The association between location, age and advanced colorectal adenoma characteristics: a propensity-matched analysis

Clinicopathologic and endoscopic features of sessile serrated lesions and conventional adenomas: a large inpatient population-based study in China

Objectives

Sessile serrated lesions (SSLs) are precursors of sporadic colorectal cancer (CRC) and have distinct characteristics compared with conventional adenomas (CAs). Several lifestyle and environmental factors may play critical roles in the development of advanced lesions. Our aim is to describe the features of SSLs and CAs and further explore risk factors for advanced lesions.

Methods

This is an observational study that collected demographic, endoscopic, and histological data from the China-Japan Friendship Hospital among the inpatient population with pathologically reported as SSL or CA between 2015 and 2022. We analyzed the clinicopathology and endoscopic differences between SSL alone, CA alone, and synchronous SSL+CA groups, and identified risk factors using multiple regression analysis.

Results

A total of 9236 polyps from 6598 patients were included in the cohort. Patients with SSL+CA were more likely to be older (p=0.008), while individuals with SSL alone had a higher proportion of early-onset polyps (p<0.001), and SSLs were more common in advanced polyps than CAs (p<0.001). A greater proportion of advanced polyps in the SSL and CA groups were diagnosed as Yamada III, Yamada IV, and laterally spreading tumor (p=0.002, p<0.001, respectively), and multiple SSLs and CAs were more represented in nonadvanced polyps than in advanced polyps. In multiple regression analysis, older patients were more likely to develop advanced SSLs (aOR 1.05, 95% CI 1.02-1.09, p=0.005).

Conclusion

SSLs and CAs have diverse demographic, endoscopic, and histological characteristics, and their advanced lesions share different risk factors, which advances the understanding of the etiology and progression of SSLs.

Unlocking quality in endoscopic mucosal resection

A review of the development of the key performance metrics of endoscopic mucosal resection (EMR), learning from the experience of the establishment of widespread colonoscopy quality measurements. Potential future performance markers for both colonoscopy and EMR are also evaluated to ensure continued high quality performance is maintained with a focus service framework and predictors of patient outcome.

Extracellular Nicotinamide Phosphoribosyltransferase as a Surrogate Marker of Prominent Malignant Potential in Colonic Polyps: A 2-Year Prospective Study

BACKGROUND/AIMS

The implications of extracellular nicotinamide phosphoribosyltransferase (eNAMPT), a cancer metabokine, in colonic polyps remain uncertain.

METHODS

A 2-year prospective cohort study of patients who underwent colonoscopy was conducted. Biochemical parameters and serum eNAMPT levels were analyzed at baseline and every 24 weeks postpolypectomy. NAMPT-associated single-nucleotide polymorphisms (SNPs), including rs61330082, rs2302559, rs10953502, and rs23058539, were assayed.

RESULTS

Of 532 patients, 80 (15%) had prominent malignant potential (PMP) in colonic polyps, including villous adenomas (n = 18, 3.3%), adenomas with high-grade dysplasia (n = 33, 6.2%), and adenocarcinomas (n = 29, 5.5%). Baseline associations were as follows: colonic polyp pathology (p < 0.001), total cholesterol (p = 0.019), and neutrophil-to-lymphocyte ratio (p = 0.023) with eNAMPT levels; and age (p < 0.001), polyp size (p < 0.001), and eNAMPT levels (p < 0.001) with polyp pathology. Higher baseline eNAMPT levels were noted in patients harboring polyps with PMP than in patients without PMP (p < 0.001), and baseline eNAMPT levels significantly predicted PMP (cutoff: >4.238 ng/mL, p < 0.001). Proportions of eNAMPT-positive glandular and stromal cells were higher in polyps with PMP than in polyps without PMP (64.55 ± 11.94 vs. 14.82 ± 11.45%, p = 0.025). eNAMPT levels decreased within 48 weeks postpolypectomy (p = 0.01) and remained stable afterward regardless of PMP until 96 weeks postpolypectomy. However, those with PMP had a higher degree of eNAMPT decline within 24 weeks (p = 0.046). All investigated SNPs were in linkage disequilibrium with each other but were not associated with eNAMPT levels.

CONCLUSION

With a link to inflammation and lipid metabolism, along with its decreasing trend after polypectomy, serum eNAMPT may serve as a surrogate marker of PMP in colonic polyps. In situ probing of the NAMPT-associated pathway holds promise in attenuating PMP, as much of the eNAMPT likely originates from colonic polyps.

Development and Interpretation of a Clinicopathological-Based Model for the Identification of Microsatellite Instability in Colorectal Cancer

Chemotherapy is not recommended for patients with deficient mismatch repair (dMMR) in colorectal cancer (CRC); therefore, assessing the status of MMR is crucial for the selection of subsequent treatment. This study is aimed at building predictive models to accurately and rapidly identify dMMR. A retrospective analysis was performed at Wuhan Union Hospital between May 2017 and December 2019 based on the clinicopathological data of patients with CRC. The variables were subjected to collinearity, least absolute shrinkage and selection operator (LASSO) regression, and random forest (RF) feature screening analyses. Four sets of machine learning models (extreme gradient boosting (XGBoost), support vector machine (SVM), naive Bayes (NB), and RF) and a conventional logistic regression (LR) model were built for model training and testing. Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive performance of the developed models. In total, 2279 patients were included in the study and were randomly divided into either the training or test group. Twelve clinicopathological features were incorporated into the development of the predictive models. The area under curve (AUC) values of the five predictive models were 0.8055 for XGBoost, 0.8174 for SVM, 0.7424 for NB, 8584 for RF, and 0.7835 for LR (Delong test, P value < 0.05). The results showed that the RF model exhibited the best recognition ability and outperformed the conventional LR method in identifying dMMR and proficient MMR (pMMR). Our predictive models based on routine clinicopathological data can significantly improve the diagnostic performance of dMMR and pMMR. The four machine learning models outperformed the conventional LR model.

Risk factor analysis of malignant adenomas detected during colonoscopy

Background

Several studies have shown that colorectal adenomas are the most important precancerous lesions. The colonoscopic identification of groups with the high risk of malignant colorectal adenomas remains a controversial issue for clinicians.

Aims

To evaluate the basic characteristics of colorectal adenomas with malignancy risk using high-grade dysplasia (HGD) as an alternative marker for malignant transformation.

Methods

Data from Shanghai General Hospital between January 2017 and December 2021 were retrospectively analyzed. The primary outcome was the incidence of HGD in adenomas, which was used as a surrogate marker for the risk of malignancy. Odds ratios (ORs) for the HGD rate in adenomas were analyzed in relation to adenoma-related factors.

Results

A total of 9,646 patients identified with polyps during 57,445 screening colonoscopies were included in the study. Patients with flat polyps, sessile polyps, and pedunculated polyps represented 27.3% (N = 2,638), 42.7% (N = 4,114), and 30.0% (N = 2,894) of the total number, respectively. HGD was found in 2.41% (N = 97), 0.92% (N = 24), and 3.51% (N = 98) of sessile adenomas, flat adenomas, and pedunculated adenomas, respectively (P < 0.001). Multivariable logistic regression showed that polyp size (P < 0.001) but not shape (P > 0.8), was an independent predictor of HGD. Contrast to the diameter ≤1 cm, the OR value for diameters 1-2, 2-3, and >3 cm was 13.9, 49.3, and 161.6, respectively. The HGD incidence also increased in multiple adenomas (>3 vs. >1, ORs 1.582) and distal adenomas (distal vs. proximal adenomas, OR 2.252). Adenoma morphology (pedunculated vs. flat) was statistically significant in univariate analysis but not when size was included in the multivariate analysis. Besides, the incidence of HGD was also significantly higher in older patients (>64 vs. <50 years old, OR = 2.129). Sex (P = 0.681) was not statistically significant. All these associations were statistically significant (P < 0.05).

Conclusion

The malignant potential of polyps is mostly affected by their size but not by their shape. In addition, distal location, multiple adenomas, and advanced age were also correlated with malignant transformation.

Genetic and epigenetic dependencies in colorectal cancer development

Recent studies have mapped key genetic changes in colorectal cancer (CRC) that impact important pathways contributing to the multistep models for CRC initiation and development. In parallel with genetic changes, normal and cancer tissues harbor epigenetic alterations impacting regulation of critical genes that have been shown to play profound roles in the tumor initiation. Cumulatively, these molecular changes are only loosely associated with heterogenous transcriptional programs, reflecting the heterogeneity in the various CRC molecular subtypes and the paths to CRC development. Studies from mapping molecular alterations in early CRC lesions and use of experimental models suggest that the intricate dependencies of various genetic and epigenetic hits shape the early development of CRC via different pathways and its manifestation into various CRC subtypes. We highlight the dependency of epigenetic and genetic changes in driving CRC development and discuss factors affecting epigenetic alterations over time and, by extension, risk for cancer.

Potential Factors Predicting Histopathologically Upgrade Discrepancies between Endoscopic Forceps Biopsy of the Colorectal Low-Grade Intraepithelial Neoplasia and Endoscopic Resection Specimens

BACKGROUND

It was gradually accepted that endoscopic fragment biopsy (EFB) diagnosis cannot accurately guarantee the absence of higher-grade neoplasms within the lesion of the digestive tract. There are no well-established predictors for histopathologically upgrade discrepancies between EFB diagnosing colorectal low-grade intraepithelial neoplasia (LGIN) and endoscopic resection (ER) specimens.

METHODS

A total of 918 colorectal LGINs was histopathologically diagnosed by EFB, including 162 cases with upgrade discrepancy and 756 concordant cases. We compared clinicopathological data of EFB and ER specimens between these two groups. Multivariate analysis was performed to identify predictors for this upgrade histopathology.

RESULTS

The predominant upgrade discrepancy of LGINs diagnosed by EFB was upgrades to high-grade dysplasia (114/918, 12.4%), followed by upgrades to intramucosal carcinoma (33/918, 3.6%), submucosal adenocarcinoma (10/918, 1.1%), and advanced adenocarcinoma (5/918, 0.5%). NSAID history (OR 4.83; 95% CI, 2.27-10.27; p < 0.001), insufficient EFB number (OR 2.99; 95% CI, 1.91-4.68; p < 0.001), maximum diameter ≥ 1.0 cm (OR 6.18; 95% CI, 1.32-28.99; p = 0.021), lobulated shape (OR 2.68; 95% CI, 1.65-4.36; p < 0.001), erythema (OR 2.42; 95% CI, 1.50-3.91; p < 0.001), erosion (OR 7.12; 95% CI, 3.91-12.94; p < 0.001), surface unevenness (OR 2.31; 95% CI, 1.33-4.01; p = 0.003), and distal location of the target adenoma (OR 3.29; 95% CI, 1.68-6.41; p < 0.001) were associated with the histologically upgrade discrepancies.

CONCLUSION

NSAID history, insufficient EFB number, adenoma size and location, and abnormal macroscopic patterns are potential predictors for upgrade histopathology of LGINs diagnosed by EFBs. The standardization of EFB number and advanced imaging techniques could minimize the risk of neglecting the potential of this upgrade histopathology.

The elderly harbor greater proportions of advanced histology in subcentimeter adenomas: implications for screening colonoscopy approaches

BACKGROUND

Screening and surveillance for colorectal cancer can reduce both the incidence of this disease and mortality rates attributed to it. Normally, surveillance intervals should be based on baseline colonoscopy findings, and clinicians focus on advanced polyps and perform patient risk stratification to devise surveillance schedules. The aim of the study was to determine differences in advanced colorectal polyp characteristics and consequent risk stratifications in patients of different age groups.

MATERIAL AND METHODS

We retrospectively reviewed 14 312 patients during a 5-year period; a total of 13 842 polyps were stratified by their sizes, locations, and histologies. Participants were categorized into three age groups, the <45 years group, the 45-59 years group and the >59 years group, and each group was further stratified as normal, low risk, and high risk.

RESULTS

The <45 years group included 2431 subjects, the 45-59 years group 6258 subjects, and the >59 years group 5623 subjects. The frequency of adenoma and advanced polyps in the proximal colon slightly increased with age. Only 1.0% in the <45 years and 1.3% in the 45-59 years groups of subcentimeter polyps were identified as advanced polyps, less than that in the >59 years group (2.1%). Most patients, especially the elderly, considered as high risk had multiple subcentimeter adenomas.

CONCLUSION

The processing strategy proposed for subcentimeter polyps in the elderly still needs to be further explored in the future. Clinicians should recognize the importance of performing a detailed scan of the entire colon.

Analysis of Patients Undergoing Colonoscopies and the Importance of Exam Quality for Colorectal Cancer Screening

Objective To determine the impact of the quality of colonoscopy examination for colorectal cancer screening.

Methods Retrospective observational study of medical records from patients treated at the endoscopy and colonoscopy service of Hospital Universitário Evangélico Mackenzie (Curitiba, PR, Brazil) from January 2019 to January 2020.

Results The analysis was based on 337 medical records from patients with adenomas identified during colonoscopy, and 1,385 medical records from patients without adenomas. The estimated occurrence rate of diagnosis of adenoma during colonoscopy in the target population of the study was of 19.6%, with a 95% confidence interval ranging from 17.7 to 21.5%. Of the 337 patients with adenoma, 136 (40.4%) presented the advanced form. Statistical analysis indicated a significant association between the quality of colonoscopy preparation and test completion.

Conclusion The quality of colonoscopy images is a critical factor for colorectal cancer screening, as it leads to higher rates of adenoma detection and test completion.

Melanosis coli: A factor not associated with histological progression of colorectal polyps

OBJECTIVE

In this study we aimed to investigate the association of melanosis coli (MC) and the colorectal polyp detection rate (PDR).

METHODS

In all, 1104 MC patients and 62 181 non-MC participants were enrolled. And 2208 controls were matched by participants' age and gender, and quality of bowel preparation using the propensity score matching (PSM) method. Additionally, 490 polyps in MC and 980 in controls matched by age and gender, and size and location of polyps were analyzed. The association of PDR and pathological features of polyps with MC were also analyzed.

RESULTS

MC patients showed a higher PDR (44.3% vs 39.3%, P = 0.006) and detection rate of low-grade adenoma (45.4% vs 36.7%, P = 0.002) but fewer large polyps (≥10 mm) (18.8% vs 26.9%, P = 0.001), fewer polyps in the left colon (33.5% vs 40.0%, P = 0.018), and a lower detection rate of advanced adenoma/adenocarcinoma (17.4% vs 24.3%, P = 0.003) than the matched controls. On multivariate logistic regression analysis, MC was independently associated with an increased PDR (odds ratio 1.184, 95% confidence interval 1.045-1.343, P = 0.008). Analysis targeting polyps showed that there were significant differences in age, gender, location, and pathology (P < 0.001) between polyps with and without MC. However, after adjusting for participants' age and gender, size and location of polyps, there was no difference between the two groups in pathology (P = 0.635).

CONCLUSION

MC is independently associated with increased colorectal PDR, but not with histological progression of polyps.

Molecular Aspects of Colorectal Adenomas: The Interplay among Microenvironment, Oxidative Stress, and Predisposition

The development of colorectal cancer (CRC) is a multistep process initiated by a benign polyp that has the potential to evolve into in situ carcinoma through the interactions between environmental and genetic factors. CRC incidence rates are constantly increased for young adult patients presenting an advanced tumor stage. The majority of CRCs arise from colonic adenomas originating from aberrant cell proliferation of colon epithelium. Endoscopic polypectomy represents a tool for early detection and removal of polyps, although the occurrence of cancers after negative colonoscopy shows a significant incidence. It has long been recognized that the aberrant regulation of Wingless/It (Wnt)/β-Catenin signaling in the pathogenesis of colorectal cancer is supported by its critical role in the differentiation of stem cells in intestinal crypts and in the maintenance of intestinal homeostasis. For this review, we will focus on the development of adenomatous polyps through the interplay between renewal signaling in the colon epithelium and reactive oxygen species (ROS) production. The current knowledge of molecular pathology allows us to deepen the relationships between oxidative stress and other risk factors as lifestyle, microbiota, and predisposition. We underline that the chronic inflammation and ROS production in the colon epithelium can impair the Wnt/β-catenin and/or base excision repair (BER) pathways and predispose to polyp development. In fact, the coexistence of oxidative DNA damage and errors in DNA polymerase can foster C>T transitions in various types of cancer and adenomas, leading to a hypermutated phenotype of tumor cells. Moreover, the function of Adenomatous Polyposis Coli (APC) protein in regulating DNA repair is very important as therapeutic implication making DNA damaging chemotherapeutic agents more effective in CRC cells that tend to accumulate mutations. Additional studies will determine whether approaches based on Wnt inhibition would provide long-term therapeutic value in CRC, but it is clear that APC disruption plays a central role in driving and maintaining tumorigenesis.

Location of colorectal adenomas and serrated polyps in patients under age 50

BACKGROUND

The incidence of colorectal cancer, especially located in distal colorectum, is rising markedly in young patients. Conventional adenomas and serrated polyps have been widely recognized as precursors of colorectal cancer.

AIM

To investigate the correlation of polyp feature with polyp location in patients under age 50.

METHOD

Patients under age 50 who had received colonoscopy were included from 2010 to 2018. Clinical data including number, location, size, and histopathology of polyps were collected. Odd ratios and 95% confidence interval of adenomas with their location were calculated.

RESULT

In total, 25,636 patients aged 18-49 were enrolled, among which 4485 patients had polyps, with polyp detection rate of 17.5%. A total of 2484 and 2387 patients had conventional adenomas and serrated polyps, respectively. 76.0% advanced adenomas and 69.5% ≥ 10-mm serrated polyps were located in the distal colorectum. The detection rate of advanced adenomas was higher in patients aged 45-49. Patients with adenomas especially advanced adenomas in the distal colorectum were more likely to have advanced adenoma in the proximal colon.

CONCLUSION

Among patients under age 50, advanced adenomas and ≥ 10-mm serrated polyps were predominantly in the distal colorectum. Advanced adenomas tended to be found in patients aged 45-49. Our results might explain the rising trend of distal colorectal cancer and emphasize the necessity for colonoscopy screening among these populations.

Epidemiology and risk factors of colorectal polyps

The lifetime risk of colorectal cancer (CRC) in the Western world is around 5%. CRC commonly develops from precursor lesions termed polyps, classified as adenomatous or serrated polyps according to growth pattern. Despite the well-known connection between polyps and cancer, most polyps will never develop into CRC. For those that do, the time until CRC development is generally thought of as >10 years. This gives opportunity for interventional strategies to prevent transformation into cancer. This article aims to provide an overview of the epidemiology of and risk factors for colorectal polyps in the average risk population, and will encompass the effect of age, gender, ethnicity, smoking, obesity, alcohol, physical activity, NSAIDs and dietary factors on colorectal polyps.