Human fecal alpha-glucosidase activity and its relationship with gut microbiota profiles and early stages of intestinal mucosa damage.

OBJECTIVES: We investigated potential relationships among initial lesions of the intestinal mucosa, fecal enzymatic activities and microbiota profiles. METHODS: Fecal samples from 54 volunteers were collected after recruitment among individuals participating in a colorectal cancer (CRC) screening program in our region (Northern Spain) or attending for consultation due to clinical symptoms; intestinal mucosa samples were resected during colonoscopy. Enzymatic activities were determined in fecal supernatants by a semi-quantitative method. The fecal microbiota composition was determined by 16S rRNA gene-based sequencing. The results were compared between samples from clinical diagnosis groups (controls and polyps), according with the type of polyp (hyperplastic polyps or conventional adenomas) and considering the grade of dysplasia for conventional adenomas (low and high grade dysplasia). RESULTS: High levels of α-glucosidase activity were more frequent among samples from individuals diagnosed with intestinal polyps, reaching statistical significance for conventional adenomas and for low grade dysplasia adenomas when compared to controls. Regarding the microbiota profiles, higher abundance of Christensenellaceae_R-7 group and Oscillospiraceae_UCG-002 were found in fecal samples displaying low α-glucosidase activity as compared with those with higher activity as well as in controls with respect to conventional adenomas. A relationship was evidenced among intestinal mucosal lesions, gut glucosidase activities and intestinal microbiota profiles. CONCLUSIONS: Our findings suggest a relationship among altered fecal α-glucosidase levels, the presence of intestinal mucosal lesions, which can be precursors of CRC, and shifts in defined microbial groups of the fecal microbiota.

Accuracy and Inter-observer Agreement Among Endoscopists for Visual Identification of Colorectal Polyps Using Endoscopy Images.

BACKGROUND: It is essential to accurately distinguish small benign hyperplastic colon polyps (HP) from sessile serrated lesions (SSL) or adenomatous polyps (TA) based on endoscopic appearances. Our objective was to determine the accuracy and inter-observer agreements for the endoscopic diagnosis of small polyps. METHODS: High-quality endoscopic images of 30 small HPs, SSLs, and TAs were used randomly to create two-timed PowerPoint slide sets-one with and another one without information on polyp size and location. Seven endoscopists viewed the slides on two separate occasions 90 days apart, identified the polyp type, and graded their confidence level. Overall and polyp-specific accuracies were assessed for the group and individual endoscopists. Chi-square tests and Kappa (κ) statistics were used to compare differences as appropriate. RESULTS: When polyp size and location were provided, overall accuracy was 67.1% for TAs, 50.0% for SSLs, and 41.4% for HPs; the corresponding accuracies were 60%, 44.3%, and 34.3% when polyp size and location were withheld (p < .001). Inter-observer agreement was moderate for TAs (κ = 0.50) and fair for SSLs (κ = 0.26) and HPs (κ = 0.29); the corresponding inter-observer agreements were 0.44, 0.31, and 0.17 with polyp size and location withheld. Accuracy was not affected by knowledge of polyp size, location, or confidence level. Endoscopists with ≥ 10 years (vs. < 10 years) of colonoscopy experience had marginally higher (56% vs. 40%, p = 0.05) accuracy for SSL diagnosis. CONCLUSIONS: The ability to distinguish between small TAs, SSLs, and HPs on their endoscopic appearance is poor regardless of the endoscopists' knowledge of polyp size and location.

Increased GS-II lectin binding and SATB2 downregulation are biological features for sessile serrated lesions and microvesicular hyperplastic polyps.

Sessile serrated lesions (SSLs) and microvesicular hyperplastic polyps (MVHPs) are colorectal lesions displaying gastric differentiation. Griffonia simplicifolia-II (GS-II) is a lectin specific to terminal α/ßGlcNAc residues. Here, we assessed GS-II binding and performed immunostaining for HIK1083 (specific to terminal αGlcNAc residues), MUC5AC, MUC6, and special AT-rich sequence binding protein 2 (SATB2) in SSLs, MVHPs, and tubular adenomas (TAs). We observed MUC5AC positivity in 28 of 30 SSLs, but in only three of 23 TAs. Moreover, 24 of 30 SSLs were MUC6-positive, while none of the 23 TAs were MUC6-positive. None of the 30 SSLs or 23 TAs showed HIK1083 positivity. All 30 SSLs and 26 MVHPs were GS-II-positive, while only seven of 23 were in TAs. GS-II staining was mainly distributed in the Golgi region, but SSLs and MVHPs showed goblet cell distribution, in 20 of 30 and 19 of 26 cases, respectively. All SSLs, MVHPs, and TAs were SATB2-positive, but 21 of 30 SSLs and 12 of 26 MVHPs showed decreased staining intensity relative to adjacent mucosa, a decrease seen in only two of 23 in TAs. These results indicate overall that increased terminal ßGlcNAc and decreased SATB2 expression are characteristics of SSLs and MVHPs.

Gastric lesions in patients with autoimmune metaplastic atrophic gastritis: a retrospective study in a single center.

OBJECTIVES: The presence of autoimmune metaplastic atrophic gastritis (AMAG) may lead to an increased risk of associated gastric neoplastic lesions. This study aims to investigate the prevalence of gastric neoplasia in AMAG patients and to explore the possibility of PGI/II ratio as a predictor for AMAG diagnosis. PATIENTS AND METHODS: Retrospective audit of 135 patients diagnosed with AMAG on endoscopic gastric biopsy between January 2017 and December 2020 at Beijing Friendship Hospital. The study was registered in Chinese Clinical Trial Registry (ChiCTR2000041163). RESULTS: A total of 135 patients (the mean age 61.9 ± 10.9 years,109 female) had histologically confirmed AMAG. 31.1% (42/135) had AMAG without neoplasia on the initial biopsy; 37% (50/135) had multiple type 1 gastric neuroendocrine tumors (g-NETs), 36 grade 1 and 14 grade 2, the median diameter was 5 mm (range 1-25); 31.9% (43/135) had multiple gastric hyperplastic polyps (GHPs), including 15 cases of GHPs with neoplastic transformation, the median diameter was 14.5 mm (range 3-50). 3.7% (5/135) had single gastric low-grade dysplasia/adenoma, the median diameter was 5 mm (range 3-15). 5.9% (8/135) had single or double gastric high-grade dysplasia or adenocarcinoma, the median diameter was 15 mm (range 8-43). 40.7% (55/135) had pepsinogen (PG) I< 10 ng/ml, 45.9% (62/135) had PG I/II ratio ≤1 and each group had a median of PG I/II ratio <1. CONCLUSIONS: Lower serum PG I level and PGI/II ratio may be a predictor to indicate the diagnosis of AMAG. It's necessary to perform regular endoscopic surveillance for AMAG patients to recognize associated gastric neoplasia timely.

Effect of Helicobacter pylori eradication on hyperplastic gastric polyps: A systematic review and meta-analysis.

BACKGROUND: There is increasing evidence that the eradication of Helicobacter pylori leads to the regression of gastric hyperplastic polyps (GHPs). We performed a systematic review with a meta-analysis of randomized controlled trials and observational studies that assessed the effects of eradication. MATERIALS AND METHODS: We searched the PubMed, Embase, and Cochrane Central Register of Controlled Trials databases for relevant studies with a combination of the terms "Helicobacter pylori" and "polyps." The risk ratio was used to compare the effect of H. pylori eradication/treatment on GHP. We also calculated the pooled disappearance rate of GHP in the H. pylori eradication/treatment group and persistent infection group. RESULTS: We analyzed data from 6 studies, including 3 RCTs. A total of 58/394 patients were included in the H. pylori treatment/successful eradication group, and 57/302 patients were included in the H. pylori untreated/persistent infection group. The pooled rate of GHP elimination after H. pylori treatment/successful eradication was 59% (95% CI, 43%-75%)/79% (95% CI, 72%-86%). H. pylori treatment/successful eradication significantly increased the GHP elimination rate [ITT: (pooled rate: 58% vs. 0%, RR =22.24, 95% CI, 4.51- 109.78, p = 0.0001), PP: (pooled rate: 65% vs. 0%, RR =22.25, 95% CI, 4.52- 109.37, p = 0.0001)/(pooled rate: 79% vs. 9%, RR =26.87, 95% CI, 1.34-540.5, p = 0.03)]. CONCLUSIONS: Our meta-analysis showed that after the eradication of H. pylori, most GHPs are eliminated. Moreover, the treatment/successful eradication of H. pylori increased the GHP elimination rate by more than 20 times that in the control group.

Endoscopic diode laser therapy for gastric hyperplastic polyps in cirrhotic patients.

Purpose Endoscopic polypectomy to remove gastric hyperplastic polyps in cirrhotic patients is associated to a high risk of postprocedural bleeding. The current study set out to examine the effect of diode laser therapy used to treat this type of polyps in cirrhotic patients. Methods This single-center study retrospectively examined the data of cirrhotic patients with macroscopic bleeding or anemia who underwent diode laser therapy (940 nm wave length, 30-W power setting in continuous mode) to remove histology-confirmed hyperplastic gastric polyps. Results A total of 222 polyps (mean diameter 10 ± 8 mm) were treated in 55 patients who were included in the study. No complications such as bleeding or perforations were reported. After a mean of 5 ± 4 sessions, 31 patients (56%) were completely healed. In 16 patients (29%), there was only a partial response (mean polyp reduction diameter of 64 ± 15%), while 8 (15%) patients did not respond to treatment. Statistically significant better results were noted in the patients who underwent ≥ 2 laser sessions. Hemoglobin levels and number of blood transfusions required were not statistically different after treatment. After a mean study period of 21 ± 17 months, polyp recurrences were noted in 11 patients (20%), but none of the polyps had degenerated. Conclusion Diode laser therapy was found to be a safe treatment for hyperplastic polyps in cirrhotic patients. Due to the presence of others bleeding lesions in cirrhotic patients, this treatment did not have an impact on anemia and transfusion requirements.

Yogurt consumption and colorectal polyps.

Diet modifies the risk of colorectal cancer (CRC), and inconclusive evidence suggests that yogurt may protect against CRC. We analysed the data collected from two separate colonoscopy-based case-control studies. The Tennessee Colorectal Polyp Study (TCPS) and Johns Hopkins Biofilm Study included 5446 and 1061 participants, respectively, diagnosed with hyperplastic polyp (HP), sessile serrated polyp, adenomatous polyp (AP) or without any polyps. Multinomial logistic regression models were used to derive OR and 95 % CI to evaluate comparisons between cases and polyp-free controls and case-case comparisons between different polyp types. We evaluated the association between frequency of yogurt intake and probiotic use with the diagnosis of colorectal polyps. In the TCPS, daily yogurt intake v. no/rare intake was associated with decreased odds of HP (OR 0·54; 95 % CI 0·31, 0·95) and weekly yogurt intake was associated with decreased odds of AP among women (OR 0·73; 95 % CI 0·55, 0·98). In the Biofilm Study, both weekly yogurt intake and probiotic use were associated with a non-significant reduction in odds of overall AP (OR 0·75; 95 % CI 0·54, 1·04) and (OR 0·72; 95 % CI 0·49, 1·06) in comparison with no use, respectively. In summary, yogurt intake may be associated with decreased odds of HP and AP and probiotic use may be associated with decreased odds of AP. Further prospective studies are needed to verify these associations.

Detection and clinical characteristics of serrated polyps and conventional adenomas between patients in the outpatient and physical checkup unit receiving colonoscopy.

PURPOSE: The sessile serrated adenoma/polyp detection rate (SSA/PDR) among different colonoscopy indications from daily practice has not been fully understood. This study aimed to evaluate the detection and clinical characteristics of serrated polyps and conventional adenomas between outpatient department (OPD) and physical checkup unit (PCU) patients receiving colonoscopy. METHODS: The data for this retrospective study were collected between 2016 and 2017 at Kaohsiung Veterans General Hospital in Taiwan. A total of 7047 individuals were included, and information on polyp and adenoma detection was extracted from the colonoscopy reports. RESULTS: The adenoma detection rate, the SSA/PDR, and the detection rate of traditional serrated adenoma (TSA) were 32.2%, 0.60%, and 0.50%, respectively. Risk analysis revealed no significant difference (p = 0.095) in SSA/PDR between individuals < 50 years and ≥ 50 years, and no trend of increased SSA/PDR as age increased was observed (p = 0.320). SSA/P and TSA had higher risks for synchronous advanced neoplasia than conventional adenoma, but with proximal hyperplastic polyps lower (p < 0.001, respectively). No significant difference of SSA/PDR between OPD and PCU patients was observed (p = 1.000); however, the age of SSA/P was significantly older in OPD than in PCU patients (p = 0.048). CONCLUSION: The detection rates of CA and TSA were associated with age groups; however, SSA/PDR was insignificantly higher among individuals aged < 50 years than those with other age groups. In addition, SSA/PDR between OPD and PCU patients was not significantly found in daily practice of colonoscopies.

Small RNA sequencing of sessile serrated polyps identifies microRNA profile associated with colon cancer.

Sessile serrated adenoma/polyps (SSA/Ps) of the colon account for 20-30% of all colon cancers. Small non-coding RNAs, including microRNAs (miRNAs), may function as oncogenes or tumor suppressor genes involved in cancer development. Small RNA sequencing (RNA-seq) was used to characterize miRNA profiles in SSA/Ps, hyperplastic polyps (HPs), adenomatous polyps and paired uninvolved colon. Our 108 small RNA-seq samples' results were compared to small RNA-seq data from 212 colon cancers from the Cancer Genome Atlas. Twenty-three and six miRNAs were differentially expressed in SSA/Ps compared to paired uninvolved colon and HPs, respectively. Differential expression of MIR31-5p, MIR135B-5p and MIR378A-5p was confirmed by RT-qPCR. SSA/P-specific miRNAs are similarly expressed in colon cancers containing genomic aberrations described in serrated cancers. Correlation of miRNA expression with consensus molecular subtypes suggests more than one subtype is associated with the serrated neoplasia pathway. Canonical pathway analysis suggests many of these miRNAs target growth factor signaling pathways.

Impact of reassessment of colonic hyperplastic polyps by expert GI pathologists.

BACKGROUND: Recommended follow-up intervals after endoscopic removal of hyperplastic polyps (HP) and sessile serrated adenomas (SSA) differ because of assumed differences in biological behaviour. However, histopathologic differentiation is difficult, with higher SSA rates reported from specialist GI histopathologists. OBJECTIVE: The objective of this study was to clarify the relevance of histologic reassessment of HP. DESIGN AND SETTING: From a prospective screening colonoscopy study relevant serrated lesions (excluding distal small HP ≤5 mm) diagnosed by private practice pathologists were reassessed by four specialized GI pathologists PATIENTS: One thousand sixty-nine screening colonoscopies were performed in patients. MAIN OUTCOME MEASUREMENTS: In terms of main outcome measurements, there is a likelihood of changes of the HP diagnosis on reassessment, as well as interrater variability. RESULTS: SSA were initially diagnosed in 7 cases (0.7%) and relevant HP in 83 (7.8%; 101 lesions). Of the latter, the chance of a change in diagnosis from HP to SSA by any of the four specialist histopathologists was higher for larger (>5 mm) and right-sided lesions (19.1 vs 1.3%, OR 18.4, p = 0.04) including a higher likelihood to change recommended follow-up intervals (32.1 vs 3.3%, p < 0.01). However, follow-up intervals were determined by concomitant adenomas in 41%. Interrater variability was also higher for these lesions (p = 0.04), with an overall kappa value of 0.48. However, this issue related to only 1.2% of the 1069 study cases. LIMITATION: The limitations this study are the limited case number as well as limited retrospective assessment. CONCLUSIONS: Right-sided HP >5 mm had a higher chance of change in diagnosis to SSA; therefore, they should probably be treated like adenomas and be removed. However, reliable data for recommendations on follow-up intervals of HP or SSA will require follow-up studies.

Risk of Colorectal and Other Cancers in Patients With Serrated Polyposis.

Patients with serrated polyposis develop multiple colorectal hyperplastic and/or serrated sessile adenomas/polyps. We investigated the risk of colorectal and other cancers by analyzing data from 64 patients with serrated polyposis (mean age at diagnosis, 54 y; 41% men; 92% white) listed in the Johns Hopkins Polyposis Registry. Medical, endoscopic, and histopathology reports were evaluated. Six patients (9.4%) had a history of colorectal cancer, diagnosed at a mean age of 56 years; 6 additional patients (9.4%) had at least 1 advanced colorectal adenoma. Extracolonic cancers were found in 16% of the study population. The standard incidence ratio for colorectal cancer in patients with serrated polyposis was 18.72 (95% confidence interval, 6.87-40.74) and for extracolonic cancer was 31.20 (95% confidence interval, 14.96-57.37), compared with the Surveillance, Epidemiology, and End Results population. Patients with serrated polyposis therefore have a high risk for colorectal cancer and require vigilant colorectal surveillance, starting at the time of diagnosis of serrated polyposis. The risk of extracolonic cancer also appears to be increased, but this requires further evaluation.

Colonoscopy findings in high-risk individuals compared to an average-risk control population.

BACKGROUND AND AIMS: There is clear evidence of reduced morbidity and mortality from regular colonoscopy programs in patients with Lynch syndrome (LS). Today, also individuals with empirically increased risks of colorectal cancer (CRC) are offered colonoscopic surveillance. The aim was to compare the findings at the first screening colonoscopy in LS carriers, and individuals with an increased risk of bowel cancer due to family history of CRC with a control population. METHODS: Altogether 1397 individuals with an increased risk for CRC were divided in four risk groups: one with LS carriers and three groups with individuals with different family history of CRC. The findings were compared between the different risk groups and a control group consisting of 745 individuals from a control population who took part in a population-based colonoscopy study. RESULTS: In LS, 30% of the individuals had adenomas and 10% advanced adenomas. The corresponding figures in the other risk groups were 14-24% and 4-7%, compared with 10% and 3% in the control group. The relative risk of having adenomas and advanced adenomas was, compared to controls, significantly higher for all risk groups except the group with the lowest risk. Age was a strong predictor for adenomas and advanced adenomas in both risk individuals and controls. CONCLUSIONS: Individuals with a family history of CRC have a high prevalence and cumulative risk of adenomas and advanced adenomas, and screening is motivated also in this risk group.

Phenotype characteristics of patients with colonic serrated polyposis syndrome: a study of 23 cases.

INTRODUCTION: Serrated polyposis syndrome (SPS) is a rare entity characterized by the presence of multiple hyperplastic polyps in the colon and an increased risk of presentation and development of colorectal cancer (CRC). OBJECTIVE: To evaluate the clinical and phenotypical characteristics of patients that present one of the 3 WHO criteria for the diagnosis of SPS diagnosed and treated a tour hospital. PATIENTS AND METHODS: Patients with the diagnosis of SPS during 2005-2012 were revised; 24.208 colonoscopies were performed during this period. Age, sex, family history of CRC (APC/MYH), proximal/mixed/distal phenotype, indication for colonoscopy, number, size, location of the hyperplastic polyps, presence of mixed/adenomatous polyps, CRCI, follow-up and endoscopio/surgical treatment. RESULTS: A total of 23 cases were included (19 male). The median age was 51. A total of 34% had a prior family history of CRC or polpyps. Distal phenotype was more frequent (48%). Another 73% presented synchronous adenomatous polyps, and 26% a CRC. A total of 57% were asymptomatic. Surgery was performed in 9 cases (6 for cancer and 3 for polyposis), and 14 were treated by polypectomy and observation. Eleven patients (47%) presented recurrent/persistent lesions after initial surgical/endoscopic treatment. CONCLUSION: SPS is an heterogeneous syndrome that is variable in the type, size, distribution and number of polyps, and is more common in male smokers with a distal phenotype. The majority of patients also present synchronous adenomatous polyps. These patients require an organized multidisciplinary evaluation.

A Large Xanthomatous Hyperplastic Polyp: An Unusual Case of Dyspepsia.

Gastric hyperplastic polyps (GHP) are one of the most common gastric epithelial polyps. They are generally asymptomatic and often discovered incidentally during endoscopic procedures. In this article, we present the case of a 36-year-old patient with dyspepsia attributed to the prolapse of a large gastric hyperplastic polyp with extensive xanthomatous change. The endoscopic findings revealed that the motion of the large polyp caused an intermittent pyloric obstruction. The large polyp was removed through a successful snare polypectomy, resolving the patient's symptoms. While dyspepsia is predominantly associated with functional causes, it is crucial to consider structural factors like GHP, particularly in the case of large polyps, as part of the differential diagnosis.

Increased circulating regulatory T cells and decreased follicular T helper cells are associated with colorectal carcinogenesis.

Objective: Colorectal cancer (CRC) is the third most prevalent cancer worldwide and is associated with high morbidity and mortality rates. Colorectal carcinogenesis occurs via the conventional adenoma-to-carcinoma and serrated pathways. Conventional T helper (Th) and innate lymphoid cells (ILCs) play vital roles in maintaining intestinal homeostasis. However, the contribution of these two major lymphoid cell populations and their associated cytokines to CRC development is unclear. Therefore, we aimed to analyze peripheral lymphocyte profiles during colorectal carcinogenesis. Methods: We collected 86 blood samples concurrently, and pathologists confirmed the presence of various pathological conditions (i.e., HPs, adenoma, and carcinoma) using hematoxylin and eosin staining. Ten healthy donors were recruited as healthy controls (HCs) from the physical examination center. We performed flow cytometry on peripheral blood mononuclear cells collected from patients with various pathological conditions and the HCs, and cytokines (interleukin-2, interleukin-4, interleukin-5, interleukin-13, interleukin-17A, interleukin-17F, interleukin-22, interferon-γ, and tumor necrosis factor-α) were quantified. We also analyzed the published single-cell RNA sequence data derived from tissue samples from different stages of colorectal carcinogenesis. Results: The cytokine response in peripheral CD4+ T cells was upregulated during the carcinoma process. The frequency of peripheral regulatory T cells (Tregs) increased in the adenoma and carcinoma stages. While the T follicular helper (Tfh) cell proportion was downregulated in the adenoma and carcinoma processes. Thus, Th cell subsets, especially Tregs and Tfh cells, were involved in colonic diseases. Moreover, the immunological profile characteristics in the HPs were clarified. Conclusion: We comprehensively analyzed circulating ILCs and adaptive T-cell lymphocyte subtypes in colorectal carcinoma progression. Our results show the immunological profile characteristics and support the involvement of Th subsets, especially Treg and Tfh cell populations, in colonic diseases. These findings significantly enhance our understanding of the immune mechanisms underlying CRC and its precancerous lesions. Further investigation of the Treg and Tfh cells' function in colorectal disease development will provide potential therapeutic targets for monitoring and preventing CRC development.

Development of Gastric Polyps: 15 Years of Proton Pump Inhibitor Therapy.

Gastroesophageal reflux disease (GERD) is a common disease affecting millions of people worldwide. Proton pump inhibitors (PPI) are the most common drugs used to treat this acid-related disorder due to their high efficacy and fewer side effects. However, long-term use of these drugs can cause histopathological changes, including cystic dilation of gastric fundic glands. The present report describes a 53-year-old man with chronic GERD and daily use of PPIs 20 mg once a day for over 15 years. This case demonstrates the association between PPI and the development of fundic gland polyps.

Novel classification of gastric polyps: The good, the bad and the ugly.

Gastric polyps (GPs) are increasingly common. On upper endoscopy, they should be examined with white light and occasionally chromoendoscopy, and their morphology classified according to the Paris classification. Most GPs have a typical endoscopic appearance and can be associated with diseases like Helicobacter pylori infection. Histological examination is necessary for an accurate diagnosis. While most polyps are non-neoplastic and do not require treatment, some carry a risk of malignancy or are already malignant. Therefore, understanding the diagnosis, classification, and management of GPs is crucial for patient prognostication. Our new classification categorizes GPs into "good", "bad", and "ugly" based on their likelihood of becoming malignant. We aim to provide descriptions of the endoscopic appearance, pathology, treatment, and follow-up for different GPs, as well as clinical management flowcharts.

Dietary Nitrosamines from Processed Meat Intake as Drivers of the Fecal Excretion of Nitrosocompounds.

Diet is one of the main exogenous sources of potentially carcinogenic nitrosamines (NAs) along with tobacco and cosmetics. Several factors can affect endogenous N-nitroso compounds (NOCs) formation and therefore the potential damage of the intestinal mucosa at initial colorectal cancer stages. To address this issue, 49 volunteers were recruited and classified according to histopathological analyses. Lifestyle and dietary information were registered after colonoscopy. The mutagenicity of fecal supernatants was assayed by a modified Ames test. Fecal heme-derived NOCs and total NOC concentrations were determined by selective denitrosation and chemiluminescence-based detection. Results revealed processed meats as the main source of dietary nitrites and NAs, identifying some of them as predictors of the fecal concentration of heme-derived and total NOCs. Furthermore, increased fecal NOC concentrations were found as the severity of colonic mucosal damage increased from the control to the adenocarcinoma group, these concentrations being strongly correlated with the intake of the NAs N-nitrosodimethylamine, N-nitrosopiperidine, and N-nitrosopyrrolidine. Higher fecal NOC concentrations were also noted in higher fecal mutagenicity samples. These results could contribute to a better understanding of the importance of modulating dietary derived xenobiotics as related with their impact on the intestinal environment and colonic mucosa damage.

The histologic features, molecular features, detection and management of serrated polyps: a review.

The serrated pathway to colorectal cancers (CRCs) is a significant pathway encompassing five distinct types of lesions, namely hyperplastic polyps (HPs), sessile serrated lesions (SSLs), sessile serrated lesions with dysplasia (SSL-Ds), traditional serrated adenomas (TSAs), and serrated adenoma unclassified. In contrast to the conventional adenoma-carcinoma pathway, the serrated pathway primarily involves two mechanisms: BRAF/KRAS mutations and CpG island methylator phenotype (CIMP). HPs are the most prevalent non-malignant lesions, while SSLs play a crucial role as precursors to CRCs, On the other hand, traditional serrated adenomas (TSAs) are the least frequently encountered subtype, also serving as precursors to CRCs. It is crucial to differentiate these lesions based on their unique morphological characteristics observed in histology and colonoscopy, as the identification and management of these serrated lesions significantly impact colorectal cancer screening programs. The management of these lesions necessitates the crucial steps of removing premalignant lesions and implementing regular surveillance. This article provides a comprehensive summary of the epidemiology, histologic features, molecular features, and detection methods for various serrated polyps, along with recommendations for their management and surveillance.