3.22) and villous histology (aHR 2.55; 95% CI, 2.31-2.81showed the largest effect sizes for early recurrence. Females had stronger associations with tubulovillous histology, mixed adenomas, and large lesions.

Interpretation

Temporal, demographic, and histologic differences in adenoma recurrence highlight the need for surveillance strategies that incorporate population- and time-specific risk profiles to enhance colorectal cancer prevention.

Funding

This work was supported by the National Cancer Institute (Grant No. R37CA227130 to Xingyi Guo).

Research in context

Evidence before this study: We conducted a PubMed search for publications dated before June 2024 using combinations of keywords such as "colonoscopic polypectomy," "Demographic and Clinicopathologic Risk Factors," "Vannderbilt," and "electronic health records." We found no studies that comprehensively evaluated the associations of demographic characteristics, obesity, and adenoma features with recurrence risk over time in a large, longitudinal surveillance cohort.Added Value of This Study: Using a longitudinal cohort of 59,667 patients, our study reveals substantial temporal heterogeneity in adenoma recurrence. Non-Hispanic Black and Asian or Pacific Islander individuals exhibited a lower risk of recurrence within the first 5 years but experienced increased risk at 5-10 and >10 years post-polypectomy. Females showed heightened early recurrence risk, particularly when initial adenomas were tubulovillous, mixed-type, or large. Early recurrence was predominantly driven by high-grade dysplasia, high-risk adenomas, villous or tubulovillous histology, and multiplicity.Implications of All the Available Evidence: These findings highlight the critical need to recognize and address temporal, racial, and sex-specific heterogeneity in adenoma recurrence risk. The observed variability in histopathologic and demographic factors over time underscores the importance of personalized, adaptive surveillance strategies to reduce adenoma recurrence and enhance colorectal cancer prevention.

Potential utility of CYFRA 21-1 and neuron-specific enolase molecular structures for the recognition and surveillance of sessile serrated lesions and traditional serrated adenomas

Sessile serrated lesions (SSL) and conventional serrated adenomas (TSA) are precursors to colon cancer. This study explores the potential use of medical thermal imaging to detect CYFRA 21-1 and neuronal specific enolase (NSE) in the identification and monitoring of sessile serrated lesions and conventional serrated adenomas. To evaluate the association between serum levels of CYFRA 21-1 and NSE with sessile serrated lesions and conventional serrated adenomas, and to explore the validity of a diagnostic scoring system based on thermal imaging. In this study, clinical data and relevant laboratory indicators, including serum levels of CYFRA 21-1 and NSE, were collected from eligible patients. Statistical analysis was used to assess the association of these tumor markers with the risk of SSL/TSA, and a diagnostic scoring system was developed to improve the identification accuracy. The study showed that levels of CYFRA 21-1 and NSE were significantly associated with SSL/TSA risk. Through data analysis, the diagnostic scoring system developed can effectively improve the accuracy of SSL/TSA recognition. The auxiliary analysis showed that medical thermal imaging technology provides additional value in monitoring lesions, and combined with medical thermal imaging technology can significantly improve the accuracy of diagnosis and provide new strategies for the early prevention of colon cancer.

Development of an AI-Assisted System for Automatic Recognition and Localization Marking of Colonic Polyps (With Video)

BACKGROUND

Localizing colorectal polyps identified during the initial colonoscopy in minimally invasive endoscopic surgery presents significant challenges. These challenges include imprecise location descriptions, unclear images, a high number of polyps, and polyp characteristics such as flat shapes and low color contrast. To address these issues, we developed an AI-assisted system for the automatic detection and localization of colorectal polyps.

METHODS

Colonic images and videos from three medical centers, collected between January 2018 and August 2024, were categorized based on pathology results into normal, adenomatous polyp, and serrated lesion groups. Transfer learning and fine-tuning were conducted on five pretrained CNN models, with performance evaluated using metrics such as accuracy, precision, sensitivity, and AUC. The best-performing model was selected for interpretability analysis and developed into an AI-assisted system capable of both polyp recognition and location marking.

RESULTS

Among the five models, EfficientNetV2 performed the best, achieving accuracy, precision, sensitivity, and F1 scores of 0.933, 0.917, 0.916, and 0.917, respectively, on the validation set. On the test set, the model's overall weighted average precision, specificity, and AUC were 0.903, 0.946, and 0.983, respectively. Two representative colonoscopy case videos predicted by the model further demonstrated the feasibility of this AI system in clinical practice.

CONCLUSIONS

The AI system we developed for the automatic recognition and localization marking of colonic polyps in colonoscopy aids in the rapid localization of polyps during minimally invasive endoscopic surgery.

A Blood-Based Assay for Detection of Patients with Advanced Adenomas

SIGNIFICANCE

Blood-based screening for colorectal cancer could improve testing uptake and outcomes. We propose novel methods to detect AAs in plasma using cfDNA fragmentation patterns, cancer-associated proteins, and aneuploidy with high specificity. Larger studies are needed to validate clinical utility.

Acetic Acid-Indigo Carmine Chromocolonoscopy for Proximal Serrated Lesions: A Randomized, 3-Arm Colonoscopy Study

INTRODUCTION

Aggressive colorectal cancer (CRC) frequently originates from serrated lesions (SLs), particularly in the proximal colon, which are challenging to detect using standard screening colonoscopy. Although duplicate examinations or chromocolonoscopies are recommended for detecting proximal SLs, evidence from randomized trials is limited. We evaluated the effectiveness of tandem colonoscopy with an acetic acid-indigo carmine mixture (AIM) for detecting SLs in the proximal colon compared with white-light imaging (WLI) and indigo carmine (IC).

METHODS

This 3-arm, multicenter, randomized controlled trial involving 9 institutions enrolled patients undergoing colonoscopy and assigned them randomly to the WLI, IC, or AIM group. The primary outcomes were the SL-detection rate (SDR) of proximal lesions during the second examination (SDR 2nd ) and SL additional rate (SAR). Secondary outcomes included the detection and additional rates of other polyps, factors contributing to SAR, and complications.

RESULTS

Between 2021 and 2024, 1,319 participants with 1,267 polyps were included in the analysis. With AIM, the SDR 2nd and SAR were significantly higher compared with WLI or IC (WLI vs AIM: 2.7% vs 14.0%, P < 0.001; IC vs AIM: 7.9% vs 14.0%, P = 0.002, and WLI vs AIM: 22.4% vs 69.3%, P < 0.001; IC vs AIM: 45.8% vs 69.3%, P = 0.001). AIM conferred a higher adenoma detection rate 2nd than with WLI (10.5% vs 24.7%; P < 0.001) and was an independent factor for SAR (odds ratio [95% confidence interval]: 7.79 [3.76-17.08]). No major adverse events were observed.

DISCUSSION

AIM significantly improved proximal colon SDRs and outperformed WLI and IC. The relationship between SDR and CRC incidence warrants further investigation.

Low-residue diet with oral nutritional supplements prior to colonoscopy improves the quality of bowel preparation: an endoscopist-blinded, randomized controlled trial

BACKGROUND

Poor bowel preparation has been a great problem of endoscopists for a long time. Low-residue diet (LRD) is often recommended on the day before colonoscopy. However, the quality of bowel preparation with LRD alone is suboptimal. The aim of our study was to examine whether patients who consumed LRD with oral nutritional supplements (ONSs) had higher quality of bowel preparation than patients who consumed LRD alone before colonoscopy.

METHODS

An endoscopist-blinded, randomized controlled trial was conducted in inpatients who scheduled for colonoscopy with sedation. Patients were randomized to the non-ONS group and the ONS group. The primary outcomes were the rates of adequate bowel preparation measured by the Boston Bowel Preparation Scale (BBPS), the Ottawa Bowel Preparation Scale (OBPS) and the Colon Endoscopic Bubble Scale (CEBuS). The secondary outcomes were the adenoma detection rate (ADR), polyp detection rate (PDR), intubation time, withdrawal time and rates of adverse events.

RESULTS

In both groups, 100 patients were analyzed. The rates of adequate bowel preparation measured by the BBPS and OBPS and PDR were significantly higher in the ONS group than in the non-ONS group (all P < 0.05). However, no significant differences were observed in the CEBuS scores, ADR, intubation time and rates of adverse events between the two groups (all P > 0.05). The withdrawal time was longer in the non-ONS group than the in the ONS group (P < 0.05).

CONCLUSIONS

LRD with ONSs helps increase the quality of bowel preparation. To help with colorectal cancer (CRC) screening, further studies are warrant.

TRIAL REGISTRATION

[Chinese Clinical Trial Registry], [ChiCTR2400091660], [31/10/2024], [Retrospectively registered].

Microbiome analysis of gut microbiota in patients with colorectal polyps and healthy individuals

Colorectal polyps serve as the primary precursors for colorectal cancer. A close relationship has been observed between colorectal polyps and gut microbiota. However, the composition and role of the microbiome associated with tubular adenoma are not well understood. In this study, we prospectively evaluated alterations in gut microbiota among patients with colorectal polyps. A total of 60 subjects were enrolled in this study, including 30 patients with colorectal polyps (CP group) and 30 healthy controls (control group). The 16S rRNA sequencing was employed to characterize the gut microbiome in fecal samples. The results revealed that the beta diversity of the gut microbiota in the CP group significantly differs from that of the control group (p = 0.001). At the phylum level, the relative abundance of Bacteroides, Fusobacteria, and Proteobacteria was higher in the CP group compared to the control group (p < 0.05), whereas the relative abundance of Actinobacteria was higher in the control group in comparison to the CP group (p < 0.05). At the genus level, the abundance of Bacteroides increased in the CP group (p < 0.05), while Bifidobacterium declined in the CP group (p < 0.05). At the species level, the abundance of Clostridium perfringens, unidentified_Bacteroides, unidentified_Dorea, Escherichia coli, Clostridium ramosum, and Ruminococcus gnavus was higher (p < 0.05), whereas the abundance of Bifidobacterium adolescentis, unclassified_Bifidobacterium, Bifidobacterium longum, Faecalibacterium prausnitzii, and unidentified_Bifidobacterium is lower in CP group compared to the control group (p < 0.05). There was a structural imbalance in the composition of intestinal colonization flora for CP patients, characterized by a decrease in beneficial bacteria and an increase in harmful bacteria. Escherichia, Shigella, and Bacteroides may serve as promising biomarkers for early detection of colorectal polyps.

Intestinal microbiota as biomarkers for different colorectal lesions based on colorectal cancer screening participants in community

Introduction

The dysregulation of intestinal microbiota has been implicated in the pathogenesis of colorectal cancer (CRC). However, the utilization of intestinal microbiota for identify the lesions in different procedures in CRC screening populations remains limited.

Methods

A total of 529 high-risk individuals who underwent CRC screening were included, comprising 13 advanced adenomas (Aade), 5 CRC, 59 non-advanced adenomas (Nade), 129 colon polyps (Pol), 99 cases of colorectal inflammatory disease (Inf), and 224 normal controls (Nor). 16S rRNA gene sequencing was used to profile the intestinal microbiota communities. The Gut Microbiota Health Index (GMHI) and average variation degree (AVD) were employed to assess the health status of the different groups.

Results

Our findings revealed that the Nor group exhibited significantly higher GMHIs and the lowest AVD compared to the four Lesion groups. The model incorporating 13 bacterial genera demonstrated optimal efficacy in distinguishing CRC and Aade from Nor, with an area under the curve (AUC) of 0.81 and a 95% confidence interval (CI) of 0.72 to 0.89. Specifically, the 55 bacterial genera combination model exhibited superior performance in differentiating CRC from Nor (AUC 0.98; 95% CI, 0.96-1), the 25 bacterial genera combination showed superior performance in distinguishing Aade from Nor (AUC 0.95). Additionally, the 27 bacterial genera combination demonstrated superior efficacy in differentiating Nade from Nor (AUC 0.82). The 13 bacterial genera combination exhibited optimal performance in distinguishing Inf from Nor (AUC 0.71).

Discussion

Our study has identified specific microbial biomarkers that can differentiate between colorectal lesions and healthy individuals. The intestinal microbiota markers identified may serve as valuable tools in community-based CRC screening programs.

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.

Innovative approaches in colorectal cancer screening: advances in detection methods and the role of artificial intelligence

Colorectal cancer (CRC) is the third most prevalent cancer globally and poses a significant health threat, making early detection crucial. This review paper explored emerging detection methods for early screening of CRC, including gut microbiota, metabolites, genetic markers, and artificial intelligence (AI)-based technologies. Current screening methods have their respective advantages and limitations, particularly in detecting precursors. First, the importance of the gut microbiome in CRC progression is discussed, highlighting how specific microbial alterations can serve as biomarkers for early detection, potentially enhancing diagnostic accuracy when combined with traditional screening methods. Next, research on metabolic reprogramming illustrates the relationship between metabolic changes and CRC, with studies developing metabolite-based detection models that show good sensitivity for early diagnosis. In terms of genetic markers, methylated DNA markers like SEPTIN9 have demonstrated high sensitivity, although further validation across diverse populations is necessary. Lastly, AI technology has shown immense potential in improving adenoma detection rates, significantly enhancing the quality of colonoscopic examinations through image recognition techniques. This review aims to provide a comprehensive perspective on new strategies for CRC screening, emphasizing the potential of noninvasive detection technologies and the prospects of AI and genomics in clinical applications. Despite several challenges, this review advocates for future large-scale prospective studies to validate the effectiveness and cost-effectiveness of these new screening methods while promoting the implementation of screening protocols tailored to individual characteristics.

Global, regional, and national burden of early-onset colorectal cancer and projection to 2050: An analysis based on the Global Burden of Disease Study 2021

OBJECTIVES

Early-onset colorectal cancer (EO-CRC) is becoming increasingly concerning due to its impact on individuals under 50 years old. We explored the burden of EO-CRC to provide information for planning effective management and prevention strategies.

STUDY DESIGN

We conducted secondary analyses to assess the burden of EO-CRC using data from GBD 2021.

METHODS

The incidence, prevalence, deaths, disability-adjusted life years (DALYs) and their rates across 204 countries and territories were obtained from GBD 2021 database. The estimated annual percentage change (EAPC) calculation was used to assess temporal trends in these metrics. Additionally, we reported the proportion of DALYs attributable to risk factors and projected future disease burden till 2050.

RESULTS

The global number of new EO-CRC cases increased from 107,310 in 1990 to 211,890 in 2021. Both age-standardized incidence rate (ASIR) and prevalence rate (ASPR) of EO-CRC showed overall increases over the study period (ASIR: EAPC = 0.96 (0.9-1.02), ASPR: EAPC = 1.5 (1.44-1.55)). However, a decline in ASIR and ASPR was observed in 2020 and 2021. Males consistently showed higher EO-CRC indicators compared to females. Furthermore, projections indicated that deaths and DALYs cases are likely to fluctuate but generally increase by 2050, reaching 85,602 and 4,283,093, respectively.

CONCLUSIONS

The global impact of EO-CRC has increased significantly from 1990 to 2021, revealing notable variations across SDI regions, countries, age groups, and sexes. Besides, deaths and DALYs are predicted to rise by 2050. These results highlight the importance of implementing measures to address the growing burden of EO-CRC globally.

Evaluating the Use of Environmental and Polygenic Risk Scores to Inform Colorectal Cancer Risk-Based Surveillance Intervals

INTRODUCTION

United States Multi-Society Task Force colonoscopy surveillance intervals are based solely on adenoma characteristics, without accounting for other risk factors. We investigated whether a risk model including demographic, environmental, and genetic risk factors could individualize surveillance intervals under an "equal management of equal risks" framework.

METHODS

Using 14,069 individuals from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial who had a diagnostic colonoscopy following an abnormal flexible sigmoidoscopy, we modeled the risk of colorectal cancer, considering the diagnostic colonoscopy finding, baseline risk factors (e.g., age and sex), 19 lifestyle and environmental risk factors, and a polygenic risk score for colorectal cancer. Ten-year absolute cancer risks for each diagnostic colonoscopy finding (advanced adenomas [N = 2,446], ≥3 non-advanced adenomas [N = 483], 1-2 non-advanced adenomas [N = 4,400], and no adenoma [N = 7,183]) were used as implicit risk thresholds for recommended surveillance intervals.

RESULTS

The area under the curve for the model including colonoscopy findings, baseline characteristics, and polygenic risk score was 0.658. Applying the equal management of equal risks framework, 28.2% of individuals with no adenoma and 42.7% of those with 1-2 non-advanced adenomas would be considered high risk and assigned a significantly shorter surveillance interval than currently recommended. Among individuals who developed cancer within 10 years, 52.4% with no adenoma and 48.3% with 1-2 non-advanced adenomas would have been considered high risk and assigned a shorter surveillance interval.

DISCUSSION

Using a personalized risk-based model has the potential to identify individuals with no adenoma or 1-2 non-advanced adenomas, who are higher risk and may benefit from shorter 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.

Integrative Multi-Omics Analysis Reveals Critical Molecular Networks Linking Intestinal-System Diseases to Colorectal Cancer Progression

Background/Objectives: Colorectal cancer (CRC) frequently co-occurs with intestinal system diseases (ISDs), yet their molecular interplay remains poorly understood. We employed a comprehensive bioinformatics approach to elucidate shared genetic signatures and pathways between CRC and ISDs. Methods: We systematically analyzed 12 microarray and RNA-seq datasets encompassing 989 samples across seven ISDs and CRC. Differentially expressed genes (DEGs) were identified using Limma and DESeq2. Functional enrichment analysis was performed using clusterProfiler. Protein-protein interaction networks were constructed via STRING and visualized with Cytoscape to identify hub genes. Clinical significance of shared genes was further assessed through survival analysis and validated by immunohistochemistry staining of 30 paired CRC-normal tissue samples. Results: Integrating bioinformatics and machine learning approaches, we uncovered 160 shared DEGs (87 upregulated, 73 downregulated), which predominantly enriched cell metabolism, immune homeostasis, gut-brain communication, and inflammation pathways. Network analysis revealed nine key hub proteins linking CRC and ISDs, with seven upregulated (CD44, MYC, IL17A, CXCL1, FCGR3A, SPP1, and IL1A) and two downregulated (CXCL12 and CCL5). Survival analysis demonstrated the prognostic potential of these shared genes, while immunohistochemistry confirmed their differential expression in CRC tissues. Conclusions: Our findings unveil potential biomarkers and therapeutic targets, providing insights into ISD-influenced CRC progression and offering a robust foundation for improved diagnostic and treatment strategies in ISD-associated CRC.

Stool and blood biomarkers for colorectal cancer management: an update on screening and disease monitoring

BACKGROUND

Biomarkers have revolutionized the management of colorectal cancer (CRC), facilitating early detection, prevention, personalized treatment, and minimal residual disease (MRD) monitoring. This review explores current CRC screening strategies and emerging biomarker applications.

MAIN BODY

We summarize the landscape of non-invasive CRC screening and MRD detection strategies, discuss the limitations of the current approaches, and highlight the promising potential of novel biomarker solutions. The fecal immunochemical test remained the cornerstone of CRC screening, but its sensitivity has been improved by assays that combined its performance with other stool analytes. However, their sensitivity for advanced adenomas and the patient compliance both remain suboptimal. Blood-based tests promise to increase compliance but require further refinement to compete with stool-based biomarker tests. The ideal scenario involves leveraging blood tests to increase screening participation, and simultaneously promote stool- and endoscopy-based screening among those who are compliant. Once solely reliant on upfront surgery followed by stage and pathology-driven adjuvant chemotherapy, the treatment of stage II and III colon cancer has undergone a revolutionary transformation with the advent of MRD testing after surgery. A decade ago, the concept of using a post-surgical test instead of stage and pathology to determine the need for adjuvant chemotherapy was disruptive. Today, a blood test may be more informative of the need for chemotherapy than the stage at diagnosis.

CONCLUSION

Biomarker research is not just improving, but bringing a transformative change to CRC clinical management. Early detection is not just getting better, but improving thanks to a multi-modality approach, and personalized treatment plans are not just becoming a reality, but a promising future with MRD testing.

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.

Polyp size is associated with colorectal cancer death across histologic polyp subtypes: a retrospective study of a screening colonoscopy registry

BACKGROUND

Surveillance colonoscopy after polyps have been detected at screening aims to reduce the risk for subsequent colorectal cancer, so-called post-colonoscopy colorectal cancer (PCCRC). Inconsistencies exist as to whether the risk should be stratified by histologic subtype. We aimed to compare the risk for PCCRC mortality in screening participants with sessile serrated lesions (SSLs)/traditional serrated adenomas (TSAs), hyperplastic polyps (HPPs), or conventional adenomas.

METHODS

Screening colonoscopy registry data were linked to death registry data between 2010 and 2022. We assessed the association of PCCRC death after a diagnosis of SSL/TSA, conventional adenoma, or HPP by Cox regression, and stratified by polyp size ≥10 and <10 mm.

RESULTS

383,801 participants were included in the analysis. There were 1490 HPPs ≥10 mm (2.6%), compared with 1853 SSL/TSAs (19.6%) and 10,960 conventional adenomas (12.9%). When adjusted for polyp location, the association of polyp size ≥10 mm with PCCRC death was of similar magnitude in participants with conventional adenomas (hazard ratio [HR] 3.68, 95%CI 2.49-5.44), SSL/TSAs (HR 2.55, 95%CI 1.13-5.72), and HPPs (HR 5.01, 95%CI 2.45-10.22). Participants with HPPs mostly died of tumors in the distal colon (54.1%; n = 20), while participants with SSL/TSAs more frequently died of proximal tumors (33.3%; n = 3).

CONCLUSIONS

Across all histologic types, participants with polyps ≥10 mm had at least a two-fold increase in the likelihood of PCCRC death compared with those with polyps <10 mm. These data suggest that size, rather than histologic subtype, should be a determinant for risk stratification after screening colonoscopy.

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.

Risk factors for metachronous colorectal cancer or advanced lesions after endoscopic resection of serrated polyps: a systematic review and meta-analysis

BACKGROUND AND AIMS

Serrated polyps (SPs) are precursors to 15% to 20% of colorectal cancers (CRCs). However, there are uncertainties regarding which SPs require surveillance and at what intervals, with recommendations adapted from those for adenomas in the absence of solid evidence. Our aim was to assess which SP risk characteristics relate to a higher risk of metachronous CRC or advanced polyps.

METHODS

We systematically searched PubMed, Embase, and Cochrane for cohort studies, case-control studies, and clinical trials from inception to December 31, 2023, of CRC or advanced polyps (advanced adenoma [AA] or advanced SP) incidence at surveillance stratified by baseline SP size, dysplasia, location, and multiplicity. We defined advanced SPs as those ≥10 mm or with dysplasia. CRC and advanced polyp incidence per 1000 person-years were estimated. We performed a meta-analysis by calculating pooled relative risks (RRs) using a random-effects model.

RESULTS

A total of 5903 studies were reviewed, and 14 were included with 493,949 patients (mean age, 59.5 years; 55% men). The mean follow-up was 4.9 years. CRC incidence per 1000 person-years was 2.09 (95% confidence interval [CI], 1.29-2.90) for advanced SPs, 1.52 (95% CI, 0.78-2.25) for SPs of ≥10 mm, 5.86 (95% CI, 2.16-9.56) for SPs with dysplasia, 1.18 (95% CI, 0.77-1.60) for proximal SPs, 0.52 (95% CI, 0.08-1.12) for ≥3 SPs, 0.50 (95% CI, 0.35-0.66) for nonadvanced SPs, and 0.44 (95% CI, 0.41-0.46) for normal colonoscopy findings. Metachronous CRC risk was higher in advanced SPs versus nonadvanced SPs (RR, 1.84; 95% CI, 1.11-3.04) and versus normal colonoscopy findings (RR, 2.92; 95% CI, 2.26-3.77), in SPs of ≥10 mm versus <10 mm (RR, 2.61; 95% CI, 1.43-4.77) and versus normal colonoscopy findings (RR: 3.52; 95% CI, 2.17-5.69); and in SPs with dysplasia versus normal colonoscopy findings (RR: 2.71; 95% CI, 2.00-3.67). No increase in CRC or advanced polyp risk was found in patients with proximal versus distal SPs, nor in ≥3 SPs versus 1 or 2 SPs.

CONCLUSIONS

CRC risk is significantly higher in patients with baseline advanced SPs after 4.9 years of follow-up, with risk magnitudes similar to those described for AA, supporting the current recommendation for 3-year surveillance in patients with advanced SPs.

Identifying modifiable risk factors to prevent aggressive colorectal cancer

It remains unclear if pre-diagnostic factors influence the developmental pathways of colorectal cancer (CRC) that could enhance tumor aggressiveness. This study used prospective data from 205,489 cancer-free US health professionals to investigate the associations of 31 known or putative risk factors with the risk of aggressive CRC. Tumor aggressiveness was characterized by three endpoints: aggressive CRC (cancer that causes death within 5 years of diagnosis), fatal CRC, and tumor stage at diagnosis. The data augmentation method was used to assess the difference in the associations between risk factors and endpoints. We documented 3201 CRC cases, of which 899 were aggressive. The protective associations of undergoing lower endoscopy (hazard ratios [HR] 0.43, 95% confidence interval (CI) 0.37, 0.49 for aggressive versus HR 0.61, 95% CI 0.56, 0.67 for non-aggressive) and regular use of aspirin (HR 0.70, 95% CI 0.61, 0.81 versus HR 0.84, 95% CI 0.77, 0.92) were stronger for aggressive than non-aggressive CRC (pHeterogeneity <0.05). Lower intake of whole grains or cereal fiber and greater dietary inflammatory potential were associated with a higher risk of aggressive but not non-aggressive CRC. The remaining risk factors showed comparable associations with aggressive CRC and non-aggressive CRC. Aggressive cases were more likely to have KRAS-mutated tumors but less likely to have distal or MSI-high tumors (p < .007). Similar results were observed for fatal CRC and advanced tumor stages at diagnosis. These findings provide initial evidence for the role of pre-diagnostic risk factors in the pathogenesis of aggressive CRC and suggest research priorities for preventive interventions.

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.

Risk of colorectal neoplasia after removal of conventional adenomas and serrated polyps: a comprehensive evaluation of risk factors and surveillance use

BACKGROUND

Surveillance colonoscopy after polyp removal is recommended to prevent subsequent colorectal cancer (CRC). It is known that advanced adenomas have a substantially higher risk than non-advanced ones, but optimal intervals for surveillance remain unclear.

DESIGN

We prospectively followed 156 699 participants who had undergone a colonoscopy from 2007 to 2017 in a large integrated healthcare system. Using multivariable Cox proportional hazards regression we estimated the subsequent risk of CRC and high-risk polyps, respectively, according to index colonoscopy polyps, colonoscopy quality measures, patient characteristics and the use of surveillance colonoscopy.

RESULTS

After a median follow-up of 5.3 years, we documented 309 CRC and 3053 high-risk polyp cases. Compared with participants with no polyps at index colonoscopy, those with high-risk adenomas and high-risk serrated polyps had a consistently higher risk of CRC during follow-up, with the highest risk observed at 3 years after polypectomy (multivariable HR 5.44 (95% CI 3.56 to 8.29) and 8.35 (95% CI 4.20 to 16.59), respectively). Recurrence of high-risk polyps showed a similar risk distribution. The use of surveillance colonoscopy was associated with lower risk of CRC, with an HR of 0.61 (95% CI 0.39 to 0.98) among patients with high-risk polyps and 0.57 (95% CI 0.35 to 0.92) among low-risk polyps. Among 1548 patients who had high-risk polyps at both index and surveillance colonoscopies, 65% had their index polyps in the proximal colon and 30% had index and interval polyps in the same segments.

CONCLUSION

Patients with high-risk polyp findings were at higher risk of subsequent CRC and high-risk polyps and may benefit from early surveillance within 3 years. The subsite distribution of the index and recurrent high-risk polyps suggests the contribution of incomplete resection and missed lesions to the development of interval neoplasia.

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.

Low Colorectal Cancer Risk After Resection of High-Risk Pedunculated Polyps

BACKGROUND

Post-fecal immunochemical test (FIT) colonoscopy represents a setting with an enriched prevalence of advanced adenomas. Due to an expected higher risk of colorectal cancer (CRC), postpolypectomy surveillance is recommended, generating a substantially increased load on endoscopy services. The aim of our study was to investigate postpolypectomy CRC risk in a screening population of FIT+ subjects after resection of low-risk adenomas (LRAs) or high-risk adenomas (HRAs).

METHODS

We retrieved data from a cohort of patients undergoing postpolypectomy surveillance within a FIT-based CRC screening program in Italy between 2002 and 2017 and followed-up to December 2021. Main outcomes were postpolypectomy CRC incidence and mortality risks according to type of adenoma (LRA/HRA) removed at colonoscopy as well as morphology, size, dysplasia, and location of the index lesion. We adopted as comparators FIT+/colonoscopy-negative and FIT- patients. The absolute risk was calculated as the number of incident CRCs per 100,000 person-years of follow-up. We used Cox multivariable regression models to identify associations between CRC risks and patient- and polyp-related variables.

RESULTS

Overall, we included 87,248 post-FIT+ colonoscopies (133 endoscopists). Of these, 42,899 (49.2%) were negative, 21,650 (24.8%) had an LRA, and 22,709 (26.0%) an HRA. After a median follow-up of 7.25 years, a total of 635 CRCs were observed. For patients with LRAs, CRC incidence (hazard ratio [HR], 1.18; 95% confidence interval [CI], 0.92-1.53) was not increased compared with the FIT+/colonoscopy-negative group, while for HRAs a significant increase in CRC incidence (HR, 1.53; 95% CI, 1.14-2.04) was found. The presence of 1 or more risk factors among proximal location, nonpedunculated morphology, and high-grade dysplasia explained most of this excess CRC risk in the HRA group (HR, 1.85; 95% CI, 1.36-2.52). Patients with only distal pedunculated polyps without high-grade dysplasia, representing 39.2% of HRA, did not have increased risk compared with the FIT- group (HR, 0.87; 95% CI, 0.59-1.28).

CONCLUSIONS

CRC incidence is significantly higher in patients with HRAs diagnosed at colonoscopy. However, such excess risk does not appear to apply to patients with only distal pedunculated polyps without high-grade dysplasia, an observation that could potentially reduce the burden of surveillance in FIT programs.

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.

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.

Risk factors for synchronous high-risk polyps in patients with colorectal cancer

Purpose

Colorectal cancer (CRC) patients may experience inadequate preoperative colonoscopy due to bowel obstruction or inadequate bowel preparation, leading to potential oversight of other polyps. We aimed to identify risk factors for CRC complicated with synchronous high-risk polyps.

Methods

A retrospective analysis of 6,674 CRC patients from December 2014 to September 2018 was conducted. High-risk polyps were defined as adenomas or serrated polyps that were ≥10 mm, or with tubulovillous/villous components or high-grade dysplasia. All other polyps were defined as low-risk polyps. Patients with complete pathological and clinical information were categorized into three groups: the no polyp group, the low-risk polyp group, and the high-risk polyp group. Univariate and multivariate logistic regression analyses were performed to calculate the odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for all potential risk factors.

Results

Among the 4,659 eligible patients, 848 (18.2%) were found to have low-risk polyps, while 675 (14.5%) were diagnosed with high-risk polyps. In a multivariate logistic regression model, compared to patients without polyps, those with synchronous high-risk polyps were more likely to be male (OR = 2.07), aged 50 or older (OR = 2.77), have early-stage tumors (OR = 1.46), colon tumors (OR = 1.53), NRAS mutant tumors (OR = 1.66), and BRAF wild-type tumors (OR = 2.43).

Conclusion

Our study has identified several risk factors associated with the presence of synchronous high-risk polyps in CRC patients. Based on these findings, we recommend that patients who exhibit these high-risk factors undergo early follow-up of colonoscopy to detect synchronous polyps early.

Randomized Trial of Patient Outreach Approaches to De-implement Outdated Colonoscopy Surveillance Intervals

BACKGROUND AND AIMS

Guidelines now recommend patients with low-risk adenomas receive colonoscopy surveillance in 7-10 years and those with the previously recommended 5-year interval be re-evaluated. We tested 3 outreach approaches for transitioning patients to the 10-year interval recommendation.

METHODS

This was a 3-arm pragmatic randomized trial comparing telephone, secure messaging, and mailed letter outreach. The setting was Kaiser Permanente Northern California, a large integrated healthcare system. Participants were patients 54-70 years of age with 1-2 small (<10 mm) tubular adenomas at baseline colonoscopy, due for 5-year surveillance in 2022, without high-risk conditions, and with access to all 3 outreach modalities. Patients were randomly assigned to the outreach arm (telephone [n = 200], secure message [n = 203], and mailed letter [n = 201]) stratified by age, sex, and race/ethnicity. Outreach in each arm was performed by trained medical assistants (unblinded) communicating in English with 1 reminder attempt at 2-4 weeks. Participants could change their assigned interval to 10 years or continue their planned 5-year interval.

RESULTS

Sixty-day response rates were higher for telephone (64.5%) and secure messaging outreach (51.7%) vs mailed letter (31.3%). Also, more patients adopted the 10-year surveillance interval in the telephone (37.0%) and secure messaging arms (32.0%) compared with mailed letter (18.9%) and rate differences were significant for telephone (18.1%; 97.5% confidence interval: 8.3%-27.9%) and secure message outreach (13.1%; 97.5% confidence interval: 3.5%-22.7%) vs mailed letter outreach.

CONCLUSIONS

Telephone and secure messaging were more effective than mailed letter outreach for de-implementing outdated colonoscopy surveillance recommendations among individuals with a history of low-risk adenomas in an integrated healthcare setting. (ClinicalTrials.gov, Number: NCT05389397).

The durability of previous examinations for cancer: Danish nationwide cohort study

OBJECTIVE

Patients previously examined for cancer with a negative result may present in general practice with ongoing or new symptoms or signs suggestive of cancer. This paper explores the potential existence of a relatively safe period for cancer occurrence after receiving negative examination results for specific types of cancer, including lung (CT thorax), upper gastrointestinal (gastroscopy), colorectal (colonoscopy), bladder (cystoscopy), and breast (clinical mammography).

DESIGN

Register-based time-to-event analyses.

SETTING

Denmark.

SUBJECTS

All 3.3 million citizens aged 30-85 years who on January first, 2017, had not previously been diagnosed with the specific type of cancer were categorized based on the time since their most recent examination.

MAIN OUTCOME MEASURES

Using 1-year follow-up, we calculated the age- and sex-adjusted hazard ratios of being diagnosed with the related cancer, with non-examined individuals as reference. Negative examination results were defined as the absence of a cancer diagnosis within 6 months following the examination.

RESULTS

Previous negative examination results were common, also among those diagnosed with cancer during follow-up. For 10 years after a negative colonoscopy the risk of diagnosing a colorectal cancer was nearly halved. However, already 1 year after a clinical mammography and 2 years after a CT thorax the risk of diagnosing the related cancers was significantly higher among those with a previous negative result compared to non-examined individuals.

CONCLUSION

This study did not identify a post-examination period in which the cancer risk, compared to non-examined individuals, was sufficiently low to confidently rule out any of the investigated cancers.

Efficacy and safety of salvage endoscopy in the treatment of residual or recurrent colorectal neoplasia after endoscopic resection: a systematic review and meta-analysis

OBJECTIVE

To systematically review and meta-analyze the efficacy and safety of salvage endoscopy for residual or recurrence of colorectal tumors after endoscopic resection.

METHODS

Multiple databases including PubMed, EMBASE and the Cochrane Library were searched to screen for eligible studies and perform data extraction and pooled analysis.

RESULTS

Sixteen studies on salvage endoscopy for residual or recurrent colorectal cancer after endoscopic resection were included, covering approximately 994 patients. The results of the meta-analysis demonstrated that salvage endoscopic therapy for residual or recurrent colorectal tumors following endoscopic resection achieved an en bloc resection rate of 92% (95% CI 0.85-0.97; I2 = 91%) and an R0 resection rate of 82% (95% CI 0.75-0.87; I2 = 78%). The rates of intraoperative or postoperative bleeding and perforation were 10%/1% and 5%/2%, and the recurrence rate was 2%.

CONCLUSIONS

Salvage endoscopic resection is an effective and safe treatment strategy for residual or recurrent colorectal tumors after endoscopic resection.

Multiple colorectal adenomas syndrome: The role of MUTYH mutation and the polyps' number in clinical management and colorectal cancer risk

BACKGROUND & AIMS

Multiple colorectal adenomas (MCRAs) can result from APC (AFAP) or biallelic MUTYH (MAP) mutations, but most patients are wild type and referred to as non-APC/MUTYH polyposis (NAMP). We aim to examine the risk of colorectal cancer (CRC) and the role of endoscopy in managing patients with MCRAs, with a specific focus on clinical features and genotype.

METHODS

Records of MRCAs between 2000 and 2022 were retrospectively analysed. Patients were divided according to the genotype (MAP vs. NAMP) and the number of categorised polyps' burden (group 1: 10-24, group 2: 25-49, and group 3: 50-99 adenomas). Predictors of outcome were CRC-free survival (CRC-FS) and Surgery free-survival (S-FS).

RESULTS

220 patients were enrolled (NAMP n = 178(80.0%)). CRC at diagnosis was more frequent in group 3 (p = 0.01), without significant differences between the genotypes (p = 0.20). At a follow-up of 83(41-164) months, 15(7%) patients developed CRC during surveillance. CRC-FS was not correlated to genotype (p = 0.07) or polyps' number (p = 0.33), while S-FS was similar in MAP and NAMP (p = 0.22) and lower in groups 2 and 3 (p = 0.0001).

CONCLUSIONS

MAP and NAMP have the same CRC risk and no difference in treatment. Endoscopic surveillance compared favorably with surgery in avoiding CRC risk, even in patients with more severe colorectal polyposis.

Differences in circulating lymphocyte subpopulations among patients with inflammatory polyps, colorectal adenomas and colorectal cancer

BACKGROUND AND STUDY AIMS

Colorectal cancer (CRC) may develop from focal changes within benign or precancerous polyps. The immune system's failure to detect and eradicate tumor cells due to immune surveillance evasion, allows cancer to develop and spread. This study aims to analyze the differences in circulating lymphocyte subpopulations in patients with colorectal inflammatory polyps, colorectal adenomas and CRC.

PATIENTS AND METHODS

We retrospectively reviewed patients from September 2016 to December 2019 at the Shaoxing Second Hospital. Using flow cytometry, the subset distribution and immunophenotype of T cells, CD4+ T cells, CD8+ T cells, B cells and NK cells were investigated in peripheral blood mononuclear cell samples. The counts of lymphocytes were determined by white blood cell counts.

RESULTS

In total, 518 patients were included in this study. The counts of lymphocytes, T cells and NK cells in patients with inflammatory polyps, colorectal adenomas and CRC were lower than controls. The counts and percentages of CD8+ T cells in patients with inflammatory polyps, colorectal adenomas and CRC were lower than controls. The counts of CD4+ T cells were lower in patients with CRC than inflammatory polyps. The percentages of CD4+ T cells in patients with inflammatory polyps, colorectal adenomas and CRC were higher than controls, but lower in the CRC than inflammatory polyps, colorectal adenomas. The counts and percentages of B cells were lower in CRC patients than colorectal adenomas patients. In addition, the percentages of B cells were higher in patients with inflammatory polyps and colorectal adenomas than in controls.

CONCLUSIONS

The decrease in counts of lymphocyte, T cells, CD8+ T cells and NK cells in patients may be related to the dysplasia of epithelial cells. Furthermore, the B cells and CD4+ T cells may be related to the malignant growth of the dysplastic epithelial cells.

Impact of Clinical and Endoscopic Features on the Development of Metachronous Colorectal Advanced Serrated Lesions

BACKGROUND AND AIMS

High-risk adenomas predict metachronous advanced adenomatous neoplasia. Limited data exist on predictors of metachronous advanced serrated lesions (mASLs). We analyzed clinical and endoscopic predictors of mASLs.

METHODS

In this retrospective cohort study, adults with >1 outpatient colonoscopy between 2008 and 2019 at a tertiary center were included. Serrated lesions (SLs) included sessile SLs (SSLs), traditional serrated adenomas (TSAs), and hyperplastic polyps (HPs). Patient and endoscopic characteristics were obtained using electronic medical records. Five-year cumulative incidence of mASL (HP ≥10 mm, SSL ≥10 mm or with dysplasia, any TSA) and factors associated with mASL were evaluated using Kaplan-Meier estimates and Cox proportional hazards models.

RESULTS

A total of 4990 patients were included and 45.4% were women. Mean age was 60.9 ± 9.2 years and median follow-up time was 3.7 years. Female sex and active smoking were associated with mASL. Endoscopically, any SSL and TSA were associated with mASL. The 5-year cumulative incidence for mASL was 26% (95% confidence interval [CI], 18%-32%) for SSL ≥10 mm, 17% (95% CI, 3.5%-29%) for HP ≥10 mm, 21% (95% CI, 0%-42%) for 3-4 SSLs <10 mm, 18% (95% CI, 0%-38%) for TSA, and 27% (95% CI, 3.6%-45%) for SSL with low-grade dysplasia. Baseline synchronous nonadvanced SL and nonadvanced adenoma were not associated with mASL.

CONCLUSIONS

Our data support current recommendations for a 3-year surveillance interval in patients with baseline SSL ≥10 mm, SSL with dysplasia, and TSA. A 3-year interval may be more appropriate than 3-5 years for patients with baseline HP ≥10 mm or 3-4 SSLs <10 mm. Patients with synchronous nonadvanced SLs and adenomas do not appear to be at increased risk of mASL.

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 diverse colorectal polyps and risk factors for colorectal carcinoma in situ and neoplastic polyps

BACKGROUND

Most colorectal cancers originate from precancerous polyps. This study aimed to determine the prevalence of colorectal polyps with diverse pathological morphologies and to explore the risk factors for colorectal carcinoma in situ (CCS) and neoplastic polyps.

METHODS

Inpatients admitted from January 2018 to May 2023 were screened through the hospital information system. Polyps were classified according to pathological morphology. The prevalence of polyps was described by frequency and 95% confidence interval. Univariate and multivariate logistic regression analyses were used to explore the risk factors for CCS and neoplastic polyps.

RESULTS

In total, 2329 individuals with 3550 polyps were recruited. Among all patients, 76.99% had neoplastic polyps and 44.31% had advanced adenomas. Tubular adenoma had the highest prevalence at 60.15%, and the prevalence of CCS was 3.86%. Patients with a colorectal polyp diameter ≥ 1.0 cm or number ≥ 3 were 8.07 times or 1.98 times more likely to develop CCS than were those with a diameter < 1.0 cm or number < 3, respectively (OR 8.07, 95%CI 4.48-14.55, p < 0.0001; and OR 1.98, 95%CI 1.27-3.09, p = 0.002). The risk of CCS with schistosome egg deposition was also significantly increased (OR 2.70, 95%CI 1.05-6.98). The higher the levels of carbohydrate antigen (CA) 724 (OR 1.01, 95%CI 1.00-1.02) and CA211 (OR 1.16, 95%CI 1.03-1.32) in patients with colorectal polyps were, the greater the risk of CCS. When colorectal neoplastic polyps were analyzed, we discovered that for each 1-year increase in age, the risk of neoplastic polyps increased by 3% (OR 1.03, 95%CI 1.02-1.04), p < 0.0001. Patients with a polyp diameter ≥ 1.0 cm had a 2.11-fold greater risk of neoplastic polyps compared to diameter < 1.0 cm patients (OR 3.11, 95%CI 2.48-3.92), p < 0.0001. In addition, multiple polyps and CA199 levels are risk factors for neoplastic polyps.

CONCLUSION

More than 3/4 of colorectal polyp patients have neoplastic polyps. Patients are more inclined to develop CCS and neoplastic polyps if they have large polyps (> 1.0 cm) or multifocal polyps. The levels of the tumor markers CA724 and CA211 show some potential usefulness for predicting CCS and may be exploited for early identification of high-risk populations.

Sporadic Polyps of the Colorectum

Colorectal polyps are common, and their diagnosis and classification represent a major component of gastrointestinal pathology practice. The majority of colorectal polyps represent precursors of either the chromosomal instability or serrated neoplasia pathways to colorectal carcinoma. Accurate reporting of these polyps has major implications for surveillance and thus for cancer prevention. In this review, we discuss the key histologic features of the major colorectal polyps with a particular emphasis on diagnostic pitfalls and areas of contention.

Colorectal adenomatous and serrated polyps in rural South Australia: who, why, what and where?

BACKGROUNDS

The adenoma-carcinoma and serrated pathways offer a window of opportunity for the removal of pre-malignant polyps and prevention of colorectal cancer (CRC) through the use of colonoscopy. The aim of this study was to investigate variation in polyp incidence in different age groups, gender and indications for undertaking colonoscopy. We also address histological types of polyps found and where in the bowel they are located.

METHODS

This study is based on the colonoscopy data collected prospectively over a one-year period in multiple South Australian rural centres, 24 general surgeons contributed to this study. All histopathology results were subsequently entered into the dataset.

RESULTS

A total of 3497 colonoscopies were performed, with a total of 2221 adenomatous and serrated polyps removed. Both serrated and adenomatous polyps were more common in the distal colon. Patients of male gender, aged 70 years and over and with an indication of polyp surveillance had higher adenoma and serrated polyp detection rates (ADR and SPDR). Patients aged 40-49 years old who underwent colonoscopy for positive faecal occult blood had an ADR and SPDR of 25.0% and 6.3%, respectively.

CONCLUSIONS

This study has shown variation in ADR and SPDR depending on age, gender and indication for colonoscopy. This variation will help further develop key performance indicators in colonoscopy. The high ADR and SPDR in patients aged 40-49 years old whom underwent colonoscopy for positive faecal occult blood may support lowering the age of commencement of CRC screening in Australia.

Giant Villous Adenoma of the Rectum With Prolapse: Case Report

Colorectal polyps, frequently adenomas, are common in older adults, with villous adenomas being a notable subset due to their potential for significant malignancy risk. This case report highlights a rare instance of a giant villous adenoma in a 79-year-old female patient, challenging in both diagnosis and treatment. The patient, with a history of untreated essential arterial hypertension, was hospitalized for severe anemia following a massive rectal hemorrhage. An irreducible, prolapsed rectal mass was evident upon examination, and further investigations, including rectoscopy and abdominopelvic computed tomography scan, confirmed a villous adenoma with severe dysplasia. Given the tumor's substantial size, circumferential nature, and proximity to the dentate line, an abdominoperineal resection using the Miles technique was performed. The histopathological examination post-surgery confirmed the presence of a villous adenoma with high-grade epithelial neoplasia and localized areas of well-differentiated tubular adenocarcinoma. This case underscores the diagnostic and management complexities of large villous adenomas, emphasizing the need for meticulous surgical decision-making to ensure oncological safety and patient welfare, particularly when conservative resection may be inadequate.

Risk Prediction of Metachronous Colorectal Cancer from Molecular Features of Adenomas: A Nested Case-Control Study

Current morphologic features defining advanced adenomas (size ≥10 mm, high-grade dysplasia or ≥25% villous component) cannot optimally distinguish individuals at high risk or low risk of metachronous colorectal cancer (me-CRC), which may result in suboptimal surveillance. Certain DNA copy-number alterations (CNAs) are associated with adenoma-to-carcinoma progression. We aimed to evaluate whether these molecular features can better predict an individual's risk of me-CRC than the morphologic advanced adenoma features.In this nested case-control study, 529 individuals with a single adenoma at first colonoscopy were selected from a Norwegian adenoma cohort. DNA copy-number profiles were determined, by low-coverage whole-genome sequencing. Prevalence of CNAs in advanced and non-advanced adenomas and its association (OR) with me-CRC was assessed. For the latter, cases (with me-CRC) were matched to controls (without me-CRC) on follow-up, age and sex.CNAs associated with adenoma-to-carcinoma progression were observed in 85/267 (32%) of advanced adenomas and in 27/262 (10%) of non-advanced adenomas. me-CRC was statistically significantly associated, also after adjustment for other variables, with age at baseline [OR, 1.14; 95% confidence interval CI), 1.03-1.26; P = 0.012], advanced adenomas (OR, 2.46; 95% CI, 1.50-4.01; P < 0.001) and with the presence of ≥3 DNA copy-number losses (OR, 1.90; 95% CI. 1.02-3.54; P = 0.043).Molecularly-defined high-risk adenomas were associated with me-CRC, but the association of advanced adenoma with me-CRC was stronger.

SIGNIFICANCE

Identifying new biomarkers may improve prediction of me-CRC for individuals with adenomas and optimize surveillance intervals to reduce risk of colorectal cancer and reduce oversurveillance of patients with low risk of colorectal cancer. Use of DNA CNAs alone does not improve prediction of me-CRC. Further research to improve risk classification is required.

Frequency of endoscopic photodocumentation of large colorectal polyps

BACKGROUND AND AIMS

Colonoscopy quality affects colorectal cancer (CRC) incidence and mortality. The U.S. Multi-Society Task Force on Colorectal Cancer strongly recommends photodocumentation (PD) of lesions ≥10 mm in size (ie, large polyps [LPs]) pre-resection and suggests PD postresection to enhance the quality of colonoscopy. No studies have assessed the frequency of LP PD. We evaluated the frequency of and factors associated with PD of LPs.

METHODS

Reports from endoscopists performing ≥50 colonoscopies with LP resection between 2016 and 2021 were reviewed. The frequency of LP PD pre-resection and post-resection and factors associated with PD were collected. A composite score of 2 quality metrics (PD of completeness of examination and bowel preparation quality) was created. Endoscopists were divided into 2 tiers based on the frequency of the score on all included examinations: Tier 1, ≥95% of examinations; and Tier 2, <95% of examinations. Univariate and multivariate analyses were used to assess factors associated with PD.

RESULTS

A total of 1322 colonoscopies, 1693 LPs, and 25 endoscopists were included in this study. PD of LPs occurred in 1392 (82%) pre-resection and in 878 (52%) post-resection. Factors associated with pre-resection PD include endoscopist subspecialty (colorectal surgery vs gastroenterology: odds ratio [OR], .12; 95% confidence interval [CI], .04-.42); >1 LP on examination (2 vs 1 LP: OR, .41 [95% CI, .27-.61]; and ≥3 vs 1 LP: OR, .41 [95% CI, .24-.70]), and longer withdrawal time (OR, 1.02; 95% CI, 1.01-1.04).

CONCLUSIONS

We provide the first data on PD of LP pre-resection and post-resection, which can inform future benchmarking in this area. The implications of PD on metachronous advanced neoplasia need to be studied.

Evaluation of Colonoscopic Results of Patients with Incidental Colonic FDG Uptake in PET/CT Imaging

BACKGROUND

Colorectal cancer is a significant global health concern, ranking as the second most deadly and third most common cancer worldwide. Early detection and removal of precancerous lesions play a crucial role in preventing cancer development and reducing mortality. Since FDG uptake is not specific for malignancy, incidental increased FDG uptake in the gastrointestinal tract may be challenging to interpret and may require further colonoscopic examination. This study aimed to investigate the features associated with malignant and premalignant pathology in patients with incidental colonic FDG uptake and determine the necessity of colonoscopy for each FDG uptake.

METHODS

Retrospective analysis was performed on data from patients who underwent colonoscopies between January 2016 and December 2021. Patients with FDG uptake in known colorectal malignancy regions were excluded. The study included 56 patients with incidental colonic FDG uptake. PET/CT images were visually and quantitatively analyzed, and the corresponding colonoscopy and histopathological results were recorded. Statistical analyses were conducted to evaluate the relationship between FDG uptake patterns, SUVmax values, and histopathological diagnoses. Colonoscopic findings were categorized as malignancy, polyps, and non-neoplastic lesions.

RESULTS

Among the 56 patients with incidental colonic FDG uptake, 36 lesions were identified, and histopathology revealed malignancy in 10 (17.9%) patients and premalignant polyps in the 26 (46.4%) cases. Focal FDG uptake with corresponding wall thickening or soft tissue density on CT was associated with a higher likelihood of premalignant or malignant lesions. The SUVmax values demonstrated a significant difference between negative findings and polyps/malignancies. However, no significant difference was observed between malignant and premalignant lesions. A ROC curve analysis was made and assesed a cut-off value of 11.1 SUVmax (sensitivity: 83.3% and specificity: 90%) to distinguish premalignant or malignant lesions from non-malignant lesions.

CONCLUSION

Incidental colonic FDG uptake with a focal pattern and corresponding CT findings were more likely to indicate premalignant or malignant lesions. SUVmax values were helpful in predicting the presence of pathological findings, but histopathological verification remains necessary for a definitive diagnosis. These findings contribute to our understanding of the clinical implications of incidental colonic FDG uptake and highlight the importance of follow-up colonoscopy for further evaluation.

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.

Older Age at First Screening Colonoscopy is Associated With an Increased Risk of Colorectal Adenomas and Cancer

INTRODUCTION

The goal of colorectal cancer (CRC) screening is to detect precancerous polyps before cancer development or identification of cancer at an early stage. Guidelines have recommended screening colonoscopy to start at age 45. Our aim was to determine the impact of delays in performing the first screening colonoscopy on the risk of adenoma or CRC detection.

METHODS

We analyzed colonoscopy and histopathology data of average CRC risk patients who had their first screening colonoscopy between 2010 and 2017. Univariate and multivariable logistic regression was performed to determine the association between demographic variables and the risk of adenomas or CRC.

RESULTS

A total of 1155 average risk patients underwent their initial screening colonoscopy during the study period. Median age was 54 years (range of 45-87) and 58.2% were females. In multivariable analysis, older age at first screening colonoscopy was significantly associated with the detection of adenomatous polyps (odds ratio 1.05, 95% confidence interval 1.04-1.07, P <0.001) and CRC (odds ratio 1.11, 95% confidence interval 1.06-1.16, P <0.001). The association between age and risk of adenomatous polyps (F-test 35.43, P =0.0019) and CRC (F-test 36.94, P =0.0017) fit an exponential growth model. It was estimated that the detection rate doubled every 14.20 years and 4.75 years for adenomas and CRC, respectively.

CONCLUSION

We found that older age at the initial performance of a screening colonoscopy was associated with increased detection of adenomatous polyps and CRC. This work highlights the need for guideline adherence for the prevention of CRC development.

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.

Development and validation of a risk prediction model for post-polypectomy colorectal cancer in the USA: a prospective cohort study

Background

Effective risk stratification tools for post-polypectomy colorectal cancer (PPCRC) are lacking. We aimed to develop an effective risk stratification tool for the prediction of PPCRC in three large population-based cohorts and to validate the tool in a clinical cohort.

Methods

Leveraging the integrated endoscopic, histopathologic and epidemiologic data in three U.S population-based cohorts of health professional (the Nurses' Health Study (NHS) I, II and Health Professionals Follow-up Study (HPFS)), we developed a risk score to predict incident PPCRC among 26,741 patients with a polypectomy between 1986 and 2017. We validated the PPCRC score in the Mass General Brigham (MGB) Colonoscopy Cohort (Boston, Massachusetts, U.S) of 76,603 patients with a polypectomy between 2007 and 2018. In all four cohorts, we collected detailed data on patients' demographics, endoscopic history, polyp features, and lifestyle factors at polypectomy. The outcome, incidence of PPCRC, was assessed by biennial follow-up questionnaires in the NHS/HPFS cohorts, and through linkage to the Massachusetts Cancer Registry in the MGB cohort. In all four cohorts, individuals who were diagnosed with CRC or died before baseline or within six months after baseline were excluded. We used Cox regression to calculate the hazard ratio (HR), 95% confidence interval (CI) and assessed the discrimination using C-statistics and reclassification using the Net Reclassification Improvement (NRI).

Findings

During a median follow-up of 12.8 years (interquartile range (IQR): 9.3, 16.7) and 5.1 years (IQR: 2.7, 7.8) in the NHS/HPFS and MGB cohorts, we documented 220 and 241 PPCRC cases, respectively. We identified a PPCRC risk score based on 11 predictors. In the validation cohort, the PPCRC risk score showed a strong association with PPCRC risk (HR for high vs. low, 3.55, 95% CI, 2.59-4.88) and demonstrated a C-statistic (95% CI) of 0.75 (0.70-0.79), and was discriminatory even within the low- and high-risk polyp groups (C-statistic, 0.73 and 0.71, respectively) defined by the current colonoscopy surveillance recommendations, leading to a NRI of 45% (95% CI, 36-54%) for patients with PPCRC.

Interpretation

We developed and validated a risk stratification model for PPCRC that may be useful to guide tailored colonoscopy surveillance. Further work is needed to determine the optimal surveillance interval and test the added value of other predictors of PPCRC beyond those included in the current study, along with implementation studies.

Funding

US National Institutes of Health, the American Cancer Society, the South-Eastern Norway Regional Health Authority, the Deutsche Forschungsgemeinschaft.

Intestinal topical lidocaine spray improves the efficacy and safety of endoscopic sigmoid polypectomy

BACKGROUND AND AIMS

Endoscopic polypectomy can prevent colorectal cancer. Adequate surgical field visualization is crucial to complete resection. To prevent visual field loss caused by intestinal peristalsis, we investigated the efficacy and safety of topical lidocaine spraying during the endoscopic sigmoid polypectomy (ESP).

METHODS

Retrospective analysis was performed on 100 ESP patients admitted from July 2021 to October 2021, among which 50 patients received lidocaine (case group) and other 50 patients received normal saline (control group). Lidocaine or saline was sprayed on the colonic mucosa within 5 cm above and below the polyps before polypectomy. The en-bloc resection rate (EBRR) and complete resection rate (CRR) were primarily evaluated. Secondary outcomes included EBRR for polyps located in the 5-11 o'clock position, sigmoid colon peristalsis frequency, degree of exposure to the surgical field, operative times, and adverse events.

RESULTS

There were no significant differences in the basic demographic characteristics between the two groups. EBRR and CRR in the case group were 72.9% and 95.8%, and in the control group were 53.3% and 91.1%, respectively. The EBRR of sigmoid polyps located at the 5-11 o'clock positions was significantly higher in the case group (82.8%) than in the control group (56.7%) (P = 0.03). Sigmoid colonic peristalsis was significantly inhibited after lidocaine spraying (P < 0.01). There was no statistical difference in the operative times and adverse event rates between the two groups.

CONCLUSION

Topical spraying lidocaine around polyps can safely and effectively reduce intestinal peristalsis, thus improving the EBRR of sigmoid polypectomy.