Clinicopathological characteristics of serrated polyps as precursors to colorectal cancer: Current status and management

A non-aligned translation with a neoplastic classifier regularization to include vascular NBI patterns in standard colonoscopies

Polyp vascular patterns are key to categorizing colorectal cancer malignancy. These patterns are typically observed in situ from specialized narrow-band images (NBI). Nonetheless, such vascular characterization is lost from standard colonoscopies (the primary attention mechanism). Besides, even for NBI observations, the categorization remains biased for expert observations, reporting errors in classification from 59.5% to 84.2%. This work introduces an end-to-end computational strategy to enhance in situ standard colonoscopy observations, including vascular patterns typically observed from NBI mechanisms. These retrieved synthetic images are achieved by adjusting a deep representation under a non-aligned translation task from optical colonoscopy (OC) to NBI. The introduced scheme includes an architecture to discriminate enhanced neoplastic patterns achieving a remarkable separation into the embedding representation. The proposed approach was validated in a public dataset with a total of 76 sequences, including standard optical sequences and the respective NBI observations. The enhanced optical sequences were automatically classified among adenomas and hyperplastic samples achieving an F1-score of 0.86%. To measure the sensibility capability of the proposed approach, serrated samples were projected to the trained architecture. In this experiment, statistical differences from three classes with a ρ-value <0.05 were reported, following a Mann-Whitney U test. This work showed remarkable polyp discrimination results in enhancing OC sequences regarding typical NBI patterns. This method also learns polyp class distributions under the unpaired criteria (close to real practice), with the capability to separate serrated samples from adenomas and hyperplastic ones.

Clinical and endoscopic characteristics and management of 220 cases with serrated polyps

BACKGROUND

Serrated polyps are considered the precursor lesions of colorectal cancer through the serrated pathway. In the present study, we aimed to evaluate and discuss the clinical and endoscopic characteristics and management of serrated polyps.

METHODS

The data of 220 cases with serrated polyps between September 2018 and November 2021 in Shenzhen People's Hospital were retrospectively analyzed.

RESULTS

Of all these cases, 32 were hyperplastic polyps, 36 were traditional serrated adenomas, 126 were sessile serrated lesions, 25 were SSLs with dysplasia, and one was an unclassified serrated adenoma. Although most patients were males aged ≥50 years and most serrated polyps were located in the distal colon and rectum with a size of 6-10 mm and the shape of type 0-Is, there was no significant difference (P > 0.05). Serrated polyps of ≤5 mm in size and type 0-IIa were mostly removed by cold biopsy forceps. Cold snare polypectomy was primarily used for those of 6-10 mm in size. Endoscopic mucosal resection was used for those of 6-20 mm, and endoscopic submucosal dissection was used for those of ≥20 mm (P < 0.05). All complications occurred in SSL patients with or without dysplasia (P < 0.05).

CONCLUSIONS

Clinical and endoscopic characteristics were beneficial for distinguishing and diagnosing serrated polyps. In addition, management options were crucial to prevent recurrence and progression. However, the detection rate of serrated polyps was relatively low. Therefore, prospective multicenter studies with large samples are necessary to better assess colorectal serrated polyps.

Dietary Inflammatory Potential and the Risk of Serrated and Adenomatous Colorectal Polyps

Studies of dietary inflammation potential and risks of colorectal cancer precursors are limited, particularly for sessile serrated lesions (SSLs). This study examines the association using the energy-adjusted dietary inflammatory index (E-DIITM), a measure of anti- and/or pro-inflammatory diet, in a large US colonoscopy-based case-control study of 3246 controls, 1530 adenoma cases, 472 hyperplastic polyp cases, and 180 SSL cases. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived from logistic regression models. Analyses were stratified by participant characteristics, and urinary prostaglandin E2 metabolite (PGE-M) and high-sensitivity plasma C-reactive protein (hs-CRP) levels, inflammation biomarkers. Highest E-DII™ intake was associated with significantly increased risks of colorectal adenomas (OR 1.36, 95% CI 1.11, 1.67), and hyperplastic polyps (OR 1.43, 95% CI 1.06, 1.98), compared with participants consuming the lowest E-DII™ quartile. A similar, but non-significant, increased risk was also observed for SSLs (OR 1.41, 95% CI 0.82, 2.41). The positive association was stronger in females (pinteraction <0.001), normal weight individuals (ptrend 0.01), and in individuals with lower inflammatory biomarkers (ptrend 0.02 and 0.01 for PGE-M and hs-CRP, respectively). A high E-DII™ is associated with colorectal polyp risk, therefore promoting an anti-inflammatory diet may aid in preventing colorectal polyps.

Atrophic gastritis rather than Helicobacter pylori infection can be an independent risk factor of colorectal polyps: a retrospective study in China

BACKGROUND

Colonoscopy is considered the most effective screening method for colorectal polyps. However, the longevity and complexity of the procedure makes it less desirable to screen for colorectal polyps in the general population. Therefore, it is essential to identify other independent risk factors. In this study, we explored the link between Hp infection, atrophic gastritis, and colorectal polyps to identify a new potential risk factors of colorectal polyps.

METHODS

In this study, atrophic gastritis and intestinal polyps were diagnosed by endoscopy and pathology. All the 792 patients in this retrospective study were divided into sub-groups based on the presence of colorectal polyps. The correlation between polyps and atrophic gastritis was analyzed using the chi-square test and Kruskal-Wallis test. The receiver operating characteristic (ROC) curve was used to compare the predictive value for colorectal polyps between Hp infection and atrophic gastritis. Binary logistic regression was utilized to identify independent risk factors for colorectal polyps.

RESULTS

Patients with colorectal polyps were primarily male with advanced age, and the number of patients with colorectal polyps had a higher association with smoking, alcohol drinking, and Hp infection than the control group. A positive correlation between the number of colorectal polyps and the severity of atrophic gastritis was observed. ROC analysis showed that atrophic gastritis was a better risk factors for colorectal polyps. Multivariate analysis identified atrophic gastritis as an independent risk factor for colorectal polyps (OR 2.294; 95% CI 1.597-3.296).

CONCLUSIONS

Atrophic gastritis confirmed could be an independent risk factors for colorectal polyps.

Microvesicular hyperplastic polyp and sessile serrated lesion of the large intestine: a biological continuum or separate entities?

The range of lesions with a serrated appearance within the large intestine has expanded and become more complex over the last 30 years. The majority of these were previously known as metaplastic polyps but are today called hyperplastic polyps (HPs). HPs show two main growth patterns: microvesicular and goblet cell-rich. The former type shows morphological and molecular similarities (eg, BRAF mutations) to the more recently described sessile serrated lesion (SSL). In this review, we debate whether these lesions represent a biological spectrum or separate entities. Whichever view is held, microvesicular HPs and SSLs are distinct from the goblet cell-rich HP and the traditional serrated adenoma (TSA), which may themselves share molecular changes (eg, KRAS mutations), with the goblet cell-rich HP representing a precursor to the TSA. Both SSLs and the goblet cell-rich HP-TSA pathway are routes to colorectal cancer within the serrated pathway and overlaps between them can occur, for example, a (BRAF-mutated) TSA may arise from an SSL.

Morphological and molecular characterization of colorectal sessile serrated lesions with dysplasia

In sessile serrated lesions (SSLs) with adenomatous dysplasia, the dysplastic component and the serrated component without dysplasia should be considered as part of the same lesion, classified as SSL with dysplasia. However, some of these lesions may actually represent collisions between a serrated polyp and a conventional adenoma. Further supporting the "collision theory", conventional adenomatous dysplasia may be found in association with hyperplastic polyps (HPs). In order to determine the molecular and biological landscape of conventional type dysplasia in serrated lesions, we collected 17 cases of colorectal serrated lesions with adenomatous dysplasia, classifying them as SSL with dysplasia (n = 10) or as mixed lesions comprising a HP component and a conventional adenomatous component (n = 7). We characterized the dysplastic and the non-dysplastic component of each lesion, after microdissection, through the targeted mutational analysis of 11 commonly altered genes in colorectal cancer (AKT1, APC, BRAF, CTNNB1, KIT, KRAS, NRAS, PDGFRA, PIK3CA, PTEN and TP53). We also characterized MMR and p53 status by immunohistochemistry. Overall, 14/17 (82.4 %) cases harbored a mutation in at least one of the two components. The most altered genes were BRAF in 10/17 (58.8 %) cases, APC in 2/17 (11.8 %) and TP53 in 4/17 (23.5 %). Among the SSL with dysplasia, the mutational profile was concordant between the two components in 7/10 (70 %) cases, while among the mixed lesions, the mutational profile was concordant in 1/7 (14.3 %). In all but two cases of SSL with dysplasia, MMR status was concordant between the two components of the serrated lesions. Our findings suggest that adenomatous dysplasia may develop in SSL as part of the serrated lesion, even if some SSL with dysplasia may actually be collision lesions. On the other hand, the polyps that are morphologically classifiable as mixed lesions composed of a HP and a conventional adenomatous component are more likely to be collision lesions.

Irrigating Acetic Acid Solution During Colonoscopy for the Detection of Sessile Serrated Neoplasia: A Randomized Controlled Trial

BACKGROUND

Misdiagnosed sessile serrated lesions (SSLs) are important precursors for interval colorectal cancers.

AIMS

We investigated the usage of acetic acid (AA) solution for improving the detection of SSLs in the right colon in a randomized controlled trial.

METHODS

A tandem observation of the right colon was performed in 412 consecutive patients. A first inspection was performed under white light high-definition endoscopy. In the AA group, a low concentration vinegar solution (AA: 0.005%) irrigated by a water pump in the right colon was compared with a plain solution of normal saline (NS) in the diagnostic yield of SSLs during the second inspection. Secondary outcomes in overall polyp detection were measured.

RESULTS

Qualitative comparisons showed significant differences in the detection rates of all polyps except adenomas, with remarkable improvement in the demonstration of advanced (> 20 mm), SSLs, and hyperplastic polyps during the second inspection of the right colon using the AA solution. Significant improvement was also noted in the AA group, as far as the mean number of polyps/patient detected, not only in SSLs (AA group: 0.14 vs. NS group: 0.01, P < 0.001), but also in all histological types and all size-categories in the right colon. Small (≤ 9 mm) polyps were detected at a higher rate in the sigmoid colon expanding the effect of the method in the rest of the colon.

CONCLUSION

AA-assisted colonoscopy led to a significant increase in SSLs detection rate in the right colon in a safe, quick, and effective manner.

Molecular pathways in post-colonoscopy versus detected colorectal cancers: results from a nested case-control study

BACKGROUND

Post-colonoscopy colorectal cancers (PCCRCs) pose challenges in clinical practice. PCCRCs occur due to a combination of procedural and biological causes. In a nested case-control study, we compared clinical and molecular features of PCCRCs and detected CRCs (DCRCs).

METHODS

Whole-genome chromosomal copy number changes and mutation status of genes commonly affected in CRC were examined by low-coverage WGS and targeted sequencing, respectively. MSI and CIMP status was also determined.

RESULTS

In total, 122 PCCRCs and 98 DCRCs with high-quality DNA were examined. PCCRCs were more often located proximally (P < 0.001), non-polypoid appearing (P = 0.004), early stage (P = 0.009) and poorly differentiated (P = 0.006). PCCRCs showed significantly less 18q loss (FDR < 0.2), compared to DCRCs. No significant differences in mutations were observed. PCCRCs were more commonly CIMP high (P = 0.014) and MSI (P = 0.029). After correction for tumour location, only less 18q loss remained significant (P = 0.005).

CONCLUSION

Molecular features associated with the sessile serrated lesions (SSLs) and non-polypoid colorectal neoplasms (CRNs) are more commonly seen in PCCRCs than in DCRCs. These together with the clinical features observed support the hypothesis that SSLs and non-polypoid CRNs are contributors to the development of PCCRCs. The future focus should be directed at improving the detection and endoscopic removal of these non-polypoid CRN and SSLs.

CLINICAL TRIAL REGISTRATION

NTR3093 in the Dutch trial register ( www.trialregister.nl ).

Proliferation, apoptosis and their regulatory protein expression in colorectal adenomas and serrated lesions

BACKGROUND

Adenomas and serrated lesions represent heterogeneous sets of early precursors in the colorectum with varying malignant potential. They are often distinguished by their histopathologic differences, but little is known about potential differences in regulation of epithelial proliferation and apoptosis.

METHODS

We conducted a protein expression analysis using tissue microarrays of 625 colorectal adenomas and 142 serrated lesions to determine potential differences in regulation of epithelial proliferation and apoptosis. We quantitated proliferation with Ki-67; apoptosis with activated caspase-3 (CASP3); up- and down-regulators of proliferation with cyclin D1, p16INK2, and p21Cip1; and apoptosis regulators with BAX, BCL2, and survivin. Linear mixed effects models and circos diagrams were used to determine relationships among expression and lesion characteristics.

RESULTS

Adenomas had a significantly higher CASP-3 labeling index (LI) than serrated lesions, resulting in a lower net growth ratio (Ki-67 LI/activated CASP-3 LI, p-value<0.0001). Cyclin D1 LI, p16 LI and p21 LI were lower in adenomas compared to serrated lesions, while expression of both BCL2 and BAX were higher (p <0.001). Among adenomas, cyclin D1 LI and p16 LI levels increased with greater villous component, and the highest BAX expression was detected in adenomas larger than 2 cm (both p<0.0001). Right-sided adenomas had higher CASP3 LI than left colorectal adenomas (p = 0.008). Significant differences in cyclin D1 LI, p21 LI and survivin LI were also observed across histopathologic subtypes of serrated lesions.

CONCLUSIONS

Our findings demonstrate different patterns of regulatory protein expression in adenomas than serrated lesions, especially involving apoptosis. ClinicalTrials.gov Identifier: NCT00272324.

The Differential Diagnosis of Colorectal Polyps Using Colon Capsule Endoscopy

Objective Although colorectal polyps (CPs) can be observed with colon capsule endoscopy (CCE), it is difficult to determine the type of polyp using CCE. The objective of this study was to differentiate adenomatous polyps (APs) from hyperplastic polyps (HPs) with CCE. Methods In this single-center retrospective study, an analysis was conducted on the same CPs with both CCE and colonoscopy (CS) and histopathologically diagnosed as AP or HP. The color difference (ΔE) between the polyp surface and the surrounding mucosa was calculated using the CIE1976 L*a*b* color space method on white light (WL), flexible spectral imaging color enhancement (FICE), and blue mode (BM) CP images. We investigated the ability of the ratio of the color differences (ΔE') to differentiate between APs and HPs. Results The size of all 51 polyps (34 APs, 17 HPs) was 7.5±4.6 mm with CCE and 7.3±4.2 mm with CS, and this difference was not significant (p=0.28). The FICEΔE' of APs was 3.3±1.8, which was significantly higher than the FICEΔE' of HPs (1.3±0.6; p<0.001). A receiver operating characteristic analysis showed that FICEΔE' was useful for differentiating between APs and HPs, with an area under the curve of 0.928 (95% confidence interval, 0.843-1). The sensitivity was 91.2%, and the specificity was 88.2% with a cut-off value of 1.758. Conclusion Using FICE on CCE images of CPs and applying the CIELAB color space method, we were able to differentiate between APs and HPs with high accuracy. This method has the potential to reduce unnecessary CS procedures.

Improved differentiation classification of variable precision artificial intelligence higher education management

The wide application of artificial intelligence technology in various fields has accelerated the pace of people exploring the hidden information behind large amounts of data. People hope to use data mining methods to conduct effective research on higher education management, and decision tree classification algorithm as a data analysis method in data mining technology, high-precision classification accuracy, intuitive decision results, and high generalization ability make it become a more ideal method of higher education management. Aiming at the sensitivity of data processing and decision tree classification to noisy data, this paper proposes corresponding improvements, and proposes a variable precision rough set attribute selection standard based on scale function, which considers both the weighted approximation accuracy and attribute value of the attribute. The number improves the anti-interference ability of noise data, reduces the bias in attribute selection, and improves the classification accuracy. At the same time, the suppression factor threshold, support and confidence are introduced in the tree pre-pruning process, which simplifies the tree structure. The comparative experiments on standard data sets show that the improved algorithm proposed in this paper is better than other decision tree algorithms and can effectively realize the differentiated classification of higher education management.

Role of the β-Catenin/REG Iα Axis in the Proliferation of Sessile Serrated Adenoma/Polyps Associated with Fusobacterium nucleatum

Although sessile serrated adenoma/polyps (SSA/Ps) may arise through a pathway different from the traditional adenoma–carcinoma sequence, details of SSA/P tumorigenesis still remain unclear. Fusobacterium nucleatum (Fn) is frequently detected in colorectal cancer (CRC) tissues and may play a pivotal role in colorectal carcinogenesis. Here, we investigated the relationship between Fn and the β-catenin/REG Iα axis in SSA/Ps and their involvement in the proliferation of these lesions. Fn was detected in SSA/Ps by fluorescence in situ hybridization using a Fn-targeted probe, and expression of β-catenin, REG Iα and Ki67 was examined using immunohistochemistry. Sixteen of 30 SSA/P lesions (53.3%) were positive for Fn. Eighteen SSA/P lesions (60%) showed β-catenin immunoreactivity in the tumor cell nuclei. A significant majority of Fn-positive lesions showed nuclear expression of β-catenin (87.5%) and higher REG Iα scores and Ki67 labeling indices relative to Fn-negative lesions. The SSA/P lesions expressing β-catenin in nuclei had significantly higher REG Iα scores and Ki67 labeling indices than those expressing β-catenin on cytomembranes. The REG Iα score was positively correlated with the Ki67 labeling index in SSA/P lesions. The treatment with Wnt agonist SKL2001 promoted nuclear β-catenin translocation and enhanced REG Ia expression in Caco2 cells. Fn may play a role in the proliferation of SSA/P lesions through promotion of β-catenin nuclear translocation and REG Iα expression.

The spectrum of serrated colorectal lesions-new entities and unanswered questions

Hyperplastic polyps (HPs) of the colon and rectum were historically thought not to be associated with an increased risk of development of colorectal cancer (CRC). The recognition of variants of serrated colorectal lesions that possessed relatively subtle but significant morphological differences from those of HPs and that could be associated with epithelial dysplasia and CRC led to the characterisation of sessile serrated lesions (SSLs) and traditional serrated adenomas (TSAs). These links were supported by the identification of genetic alterations that are commonly found in HPs, SSLs, TSAs, and CRC, e.g. BRAF and KRAS mutations. The 'serrated pathway' to CRC may progress faster than the traditional 'adenoma-carcinoma sequence', underlining the importance of identifying these lesions. The diagnostic histological criteria for SSLs have since been more clearly defined, in parallel with a drive to increase the recognition of these lesions at endoscopy. The existence of lesions showing overlapping morphological and molecular features with those of HPs, SSLs and TSAs has most recently been highlighted-including mucin-rich TSA, serrated tubulovillous adenoma, and those showing mixed histological features, e.g. comprising differing combinations of HP, SSL, and TSA. Morphological and molecular studies of this range of lesions are providing insights into the relationships of serrated colorectal lesions with each other and with CRC. This article provides an overview of the current understanding of serrated colorectal lesions, including a discussion of those with overlapping and mixed features.

Non-conventional dysplasia in inflammatory bowel disease is more frequently associated with advanced neoplasia and aneuploidy than conventional dysplasia

AIMS

Several different non-conventional morphological patterns of epithelial dysplasia have been recently described in inflammatory bowel disease (IBD), but there is limited information regarding their clinicopathological and molecular features, as well as potential risk for high-grade dysplasia (HGD) or colorectal cancer (CRC) compared with conventional dysplasia developing in IBD.

METHODS AND RESULTS

A total of 317 dysplastic lesions from 168 IBD patients were analysed. All lesions were re-reviewed and subtyped as either conventional [including tubular adenoma-like (n = 183) and tubulovillous/villous adenoma-like (n = 56)] or non-conventional dysplasia [including dysplasia with increased Paneth cell differentiation (DPD, n = 40), crypt cell dysplasia (CCD, n = 14), goblet cell deficient (GCD, n = 10), hypermucinous (n = 7), sessile serrated lesion (SSL)-like (n = 4) and traditional serrated adenoma (TSA)-like (n = 3)]. DNA flow cytometry was performed on 70 low-grade conventional (n = 24) and non-conventional (n = 46) dysplastic biopsies to determine their malignant potential and molecular pathways to HGD or CRC. Eleven sporadic tubular adenomas with low-grade dysplasia (LGD) were utilised as controls. Seventy-eight non-conventional dysplastic lesions were identified in 56 (33%) of the 168 patients, whereas 239 conventional dysplastic lesions were identified in 149 (89%) patients. Although both non-conventional and conventional dysplasias were most often graded as LGD at diagnosis (83% and 84%, respectively), non-conventional dysplasia (38%) was more likely to develop HGD or CRC in the same colonic segment than conventional dysplasia (19%) on follow-up (P < 0.001). Almost half (46%) of non-conventional dysplastic samples showed aneuploidy, whereas only 8% of conventional dysplasia (P = 0.002) and 9% of sporadic tubular adenomas (P = 0.037) did. Also, non-conventional dysplasia more frequently presented as a flat/invisible lesion (41%) compared with conventional dysplasia (18%) (P < 0.001). Among the non-conventional subtypes (n = 78), DPD was the most common (n = 40; 51%), followed by CCD (n = 14; 18%), GCD (n = 10; 13%), hypermucinous (n = 7; 9%), SSL-like (n = 4; 5%) and TSA-like (n = 3; 4%) variants. Hypermucinous dysplasia (mean = 2.1 cm) was significantly larger than DPD, SSL-like, TSA-like and GCD variants (mean = 1.0, 1.2, 1.2 and 1.9 cm, respectively) (P = 0.037). HGD or CRC was more likely to be associated with CCD (n = 13; 93%), hypermucinous (n = 4; 57%), GCD (n = 4; 40%) and SSL-like (n = 3; 75%) variants than DPD (n = 6; 15%) and TSA-like dysplasia (n = 0; 0%) on follow-up (P < 0.001). Furthermore, the rate of aneuploidy was significantly higher in CCD (100%), hypermucinous (80%) and GCD (25%) variants than in DPD (12%), SSL-like dysplasia (0%) and TSA-like dysplasia (0%) (P < 0.001).

CONCLUSIONS

Non-conventional morphological patterns of dysplasia are not uncommon in IBD, detected in 33% of the patients. The higher frequencies of advanced neoplasia (HGD or CRC) and aneuploidy in non-conventional dysplasia, in particular CCD, hypermucinous and GCD variants, suggest that they may have a higher malignant potential than conventional dysplasia or sporadic tubular adenomas, and thus need complete removal and/or careful follow-up. Greater than 40% of non-conventional dysplasia presented as a flat/invisible lesion, suggesting that IBD patients may benefit from random biopsy sampling in addition to targeted biopsies. The majority of non-conventional subtypes appear to develop via the chromosomal instability pathway, whereas an alternative serrated pathway may be responsible for the development of at least a subset of SSL-like and TSA-like dysplasias.

An online deep convolutional polyp lesion prediction over Narrow Band Imaging (NBI)

Polyps, represented as abnormal protuberances along intestinal track, are the main biomarker to diagnose gastrointestinal cancer. During routine colonoscopies such polyps are localized and coarsely characterized according to microvascular and surface textural patterns. Narrow-band imaging (NBI) sequences have emerged as complementary technique to enhance description of suspicious mucosa surfaces according to blood vessels architectures. Nevertheless, a high number of misleading polyp characterization, together with expert dependency during evaluation, reduce the possibility of effective disease treatments. Additionally, challenges during colonoscopy, such as abrupt camera motions, changes of intensity and artifacts, difficult the diagnosis task. This work introduces a robust frame-level convolutional strategy with the capability to characterize and predict hyperplastic, adenomas and serrated polyps over NBI sequences. The proposed strategy was evaluated over a total of 76 videos achieving an average accuracy of 90,79% to distinguish among these three classes. Remarkably, the approach achieves a 100% of accuracy to differentiate intermediate serrated polyps, whose evaluation is challenging even for expert gastroenterologist. The approach was also favorable to support polyp resection decisions, achieving perfect score on evaluated dataset.Clinical relevance- The proposed approach supports observable hystological characterization of polyps during a routine colonoscopy avoiding misclassification of potential masses that could evolve in cancer.

Imaging predictors of BRAF mutation in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the leading causes of cancer deaths and is associated with various genetic mutations. BRAF mutations, found in approximately 10% of all CRCs, are associated with negative predictive outcomes. The goal of this study was to assess the relationship between the imaging findings and BRAF statuses of CRC patients.

MATERIALS AND METHODS

The study population was colorectal cancer patients who underwent biopsy or surgery in a single institution from September 2004 to October 2018, and in whom the pathologic specimens were tested for BRAF mutation. The exclusion criteria were (1) patients without pre-operative cross-sectional imaging, and (2) patients whose tumors were invisible on imaging. Two hundred and eighty-three patients met the inclusion criteria. Among them, 128 were excluded, and a total of 155 patients were enrolled in the study.

RESULTS

BRAF mutations were significantly more common in female patients (p = 0.007). Patients with mutated BRAF were significantly older than those with wild-type BRAF (p = 0.001). BRAF-mutant tumors were predominant in right-sided colon (p = 0.001) with higher numbers of polypoid- or mass-like morphology (p = 0.019) and heterogeneous enhancement (p = 0.009). Compared to their wild-type counterparts, BRAF-mutated CRCs have a lower occurrence of non-peritoneal, and overall metastases (p = 0.013 and p = 0.004, respectively). Logistic regression analysis showed three significant factors for the prediction of BRAF mutations in CRC patients: right-sided location (p = 0.002), heterogeneous tumor enhancement (p = 0.039), and lack of non-peritoneal metastasis (p = 0.043).

CONCLUSION

By recognizing the specific imaging features of BRAF-mutant CRCs, it would be possible to identify a patient who has a higher risk of carrying BRAF mutation.

Long-term follow-up after EMR of large colorectal lesions: metachronous lesions, predictors and surveillance timing

Background: Endoscopic mucosal resection (EMR) is the first-line approach to large colorectal sessile lesions. These patients have been associated with high rates of metachronous lesions (ML), but long-term follow-up (LtFU) data are lacking. We aimed at evaluating the efficacy of an LtFU protocol and analyse the development and risk factors for ML.Methods: A prospectively collected database was analysed. Seventy-six patients submitted to EMR of large colorectal sessile lesions between 2007 and 2013 complied with a specific endoscopic surveillance, consisting of two protocols - initial follow-up (iFU) and LtFU. iFU intended to inspect the mucosectomy scars twice (at 3-6 and 12 months) and remove synchronous lesions (SL). Protocol examinations of LtFU were carried out at the first- and fourth-year post-iFU, aiming to remove ML. Statistical analysis included variables related to patient, index lesion, SL and ML characteristics.Results: Rates of ML were 39.5% and 20.4% at the first- and fourth-year of LtFU, and respectively 11.8% and 3.7% of them were advanced ML. All ML were endoscopically resectable. At univariate analysis, male gender (OR: 2.91; p=.029), the presence of SL (OR 3.86, p=.010) and advanced SL (OR 4.25, p=.006) were risk factors for ML. At multivariate analysis, male gender (p=.031) and advanced SL (p=.006) were significant predictors of ML development.Conclusions: We confirmed the increased risk of ML in patients with large colorectal lesions. A significant number of advanced ML was removed at the first LtFU colonoscopy, probably it should be carried out earlier than currently recommended.

Microsatellite Instability assessment in Black South African Colorectal Cancer patients reveal an increased incidence of suspected Lynch syndrome

Microsatellite Instability (MSI) is a hallmark of colorectal cancer (CRC) and occurs in 15–16% of CRC. Molecular biological information of CRC in South Africa (SA) is largely unrecorded. This study was undertaken to determine the frequency of MSI, with particular reference to Lynch syndrome (LS) with a view to improve surveillance and prevention strategies. This was a retrospective study on CRC samples diagnosed between 2011–2015 at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH). Samples diagnosed between 2011–2012 were screened for MSI by PCR and mismatch repair (MMR) immunohistochemistry (IHC), and additional BRAFV600E mutational analysis performed. T-tests, Fischer’s exact and Chi square statistical tests were applied. Twelve percent of patients displayed MSI, with increased frequency in black (15%) versus other ethnic group (OEG) (8%) patients. MSI patients were significantly younger than microsatellite stable (MSS) patients, however when stratified by ethnicity, black patients were predominantly younger (median age: 47), with increased MSH2/6 loss, and no BRAF mutations. These findings suggest a large proportion of young black SA CRC patients develop via the LS pathway due to earlier age onset and predominant MSH2/6 protein loss. SA patients of other ethnicities appear to follow the more well established sporadic MSI pathway.

Clinicopathological features, diagnosis, and treatment of sessile serrated adenoma/polyp with dysplasia/carcinoma

Sessile serrated adenoma/polyps (SSA/Ps) are early precursor lesions in the serrated neoplasia pathway, which results in BRAF-mutated colorectal carcinomas with not only high levels of microsatellite instability but also microsatellite stable. SSA/Ps with advanced histology, including cytological dysplasia or minimally invasive carcinomas, are important lesions because SSA/Ps are considered major contributors to "interval cancers" and these lesions can rapidly become dysplastic or invasive carcinomas. Clinicopathologically, SSA/Ps with dysplasia or invasive carcinoma were associated with advanced age, female sex, and proximal colon. Although SSA/Ps with submucosal invasive carcinoma were smaller and invaded less deeply into the submucosal layer than conventional tubular adenomas with submucosal invasive carcinoma, SSA/Ps with submucosal invasive carcinoma frequently had a mucinous component and exhibited a higher potential for lymphatic invasion and lymph node metastasis. In an SSA/P series, endoscopic characteristics, including (semi)pedunculated morphology, double elevation, central depression, and reddishness, may help accurately diagnose SSA/Ps with advanced histology. Removal of SSA/Ps with dysplasia or invasive carcinoma was recommended. Endoscopic treatment such as endoscopic mucosal resection or endoscopic submucosal dissection is useful for those lesions. However, surgical resection with lymph node dissection might be indicated when SSA/Ps with invasive carcinoma are endoscopically suspected, because these have the high risk of lymph node metastasis. Greater awareness may promote further research into improving the detection, recognition, and complete resection rates of SSA/Ps with dysplasia or invasive carcinoma and reduce the interval cancer rates.

Right-Sided Location Not Associated With Missed Colorectal Adenomas in an Individual-Level Reanalysis of Tandem Colonoscopy Studies

BACKGROUND & AIMS

Interval cancers occur more frequently in the right colon. One reason could be that right-sided adenomas are frequently missed in colonoscopy examinations. We reanalyzed data from tandem colonoscopies to assess adenoma miss rates in relation to location and other factors.

METHODS

We pooled data from 8 randomized tandem trials comprising 2218 patients who had diagnostic or screening colonoscopies (adenomas detected in 49.8% of patients). We performed a mixed-effects logistic regression with patients as cluster effects with different independent parameters. Factors analyzed included location (left vs right, splenic flexure as cutoff), adenoma size, form, and histologic features. Analyses were controlled for potential confounding factors such as patient sex and age, colonoscopy indication, and bowel cleanliness.

RESULTS

Right-side location was not an independent risk factor for missed adenomas (odds ratio [OR] compared with the left side, 0.94; 95% CI, 0.75-1.17). However, compared with adenomas ≤5 mm, the OR for missing adenomas of 6-9 mm was 0.62 (95% CI, 0.44-0.87), and the OR for missing adenomas of ≥10 mm was 0.51 (95% CI, 0.33-0.77). Compared with pedunculated adenomas, sessile (OR, 1.82; 95% CI, 1.16-2.85) and flat adenomas (OR, 2.47; 95% CI, 1.49-4.10) were more likely to be missed. Histologic features were not significant risk factors for missed adenomas (OR for adenomas with high-grade intraepithelial neoplasia, 0.68; 95% CI, 0.34-1.37 and OR for sessile serrated adenomas, 0.87; 95% CI, 0.47-1.64 compared with low-grade adenomas). Men had a higher number of adenomas per colonoscopy (1.27; 95% CI, 1.21-1.33) than women (0.86; 95% CI, 0.80-0.93). Men were less likely to have missed adenomas than women (OR for missed adenomas in men, 0.73; 95% CI, 0.57-0.94).

CONCLUSIONS

In an analysis of data from 8 randomized trials, we found that right-side location of an adenoma does not increase its odds for being missed during colonoscopy but that adenoma size and histologic features do increase risk. Further studies are needed to determine why adenomas are more frequently missed during colonoscopies in women than men.

Can the rate and location of sessile serrated polyps be part of colorectal Cancer disparity in African Americans?

BACKGROUND

Up to 30% of colorectal cancers develop through the serrated pathway. African Americans (AAs) suffer a disproportionate burden of colorectal cancer. The aim of this study was to evaluate clinicopathological features of AA patients diagnosed with sessile serrated polyps (SSPs).

METHODS

We conducted a retrospective study of all colonoscopies (n = 12,085) performed at Howard University Hospital, from January 1st, 2010 to December 31st, 2015, of which 83% were in AA patients, (n = 10,027). Among AAs, pathology reports confirmed 4070 patients with polyps including 252 with SSPs. Demographic and clinical variables (i.e. sex, age, BMI, anatomic location, clinical symptoms, polyp size, and clinical indications were collected at colonoscopy.

RESULTS

In the AA population, the median age was 56 with interquartile range (IQR) of 51 to 62 years, 54% were female, and 48% had a BMI > 30. The most common reason for colonoscopy was screening (53%), whereas the prevalent reasons for diagnostic colonoscopies were changes in bowel habits (18%) and gastrointestinal bleeding (17%). The total number of SSPs among the 252 AA (diagnosed with SSPs) was 338. Of these, 9% (n = 29/338) had some degree of cytological dysplasia, primarily in the ascending colon (n = 6/42, 14%), Transverse colon (n = 2/16, 13%) and rectosigmoid (n = 19/233, 8%). About 24% of patients had more than 2 polyps. Most patients (76%) had distal SSPs (rectal and rectosigmoid), in comparison to 14% of proximal polyps and 10% of bilateral locations. Median SSA/P size for all locations was 0.6 cm.

CONCLUSION

The prevalence of SSPs accounts for 6% of all polyps in AA patients and was diagnosed in 2.5% of all colonoscopies (n = 252/10,027), which is higher than Caucasians in the US. SSPs were predominantly located in the left side, as compared to published literature showing the predominance in the right side of the colon. Screening of CRC will have the chance to detect high risk SSA/P in this population.

Low detection rate of advanced neoplasia within 5 years after polypectomy of small serrated adenoma

AIM

Patients with small serrated adenomas (SAs) (<10 mm) often undergo surveillance colonoscopy before the routine recommended time. We aimed to determine the appropriate surveillance intervals following polypectomy of small SAs for symptomatic patients.

METHOD

We retrospectively reviewed the data of 638 patients, including 122 cases and 516 controls. Subjects in the case group had small SAs at baseline colonoscopy, including sessile SA/polyps and traditional SAs, while subjects in the control group had negative findings. All patients underwent at least one surveillance colonoscopy during the following 5 years.

RESULTS

There was no significant difference in the incidence rate of advanced neoplasia between the two groups over a 5-year duration (3.6% vs 2.6%, p=0.455). Moreover, both groups also showed a low prevalence of SA formation over 1-5 years (3.6% vs 1.0%, p=0.145). Patients with baseline SA tended to undergo the first surveillance colonoscopy earlier than those without adenoma (≤1 year vs 1 to ≤3 years). Seventy-one (11.1%) of the total included subjects underwent inadequate initial colonoscopy, and 30 (42.3%) underwent early surveillance of adenoma formation within 1 year. Patients with a family history of colorectal cancer (OR 4.69, 95% CI 1.48 to 14.71, p=0.017) or inadequate baseline colonoscopy (OR 3.17, 95% CI 1.202 to 8.409, p=0.035) were at a higher risk of metachronous adenoma formation during the surveillance period.

CONCLUSION

Patients with small SAs at baseline gain little benefit from follow-up of colonoscopy within 5 years after complete polypectomy.

Clinical and endoscopic characteristics of sessile serrated adenomas/polyps with dysplasia/adenocarcinoma in a Korean population: A Korean Association for the Study of Intestinal Diseases (KASID) multicenter study

Sessile serrated adenomas/polyps (SSA/Ps) are precancerous lesions that account for one-third of colorectal cancers. The endoscopic and pathologic differentiation between SSA/Ps without dysplasia (SSA/POs) and SSA/Ps with dysplasia or adenocarcinoma (SSA/PDAs) can be difficult. This study aimed to assess the clinical characteristics of SSA/PDs. This multicenter retrospective cohort study included 532 patients who underwent endoscopic resection and were pathologically diagnosed with SSA/POs and SSA/PDAs. Initially, medical, endoscopic, and histopathological records of patients who underwent endoscopic resection of SSA/POs and SSA/PDAs at eight university hospitals in Korea between January 2005 and December 2015 were reviewed. A total of 307 (57.7%) patients were detected in men and 319 (60.0%) were located in the proximal colon. Most SSA/Ps had a flat, slightly elevated, or sessile morphology. The most prevalent endoscopic findings of SSA/Ps were nodular surface (244, 45.9%), disrupted vascular pattern (232, 43.6%), altered fold contour (141, 26.5%), dome-shaped morphology (135, 25.4%), and pale color (115, 21.6%). SSA/POs were more commonly found in the proximal colon, compared to SSA/PDAs. SSA/PDAs displayed 0-Ip, Isp, IIb or IIa + IIc morphologies more frequently, while SSA/POs displayed 0-Is or IIa morphology more frequently. The frequency of a rim of debris/bubbles was significantly higher in SSA/POs, while nodular surface and disrupted vascular pattern were significantly higher in SSA/PDAs. In the univariate analysis of endoscopic features, SSA/PDAs were significantly associated with the distal colon location, 0-Isp and IIb morphologies, nodular surface, and disrupted vascular pattern. In the multivariate analysis, 0-IIb, nodular surface, and disrupted vascular pattern were significantly associated with SSA/PDAs. SSA/Ps with 0-IIb morphology, nodular surface and disrupted vascular pattern are associated with an increased risk of dysplasia or adenocarcinoma.

Clinicopathological features and endoscopic characteristics of inverted sessile serrated adenomas/polyps

Background and study aims  This study was designed to clarify clinicopathological, endoscopic, and genetic characteristics of inverted sessile serrated adenomas/polyps. Patients and methods  In this retrospective study, we reviewed the pathology reports of patients treated in our hospital between January 2010 and June 2015 and identified sessile serrated adenomas/polyps that were diagnosed with endoscopic resected specimens. Clinicopathological, endoscopic, and genetic features were compared between the inverted and ordinary types. Results  Among the 104 sessile serrated adenomas/polyps, 37 lesions were inverted (35.6 %). The inverted types had two patterns of invasion: expansive and infiltrating growth. Expansive growth was observed in 15 cases (40.5 %) and infiltrating in 22 (59.5 %). Regarding the clinicopathological findings and endoscopic characteristics of the inverted types, presence of adherent mucous, location in the right-side colon, an expanded type-II pit pattern, irregularly dilated vessels, and a depression were demonstrated in 89 % (33/37), 73 % (27/37), 54 % (20/37), 75 % (28/37), and 35 % (13/37), respectively. Contrastingly, these were demonstrated in 86 % (58/67), 84 % (56/67), 55 % (37/67), 58 % (39/67), and 0 % (0/67), respectively, in the ordinary type. In the univariate analysis, male sex and a depression in the adenoma/polyp were significantly associated with inverted types ( P  < 0.001). BRAF mutation at codon 600 was found in six of seven ordinary types and in 11 of 11 of the inverted types. KRAS, NRAS, and PIK3CA mutations were not found in the ordinary and inverted types. Conclusion  More than 30 % of sessile serrated adenomas/polyps were pathologically diagnosed as inverted, and approximately 40 % of them were of the expansive growth type and easily diagnosed with endoscopy.

Impact of 2 generational improvements in colonoscopes on adenoma miss rates: results of a prospective randomized multicenter tandem study

BACKGROUND AND AIMS

Numerous randomized studies have shown that changing certain features of colonoscopes, usually incorporated when switching from one endoscope generation to the next, mostly do not increase adenoma yield. There is, however, indirect evidence that it may be necessary to skip one instrument generation (ie, changing from one generation to the next but one) to achieve this effect.

METHODS

We compared the latest-generation colonoscopes from one company (Olympus Exera III, 190-C) with the next to last one (Olympus 160/5-C) in a prospective multicenter study randomized for the order of colonoscopes in a tandem fashion, involving 2 different examiners. Patients with increased risk for colorectal neoplasia undergoing colonoscopy (positive fecal occult blood test, personal/familial history of colorectal cancer/adenoma, rectal bleeding, recent change in bowel movements) were included. The primary outcome was the adenoma miss rate with the 190 (190-C) colonoscope in comparison with the 160/5 colonoscope (160/5-C).

RESULTS

A total of 856 patients (48.8% male; mean age, 58.3 years) with a personal (41%) or family (38%) history of colorectal neoplasia, rectal bleeding (19%), and other indications were included. Of the 429 patients in the 190-C first group, 16.6% (95% confidence interval [CI], 13.0%-20.1%) had at least one adenoma missed during the first procedure, compared with 30.2% (95% CI, 25.9%-34.6%) in the group with 160/5-C first (P < .001). Similarly, the adenoma detection rate during the first colonoscopy was 43.8% versus 36.5% (P = .030) for 190-C versus 160/5-C, respectively.

CONCLUSIONS

This randomized tandem trial showed lower adenoma miss rates and higher adenoma detection rates for the newer 190 colonoscopes compared with the 160/5 series. These results suggest that it takes multiple improvements, such as those implemented over 2 instrument generations, before an effect on adenoma (miss) rate can be observed. (Study registration number: ISRCTN 2010-A01256-33.).

Helicobacter pylori is associated with increased risk of serrated colonic polyps: Analysis of serrated polyp risk factors

BACKGROUND

Sessile serrated adenomas (SSA) and traditional serrated adenomas (TSA) are recognized precursors of colorectal cancer, but their risk factors are not well established. We investigated the association between Helicobacter pylori infection (HPI) and the development of SSA and TSA.

METHODS

Retrospective data were collected on patients aged ≥ 18 years that underwent colonoscopy with biopsy between 2006 and 2016. Based on histology, patients were classified into three groups: those with SSA and/or TSA, (serrated neoplasia group, SN); conventional adenomas only (CA); and with no polyps (NP). Gastric HPI status, demographic, and clinical risk factors were compared between groups using bivariate and multivariable analysis.

RESULTS

HPI was significantly associated with increased risk of SN (SN vs. NP: OR 1.71 [95% CI 1.29-2.27]; SN vs. CA: 1.49 [1.14-1.96]). Additional factors associated with increased risk of SN included the following: age 50-75 years, compared to younger age (SN vs. NP: 2.83 [1.69-4.74]), female gender (SN vs. CA: 1.28 [0.99-1.64]), White race, compared to Blacks (SN vs. CA: 1.52 [1.07-2.15)], overweight and obese body mass index [SN vs. NP: p < 0.001) and current smoking status (SN vs. CA: 2.09 [1.55-2.82)]. Among SN, higher HPI prevalence was associated with dysplasia (p = 0.05) and proximal location (p = 0.01).

CONCLUSIONS

Our data suggest that gastric HPI is associated with increased risk of SN and CA, with a stronger association with SN as compared to CA. Age 50-75 years, female gender, White race, obesity, and smoking were also predictors of SN. A positive correlation of HPI with proximal and dysplastic SN suggests a possible role in serrated pathway carcinogenesis. Prospective studies with large patient population are needed to further investigate this association.

Exome sequencing characterizes the somatic mutation spectrum of early serrated lesions in a patient with serrated polyposis syndrome (SPS)

Background

Serrated or Hyperplastic Polyposis Syndrome (SPS, HPS) is a yet poorly defined colorectal cancer (CRC) predisposition characterised by the occurrence of multiple and/or large serrated polyps throughout the colon. A serrated polyp-CRC sequence (serrated pathway) of CRC formation has been postulated, however, to date only few molecular signatures of serrated neoplasia (BRAF, KRAS, RNF43 mutations, CpG Island Methylation, MSI) have been described in a subset of SPS patients and neither the etiology of the syndrome nor the distinct genetic alterations during tumorigenesis have been identified.

Methods

To identify somatic point mutations in potential novel candidate genes of SPS-associated lesions and the involved pathways we performed exome sequencing of eleven early serrated polyps obtained from a 41 year-old female patient with clinically confirmed SPS. For data filtering and analysis, standard pipelines were used. Somatic mutations were identified by comparison with leukocyte DNA and were validated by Sanger sequencing.

Results

The BRAF p.V600E or KRAS p.G12D mutation was identified in six polyps (~50%) and not found in polyps from the distal colon. In addition, we found seven unique rare somatic alterations of seven different genes in four serrated tumours, all of which are missense variants. The variant in ABI3BP and CATSPERB are predicted to be deleterious. No established cancer gene or candidate genes related to serrated tumorigenesis were affected.

Conclusions

Somatic mutations seem to be rare events in early hyperplastic and serrated lesions of SPS patients. Neither frequently affected genes nor enrichment of specific pathways were observed. Thus, other alterations such as non-coding variants or epigenetic changes might be the major driving force of tumour progression in SPS.

Electronic supplementary material

The online version of this article (10.1186/s13053-017-0082-9) contains supplementary material, which is available to authorized users.

Carbon dioxide insufflation is associated with increased serrated polyp detection rate when compared to room air insufflation during screening colonoscopy

BACKGROUND AND STUDY AIMS

Sessile serrated adenomas (SSA) and traditional serrated adenomas (TSA) have been increasingly recognized as precursors of colorectal cancer. The aim of this study was to compare the effect of carbon dioxide insufflation (CO ₂ I) vs. room air insufflation (AI) on serrated polyp detection rate (SPDR) and to identify factors associated with SPDR.

PATIENTS AND METHODS

Single-center retrospective cohort study of 2083 screening colonoscopies performed with AI (November 2011 through January 2013) or CO ₂ I (February 2013 to June 2015). Data on demographics, procedure characteristics and histology results were obtained from a prospectively maintained endoscopy database and chart review. SPDR was defined as proportion of colonoscopies in which ≥ 1 SSA, TSA or hyperplastic polyp (HP) ≥ 10 mm in the right colon was detected. Multi-variate analysis (MVA) was performed to identify predictors of SPDR.

RESULTS

A total of 131 histologically confirmed serrated polyps (129 SSA, 2 TSA and 0 HP ≥ 10 mm) were detected. SPDR was higher with CO ₂ I vs. AI (4.8 % vs. 1.4 %; P  < 0.0001). On MVA, CO ₂ I was associated with higher SPDR when compared to AI (OR: 9.52; 95 % CI: 3.05 - 30.3). Both higher body mass index (OR 1.05; 95 % CI:1.02 - 1.09) and longer colonoscope withdrawal time (OR 1.11; 95 % CI: 1.07 - 1.16) were also associated with higher SPDR.

CONCLUSION

CO ₂ I is associated with higher SPDR when compared to AI during screening colonoscopy. While the mechanism remains unknown, we speculate that the favorable gas characteristics of CO ₂ compared to room air results in improved polyp detection by optimizing bowel insufflation. These findings suggest an additional reason to prefer the use of CO ₂ I over AI during colonoscopy.

XB130 enhances invasion and migration of human colorectal cancer cells by promoting epithelial‑mesenchymal transition

The expression of XB130 is associated with invasion and migration of many tumor cells, but its roles in human colorectal cancer (CRC) remains unknown. To investigate this, protein expression levels of XB130 in numerous human CRC cell lines were compared with a normal colorectal mucosa cell line by western blotting. Knockdown of XB130 using small interfering (si)RNA was performed to assess the effects on cell invasion and migration in a Transwell assay and a scratch test. Western blotting was also used to quantify the levels of proteins associated with epithelial‑mesenchymal transition (EMT), including E‑cadherin, vimentin, phosphorylated (p)‑protein kinase B (AKT), p‑forkhead homeobox type O 3a (FOXO3a) and zinc finger E‑box‑binding homeobox 1 (ZEB‑1). The relative expression of XB130 protein was significantly higher in CRC cells compared with control cells (P<0.01). Knockdown of XB130 using siRNA significantly decreased the invasive and migratory responses of CRC cells (P<0.01). In addition, levels of E‑cadherin were increased, while vimentin, p‑AKT, p‑FOXO3a and ZEB‑1 were decreased (P<0.01). In conclusion, the present study demonstrated that the expression of XB130 is elevated in CRC cells. Loss of XB130 was associated with decreased invasion and migration of CRC cells, possibly as a result of EMT inhibition. Thus, upregulation of XB130 may underlie some of the tumorigenic events observed in human CRCs. XB130 may be a promising target for CRC therapy in humans; further mechanistic studies exploring the function of XB130 in CRC cells are warranted.

Colon capsule endoscopy: toward the future

Colon capsule endoscopy is a wireless and minimally invasive technique for visualization of the whole colon. With recent improvements of technical features in second-generation systems, a more important role for colon capsule endoscopy is rapidly emerging. Although several limitations and drawbacks are yet to be resolved, its usefulness as a tool for colorectal cancer screening and monitoring disease activity in inflammatory bowel diseases has become more apparent with increased use. Further investigations, including multicenter trials, are required to evaluate the substantial role of the colon capsule in managing colorectal diseases.

Role of CDH13 promoter methylation in the carcinogenesis, progression, and prognosis of colorectal cancer: A systematic meta-analysis under PRISMA guidelines

BACKGROUND

H-cadherin (CDH13) is commonly downregulated through promoter methylation in various cancers. However, the role of CDH13 promoter methylation status in patients with colorectal cancer (CRC) remains to be clarified.

METHODS

Eligible articles were identified from online electronic database based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement criteria. The pooled odds ratio (OR) and the corresponding 95% confidence interval (95% CI) were calculated and analyzed.

RESULTS

Eventually, a total of nine studies were included in this meta-analysis, including 488 CRC, 298 adjacent, 144 normal, 68 premalignant tissues. The results demonstrated that CDH13 promoter methylation was notably higher in CRC than in normal, adjacent, and premalignant tissues (cancer tissues vs normal tissues: OR = 16.94, P < 0.001; cancer tissues vs adjacent tissues: OR = 20.06, P < 0.001; cancer tissues vs premalignant tissues: OR = 2.23, P = 0.038). CDH13 promoter methylation had a significantly increased risk for poorly differentiated CRC (OR = 4.07, P = 0.001). CDH13 promoter methylation was not associated with sex status, tumor stage, and lymph node status (all P > 0.05). One study with 85 CRC patients reported that CDH13 promoter methylation was correlated with poor prognosis in overall survival (OS).

CONCLUSIONS

CDH13 promoter methylation may play an important role in the initiation and progression of CRC, and may be correlated with OS of patients with CRC. Additional studies with large sample sizes are needed to further confirm our findings in the future.