Risk of Metachronous High-Risk Adenomas and Large Serrated Polyps in Individuals With Serrated Polyps on Index Colonoscopy: Data From the New Hampshire Colonoscopy Registry

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.

Emerging and under-recognised patterns of colorectal carcinoma morphologies: a comprehensive review

While the overwhelming majority of colorectal carcinomas (CRC) are diagnosed as adenocarcinoma not otherwise specified, there are numerous under-recognised morphologic patterns of CRC. These patterns are recognised by the WHO, appear in reporting manuals for the American Joint Committee of Cancer, and/or are listed on synoptic reports, while many other variants have either fallen out of favour or are emerging as future bona fide patterns. Herein, we discuss 13 variants: serrated adenocarcinoma, micropapillary adenocarcinoma, medullary carcinoma, neuroendocrine carcinoma, mucinous adenocarcinoma, signet-ring cell carcinoma, adenosquamous carcinoma, adenoma-like adenocarcinoma, lymphoglandular complex-like CRC, carcinoma with sarcomatoid components, cribriform-comedo-type adenocarcinoma, undifferentiated carcinoma and low-grade tubuloglandular adenocarcinoma. The purpose of this review is to scrutinise these variants by assessing their clinical characteristics, morphologic cues, as well as pitfalls, and address their prognostic significance. Our analysis aims to bring clarity and updated understanding to these variants, offering valuable insights for pathologists. This contributes to more nuanced CRC diagnosis and treatment strategies, highlighting the importance of recognising a broad spectrum of morphologic patterns in CRC.

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.

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.

Age-Based Comparative Analysis of Colorectal Cancer Colonoscopy Screening Findings

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

Multitarget Stool RNA Test for Colorectal Cancer Screening

Importance

Noninvasive tests for colorectal cancer screening must include sensitive detection of colorectal cancer and precancerous lesions. These tests must be validated for the intended-use population, which includes average-risk individuals 45 years or older.

Objective

To evaluate the sensitivity and specificity of a noninvasive, multitarget stool RNA (mt-sRNA) test (ColoSense) test compared with results from a colonoscopy.

Design, Setting, and Participants

This phase 3 clinical trial (CRC-PREVENT) was a blinded, prospective, cross-sectional study to support a premarket approval application for a class III medical device. A total of 8920 participants were identified online using social media platforms and enrolled from June 2021 to June 2022 using a decentralized nurse call center. All participants completed the mt-sRNA test, which incorporated a commercially available fecal immunochemical test (FIT), concentration of 8 RNA transcripts, and participant-reported smoking status. Stool samples were collected prior to participants completing a colonoscopy at their local endoscopy center. The mt-sRNA test results (positive or negative) were compared with index lesions observed on colonoscopy. Over the course of 12 months, individuals 45 years and older were enrolled in the clinical trial using the decentralized recruitment strategy. Participants were enrolled from 49 US states and obtained colonoscopies at more than 3800 different endoscopy centers.

Main Outcomes and Measures

The primary outcomes included the sensitivity of the mt-sRNA test for detecting colorectal cancer and advanced adenomas and the specificity for no lesions on colonoscopy.

Results

The mean (range) age of participants was 55 (45-90) years, with 4% self-identified as Asian, 11% as Black, and 7% as Hispanic. Of the 8920 eligible participants, 36 (0.40%) had colorectal cancer and 606 (6.8%) had advanced adenomas. The mt-sRNA test sensitivity for detecting colorectal cancer was 94%, sensitivity for detecting advanced adenomas was 46%, and specificity for no lesions on colonoscopy was 88%. The mt-sRNA test showed significant improvement in sensitivity for colorectal cancer (94% vs 78%; McNemar P = .01) and advanced adenomas (46% vs 29%; McNemar P < .001) compared with results of the FIT.

Conclusions and Relevance

In individuals 45 years and older, the mt-sRNA test showed high sensitivity for colorectal neoplasia (colorectal cancer and advanced adenoma) with significant improvement in sensitivity relative to the FIT. Specificity for no lesions on colonoscopy was comparable to existing molecular diagnostic tests.

Trial Registration

ClinicalTrials.gov Identifier: NCT04739722.

Higher Serrated Polyp Detection Rates Are Associated With Lower Risk of Postcolonoscopy Colorectal Cancer: Data From the New Hampshire Colonoscopy Registry

INTRODUCTION

We used New Hampshire Colonoscopy Registry data to examine the association between postcolonoscopy colorectal cancer (PCCRC) and sessile serrated detection rates (SSLDRs).

METHODS

We included patients with either a colonoscopy or a CRC diagnosis in the NH State Cancer Registry. PCCRC was any CRC diagnosed ≥ 6 months after index examination.

RESULTS

Of 26,901 patients, 162 were diagnosed with PCCRC. The hazard ratio for PCCRC was lowest for patients whose endoscopists had the highest SSLDR quintile (≥6%) (hazard ratio 0.29; 95% confidence interval 0.16-0.50).

DISCUSSION

Endoscopists with higher SSLDRs had lower risks of PCCRC. These data validate SSLDR as a clinically relevant quality measure.

Trends in pathology diagnoses during 10 years of a colorectal cancer screening programme

AIMS

We report pathology findings from the first 10 years of the faecal-occult blood-based Northern Ireland Bowel Cancer Screening Programme, presenting summary data and trends in pathology diagnoses and clinicopathological features of screen-detected cancers.

METHODS AND RESULTS

Data were analysed from a comprehensive polyp-level pathology database representing all endoscopy specimens from programme inception in 2010 until 2021. A total of 9800 individuals underwent 13 472 endoscopy procedures, yielding 25 967 pathology specimens and 32 119 diagnoses. Index specimen diagnoses (4.1%) and index colonoscopies (10.4%) yielded a diagnosis of colorectal cancer, representing 1045 cancers from 1020 individuals (25 with synchronous cancers). A further 13 index cancers were identified via computed tomography colonography; 65.3% of cancer diagnoses were in males; 41.7% were stage I, 23.1% stage II, 25.8% stage III and 1.8% stage IV (7.6% unstaged). Of 233 pT1 cancers diagnosed within local excision specimens, 79 (33.9%) had completion surgery. Ten-year trends showed a steady decline in the proportion of index colonoscopies that yielded a diagnosis of cancer (14.7% in year 1; 4.8% in year 11) or advanced colorectal polyp. There was a strong upward trend in diagnoses of sessile serrated lesions, which overtook hyperplastic polyps in proportions of total index diagnoses by the end of the study time-frame (8.7% compared to 8.5%).

CONCLUSIONS

Over the first 10 years of a population colorectal cancer screening programme, 'real world' pathology data demonstrate success in the form of reduced diagnoses of cancer and advanced colorectal polyp with passage of successive screening rounds. Interesting trends with respect to serrated polyp diagnoses are also evident, probably related to pathologist and endoscopist behaviour.

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.

What do 'false-positive' stool tests really mean? Data from the New Hampshire colonoscopy registry

We utilized the population-based New Hampshire Colonoscopy Registry to calculate false discovery rates (FDR) and positive predictive values (PPVs) using three 'positive' colonoscopy definitions. Understanding the frequency of meaningful 'true positive' mt-sDNA and Fecal Immunochemical Test (FIT) results can optimize the use of these colorectal cancer (CRC) screening tests. We calculated FDR (positive stool test followed by negative colonoscopy divided by all positive stool tests) and PPV for mt-sDNA and FIT cohorts using the following definitions: 1) DeeP-C Study (CRC, adenomas/serrated polyps ≥ 1 cm, villous/High Grade Dysplasia); 2) < 10 year US Multi-Society Task Force (USMSTF) follow-up: DeeP-C findings & ≥1 sessile serrated polyps (SSPs) < 1 cm (with/without dysplasia) or ≥ 1 tubular adenomas < 1 cm. 3) Clinically Significant: DeeP-C + USMSTF + clinically significant serrated polyps: traditional serrated adenomas, SSPs, hyperplastic polyps (HPs) > 1 cm, and 5-9 mm proximal HPs. The sample included 549 mt-sDNA + and 410 FIT + and patients (mean age 66.4, 43.0% male). Using the most limited definition of positive colonoscopy, DeeP-C, FDR was 71.9% for mt-sDNA + and 81.7% for FIT +. Using the USMSTF definition, FDR decreased substantially: mt-sDNA+:33.2% and FIT+:47.6%. Adding all CSSPs resulted in the lowest FDR: mt-sDNA+:32.2% and FIT+:47.1%. Decreasing FDRs corresponded to increasing PPVs: mt-sDNA+:28.1% and FIT+:18.3% (DeeP-C definition) and mt-sDNA+:67.8% and FIT+:52.9% (DeeP-C + USMSTF + CSSP) (Table 1). FDRs decreased substantially when the definition of positive exams included all significant precancerous findings. These data present a comprehensive understanding of false positive outcomes at colonoscopies following positive stool tests, which to our knowledge is the first such analysis.

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 of total metachronous advanced neoplasia at surveillance colonoscopy after detection of serrated lesions: a matched case-cohort study

BACKGROUND : Serrated lesions are potential colorectal cancer precursors. This study evaluated the presence of total metachronous advanced neoplasia (T-MAN) at follow-up in patients with index serrated lesions compared with a matched cohort without serrated lesions. METHODS : Patients aged 45-74 years with serrated lesions were matched 2:1 by sex, age, synchronous polyps, and timing of index colonoscopy, to patients without serrated lesions. The primary outcome was T-MAN (advanced adenoma or high-risk serrated lesion) at follow-up. Secondary outcomes included presence of T-MAN stratified by synchronous polyps and serrated lesion characteristics. RESULTS : 1425 patients were included (475 patients, 642 serrated lesions; 950 controls; median follow-up 2.9 versus 3.6 years). Patients with serrated lesions had greater risk of T-MAN than those without (hazard ratio [HR] 6.1, 95 %CI 3.9-9.6). Patients with serrated lesions and high-risk adenoma (HRA) had higher risk of T-MAN than those with HRA alone (HR 2.6, 95 %CI 1.4-4.7); similarly, patients with serrated lesions plus low-risk adenoma (LRA) had higher risk than those with LRA alone (HR 7.0, 95 %CI 2.8-18.4), as did patients with serrated lesions without adenoma compared with no adenoma (HR 14.9, 95 %CI 6.5-34.0). Presence of proximal sessile serrated lesion (SSL; HR 9.3, 95 %CI 5.4-15.9), large SSL (HR 17.8, 95 %CI 7.4-43.3), and proximal large SSL (HR 25.0, 95 %CI 8.8-71.3), but not distal SSL, were associated with greater risk for T-MAN. CONCLUSION : Patients with serrated lesions had higher risk for T-MAN regardless of synchronous adenomas. Patients with serrated lesions and HRA, and those with large or proximal SSLs, were at greatest risk.

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

Background

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

Methods

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

Findings

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

Interpretation

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

Funding

None.

Using New Hampshire Colonoscopy Registry data to assess United States and European post-polypectomy surveillance guidelines

BACKGROUND

Our goal was to compare the updated European Society of Gastrointestinal Endoscopy (ESGE) and United States Multi-Society Task Force on Colorectal Cancer (USMSTF) high risk groups in predicting metachronous advanced neoplasia on first follow-up colonoscopy and long-term colorectal cancer (CRC).

METHODS

We compared advanced metachronous neoplasia risk (serrated polyps ≥ 1 cm or with dysplasia, advanced adenomas [≥ 1 cm, villous, high grade dysplasia], CRC) on first surveillance colonoscopy in patients with high risk findings according to ESGE versus USMSTF guidelines. We also compared the positive and negative predictive values (PPV, NPV) of both guidelines for metachronous neoplasia.

RESULTS

The risk for metachronous neoplasia in our sample (n = 20 458) was higher in the high risk USMSTF (3 year) (13.6 %; 95 %CI 12.3-14.9) and ESGE groups (13.6 %; 95 %CI 12.3-15.0) compared with the lowest risk USMSTF (5.1 %; 95 %CI 4.7-5.5; P < 0.001) and ESGE categories (6.3 %; 95 %CI 6.0-6.7; P < 0.001), respectively. Adding other groups such as USMSTF 5-10-year and 3-5-year groups to the 3-year category resulted in minimal change in the PPV and NPV for metachronous advanced neoplasia. High risk ESGE (hazard ratio [HR] 3.03, 95 %CI 1.97-4.65) and USMSTF (HR 3.07, 95 %CI 2.03-4.66) designations were associated with similar long-term CRC risk (CRC per 100 000 person-years: USMSTF 3-year group 3.54, 95 %CI 2.68-4.68; ESGE high risk group: 3.43, 95 %CI 2.57-4.59).

CONCLUSION

Performance characteristics for the ESGE and USMSTF recommendations are similar in predicting metachronous advanced neoplasia and long-term CRC. The addition of risk groups, such as the USMSTF 5-10-year and 3-5-year groups to the USMSTF 3-year category did not alter the PPV or NPV significantly.

Risk of Metachronous Neoplasia with High-Risk Adenoma and Synchronous Sessile Serrated Adenoma: A Systematic Review and Meta-Analysis

Background: Sessile serrated adenomas are important precursors to colorectal cancers and account for 30% of colorectal cancers. The United States Multi-Society Task Force recommends that patients with sessile serrated adenomas undergo surveillance similar to tubular adenomas. However, the risk of metachronous neoplasia when the high-risk adenoma co-exists with sessile serrated adenomas is poorly defined. Objective: To examine the risk of metachronous neoplasia in the presence of high-risk adenoma and synchronous sessile serrated adenomas compared with isolated high-risk adenoma. Data sources: PubMed, Embase, Scopus, Cochrane Library. Study selection: A literature search for studies evaluating the risk of metachronous neoplasia in patients with high-risk adenoma alone and those with synchronous high-risk adenoma and sessile serrated adenomas during surveillance colonoscopy was conducted on online databases. Main outcome measures: The primary outcome of interest was the presence of metachronous neoplasia. Results: Of the 1164 records reviewed, six (four retrospective and two prospective) studies met inclusion criteria with 2490 patients (1607 males, mean age 59.98 ± 3.23 years). Average follow-up was 47.5 ± 12.5 months. There were 2068 patients with high-risk adenoma on index colonoscopy and 422 patients with high-risk adenoma and synchronous sessile serrated adenomas. Pooled estimates showed a significantly elevated risk for metachronous neoplasia in patients with high-risk adenoma and synchronous sessile serrated adenomas (pooled odds ratio 2.21; 95% confidence intervals 1.65-2.96; p < 0.01). There was low heterogeneity (I² = 11%) among the studies. Sensitivity analysis of the prospective studies alone also showed elevated risk of metachronous neoplasm (pooled odds ratio 2.56; 95%, confidence intervals 1.05-6.23; p = 0.04). Limitations: Inclusion of a small number of retrospective studies. Conclusions: The presence of high-risk adenomas and synchronous sessile serrated adenomas is associated with an increased risk of metachronous neoplasia. Therefore, shorter surveillance intervals may be considered in patients with high-risk adenoma and synchronous sessile serrated adenomas compared to those with high-risk adenoma alone.

Rates of synchronous advanced neoplasia and colorectal cancer in patients with colonic serrated lesions

BACKGROUND AND AIMS

Serrated lesions (SL) have been associated with significant risks of developing colorectal cancer (CRC). Data on synchronous findings after SL detection during colonoscopy is limited. Study aim was to evaluate the rate of synchronous advanced neoplasia (S-AN) and synchronous CRC (S-CRC) in colonoscopies where SLs were detected.

METHODS

We conducted a retrospective study of screening aged patients 45-74year with colorectal SL (sessile serrated polyp [SSP] or traditional serrated adenoma [TSA]) detected during an elective colonoscopy. Primary outcome was risk of S-AN in patients with SL. Secondary outcomes included risk of S-AN or S-CRC stratified by SL characteristics.

RESULTS

The study included 1262 patients with 1649 SLs (1214 with SSPs and 48 with TSAs). 47.2% were female and 22.9% of exams were screening colonoscopies, 48.2% surveillance, 28.9% diagnostic. The overall rates of S-AN and S-CRC were 15.1% and 1.3%, respectively. Presence of SSPs ≥ 10 mm was associated with higher rates of S-AN, (18.1 vs. 12.2%, Odds-Ratio [OR] = 1.61 [95% Confidence Interval [CI] 1.17-2.23], p = 0.004). SSP dysplasia was predictive of S-AN, (30.3 vs 14.1%, OR = 2.68 [95%CI 1.24-5.78], p = 0.012) but not S-CRC. SSP number (≥ 3) and location (proximal) were not predictors of S-AN or S-CRC.

CONCLUSION

Patients with SLs are at high-risk of S-AN and S-CRC. Findings of SSPs ≥ 10 mm and SSP dysplasia are associated with high-risk of S-AN. Endoscopists should exercise heightened vigilance for synchronous findings when SLs are detected, especially SSPs ≥ 10 mm or when bowel preparation is suboptimal. Studies contrasting synchronous risk of other polyp types are needed to confirm these results.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Third Asia-Pacific consensus recommendations on colorectal cancer screening and postpolypectomy surveillance

The Asia-Pacific region has the largest number of cases of colorectal cancer (CRC) and one of the highest levels of mortality due to this condition in the world. Since the publishing of two consensus recommendations in 2008 and 2015, significant advancements have been made in our knowledge of epidemiology, pathology and the natural history of the adenoma-carcinoma progression. Based on the most updated epidemiological and clinical studies in this region, considering literature from international studies, and adopting the modified Delphi process, the Asia-Pacific Working Group on Colorectal Cancer Screening has updated and revised their recommendations on (1) screening methods and preferred strategies; (2) age for starting and terminating screening for CRC; (3) screening for individuals with a family history of CRC or advanced adenoma; (4) surveillance for those with adenomas; (5) screening and surveillance for sessile serrated lesions and (6) quality assurance of screening programmes. Thirteen countries/regions in the Asia-Pacific region were represented in this exercise. International advisors from North America and Europe were invited to participate.

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.

[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.

Synchronous occurrence of different polyp types during colonoscopy

BACKGROUND AND AIMS

The general probabilities of finding different types of hyperplastic or neoplastic colon lesions clustering in the same patient are unknown. We hypothesised that a systematic analysis of polyp clustering would reveal a high frequency of different concurrent types and that such clustering would be influenced by the underlying histopathology of the individual polyps.

METHODS

Using an electronic database of histopathologic records, a cross-sectional study of 2,910,174 colonoscopies evaluated the concordant occurrence of hyperplastic and neoplastic mucosal lesions.

RESULTS

Amongst patients harbouring any colon polyp, one can expect to find another histopathologic type in about 22%. Being the most prevalent type of polyp, tubular adenoma was the most common type of colonic polyp to be associated with other lesions. For instance, 31% of all colonoscopies with sessile serrated adenomas or hyperplastic polyps also revealed tubular adenomas. Hyperplastic polyp, the second most prevalent type of colonic polyp, was also the second most common type of polyp to be found associated with other types of neoplasia. For instance, 25% of all colonoscopies with sessile serrated adenomas and 31% of those with tubular adenomas also revealed hyperplastic polyps.

CONCLUSIONS

Different types of colon polyps commonly coincide in individual patients. The present set of data from a large nationwide database may provide guidance for the endoscopist of what variety in colon polyps to expect during colonoscopy.

Risk of total metachronous advanced neoplasia in patients with both small tubular adenomas and serrated polyps

BACKGROUND AND AIMS

The impact of concomitant small serrated polyps (SPs) on the risk of subsequent neoplasia when small tubular adenomas (TAs) are found is uncertain.

METHODS

Patients who on index colonoscopy had ≤2 TAs of <10 mm in size in isolation were compared with those with concomitant ≤2 small-sized SPs. SP was inclusive of polyps described by pathology as sessile serrated lesions (SSLs) or proximal hyperplastic polyps (HPs) <10 mm in size. The primary endpoint was the rate of total metachronous advanced neoplasia (T-MAN) compared among the TAs in the isolation group and the groups inclusive of SPs (SSLs or proximal HPs).

RESULTS

For patients with TAs and small SPs found concomitantly, the rate of T-MAN was 9.6% (24/251), which was significantly higher than the rate of T-MAN in patients with isolated small TAs (5.2% [59/1138], P = .011). Within the concomitant SP cohort, the rate of T-MAN in the proximal HP subgroup remained significantly increased (9% [19/212]) compared with the isolated small TA group (P = .037).

CONCLUSIONS

When small TAs are found concomitantly with small SPs, there is an increase in the rate of T-MAN in comparison with isolated TAs. This increase in T-MAN also occurs when small TAs are found in conjunction with small proximal HPs. The presence of concomitant small SPs should be considered in determining surveillance intervals when small TAs are identified in colonoscopy screening programs.

Predictors of Incident Serrated Polyps: Results from a Large Multicenter Clinical Trial

BACKGROUND

Serrated polyps (SP) are important colorectal cancer precursors, yet their epidemiology is incompletely understood. We measured risk factors for incident sessile-serrated lesions (SSL) and microvesicular (MVHP) and goblet-cell rich (GCHP) hyperplastic polyp subtypes.

METHODS

We conducted a cohort study of patients undergoing colonoscopic surveillance nested within a chemoprevention trial. Outcomes of interest were ≥1 SPs, including SSLs, MVHPs, and GCHPs specifically. Multivariable generalized estimating equation models were used to estimate adjusted risk ratios (RR) and 95% confidence intervals (CI) for different polyp types.

RESULTS

Among 2,102 participants, a total of 1,615 SPs (including 212 SSLs) were found among 758 participants during follow-up. Prior history of SPs was strongly associated with subsequent occurrence of SPs. There was no apparent association between age, sex, or education and risk of SPs. Black participants were at lower risk of SSLs and MVHPs, but higher risk of GCHPs compared with white participants [RR, 0.40; 95% CI, 0.16-0.99); RR, 0.63 (95% CI, 0.42-0.96); and RR, 1.83 (95% CI, 1.23-2.72) respectively]. Alcohol and smoking exposure were also associated with SPs, including hyperplastic polyp subtypes in particular.

CONCLUSIONS

In this prospective study, the risk of SP subtypes differed by race, alcohol, and smoking status, and prior history of SPs. Risk factor associations for SPs differ from risk factors for conventional adenomas, supporting the concept of etiologic heterogeneity of colorectal cancer.

IMPACT

These findings allow for better risk stratification of patients undergoing colorectal cancer screening and could inform screening test selection.

Sessile serrated lesions in patients with adenoma on index colonoscopy do not increase metachronous advanced adenoma risk

OBJECTIVES

Post-polypectomy surveillance intervals should be determined based on index colonoscopy findings. However, the risk of metachronous lesions, resulting from the coexistence of adenoma and sessile serrated lesions (SSLs), has rarely been addressed. We evaluated the impact of synchronous SSL on the risk of metachronous lesions within similar adenoma risk groups.

METHODS

We retrieved individuals with one or more adenomas on index colonoscopy in a single-center retrospective cohort and stratified them into four groups depending on the presence of SSL and low-risk/high-risk adenoma (LRA/HRA). Participants who underwent surveillance colonoscopies at least 12 months apart were included. We compared the risks of metachronous lesions including HRA, advanced adenoma (AA), or SSL within similar adenoma risk groups according to the presence of SSL.

RESULTS

Overall 4493 individuals were included in the analysis. The risk of metachronous HRA/AA was not significantly higher in the adenoma with SSL group compared with the adenoma without SSL group, irrespective of LRA (HRA, 6/86 vs. 231/3297, P = 1.00; AA, 0/86 vs. 52/3297, P = 0.64) or HRA (HRA, 11/64 vs. 240/1046, P = 0.36; AA, 3/64 vs. 51/1046, P = 1.00). However, the risk of metachronous SSL in individuals with synchronous SSL was higher than that in those without SSL for both LRA (15/86 vs. 161/3297, P < 0.001) and HRA groups (11/64 vs. 61/1046, P = 0.002).

CONCLUSION

The presence of synchronous SSL did not increase the risk of metachronous HRA/AA, compared with isolated adenoma, but increased the risk of metachronous SSL.

Surveillance Recommendation for Colonoscopy after Polypectomy

The incidence and mortality of colorectal cancer (CRC) have declined over the past several decades, largely due to improvement and uptake in screening, particularly with colonoscopy. The US Multi-Society Task Force on CRC published guidelines for surveillance after polypectomy in 2012, which were updated in 2020 with some important changes, and this review will provide an updated overview of evidence and outcomes of surveillance after polypectomy. Notable modifications to surveillance guidelines include increasing interval time between colonoscopies from 5 to 7 to 10 years for 1 to 2 low-risk adenomas (<10 mm) and from 3 years to 3 to 5 years when 3 to 4 low-risk adenomas are identified.

Cause, Epidemiology, and Histology of Polyps and Pathways to Colorectal Cancer

Colorectal cancer is the second leading cause of cancer-associated mortality, with a lifetime risk of approximately 4% to 5%. Colorectal cancer develops from the sequential acquisition of defined genetic mutations in the colonic epithelium. Tumorigenesis from normal tissue to cancer occurs largely through 3 pathways: the chromosomal instability pathway, the microsatellite instability pathway, and the sessile serrated pathway. Colorectal cancer incidence and mortality have decreased by approximately 35% since the beginning of screening programs in the 1990s, although other factors such as use of aspirin for coronary disease prevention and decreased smoking rates may also be important. In this review, we discuss the etiology, epidemiology, and histology of colorectal polyps and cancer.

ERBB2 Mutations as Potential Predictors for Recurrence in Colorectal Serrated Polyps by Targeted Next-Generation Sequencing

Background

Follow-up guidelines for serrated polyps (SPs) are mainly based on factors such as histology and size with limited evidence. The underlying genomic mechanism of SPs in relation to recurrence risks is utterly unknown.

Methods

We applied targeted next-generation sequencing (NGS) approach on two groups of SPs [polyp-relapsed SPs (PRSPs) vs. polyp-free SPs (PFSPs)] based on the surveillance outcomes to compare differences of DNA variants in 71 colorectal cancer-associated genes. A multicenter validation cohort was established longitudinally from 2016 to 2019 to confirm the relevant results.

Results

Among the 96 NGS samples, at least one mutant after filtration was detected in 90 samples (94%). Molecular profiling presented BRAF, KRAS, and APC as top 3 mutated genes. FBXW7, MSH2, and ERBB2 might be recurrence-relevant, while DMD, BRCA1, and BRCA2 might be negatively correlated with recurrence. Notably, ERBB2 mutants (R678Q and V842I) (n = 5) had higher risks of polyp recurrence than the wild types (n = 85), with a median polyp-free interval of 15 months compared to 26 months [P &lt; 0.001; hazard ratio (HR) = 4.9; 95% confidence interval (CI) = 1.9–12.8]. Furthermore, a multicenter cohort composed by 321 SPs verified that ERBB2-mutated SPs had increased risks of polyp recurrence (P &lt; 0.001; HR = 3.7; 95% CI = 2.3–6.0) and advanced neoplastic lesion (ANL) recurrence (P &lt; 0.001; HR = 10.0; 95% CI = 2.7–36.9) compared with wild-type SPs, respectively.

Conclusions

Our results are emphasizing that SP individuals with ERBB2 mutants are at higher risks of subsequent colorectal neoplasms. ERBB2 mutants might work as facilitated markers for prediction of high-risk SPs and might implicate a potential mechanism in the serrated pathway to colorectal carcinoma (CRC).

Cancer Risk in Patients With and Relatives of Serrated Polyposis Syndrome and Sporadic Sessile Serrated Lesions

INTRODUCTION

Patients with serrated polyposis syndrome (SPS) and their first-degree relatives (FDRs) have increased colorectal cancer (CRC) risk. Patients with sporadic sessile serrated lesion (SSL) have risk for progression to CRC. Yet familial risks of common extracolonic cancers and even CRC in these cohorts are poorly understood. Our aim was to examine cancer risk for patients with SPS and sporadic SSL and their close and more distant relatives using a large population database.

METHODS

Patients with SPS (n = 59) from hereditary patient registries were eligible for study. Sporadic SSL (n = 754) and sex- and age-matched normal colonoscopy controls (n = 1,624) were selected from clinical data linked to the Utah Population Database. Cox models adjusting for the number of relatives, degree of relatedness, and person-years at risk were used to estimate CRC, extracolonic, and any-site adenocarcinoma/carcinoma cancer risk in patients and their relatives.

RESULTS

Compared with controls, CRC risk was elevated 10-fold in patients with SPS (P = 0.04) and 5-fold in their FDRs (P = 0.001). Any-site adenoma/carcinoma risk was increased 2.6-fold in FDRs of patients with SPS. No elevated risks of other common extracolonic cancers were observed in SPS and family members. The FDRs, second-degree relatives, and third-degree relatives of patients with both SSL and adenomatous polyps exhibited a 50% increased CRC risk.

DISCUSSION

Patients with SPS and their FDRs have an increased CRC risk, confirming other reports. Interestingly, patients with SSL were noted to have an increased risk of prostate cancer. Relatives of individuals with both sporadic SSL and adenomas, irrespective of size or dysplasia on examination, may have an elevated CRC risk, suggesting closer colonoscopy surveillance in this population.

Serrated Polyps and the Risk of Metachronous Colorectal Advanced Neoplasia: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Surveillance recommendations for serrated polyps (SPs) are based on insufficient evidence. We aimed to evaluate the risk of metachronous advanced colorectal neoplasia (ACRN) associated with SPs.

METHODS

We searched all relevant studies published through August 2020 that examined the risk of SPs for developing metachronous lesions. We performed meta-analyses of the risk of metachronous ACRN or colorectal cancer (CRC) between patients with SPs (or sessile serrated lesions [SSLs]) alone and those with conventional adenomas alone, and between patients with synchronous SPs (or SSLs) and conventional adenomas and those with conventional adenomas alone.

RESULTS

Eleven studies with 1,079,315 patients were included in the meta-analysis. No significant differences in the risks of metachronous ACRN and CRC were found between the SPs alone and conventional adenomas alone groups (odds ratio [OR] [95% confidence interval [CI]]: ACRN, 0.70 [0.27-1.82]; CRC, 0.74 [0.47-1.14]). The risks were similar between SSLs alone and conventional adenomas alone (OR [95% CI]: ACRN, 0.91 [0.23-3.63]; CRC, 1.11 [0.42-2.97]). Significant heterogeneity was identified in these comparisons. Synchronous SPs (or SSLs) and high-risk adenomas (HRAs) had a higher risk of metachronous ACRN than HRAs alone (OR [95% CI]: SPs+HRAs, 1.64 [1.21-2.24]; SSLs+HRAs, 3.10 [1.92-4.99]); however, there was no difference in the risk between synchronous SPs (or SSLs) and low-risk adenomas and low-risk adenomas alone.

CONCLUSIONS

The results of this meta-analysis support the current guidelines, which recommend similar surveillance intervals for SSLs and conventional adenomas. Patients with synchronous SPs (or SSLs) and HRAs appear to be at an increased risk of metachronous ACRN, and further studies are needed to determine whether they require more intensive surveillance.

Small sessile serrated polyps might not be at a higher risk for future advanced neoplasia than low-risk adenomas or polyp-free groups

BACKGROUND

Polypectomy surveillance colonoscopy is recommended according to the risk stratification of initially removed polyps. This study aimed to evaluate the risk of advanced neoplasia following low-risk SSPs compared with that following LRAs and polyp-free groups.

MATERIALS AND METHODS

From September 2013 to August 2017, asymptomatic Koreans aged 50-75 years who underwent surveillance colonoscopy post-baseline colonoscopy were enrolled. The 1314 participants who met the study design criteria were stratified into three groups according to the presence of LRAs or low-risk SSPs. The rate of advanced neoplasia was then compared between groups by surveillance colonoscopy.

RESULTS

A total of 1314 participants were classified according to baseline colonoscopy findings: no polyp (n = 551), LRA (n = 707), and low-risk SSP (n = 56). All participants underwent surveillance colonoscopy after an average of 28.1 ± 8.7 months. The rate of advanced neoplasia at surveillance was not different between groups: no polyp group (13/551, 2.4%), LRA group (27/707, 3.8%), and low-risk SSP group (0/56, 0%). The LRA group exhibited a significantly higher rate of low- and high-risk polyps (47.5, 13.4%) than did the no polyp (35.6, 7.4%, p < .001, p = .001), but no significant differences to the low-risk SSP group (35.7, 7.1%, p = .117, p = .253), respectively.

CONCLUSIONS

Patients with low-risk SSPs were not at a higher risk of advanced neoplasia than LRA patients, even in the polyp-free group. We suggest that surveillance colonoscopy after the removal of low-risk SSPs is not required more often than for LRAs.

The Frontiers of Serrated Polyps

The serrated pathway of carcinogenesis has been the subject of intense investigation over the past 2 decades, but many gaps in our understanding still need to be resolved. Serrated polyp precursors include hyperplastic polyps, sessile serrated polyps, and traditional serrated adenomas. These are considered discrete entities, but there is emerging molecular data to suggest that they may be more closely related to each other than currently believed. The recent US Multi-Society Task Force surveillance guidelines for patients with serrated polyps are admittedly based on low quality evidence. In this brief review, we discuss the limitations in endoscopic detection and pathologic interpretation of serrated polyps and the implications of these diagnostic difficulties on risk prediction and postpolypectomy surveillance recommendations.

Hp-Positive Chinese Patients Should Undergo Colonoscopy Earlier and More Frequently: The Result of a Cross-Sectional Study Based on 13,037 Cases of Gastrointestinal Endoscopy

BACKGROUND

In China, the prevalence and mortality of colorectal cancer (CRC) have always been high, and more than 95% of CRC cases have evolved from colorectal polyps (CPs), especially adenoma. Early detection and treatment of CPs through colonoscopy is essential to reduce the incidence of CRC. Helicobacter pylori (Hp) is regarded as a risk factor for gastritis and gastric cancer and may also be a risk factor for CPs and CRC. However, few studies based on vast clinical cases exist in China to clarify whether Hp is a risk factor for CPs and CRC, and whether Hp-positive patients need to undergo colonoscopy checks earlier. This article attempts to make up for that deficiency.

METHOD

This cross-sectional study was conducted based on 13,037 patients without a treatment history of Hp who underwent their first gastroscopy and colonoscopy simultaneously at The First Affiliated Hospital of Zhejiang Chinese Medical University from January 2018 to December 2019. Pearson χ2 test and logistic regression were used to determine whether Hp is a risk factor for CPs and CRC. Multifactor analysis of variance was used to define the impact of Hp on CPs prevalence with different ages, sexes.

RESULTS

For Chinese individuals, Hp is a risk factor for CPs and CRC. The odds ratio (OR) value are 1.228 (95% CI, 1.130 to 1.336) and 1.862 (95% CI 1.240-2.796), respectively. Hp-positive patients have a higher probability of multiple or large intestinal polyps. However, Hp infection does not increase the incidence of adenomas, nor does it affect the pathological type of adenomas. The OR of Hp on the risk of CPs was 1.432 (95%CI 1.275-1.608) for males but increased to 1.937 (95%CI 1.334-2.815) for those aged 35 to 40. For females, the results were similar.

CONCLUSIONS

For the Chinese, Hp is a risk factor for CPs and CRC (OR>1); the infection of Hp increased CPs risk in Chinese of all ages, especially aged 35-40, suggesting that Hp-positive patients should undergo colonoscopy frequently.

Risk stratification for colorectal cancer in individuals with subtypes of serrated polyps

OBJECTIVE

The longitudinal risk of colorectal cancer (CRC) associated with subtypes of serrated polyps (SPs) remains incompletely understood.

DESIGN

This community-based, case-control study included 317 178 Kaiser Permanente Northern California members who underwent their first colonoscopy during 2006-2016. Nested within this population, we identified 695 cases of CRC and 3475 CRC-free controls (matched 5:1 to cases for age, sex and year of colonoscopy). Two expert pathologists reviewed the tissue slides of all SPs identified on the first colonoscopy and reclassified them to sessile serrated lesions (SSLs), hyperplastic polyps (HPs) and traditional serrated adenomas. SPs with borderline characteristics of SSLs but insufficient to make a definitive diagnosis were categorised as unspecified SPs. The association with development of CRC was assessed using multivariable logistic regression.

RESULTS

Compared with individuals with no polyp, the adjusted ORs (aORs) for SSL alone or with synchronous adenoma were 2.9 (95% CI: 1.8 to 4.8) and 4.4 (95% CI: 2.7 to 7.2), respectively. The aORs for SSL with dysplasia, large proximal SSL,and small proximal SSL were 10.3 (95% CI: 2.1 to 50.3), 12.8 (95% CI: 3.5 to 46.9) and 1.9 (95% CI: 0.8 to 4.7), respectively. Proximal unspecified SP also conferred an increased risk (aOR: 5.8, 95% CI: 2.2 to 15.2). Women with SSL were associated with higher risk (aOR: 4.4; 95% CI: 2.3 to 8.2) than men (aOR: 1.7; 95% CI: 0.8 to 3.8).

CONCLUSION

Increased risk of CRC was observed in individuals with SSLs, particularly large proximal ones or with dysplasia, supporting close endoscopic surveillance. Proximal unspecified SPs were also associated with increased risk of CRC and should be managed as SSLs.

Association between baseline hyperplastic polyps and metachronous serrated lesions

BACKGROUND AND AIMS

Some data suggest that individuals with numerous, <10-mm, rectosigmoid hyperplastic polyps (HPs) are at average risk for the development of metachronous advanced adenomatous neoplasia. Guidelines suggest that these individuals do not need surveillance colonoscopy and should be followed akin to individuals with a normal colonoscopy. Less is known of the risk of metachronous neoplasia because of ≥1 HPs <10 mm proximal to the sigmoid colon. We compared the risk of metachronous neoplasia between individuals with small HPs and those with normal colonoscopy, specifically addressing the impact of location and number of HPs on risk.

METHODS

Colonoscopy and pathology reports from patients with ≥2 colonoscopies between 2004 and 2014 were reviewed. Exclusions included inpatients; age <40 or >75 years; and family or personal history of colorectal cancer, inflammatory bowel disease, previous colorectal surgery, or a previous colonoscopy with any adenoma, sessile serrated lesion (SSL), or HP ≥10 mm. The risk of metachronous neoplasia, including adenomas and SSLs, was compared in individuals with a normal index colonoscopy and those with <10-mm HPs stratified by location and number of HPs.

RESULTS

After exclusion, 1795 patients were included. At index colonoscopy, 82% (n = 1469) had a normal examination, 12% (219) had only 1, and 6% (107) had between 2 and 9 HPs <10 mm. Compared with patients with a normal index colonoscopy, patients with a proximal (odds ratio, 3.82; 95% confidence interval, 1.77-7.53) or distal HP (odds ratio, 2.23; 95% confidence interval, 1.18-4.00) had an increased risk of metachronous SSLs but not adenomas.

CONCLUSIONS

Patients with small proximal and distal HPs are at increased risk of metachronous SSLs. These preliminary findings warrant consideration during surveillance recommendations and future studies in larger cohorts.

Features associated with high-risk sessile serrated polyps at index and follow-up colonoscopy

BACKGROUND AND AIM

Clinically significant serrated polyps are precursors of colorectal cancers, with features considered high risk including size ≥10 mm, dysplasia, and presence of synchronous conventional adenoma. While these features have been described in cohorts undergoing screening colonoscopy, there is little information regarding the prevalence and patient characteristics associated with high-risk sessile serrated polyps (SSPs) in those undergoing surveillance colonoscopy.

METHODS

Polyp pathology at the index and first follow-up colonoscopy performed between 2004 and 2019 were examined in patients enrolled in a surveillance program because of an index finding of adenoma and/or SSP. Demographics and pathology features for SSP were compared between the colonoscopies.

RESULTS

Of 6297 patients undergoing index colonoscopy, 2035 underwent follow-up colonoscopy after 3.3 years (interquartile range 2.1-4.8 years). The proportion with SSP decreased from 7.6% at index to 5.0% at follow-up (P < 0.001); however, the proportion of SSPs that were considered high risk was not different between the colonoscopies (62.8% vs 62.4%). Female gender was associated with the presence of high-risk SSP at index colonoscopy (odds ratio [OR] 1.62, 95% confidence interval [CI] 1.28-2.06), while age ≥75 years (OR 3.38, 95% CI 1.67-6.81) and previous high-risk SSP (OR 9.40, 95% CI 4.23-20.88) were independently associated with high-risk SSP at follow-up.

CONCLUSIONS

The prevalence of SSP falls by one-third at first follow-up colonoscopy although the proportion of SSP with high-risk features remains the same. While females were more likely to have a high-risk SSP at the index colonoscopy, those at greatest risk for high-risk SSP at follow-up colonoscopy were age >75 years and an index high-risk SSP.

Sessile serrated lesion detection rates during average risk screening colonoscopy: A systematic review and meta-analysis of the published literature

Background and study aims  Sessile serrated lesion (SSL) detection rate has been variably reported and unlike adenoma detection rate (ADR) is not currently a quality indicator for screening colonoscopy. Composite detection rates of SSL in patients undergoing average risk screening colonoscopy are not available. Methods  Electronic database search (Medline, Embase and Cochrane) was conducted for studies reporting detection rates of serrated polyps (SSL, Hyperplastic polyp, traditional serrated adenoma) among average risk subjects undergoing screening colonoscopy. Primary outcomes were pooled SDR (SSL detection rate) and proximal serrated polyp detection rate (PSPDR). Pooled proportion rates were calculated with 95 %CI with assessment of heterogeneity (I ² ). Publication bias, regression test and 95 %prediction interval were calculated. Results  A total of 280,370 screening colonoscopies among average risk subjects that were eligible with 48.9 % males and an average age of 58.7 years (± 3.2). The pooled SDR was available from 16 studies: 2.5 % (1.8 %-3.4 %) with significant heterogeneity (I ²  = 98.66 %) and the 95 % prediction interval ranging from 0.6 % to 9.89 %. When analysis was restricted to large (n > 1000) and prospective studies (n = 4), SDR was 2 % (1.1 %-3.3 %). Pooled PSPDR was 10 % (8.5 %-11.8 %; 12 studies). There was evidence of publication bias ( P  < 0.01). Conclusion  Definitions of SSL have been varying over years and there exists significant heterogeneity in prevalence reporting of serrated polyps during screening colonoscopy. Prevalence rate of 2 % for SSL and 10 % for proximal serrated polyps could serve as targets while robust high-quality data is awaited to find a future benchmark showing reduction in colorectal cancer arising from serrated pathway.

The (ir)relevance of the abandoned criterion II for the diagnosis of serrated polyposis syndrome: a retrospective cohort study

The World Health Organization (WHO) recently updated the diagnostic criteria for serrated polyposis syndrome (SPS). One of the three previous diagnostic criteria (criterion II²⁰¹⁰) is now abandoned: ≥ 1 serrated polyp (SP) proximal to the sigmoid in a first-degree relative (FDR) of a patient with SPS. Individuals fulfilling this abandoned criterion now receive the same surveillance recommendations as all FDRs of patients with SPS. We aimed to compare the incidence of advanced neoplasia (AN) in FDRs with vs. without fulfillment of the abandoned criterion II²⁰¹⁰. We retrospectively recruited FDRs of patients with SPS who underwent a colonoscopy, and stratified them according to fulfilment of criterion II²⁰¹⁰ at baseline. Our primary and secondary outcomes were AN incidence during surveillance and at baseline, respectively. We included 224 FDRs of patients with SPS, of whom 36 (16%) fulfilled criterion II²⁰¹⁰ at baseline. One hundred and five underwent surveillance after baseline. Criterion II²⁰¹⁰-positive FDRs were at increased risk of AN, both during surveillance (hazard ratio 8.94, 95% CI 2.15-37.1, p = .003) as well as at baseline (adjusted odds-ratio 9.30, 95% CI 3.7-23.3, p < .001). FDRs of patients with SPS that underwent colonoscopy and fulfilled the abandoned criterion II²⁰¹⁰ for SPS diagnosis were at increased risk of AN at baseline and during surveillance in this small, retrospective cohort study. Our results should be interpreted with caution but suggest that adherence to surveillance recommendations for all FDRs of patients with SPS is important, especially for those that would have fulfilled the now abandoned criterion II²⁰¹⁰.

Predictors of Metachronous Risk Polyps After Index Colonoscopy

INTRODUCTION

Guidelines for surveillance after polypectomy are lacking in strong evidence. Our aim was to identify some precursors of colorectal cancer lesions at 3 years after polypectomy to improve stratification and surveillance programs.

METHODS

We included patients with high-risk lesions (HRLs), defined as advanced adenoma (AA), large serrated polyps (SPs), and multiplicity (≥3 of any adenomas/SPs). Data on age, sex, cardiovascular risk factors, pharmacological treatment, and the histological characteristics in each individual, and mutations in genes involved in the most advanced index polyp, were collected. Parameters independently associated with a metachronous HRL diagnosis were evaluated through univariate and multivariate analyses. The results are reported as odds ratios and 95% confidence intervals along with P values.

RESULTS

A total of 537 cases (median age: 60.7 years; 66% male) were included. Dyslipidemia and smoking correlated with metachronous HRLs. Multivariate logistic regression analysis showed that the presence of multiplicity with ≥3 polyps on the index colonoscopy was significantly associated with metachronous HRL, AA, proximal AA, and ≥3 polyps at 3 years. In addition, independent predictors of metachronous proximal AA were increasing age, female sex, and the loss of expression of the MLH1 protein.

DISCUSSION

Multiplicity was a strong predictor of HRLs at 3 years, although the inclusion of other clinical variables (age, sex, smoking status, and dyslipidemia) improves surveillance recommendations. Without these risk factors, the surveillance could be extended to 5 years; we propose examining the somatic expression of MHL1 in all patients.

Histopathological and epidemiological findings of colonoscopy screening in a population with an average risk of colorectal cancer in Kuwait

BACKGROUND

Colorectal cancer (CRC) is the second most common cancer in women and the third most common in men worldwide, with a significantly rising incidence in the Middle East region over the last few decades. This study investigates the histopathological and epidemiological characteristics of colonoscopic findings in a population with an average risk of CRC in Kuwait.

METHODS

In this study, 1,005 asymptomatic average-risk Kuwaiti adults aged over 40 years had their first colonoscopy screening during the 2015-2018 period. Data on lifestyle behaviors (cigarette smoking, alcohol consumption, and physical activity), body mass index (BMI), and comorbidities were routinely collected from these individuals. All colorectal polyps or masses were assessed for their site, size, and number and then resected and sent for histopathological examination.

RESULTS

The mean age of the participants was 54 years, and 52.2% were women. In screened individuals, the polyp detection rate, adenoma detection rate, and carcinoma detection rate were 43.8%, 27.7%, and 1.2%, respectively. Tubular, tubulovillous, and villous types of adenoma constituted 17.3%, 2.8%, and 1.3% of all screened participants. Neoplastic lesions, particularly in the proximal colon, were more common among men aged 40-49 years. Age of 70 years and older (OR: 9.6; 95% CI: 4.7-19.9; P < 0.001), male gender (OR: 1.6; 95% CI: 1.1-2.3; P = 0.011), increased BMI (OR: 1.05; 95% CI: 1.02-1.08; P = 0.001), and smoking (OR: 3.5; 95% CI: 2.3-5.4; P < 0.001) were the most significant independent risk factors for colorectal neoplasia.

CONCLUSIONS

The high adenoma detection rate (ADR) in Kuwaiti population calls for the establishment of a national programe for CRC screening. The higher ADR in those younger than 50 years calls for assessment of the threshold age at which to start screening.

Increased risk of metachronous large serrated polyps in individuals with 5- to 9-mm proximal hyperplastic polyps: data from the New Hampshire Colonoscopy Registry

BACKGROUND AND AIMS

Because data on metachronous risk for patients with index proximal 5- to 9-mm hyperplastic polyps (HPs) are limited, the clinical significance of these polyps is unclear. Conversely, published data suggest that sessile serrated polyps (SSPs), traditional serrated adenomas (TSAs), and large (≥1 cm) HPs are high-risk lesions requiring close surveillance. We used data from the New Hampshire Colonoscopy Registry (NHCR) to examine the risk of metachronous large SPs and advanced neoplasias (ANs) in patients with 5- to 9-mm proximal HPs.

METHODS

We included adults with at least 1 polyp resected at index colonoscopy and a surveillance examination 12 months or more after index. Outcomes were risk for metachronous large (≥1 cm) SPs and ANs (≥1 cm, villous elements, high-grade dysplasia, or colorectal cancer [CRC]). Individuals were hierarchically stratified by the most significant index SP. The risks for adults with proximal 5- to 9-mm HPs at index examination were compared with individuals with index findings of large (≥1 cm) HPs or any SSPs or TSAs, nonsignificant HPs (<1 cm in rectosigmoid or <5 mm anywhere in colon), high-risk adenomas (AAs or ≥3 adenomas, no SPs), and low-risk adenomas (no SPs). We present absolute and adjusted risks of metachronous polyps from a regression model that included age, sex, body mass index, smoking, previous polyp history, family history of CRC, year of diagnosis, endoscopist SP detection rates, and months to surveillance examination.

RESULTS

A total of 8560 NHCR participants were included (44.8% women; average age, 59.0 years; standard deviation, 9.1). Similar to those with large HPs or any SSPs/TSAs at index examination (odds ratio, 7.63; 95% confidence interval, 4.78-12.20), individuals with proximal 5- to 9-mm HPs had an elevated risk for metachronous large SPs (odds ratio, 4.77; 95% confidence interval, 2.54-8.94) as compared with adults with low-risk conventional adenomas.

CONCLUSIONS

NHCR data suggest that similar to adults with large HPs or any SSPs or TSAs at index examination, individuals with index 5- to 9-mm HPs proximal to the sigmoid are at an increased risk for metachronous large SPs. These novel data suggest that close surveillance intervals may be appropriate for patients with 5- to 9-mm proximal HPs.

Increased Risk of Colorectal Cancer in Individuals With a History of Serrated Polyps

BACKGROUND AND AIMS

Serrated polyp (SPs) are precursors to 20% to 30% of cases of colorectal tumors, but patients' long-term risk after removal of SPs is poorly understood. We investigated the risk of colorectal cancer (CRC) in individuals with a history of SPs.

METHODS

We performed a retrospective cohort study of Kaiser Permanente Northern California members who underwent colonoscopy from 2006 through 2016. Study participants were categorized based on the size and location of SPs. We used Cox proportional hazards modeling to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association of CRC diagnosed more than 1 year after colonoscopy, with polyp type vs no polyp after adjustment for year of colonoscopy, age, sex, race/ethnicity, and smoking history.

RESULTS

The study included 233,393 individuals, of whom 445 developed incident CRC. At 10 years, the cumulative incidence rates of CRC for individuals with no polyp, proximal small SPs, proximal large SPs, and distal SPs were 4.7 (95% CI, 4.0-5.6), 14.8 (95% CI, 9.0-24.3), 30.2 (95% CI, 13.2-68.4), and 5.9 (95% CI, 3.6-9.5) per 1000 persons, respectively. In patients with SPs, risk of CRC was not increased until 3 years or more after the first colonoscopy (HR for small proximal SPs 2.6; 95% CI, 1.7-3.9 and HR for large proximal SPs 8.0; 95% CI, 3.6-16.1). The presence of synchronous adenomas increased the risk for CRC (HR for proximal SPs with synchronous adenomas 4.0; 95% CI, 3.0-5.5 and HR for distal SPs with synchronous adenomas 2.4; 95% CI, 1.7-3.4).

CONCLUSIONS

In a retrospective analysis of a large cohort of individuals examined by colonoscopy, we found that risk of incident CRC increased in individuals with proximal SPs (large SPs in particular) 3 years or more after the colonoscopy. These findings support guidelines that recommend surveillance colonoscopy for individuals with SPs.