The presence of large serrated polyps increases risk for colorectal cancer

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.

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.

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.

Fourier transformation based texture analysis for differentiating between hyperplastic polyps and sessile serrated adenomas

Colorectal cancer (CRC) is the third most common type of cancer. One major pathway involved in the development of CRC is the serrated pathway. Colorectal polyps can be divided in benign, like small hyperplastic polyps and premalignant polyps, like the sessile serrated adenomas (SSA) that has a significant potential of malignant transformation. The morphological similarity between these types of polyp, not-infrequently raises diagnostic difficulties. This study aimed to morphologically differentiate between hyperplastic polyps (HP) and SSAs by using automated computerized texture analysis of Fourier transformed histological images. Thirty images of HP and 58 images of SSA were analyzed by computerized texture analysis. A fast Fourier transformation was applied to the images. The Fourier frequency plots were further transformed into gray level co-occurrence matrices and four textural variables were extracted: entropy, correlation, contrast, and homogeneity. Our study is the first to combine this type of analysis for automated classification of colonic neoplasia. The results were analyzed using statistical and neural network (NNET) classification models. The predictive values of these classifiers were compared. The statistical regression algorithm presented a sensitivity of 95% to detect the SSA and a specificity of 80% to detect the HP. The NNET analysis was superior to the statistical analysis displaying a classification accuracy of 100%. The results of this study have confirmed the hypothesis that Fourier based texture image analysis is helpful in differentiating between HP and SSA. RESEARCH HIGHLIGHTS: Colorectal polyps can be divided in benign, like hyperplastic polyps (HP) and premalignant, like the sessile serrated adenomas (SSA). There is a high morphologic similarity between these two types of polyp that not-infrequently raises diagnostic difficulties. The results of our morphometric analysis that were used to build a neural network based model of prediction of the polyp types, have a great clinical importance of identifying SSA polyps which have significant potential of malignant progression as compared to HP.

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Korean Guidelines for Postpolypectomy Colonoscopic Surveillance: 2022 revised edition

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

Korean guidelines for postpolypectomy colonoscopic surveillance: 2022 revised edition

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

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

Background and aims

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

Methods

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

Results

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

Conclusions

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

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

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

Risk of 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.

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.

Colorectal microbiota after removal of colorectal cancer

The colonic microbiome has been implicated in the pathogenesis of colorectal cancer (CRC) and intestinal microbiome alterations are not confined to the tumour. Since data on whether the microbiome normalises or remains altered after resection of CRC are conflicting, we studied the colonic microbiota of patients after resection of CRC. We profiled the microbiota using 16S rRNA gene amplicon sequencing in colonic biopsies from patients after resection of CRC (n = 63) in comparison with controls (n = 52), subjects with newly diagnosed CRC (n = 93) and polyps (i = 28). The colonic microbiota after surgical resection remained significantly different from that of controls in 65% of patients. Genus-level profiling and beta-diversity confirmed two distinct groups of patients after resection of CRC: one with an abnormal microbiota similar to that of patients with newly diagnosed CRC and another similar to non-CRC controls. Consumption levels of several dietary ingredients and cardiovascular drugs co-varied with differences in microbiota composition suggesting lifestyle factors may modulate differential microbiome trajectories after surgical resection. This study supports investigation of the colonic microbiota as a marker of risk for development of 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.

Proton pump inhibitors and risk of colorectal cancer

OBJECTIVE

To determine whether proton pump inhibitors (PPIs) are associated with an increased risk of colorectal cancer, compared with histamine-2 receptor antagonists (H2RAs).

DESIGN

The United Kingdom Clinical Practice Research Datalink was used to identify initiators of PPIs and H2RA from 1990 to 2018, with follow-up until 2019. Cox proportional hazards models were fit to estimate marginal HRs and 95% CIs of colorectal cancer. The models were weighted using standardised mortality ratio weights using calendar time-specific propensity scores. Prespecified secondary analyses assessed associations with cumulative duration, cumulative dose and time since treatment initiation. The number needed to harm was calculated at five and 10 years of follow-up.

RESULTS

The cohort included 1 293 749 and 292 387 initiators of PPIs and H2RAs, respectively, followed for a median duration of 4.9 years. While the use of PPIs was not associated with an overall increased risk of colorectal cancer (HR: 1.02, 95% CI 0.92 to 1.14), HRs increased with cumulative duration of PPI use (<2 years, HR: 0.93, 95% CI 0.83 to 1.04; 2-4 years, HR: 1.45, 95% CI 1.28 to 1.60; ≥4 years, HR: 1.60, 95% CI 1.42 to 1.80). Similar patterns were observed with cumulative dose and time since treatment initiation. The number needed to harm was 5343 and 792 for five and 10 years of follow-up, respectively.

CONCLUSION

While any use of PPIs was not associated with an increased risk of colorectal cancer compared with H2RAs, prolonged use may be associated with a modest increased risk of this malignancy.

SMAR1 suppresses the cancer stem cell population via hTERT repression in colorectal cancer cells

One of the hallmarks of a cancer cell is the ability for indefinite proliferation leading to the immortalization of the cell. Activation of several signaling pathways leads to the immortalization of cancer cells via the reactivation of enzyme telomerase (hTERT). hTERT is active in germ cells, stem cells and also cancer cells. An earlier report from our lab suggests that SMAR1, a tumor suppressor protein, is significantly downregulated in the higher grades of colorectal cancers. Our study identifies SMAR1 as a transcriptional repressor of hTERT. We find that SMAR1 interacts with HDAC1/mSin3a co-repressor complex at the hTERT promoter and brings about HDAC1-mediated transcriptional repression of the promoter. Most solid tumors including colorectal cancer reactivate hTERT expression as it confers several advantages to the cancer cells like increased proliferation and angiogenesis. One of these non-canonical functions of hTERT is inducing the pool of cancer stem cell population. We find that in the CD133HighCD44High cancer stem cells population, SMAR1 expression is highly diminished leading to elevated hTERT expression. We also find that knockdown of SMAR1 promotes total CD133+CD44+ population and impart enhanced sphere-forming ability to the colorectal cancer cells. SMAR1 also inhibits invasion and metastasis in colorectal cancer cell lines via repression of hTERT. Our study provides evidence that downregulation of SMAR1 causes activation of hTERT leading to an increase in the cancer stem cell phenotype in colorectal cancer cells.

Detection of High-Risk Sessile Serrated Lesions: Multi-Target Stool DNA Versus CT Colonography

Background: The serrated pathway for colorectal cancer (CRC) development is increasingly recognized. Patients with sessile serrated lesions (SSLs) that are large (≥10 mm) and/or have dysplasia (i.e., high-risk SSLs) are at higher risk of progression to CRC. Detection of SSLs is challenging given their predominantly flat and right-sided location. The yield of non-invasive screening tests for detection of high-risk SSLs is unclear. Objective: The aim of this study was to compare non-invasive screen detection of high-risk SSLs between the multi-target stool DNA test (mt-sDNA; Cologuard) and CT colonography (CTC). Methods: This retrospective study included 7974 asymptomatic adults (4705 women, 3269 men; mean age 60.0 years) who underwent CRC screening at a single center by mt-sDNA (Cologuard) from 2014-2019 (n=3987) or by CTC from 2009-2019 (n=3987). Clinical interpretations of CTC examinations were recorded. Subsequent colonoscopy findings and histology of resected polyps were also recorded. Chi-square or two-sample t tests were used to compare results between mt-sDNA and CTC using 6-mm and 10-mm thresholds for test positivity. Results: The overall colonoscopy referral rate for a positive screening test was 13.1% (522/3987) for mt-sDNA versus 12.2% (487/3987; p=.23) and 6.5% (260/3987; p<.001) for CTC at 6-mm and 10-mm thresholds, respectively. The PPV for high-risk SSLs was 5.5% (26/476) for mt-sDNA, versus 14.4% (66/457; p<.001) and 25.9% (63/243; p<.001) for CTC at 6-mm and 10-mm thresholds, respectively. The overall screening yield of high-risk SSLs was 0.7% (26/3987) for mt-sDNA versus 1.7% (66/3987; p<.001) and 1.6% (63/3987; p<.001) for CTC at 6-mm and 10-mm thresholds, respectively. Conclusions: CTC at 6-mm and 10-mm thresholds had significantly higher yield and PPV for high-risk SSLs compared with mt-sDNA. Clinical Impact: The significantly higher detection of high-risk SSLs by CTC than by mt-sDNA should be included in discussions with patients who decline colonoscopy and opt for noninvasive screening.

Gallstone Disease and Risk of Conventional Adenomas and Serrated Polyps: A Prospective Study

BACKGROUND

Gallstone disease has been associated with colorectal cancer and some form of polyps, although the findings are inconclusive. It remains unknown whether gallstone disease influences the initiation of colorectal cancer.

METHODS

We prospectively assessed the association of gallstone disease with risk of colorectal cancer precursors, including conventional adenomas and serrated polyps, in the Nurses' Health Study (1992-2012), the Nurses' Health Study II (1991-2011), and the Health Professionals Follow-up Study (1992-2012). Gallstone diseases were assessed using biennial follow-up questionnaires. Self-reported polyp diagnosis was confirmed by review of medical records. Logistic regression models were used to calculate the ORs with adjustment for smoking and other potential confounders.

RESULTS

Among participants who had undergone a total of 323,832 endoscopies, 16.5% had gallstone disease and 11.3% received cholecystectomy. We documented 1,724, 1,212, and 1,943 cases of conventional adenomas and 1,470, 1,090, and 1,643 serrated polyps in patients with gallstones, cholecystectomy, and either of them, respectively. The OR for adenomas was 1.00 [95% confidence interval (CI): 0.95-1.06] for gallstones, 0.99 (95% CI: 0.93-1.06) for cholecystectomy, and 1.00 (95% CI: 0.95-1.05) for either exposure. The corresponding ORs for serrated polyps were 0.98 (95% CI: 0.92-1.04), 0.99 (95% CI: 0.93-1.06), and 0.97(95% CI: 0.92-1.03), respectively.

CONCLUSIONS

Gallstone disease is not associated with colorectal polyps.

IMPACT

Patients with gallstones appear to have similar risk of colorectal polyps compared with those without and may therefore follow average-risk colorectal cancer screening guidelines.

Characteristics of Serrated Adenomas in Non-Hispanic Whites and African Americans Undergoing Screening Colonoscopy

Background and aim

Adenomatous polyps are precursor lesions for colorectal cancer (CRC). Serrated adenomas/polyps are considered a risk factor for the development of proximal and interval CRC. African-Americans are at higher risk for right-sided CRC. Minimal data evaluating serrated adenoma characteristics by race/ethnicity on initial screening colonoscopy (SC) exist. The aim of this investigation was to compare the characteristics of serrated adenomas found in non-Hispanic whites (nHw) and African-Americans (AA) undergoing initial SC.

Methods

The University of Florida-Jacksonville endoscopy database was searched for all SC performed between January 2000 and December 2014. Inclusion criteria were nHw or AA race/ethnicity and histologically proven serrated adenoma found at SC. Data were collected for all included age at SC, sex, number, location, and size of serrated adenomas found.

Results

A total of 8693 individuals (nHw - 4199 and AA - 4494) underwent SC between January 2000 and December 2014. Serrated adenomas were found in 479 individuals (nHw, n=294; AA, n=185), and AA were significantly less likely than nHw to have serrated adenomas on SC (AA 4.1% vs nHw 7%; p< 0.0001). No difference was observed in mean age, location, or size between nHw and AA with serrated adenomas.

Conclusions

Serrated adenomas are more frequent in nHw compared to AA at initial SC. No difference was seen in size or location of serrated adenomas, as well as patient age, between AA and nHw. A study of genetic factors predisposing to serrated adenoma formation and the impact of socioeconomic disparities should be performed across ethnic groups to understand this difference.

Plasma sex hormones and risk of conventional and serrated precursors of colorectal cancer in postmenopausal women

BACKGROUND

Sex hormones have been suggested to play a role in colorectal cancer (CRC), but their influence on early initiation of CRC remains unknown.

METHODS

We retrospectively examined the associations with risk of CRC precursors, including conventional adenomas and serrated polyps, for plasma estrone, estradiol, free estradiol, testosterone, free testosterone, sex hormone-binding globulin (SHBG), and the ratio of estradiol to testosterone among 5404 postmenopausal women from the Nurses' Health Study I and II. Multivariable logistic regression was used to calculate the odds ratio (OR) and 95% confidence intervals (CI). Given multiple testing, P < 0.005 was considered statistically significant.

RESULTS

During 20 years of follow-up, we documented 535 conventional adenoma cases and 402 serrated polyp cases. Higher concentrations of SHBG were associated with lower risk of conventional adenomas, particularly advanced adenomas (multivariable OR comparing the highest to the lowest quartile, 0.40, 95% CI 0.24-0.67, P for trend < 0.0001). A nominally significant association was found for SHBG with lower risk of large serrated polyps (≥ 10 mm) (OR, 0.47, 95% CI 0.17-1.35, P for trend = 0.02) as well as free estradiol and free testosterone with higher risk of conventional adenomas (OR, 1.54, 95% CI 1.02-2.31, P for trend = 0.03 and OR, 1.33, 95% CI 0.99-1.78, P for trend = 0.03, respectively).

CONCLUSIONS

The findings suggest a potential role of sex hormones, particularly SHBG, in early colorectal carcinogenesis.

Usefulness of narrow-band imaging for the detection of remnant sessile-serrated adenoma (SSA) tissue after endoscopic resection: the KASID multicenter study

BACKGROUND

A sessile-serrated adenoma (SSA) has a high risk for incomplete resection. Little is known regarding how to immediately detect remnant SSA tissue after endoscopic resection. We investigated the usefulness of narrow-band imaging (NBI) to detect remnant SSA tissue after endoscopic mucosal resection (EMR).

METHODS

We performed a prospective randomized study on 138 patients who had suspicious SSA on colonoscopy at five centers. After EMR on the suspected SSA determined on the endoscopic morphology, all lesions were randomized into two inspection methods, NBI and white light endoscopy (WLE), to detect remnant tissue on the resected margin. If remnant tissue was detected, an additional resection was performed. Finally, we obtained quadrant biopsies on the resection margin to evaluate the incomplete resection. The proportion of incomplete resection was calculated by combining the detection of remnant tissue and the positivity of SSA cells on the final quadrant biopsies. The primary outcome was the proportion of remnant tissue detection, and the secondary outcome was the proportion of incomplete resection of SSA.

RESULTS

In all, 145 lesions from 138 patients were removed. The diagnostic rate of SSA was 87.6% (127/145). After randomization, NBI inspection was performed on 69 lesions, and WLE inspection was performed on 76 lesions. The histologic diagnostic rate of SSA was 89.9% (62/69) in the NBI group and 85.5% (65/76) in the WLE group (p > 0.05). There were no significant differences in the detection of remnant tissue (12.9% (8/62) vs. 15.4% (10/65), p > 0.05), the proportion of SSA in remnant tissue (11.3% (7/62) vs. 12.3% (8/65), p > 0.05), or the proportion of incomplete resection (6.5 (4/62) vs. 10.8 (7/65), p > 0.05) between the NBI and WLE inspection groups, respectively.

CONCLUSION

NBI was not superior to WLE for detecting remnant SSA tissue after EMR and could not decrease the proportion of incomplete resection of SSA.

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.

Colorectal Cancer Screening for the Serrated Pathway

Serrated polyps are classified into hyperplastic polyps, sessile serrated adenomas/polyps, and traditional serrated adenomas. Although all serrated polyps share characteristic colonic crypts serrations, distinguishing hyperplastic polyps from sessile serrated adenomas/polyps is challenging. Traditional serrated adenomas are cytologically dysplastic lesions; sessile serrated adenomas/polyps develop cytologic dysplasia as they progress to colorectal cancer. A flat and pale appearance of serrated polyps may make detection difficult. Endoscopic mucosal resection has higher rates of complete resection. Close surveillance is recommended for sessile serrated adenomas/polyps, sessile serrated adenomas/polyp with dysplasia, hyperplastic polyps ≥10 mm, and traditional serrated adenomas.

Increased Risk of Colorectal Cancer Tied to Advanced Colorectal Polyps: An Untapped Opportunity to Screen First-Degree Relatives and Decrease Cancer Burden

Advanced adenomas represent a subset of colorectal polyps that are known to confer an increased risk of colorectal neoplasia to the affected individual and their first-degree relatives (FDRs). Accordingly, professional guidelines suggest earlier and more intensive screening for FDRs of those with advanced adenomas similar to FDRs of those with colorectal cancer (CRC). Although the risk to family members is less clear among patients with advanced serrated polyps, they are often considered in the same category. Unfortunately, there is a growing concern that patients, endoscopists, and primary care providers are unaware of the familial risk associated with these polyps, leaving a wide gap in screening these high-risk individuals. Herein, we propose a standardized language around advanced colorectal polyps and present a detailed review of the literature on associated familial risk. We outline the challenges to implementing the current screening recommendations and suggest approaches to overcome these limitations, including a proposed new colonoscopy quality metric to capture communication of familial CRC risk. Improving screening in these high-risk groups has the potential to substantially reduce the burden of CRC.

Associations between molecular characteristics of colorectal serrated polyps and subsequent advanced colorectal neoplasia

PURPOSE

BRAF mutation and DNA hypermethylation have linked sessile serrated adenomas/polyps (SSA/Ps) to serrated colorectal cancer (CRC) in cross-sectional studies, but they have not been evaluated in a longitudinal study. We aimed to evaluate the associations between molecular markers of serrated polyps and subsequent advanced colorectal neoplasia.

METHODS

Study subjects included Kaiser Permanente Washington members aged 20-75 years who received an index colonoscopy between 1/1/1998 and 12/31/2007 and had hyperplastic polyps (HPs) or SSA/Ps according to study pathology review. Polyps from index colonoscopies were removed and assayed for BRAF mutation, CpG island methylator phenotype (CIMP), and MLH1 methylation. Pathology reports and biopsies from the subsequent lower gastrointestinal endoscopy through 1/1/2013 were reviewed for advanced colorectal neoplasia. We identified additional incident CRC cases through linkage to the Seattle-Puget Sound Surveillance Epidemiology and End Results registry. We used generalized estimating equations to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) for subsequent advanced colorectal neoplasia, comparing index serrated polyps with different molecular markers.

RESULTS

We included 553 individuals with index serrated polyps (420 HPs and 133 SSA/Ps) and 795 subsequent endoscopies. The prevalence of BRAF-mutant, CIMP-high, and MLH1-methylated serrated polyps were 51%, 4%, and 2%, respectively. BRAF and CIMP were not associated with subsequent advanced colorectal neoplasia. MLH1-methylated SSP/As were significantly more likely to have subsequent advanced neoplasia (OR = 4.66, 95% CI 1.06-20.51).

CONCLUSION

Our results suggest that BRAF-mutant and CIMP-high serrated polyps are not associated with subsequent advanced colorectal neoplasia. Among SSA/Ps, MLH1 methylation may be an important marker to identify high-risk CRC precursors.

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

BACKGROUND & AIMS

Endoscopic screening reduces incidence and mortality of colorectal cancer (CRC) because precursor lesions, such as conventional adenomas or serrated polyps, are removed. Individuals with polypectomies are advised to undergo colonoscopy surveillance to prevent CRC. However, guidelines for surveillance intervals after diagnosis of a precursor lesion, particularly for individuals with serrated polyps, vary widely, and lack sufficient supporting evidence. Consequently, some high-risk patients do not receive enough surveillance and lower-risk subjects receive excessive surveillance.

METHODS

We examined the association between findings from first endoscopy and CRC risk among 122,899 participants who underwent flexible sigmoidoscopy or colonoscopy in the Nurses' Health Study 1 (1990-2012), Nurses' Health Study 2 (1989-2013), or the Health Professionals Follow-up Study (1990-2012). Endoscopic findings were categorized as no polyp, conventional adenoma, or serrated polyp (hyperplastic polyp, traditional serrated adenoma, or sessile serrated adenoma, with or without cytological dysplasia). Conventional adenomas were classified as advanced (≥10 mm, high-grade dysplasia, or tubulovillous or villous histology) or nonadvanced, and serrated polyps were assigned to categories of large (≥10 mm) or small (<10 mm). We used a Cox proportional hazards regression model to calculate the hazard ratios (HRs) of CRC incidence, after adjusting for various potential risk factors.

RESULTS

After a median follow-up period of 10 years, we documented 491 incident cases of CRC: 51 occurred in 6161 participants with conventional adenomas, 24 in 5918 participants with serrated polyps, and 427 in 112,107 participants with no polyp. Compared with participants with no polyp detected during initial endoscopy, the multivariable HR for incident CRC in individuals with an advanced adenoma was 4.07 (95% confidence interval [CI] 2.89-5.72) and the HR for CRC in individuals with a large serrated polyp was 3.35 (95% CI 1.37-8.15). In contrast, there was no significant increase in risk of CRC in patients with nonadvanced adenomas (HR 1.21; 95% CI 0.68-2.16, P = .52) or small serrated polyps (HR 1.25; 95% CI 0.76-2.08; P = .38).

CONCLUSIONS

These findings provide support for guidelines that recommend repeat lower endoscopy within 3 years of a diagnosis of advanced adenoma and large serrated polyps. In contrast, patients with nonadvanced adenoma or small serrated polyps may not require more intensive surveillance than patients without polyps.

Japan Gastroenterological Endoscopy Society guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection

Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also several types of precarcinomatous adenomas. It is important to establish practical guidelines wherein preoperative diagnosis of colorectal neoplasia and selection of endoscopic treatment procedures are appropriately outlined and to ensure that actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society compiled colorectal endoscopic submucosal dissection/endoscopic mucosal resection guidelines by using evidence-based methods in 2014. The first edition of these guidelines was published 5 years ago. Accordingly, we have published the second edition of these guidelines based on recent new knowledge and evidence.

Colorectal Serrated Polyp With Stromal Changes: An Interobserver Agreement Study

Background

Prolapse-related changes have been shown to be a confounding factor leading to misdiagnosis of serrated polyps in the rectum. Recent data on perineurial-like stromal proliferation in some sessile serrated polyps (SSPs) also highlights this issue.

Methods

Fifty-four consecutive serrated polyps with stromal changes from 42 patients were collected by one pathologist during a 2-month period (July and August of 2014). In addition, 20 cases of serrated polyps with perineurial-like stromal proliferation from 20 patients were retrieved from our pathology database from 2003 to 2010. The polyps were re-reviewed by three gastrointestinal pathologists for stromal changes, basal crypt distortion, and final classification into hyperplastic polyp (HP) or SSP. Final interpretation was correlated to clinicopathologic features and the presence of synchronous SSP and adenoma. In addition, the interobserver agreement on the stromal changes and basal crypt distortion in these polyps was determined.

Results

Upon histology review, all polyps showed stromal changes evident by at least one pathologist. Among the 74 polyps evaluated, a consensus diagnosis of HP and consensus diagnosis of SSP were reached in 39 and 11 polyps respectively. The overall interobserver agreement among three pathologists was moderate (kappa value 0.49, 95% confidence interval (CI) 0.32 - 0.66). A consensus diagnosis could not be reached in the remaining 24 polyps (32.4%). The SSPs were larger, were more often located in the right colon, and occurred more frequently in women when compared to HPs (7.3 ± 5.3 vs. 4.5 ± 2.7 mm, P = 0.019; 72.7% vs. 7.7%, P = 0.000014; and 77.7% vs. 30.7%, P = 0.019) but with comparable patient age (54.7 ± 10.6 years vs. 60.7 ± 11.4, P = 0.12). The SSPs were associated with higher risk of concurrent SSP in other parts of the colon (27.3% vs. 0%, P = 0.008) but not with the presence of concurrent adenoma (45.4% vs. 69.6%, P = 1). Among the 24 unclassifiable serrated polyps, 11 were interpreted by two reviewers as SSP and 13 interpreted by two reviewers as HP; the former group were more likely right-sided (45.4% vs. 15.4%, P = 0.046), but size of the polyps and age of the patients were comparable. Stromal changes (prolapse and perineurial-like) were agreed upon by all three pathologists in 33 (44.6%, of 74) polyps and these included 15 with prolapse changes and 18 perineurial-like stromal changes. Among those 15 with prolapse changes, 14 (93.3%) were agreed upon by three pathologists to be HP; in contrast, only four (22.2%, of 18) with perineurial-like stromal changes were diagnosed as HP by all three pathologists (P = 0.00008). Of 74 polyps, 16 were found to have basal crypt distortion involving more than one crypt and eight of them (50%) carried a final interpretation of SSP by all three pathologists and two (12.5%) HP.

Conclusions

Even though serrated polyps with stromal changes can be challenging, up to 67.7% of them could be readily classified as SSP or HP. The remaining unclassifiable serrated polyps with stromal changes may represent a heterogeneous group. Prolapse changes support the diagnosis of HP while basal crypt distortion in more than one crypt supports the diagnosis of SSP.

High Prevalence of Adenomatous Polyps in Alaska Native People Aged 40-49 years

BACKGROUND

Although colorectal cancer occurs earlier in life and at twice the frequency in Alaska Native (AN) people compared with the general population, the colorectal polyp burden in this group has not been quantified. In addition, an appropriate age for initial screening in ANs has not been defined.

MATERIALS AND METHODS

A retrospective chart review of 766 AN people who had screening colonoscopy from 2015 to 2016 was performed. The polyp burden in patients aged 40-49 y was compared with that in those aged 50-59 y in both the AN and the general US populations.

RESULTS

In total, 345 adenomas were removed: 121 (35%) from 40- to 49-year-olds and 224 (65%) from 50- to 59-year-olds. Twenty-six percent of AN people aged 40 y to 49 y and 40% of AN people aged 50 to 59 y had at least one adenoma. Low- and high-risk adenomas were significantly less frequent in the younger group (22% versus 29%, P = 0.048; 9.2% versus 15%, P = 0.035; respectively). Advanced adenomas were also less frequent in the younger group, although not statistically significant. Polyp histology, size, location, and morphology did not differ significantly between groups.

CONCLUSIONS

The adenoma and advanced adenoma prevalence in 40- to 49-year-old AN people is high, suggesting colorectal cancer screening should begin at age 40 y in ANs.

Hereditary or Not? Understanding Serrated Polyposis Syndrome

PURPOSE OF REVIEW

To present the current understanding of the diagnosis, management, and potential genetic causes of serrated polyposis syndrome.

RECENT FINDINGS

The clinical criteria for serrated polyposis syndrome was recently updated and now includes individuals with five or more serrated polyps proximal to the rectum that are 5 mm in size or greater and at least two that are 10 mm in size of greater as well as individuals with 20 or more serrated polyps throughout the colon with at least five proximal to the rectum. There is a significant risk for colon cancer in first-degree relatives of individuals with serrated polyposis syndrome. However, less than 3% of serrated polyposis syndrome cases are explained by identifiable germline mutations, with mutations in RNF43 being the only currently validated genetic cause. Serrated polyposis syndrome is rarely explained by identifiable germline mutations, but there remains an increased risk for colorectal cancer in first-degree relatives. Referral for genetic counseling and testing is recommended for individuals with serrated polyposis syndrome and a personal history of coexisting adenomatous polyposis or with a concerning family history and can be considered for all individuals with serrated polyposis syndrome. Close endoscopic surveillance of those with serrated polyposis syndrome and their first-degree relatives is recommended. Continued efforts at identifying hereditary causes of serrated polyposis are needed.

An update on the morphology and molecular pathology of serrated colorectal polyps and associated carcinomas

Our understanding of serrated colorectal polyps has increased dramatically over the past two decades and has led to a modern classification scheme for these lesions. Sessile serrated polyps with dysplasia represent the most clinically significant serrated polyp; however, the morphologic heterogeneity of dysplasia in sessile serrated polyps has only recently been recognized and correlated with MLH1 immunohistochemistry. Detailed morphologic analysis of traditional serrated adenomas has led to the recognition of flat and early forms of this polyp. Robust data on the risk of metachronous lesions in patients with serrated polyps are also beginning to emerge. This review will summarize our current understanding of serrated polyps and associated carcinomas with a focus on diagnostic criteria, morphologic heterogeneity, molecular findings, and natural history. Controversial issues in the diagnosis and classification of these polyps are also discussed.

Terminology, Molecular Features, Epidemiology, and Management of Serrated Colorectal Neoplasia

In addition to the adenoma to carcinoma sequence, colorectal carcinogenesis can occur via the serrated pathway. Studies have focused on clarification of categories and molecular features of serrated polyps, as well as endoscopic detection and risk assessment. Guidelines from the World Health Organization propose assigning serrated polyps to categories of hyperplastic polyps, traditional serrated adenomas, and sessile serrated lesions (SSLs). Traditional serrated adenomas and SSLs are precursors to colorectal cancer. The serrated pathway is characterized by mutations in RAS and RAF, disruptions to the Wnt signaling pathway, and widespread methylation of CpG islands. Epidemiology studies of serrated polyps have been hampered by inconsistencies in terminology and reporting, but the prevalence of serrated class polyps is 20%-40% in average-risk individuals; most serrated polyps detected are hyperplastic. SSLs, the most common premalignant serrated subtype, and are found in up to 15% of average-risk patients by high-detecting endoscopists. Variations in rate of endoscopic detection of serrated polyps indicate the need for careful examination, with adequate bowel preparation and sufficient withdrawal times. Risk factors for SSLs include white race, family history of colorectal cancer, smoking, and alcohol intake. Patients with serrated polyps, particularly SSLs and traditional serrated adenomas, have an increased risk of synchronous and metachronous advanced neoplasia. Surveillance guidelines vary among countries, but SSLs and proximal hyperplastic polyps require special attention in assignment of surveillance interval-especially in light of concerns regarding incomplete detection and resection.

The association between colorectal sessile serrated adenomas/polyps and subsequent advanced colorectal neoplasia

PURPOSE

Colorectal cancer (CRC) screening guidelines recommend increased surveillance of individuals with sessile serrated adenomas/polyps (SSA/Ps), but there is uncertainty about the risk associated with SSA/Ps. We aimed to determine the association between SSA/Ps and subsequent advanced colorectal neoplasia.

METHODS

This case-control study included Kaiser Permanente Washington (KPWA) members who received an index colonoscopy between 1/1/1998 and 12/31/2007, and had hyperplastic polyps (HPs) or SSA/Ps but no conventional adenomas according to study pathologist histologic review. Subsequent pathology reports and biopsies through 1/1/2013 were reviewed for advanced colorectal neoplasia. We linked to the Seattle-Puget Sound Surveillance Epidemiology and End Results (SEER) registry to identify additional CRC cases. We used generalized estimating equations with a logit link to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for advanced colorectal neoplasia, comparing those with SSA/Ps to those with HPs.

RESULTS

There were 161 individuals with index SSA/Ps, 548 with HPs, and 918 subsequent endoscopies included in analyses. Of those with index SSA/Ps, 19 had subsequent advanced colorectal neoplasia; 39 with HPs had subsequent advanced colorectal neoplasia. Compared to those with HPs, those with SSA/Ps were not statistically significantly more likely to have subsequent advanced colorectal neoplasia (adjusted OR 1.79; CI 0.98-3.28). Polyp size ≥ 10 mm, right colon location, and the presence of multiple serrated polyps were also not associated with advanced colorectal neoplasia.

CONCLUSIONS

Our results suggest that there is not a strong association between SSA/Ps and subsequent advanced colorectal neoplasia during the 5 years following SSA/P removal.

Endoscopic features of sessile serrated adenoma/polyps under narrowband imaging: A retrospective study

OBJECTIVE

Sessile serrated adenoma/polyps (SSA/P) are recognized as precancerous lesions in the colon and resemble hyperplastic polyps (HP). Definite endoscopic features under narrow band imaging (NBI) with or without magnification may help differentiate these two lesions. Our study aimed to identify specific endoscopic features of SSA/P by NBI.

METHODS

A total of 199 patients with histopathologically proven colorectal SSA/P or HP after a polypectomy were enrolled. Magnifying and non-magnifying NBI pictures of 206 matching lesions were evaluated by one expert and two non-expert endoscopists using various endoscopic characteristics retrospectively.

RESULTS

Multivariate analysis indicated that a clouded surface (odds ratio [OR] 6.48, 95% confidence interval [CI] 2.72-15.44, P = 0.000) and dilated and branching vessels (DBV) (OR 7.95, 95% CI 3.71-17.02, P = 0.000) were significant endoscopic features for diagnosing SSA/P compared with HP. The combination of these two features could improve diagnostic specificity to 96%, and the area under the receiver operating characteristic curve was 0.749. However, it seemed that the presence of dark spots (OR 1.93, 95% CI 0.94-4.00, P = 0.075) was not a definite feature in differentiating these two lesions. Neither a mucus cap nor CP-II meshed capillary vessels showed statistical significance in differentiating SSA/P from HP (P = 0.590 and 0.293, respectively).

CONCLUSIONS

A clouded surface and DBV were two indicators for diagnosing SSA/P. Combining these two factors together under NBI with or without magnification achieved better diagnostic performance than when they were used alone.

Sessile Serrated Adenomas in Young Patients may have Limited Risk of Malignant Progression

GOALS

To provide preliminary evidence that sessile serrated adenomas (SSA) are low-risk polyps in young patients.

BACKGROUND

SSAs are the dominant polyp of the serrated neoplasia pathway and as such are the precursor of up to 20% of colorectal carcinomas (CRC). Up to 90% of these cancers are expected to harbor a BRAF mutation. SSAs are being diagnosed with increasing frequency in young patients, placing a significant burden on colonoscopic services. Evidence to direct the surveillance intervals for these young patients is not available.

STUDY

We utilized 2 patient cohorts comprising (1) a consecutive series of patients who underwent outpatient colonoscopy through a tertiary hospital and (2) a consecutive series of resection specimens for CRC processed through a gastrointestinal pathology service. The prevalence of SSAs by age was determined in the patients undergoing colonoscopy and compared with the ages of patients with BRAF mutated CRC in the pathology series.

RESULTS

The prevalence of SSAs was similar irrespective of age. By comparison, BRAF mutated CRCs were very rare (3.8% of cases) in patients younger than 50 years of age and uncommon (9.3% of cases) in patients younger than 60 years of age, but increased to 39.8% in patients older than 80 years of age.

CONCLUSIONS

These results suggest that SSAs develop at a young age, but have a prolonged dwell time and are unlikely to develop into cancer in patients younger than 60 years of age. These findings highlight the need for further targeted research to determine the most appropriate surveillance intervals for young patients with sporadic SSAs.

The dark side of the colon: current issues surrounding the significance, prevalence, detection, diagnosis and management of serrated polyps

PURPOSE OF REVIEW

Hyperplastic polyps, once considered to have no malignant potential, are now recognized to be part of a larger group of polyps known as serrated polyps. Serrated polyps can progress to CRC through an epigenetic pathway known as CpG Island Methylator Phenotype (CIMP), characterized by hypermethylation of specific DNA regions such as the promoter regions of the DNA mismatch repair genes like MLH1. The CIMP pathway is tightly linked with mutations of the oncogene BRAF. There are three subtypes of serrated polyps - hyperplastic polyps, sessile serrated polyps (SSPs) and traditional serrated adenomas (TSAs). TSAs harbor cytologic dysplasia whereas hyperplastic polyps and SSPs are nondysplastic lesions. Currently, only SSPs and TSAs are believed to progress to CRC whereas hyperplastic polyps are thought to be benign with no malignant potential. This article will review the current evidence while highlighting some of the issues regarding serrated polyps.

RECENT FINDINGS

One challenge has been pathologically distinguishing hyperplastic polyps from SSPs, which is an important distinction, given the potential for progression of SSPs to CRC. Other challenges regarding serrated polyps include adequate detection and resection. Surveillance guideline recommendations for some serrated polyps have been changed in current guidelines to reflect the malignant potential, recommending closer surveillance intervals than the 10-year follow-up that has been traditionally provided for hyperplastic polyps.

SUMMARY

Given the difficulties in diagnosing as well as resecting, it is important for endoscopists to know how to detect, resect and manage follow-up in patients with serrated polyps.

Aspects of the Natural History of Sessile Serrated Adenomas/Polyps: Risk Indicators for Carcinogenesis in the Colorectal Mucosa?

BACKGROUND

Sessile serrated adenomas/polyps are potentially premalignant colorectal lesions that are precursors to colorectal cancer arising via CpG island methylator phenotype. They are caused by the combination of a BRAF mutation and promoter hypermethylation. DNA methylation is an age-dependent phenomenon in the right colon, and we would expect the occurrence and severity of serrated neoplasia to reflect this.

OBJECTIVE

The purpose of this study was to document the natural history of sessile serrated adenomas/polyps, including the ages at which they appear and the ranges of their number, size, and associated lesions.

DESIGN

This was a retrospective cohort study.

SETTINGS

The study was conducted at a tertiary referral center.

PATIENTS

Consecutive patients with sessile serrated adenomas/polyps removed between 2006 and 2015 were included. Patients with IBD, familial adenomatous polyposis, Lynch syndrome, serrated polyposis, and hereditary nonpolyposis colorectal cancer were excluded.

MAIN OUTCOME MEASURES

Age at which polyps were first diagnosed, location and size of polyps, demographics, and family history were measured.

RESULTS

A total of 440 patients had 668 sessile serrated adenomas/polyps, 257 (58%) also had ≥1 adenoma, and 28 (6%) had a history of colorectal cancer. Mean age at diagnosis was 68 ± 11 years, and 45% were men. Two hundred had had ≥1 colonoscopy before the diagnosis of the first sessile serrated adenomas/polyps. A total of 136 patients (31%) had multiple sessile serrated adenomas/polyps, including 24% synchronous and 10% metachronous. The range of total cumulative sessile serrated adenomas/polyps was from 1 to 7. A total of 554 (83%) of 668 sessile serrated adenomas/polyps were right sided; 48% were ≥1 cm diameter and 22% were >2 cm. The size of the first sessile serrated adenomas/polyps in those diagnosed under age 50 years averaged 10 mm, those between 50 and 60 years averaged 12 mm, and those between 60 and 70 years averaged 12 mm.

LIMITATIONS

No measurement of methylation or BRAF mutations in polyps or normal mucosa and a lack of subclassification of hyperplastic polyps limited this study.

CONCLUSIONS

The age of onset of sessile serrated adenomas/polyps varies, but the pattern is consistent with increasing methylation in the mucosa. Early negative colonoscopies predict a low risk of methylator cancers. See Video Abstract at http://links.lww.com/DCR/A736.

The clinical significance and synchronous polyp burden of large (≥ 20 mm) sessile serrated polyps in patients without serrated polyposis syndrome

BACKGROUND

Sessile serrated polyps (SSPs) are important precursors of colorectal carcinoma and interval cancer. Large SSPs (≥ 20 mm) outside the definition of serrated polyposis syndrome (SPS) have not been studied in comparison with SPS. We aimed to describe the characteristics of patients with large SSPs in this context.

METHODS

Patients with at least one SSP (≥ 20 mm) were eligible. Data from three consecutive colonoscopies were used to compare clinical and endoscopic characteristics in three patient groups: SPS, a solitary large SSP, and patients with at least two SSPs without fulfilling the criteria for SPS (oligo-SSP). Data on the diagnostic colonoscopy were collected retrospectively, whereas the remaining data was collected prospectively.

RESULTS

67/146 patients (45.9 %) had SPS, 53/146 (36.3 %) had a solitary SSP, and 26/146 (17.8 %) were categorized as oligo-SSP. Personal (16.4 %, 9.4 %, and 11.5 %, respectively) and family (17.9 %, 17.0 %, and 23.1 %, respectively) history of colorectal carcinoma did not differ significantly between groups. Polyp burden was greater in SPS compared with solitary SSP but was not different from oligo-SSP (advanced adenomas: SPS 32.8 % vs. solitary SSP 9.4 % [P = 0.002] vs. oligo-SSP 34.6 % [P = 0.87]; ≥ 10 conventional adenomas: 11.9 % vs. 0 % [P = 0.01] vs. 3.8 % [P = 0.44], respectively). Dysplasia in large SSPs was frequent in all groups (41.1 % overall). SPS was recognized by referring endoscopists in only 9.0 % of cases.

CONCLUSION

Patients with oligo-SSPs have similar synchronous polyp burden and clinical characteristics as patients with SPS and may require similar surveillance. Modification of the criteria for the diagnosis of SPS to include this group seems warranted. Patients with a solitary SSP have a lower risk of synchronous polyps, including advanced adenomas. Larger studies are warranted to determine whether these patients may return to standard surveillance following complete examination and clearance of the colon.

Clinical, Histologic, and Immunophenotypic Features of Serrated Polyps in Patients With Inflammatory Bowel Disease

Background

Colorectal serrated polyps (SP), which include hyperplastic polyps (HP), sessile serrated adenomas/polyps (SSA/P), and traditional serrated adenomas, are not uncommon and have been implicated to play a role in the pathogenesis in a subset of sporadic colorectal carcinomas; however, their significance in patients with prolonged inflammatory bowel disease (IBD) remains unclear.

Methods

We retrospectively studied the clinicopathologic features, BRAF and β-catenin immunohistochemistry staining patterns in 36 SPs from 28 patients with IBD compared with 40 SPs in patients without IBD.

Results

Eleven SSA/Ps and 25 HPs from IBD and site-matched controls were included. SSA/Ps in the study group were slightly more commonly seen in males (55% vs. 41%, P = 0.7) and older patients (55.2 vs. 47.8 years, P = 0.2) compared to patients with HP. They were moderately larger (7.13 mm vs. 4.83 mm, P = 0.14) and more likely located on the right (63.6% vs. 32%, P = 0.46). Smaller percentage of SSA/Ps showed BRAF staining compared to controls (55.6% vs. 73.3%, P = 0.41) and HPs showed similar features (52.0% vs. 54.2%, P = 1). β-catenin was negative in all cases. During follow-up, only one patient in the SSA/P group developed carcinoma 42 months after at the same site and two developed adenoma-like low-grade dysplasia but no patients with HPs had such findings.

Conclusions

Our findings show that SPs in IBD share similar clinicodemographic and immunophenotypical features with sporadic SPs. However, patients with SSA/Ps may have a slight increase in risk of developing dysplasia compared to patients with HPs in IBD.

Detection of serrated lesions in proximal colon by simulated sigmoidoscopy vs faecal immunochemical testing in a multicentre, pragmatic, randomised controlled trial

Background

The diagnostic yield of the faecal immunochemical test and sigmoidoscopy in detecting proximal serrated polyps in a colorectal cancer screening programme has not been fully assessed.

Aim

We determined the detection rate of proximal serrated polyps by simulated sigmoidoscopy and faecal immunochemical test compared with total colonoscopy in a population-based, multicentre, nationwide, randomised controlled trial (ColonPrev study).

Methods

Sigmoidoscopy yield was simulated based on the UK-Flexible Sigmoidoscopy Trial for total colonoscopy referral. Definitions were: proximal serrated polyp (proximal serrated polyp): sessile serrated polyp or hyperplastic polyp of any size and proximal at-risk serrated polyp (at-risk proximal serrated polyp): sessile serrated polyp of any size or hyperplastic polyp ≥ 10 mm, both located proximally to the splenic flexure.

Results

A total of 10,611 individuals underwent faecal immunochemical test and 5059 underwent total colonoscopy and were evaluated by simulated sigmoidoscopy. Sigmoidoscopy and faecal immunochemical test were less accurate in detecting proximal serrated polyps (odds ratio: 0.13; 95% confidence interval: 0.10-0.18 and 0.13; 0.09-0.18, p < 0.0001, respectively). Both tests were inferior to colonoscopy in detecting at-risk proximal serrated polyps, and sigmoidoscopy was inferior to faecal immunochemical test in detecting these lesions (odds ratio: 0.17; 95% confidence interval: 0.10-0.30 and 0.25; 0.17-0.37, p < 0.0001, respectively).

Conclusion

Sigmoidoscopy and faecal immunochemical test are less accurate in detecting proximal serrated polyps than colonoscopy, particularly in women.

Patients with small and diminutive proximal hyperplastic polyps have higher rates of synchronous advanced neoplasia compared with patients without serrated lesions

BACKGROUND AND AIMS

The association of proximal small and diminutive hyperplastic polyps (HPs) with synchronous advanced neoplasia is not well-defined. However, sessile serrated polyps (SSPs), even when small, are known to portend a risk of synchronous neoplasia. Currently, the U.S. Multi-Society Task Force on Colorectal Cancer does not recommend a change in the surveillance interval when proximal small HPs are detected. We aimed to compare the rates of synchronous advanced neoplasia in a screening colonoscopy cohort of patients with small and then diminutive proximal HPs in comparison, first to a cohort absent any serrated or proximal HPs and then in comparison with a cohort with small proximal SSPs.

METHODS

Consecutive screening colonoscopies were recorded between 2005 and 2010 at an academic medical center. Patients were divided into 3 mutually exclusive groups. Group 1 consisted of patients with at least 1 HP that was proximal to the sigmoid colon, <1 cm in endoscopic size, and up to 3 total HPs in number. Group 2 included patients without any proximal HPs or SSPs. Group 3 consisted of patients with 1 to 2 SSPs, with at least 1 being proximal to the sigmoid colon, that were <1 cm in endoscopic size and without dysplasia. Rates of synchronous advanced neoplasia in patients with small (<1 cm) and diminutive (≤5 mm) proximal HPs were compared with the rates for the other 2 groups.

RESULTS

There were 482 of 2569 patients (18.8%) with a small proximal HP who met the criteria for Group 1. The rate of synchronous advanced neoplasia in patients with a small proximal HP (61/482, 12.7%) was significantly greater compared with the average risk in the non-serrated cohort (Group 2, 133/1878, 7.1%; P < .001). There was no significant difference in the rate of synchronous advanced neoplasia when the small proximal HP group was subdivided by size (≤5 mm, 51/404, 12.6% vs 6-9 mm, 10/78, 12.8%; P = 1.00). The rate of synchronous advanced neoplasia in patients with diminutive (≤5 mm) proximal HPs (51/404, 12.6%) was not significantly different from the rate observed with proximal SSPs of similar size (17/113, 15.0%; P = .529).

CONCLUSION

Patients with small and diminutive proximal HPs tend to harbor higher rates of synchronous advanced neoplasia compared with those without any serrated lesions detected on screening colonoscopy. Surveillance outcomes for metachronous advanced neoplasia for patients with small proximal HPs deserves further study. The synchronous advanced neoplasia rate in patients with proximal diminutive HPs is similar to that of proximal diminutive SSPs and could have implications in a resect and discard strategy.

Clinicopathological features of advanced colorectal serrated lesions: A single-center study in China

OBJECTIVE

A growing body of evidence indicates that patients with colorectal serrated lesions, especially advanced serrated lesions (ASLs), are at risk of subsequent malignancy. This study aimed to analyze the clinicopathological features of ASLs and the association between ASLs and synchronous advanced colorectal neoplasia (sACN) in a single center of China.

METHODS

A retrospective cross-sectional study of consecutive symptomatic patients and healthy individuals who underwent colonoscopy between January 2010 and March 2016 was performed. Clinicopathological characteritics of the patients with ASLs were documented from the colonoscopy database.

RESULTS

Colorectal serrated lesions were pathologically confirmed in 277 (N = 38 981, 0.7%) cases. Among them, 156 (56.3%) were found to have ASLs, with a total of 161 lesions including 71 sessile serrated adenoma/polyps (SSA/P) and 90 traditional serrated adenomas (TSAs). There were no differences in age and gender between the ASL and non-ASL patients. Among the 161 ASLs, 29 (18.0%) were ≥10 mm in diameter. Compared with non-ASLs, ASLs appeared more in the proximal colon (P = 0.007). Flat and subpedunculated lesions were more commonly found in the ASL group compared with the non-ASL group. Nearly all ASLs (160/161) had dysplasia. Moreover, 16 sACN lesions were found in 156 ASL patients, and large diameter (≥10 mm) might be a significant risk factor for sACN (odds ratio 4.35, 95% confidence interval 1.467-12.894, P < 0.05).

CONCLUSIONS

ASLs are more likely to occur in the proximal colon, and mainly present as flat and sub-pedunculated types. Large ASLs are significantly associated with sACN.

Development and evaluation of a risk assessment tool to improve clinical triage accuracy for colonoscopic investigations

Background

Gastroenterology Departments at hospitals within Australia receive thousands of General Practitioner (GP)-referral letters for gastrointestinal investigations every month. Many of these requests are for colonoscopy. This study aims to evaluate the performance of the current symptoms-based triage system compared to a novel risk score using objective markers.

Methods

Patients with lower abdominal symptoms referred by their GPs and triaged by a Gastroenterology consultant to a colonoscopy consent clinic were recruited into the study. A risk assessment tool (RAT) was developed using objective data (clinical, demographic, pathology (stool test, FIT), standard blood tests and colonoscopy outcome). Colonoscopy and histology results were scored and then stratified as either significant bowel disease (SBD) or non-significant bowel disease (non-SBD).

Results

Of the 467 patients in our study, 45.1% were male, the mean age was 54.3 ± 13.8 years and mean BMI was 27.8 ± 6.2. Overall, 26% had SBD compared to 74% with non-SBD (42% of the cohort had a normal colonoscopy). Increasing severity of referral symptoms was related to a higher triage category, (rectal bleeding, P = 2.86*10^-9; diarrhoea, P = 0.026; abdominal pain, P = 5.67*10^-4). However, there was no significant difference in the prevalence of rectal bleeding (P = 0.991) or diarrhoea (P = 0.843) for SBD. Abdominal pain significantly reduced the risk of SBD (P = 0.0344, OR = 0.52, CI = 0.27-0.95). Conversely, the RAT had a very high specificity of 98% with PPV and NPV of SBD prediction, 74% and 77%, respectively. The RAT provided an odds ratio (OR) of 9.0, 95%CI 4.29-18.75, p = 2.32*10^-11), higher than the FIT test (OR = 5.3, 95%CI 2.44-11.69, p = 4.88*10^-6), blood score (OR = 2.8, 95%CI 1.72- 4.38, p = 1.47*10^-5) or age (OR = 2.5, 95%CI 1.61-4.00, 5.12*10^-5) independently. Notably, the ORs of these individual objective measures were higher than the current practice of symptoms-based triaging (OR = 1.4, 95%CI 0.88-2.11, p = 0.153).

Conclusions

It is critical that individuals with high risk of having SBD are triaged to the appropriate category with the shortest wait time. Here we provide evidence that a combination of blood markers, demographic markers and the FIT test have a higher diagnostic accuracy for SBD than FIT alone.

Detection rate and proximal shift tendency of adenomas and serrated polyps: a retrospective study of 62,560 colonoscopies

PURPOSE

The purpose of this study is to estimate the detection rates of adenomas and serrated polyps and to identify proximalization and associate risk factors in patients from Southern China.

METHODS

Consecutive patients undergoing colonoscopy from 2004 to 2013 in Guangzhou were included. The proportions of proximal adenomas to advanced adenomas and serrated polyps were compared and potential predictors were evaluated.

RESULTS

Colonoscopies (n = 62,560) were performed, and 11,427 patients were diagnosed with polyps. Detection rates for adenomas, hyperplastic polyps, and serrated adenomas were 12.0, 2.5, and 0.2 patients per 100 colonoscopies. When comparing the 1st (2004-2008) to the 2nd period (2009-2013), adenoma and serrated polyp detection in proximal and distal colon both increased significantly (proximal colon [adenoma 3.9 vs. 6.1 patients/100 colonoscopies, P < 0.001; serrated polyp 0.4 vs. 1.1 patients/100 colonoscopies, P < 0.001]; distal colon [adenoma 6.6 vs. 7.2 patients/100 colonoscopies, P = 0.003; serrated polyp 1.2 vs. 2.4 patients/100 colonoscopies, P < 0.001]). Advanced adenoma detection increased over these two periods only in proximal colon (1st vs. 2nd period: 1.5 vs. 2.4 patients/100 colonoscopies, P < 0.001), not the distal colon (P = 0.114). Multivariate analyses showed that diagnostic period was an independent predictor for adenoma proximalization (OR = 1.36, 95% CI 1.25-1.48, P < 0.001), but not for advanced adenomas (P = 0.117) or serrated polyps (P = 0.928).

CONCLUSIONS

Adenomas and serrated polyps were increasingly detected throughout the colon, whereas advanced adenomas were only in proximal colon. A proximal shift tendency detected by colonoscopy was observed for adenomas, but not advanced adenomas or serrated polyps, in Southern China. The screening for proximal polyps should be emphasized and colonoscopy might be a preferred initial screening tool.

Clinical outcomes of surveillance colonoscopy for patients with sessile serrated adenoma

Background/Aims

Sessile serrated adenomas (SSAs) are known to be precursors of colorectal cancer (CRC). The proper interval of follow-up colonoscopy for SSAs is still being debated. We sought to determine the proper interval of colonoscopy surveillance in patients diagnosed with SSAs in South Korea.

Methods

We retrospectively reviewed the medical records of patients diagnosed with SSAs who received 1 or more follow-up colonoscopies. The information reviewed included patient baseline characteristics, SSA characteristics, and colonoscopy information.

Results

From January 2007 to December 2011, 152 SSAs and 8 synchronous adenocarcinomas were identified in 138 patients. The mean age of the patients was 62.2 years and 60.1% patients were men. SSAs were located in the right colon (i.e., from the cecum to the hepatic flexure) in 68.4% patients. At the first follow-up, 27 SSAs were identified in 138 patients (right colon, 66.7%). At the second follow-up, 6 SSAs were identified in 65 patients (right colon, 66.7%). At the 3rd and 4th follow-up, 21 and 11 patients underwent colonoscopy, respectively, and no SSAs were detected. The total mean follow-up duration was 33.9 months. The mean size of SSAs was 8.1±5.0 mm. SSAs were most commonly found in the right colon (126/185, 68.1%). During annual follow-up colonoscopy surveillance, no cancer was detected.

Conclusions

Annual colonoscopy surveillance is not necessary for identifying new CRCs in all patients diagnosed with SSAs. In addition, the right colon should be examined more carefully because SSAs occur more frequently in the right colon during initial and follow-up colonoscopies.

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

BACKGROUND & AIMS

Surveillance guidelines for serrated polyps (SPs) are based on limited data on longitudinal outcomes of patients. We used the New Hampshire Colonoscopy Registry to evaluate risk of clinically important metachronous lesions associated with SPs detected during index colonoscopies.

METHODS

We collected data from a population-based colonoscopy registry that has been collecting and analyzing data on colonoscopies across the state of New Hampshire since 2004, including rates of adenoma and SP detection. Patients completed a questionnaire to determine demographic characteristics, health history, and risk factors for colorectal cancer, and were followed from index colonoscopy through all subsequent surveillance colonoscopies. Our analyses included 5433 participants (median age, 61 years; 49.7% male) with 2 colonoscopies (median time to surveillance, 4.9 years). We used multivariable logistic regression models to assess effects of index SPs (n = 1016), high-risk adenomas (HRA, n = 817), low-risk adenomas (n = 1418), and no adenomas (n = 3198) on subsequent HRA or large SPs (>1 cm) on surveillance colonoscopy (metachronous lesions). Synchronous SPs, within each index risk group, were assessed for size and by histology. SPs comprise hyperplastic polyps, sessile serrated adenomas/polyps (SSA/Ps), and traditional serrated adenomas. In this study, SSA/Ps and traditional serrated adenomas are referred to collectively as STSAs.

RESULTS

HRA and synchronous large SP (odds ratio [OR], 5.61; 95% confidence interval [CI], 1.72-18.28), HRA with synchronous STSA (OR, 16.04; 95% CI, 6.95-37.00), and HRA alone (OR, 3.86; 95% CI, 2.77-5.39) at index colonoscopy significantly increased the risk of metachronous HRA compared to the reference group (no index adenomas or SPs). Large index SPs alone (OR, 14.34; 95% CI, 5.03-40.86) or index STSA alone (OR, 9.70; 95% CI, 3.63-25.92) significantly increased the risk of a large metachronous SP.

CONCLUSIONS

In an analysis of data from a population-based colonoscopy registry, we found index large SP or index STSA with no index HRA increased risk of metachronous large SPs but not metachronous HRA. HRA and synchronous SPs at index colonoscopy significantly increased risk of metachronous HRA. Individuals with HRA and synchronous large SP or any STSA could therefore benefit from close surveillance.

Screening of colorectal cancer: present and future

INTRODUCTION

Colorectal cancer (CRC) is the third most common cancer in males and second in females, and the fourth most common cause of cancer death worldwide. Currently, about 60-70% of diagnosed cases in symptomatic patients are detected at an advanced stage of disease. Earlier stage detection through the use of screening strategies would allow for better outcomes in terms of reducing the disease burden. Areas covered: The aim of this paper is to review the current published evidence from literature which assesses the performance and effectiveness of different screening tests for the early detection of CRC. Expert commentary: Adequate screening strategies can reduce CRC incidence and mortality. In the last few decades, several tests have been proposed for CRC screening. To date, there is still insufficient evidence to identify which approach is definitively superior, and no screening strategy for CRC can therefore be defined as universally ideal. The best strategy would be the one that can be economically viable and to which the patient can adhere best to over time. The latest guidelines suggest colonoscopy every 10 years or annual fecal immuno-chemical test (FIT) for people with normal risk, while for individuals with high risk or hereditary syndromes specific recommendations are provided.

The Serrated Polyp Pathway: Is It Time to Alter Surveillance Guidelines?

PURPOSE OF REVIEW

In this manuscript, we review current surveillance guidelines for serrated polyps (SPs) and discuss how recent studies inform the selection of appropriate surveillance intervals for patients with SPs.

RECENT FINDINGS

Large and/or proximal SPs, particularly sessile serrated polyps (SSPs), are associated with increased risk of both synchronous and metachronous neoplasia, including advanced adenomas and colorectal cancer (CRC). Persons harboring multiple SSPs or dysplastic SSPs are at the highest risk. Moreover, a high percentage of large and/or proximal SPs are reclassified as SSPs when read by trained gastrointestinal pathologists, even if they were originally reported as hyperplastic polyps. These findings support the adoption of surveillance guidelines that prescribe closer surveillance of large and/or proximal SPs, regardless of subtype. SSPs remain a challenge to reliably identify, resect, and diagnose via histology. The increased risk of future neoplasia in patients with SSPs is likely driven by a combination of underdetection, inadequate removal, misclassification, and biology. Until further evidence emerges, we support guidelines that recommend close surveillance of patients with a history of large and/or proximal SPs and SSPs specifically in order to mitigate the threat of interval CRC.