Automated classification pipeline for real-time in vivo examination of colorectal tissue using Raman spectroscopy

Colorectal cancer is the third most common malignancy worldwide and one of the leading causes of death in oncological patients with its diagnosis typically involving confirmation by tissue biopsy. In vivo Raman spectroscopy, an experimental diagnostic method less invasive than a biopsy, has shown great potential to discriminate between normal and cancerous tissue. However, the complex and often manual processing of Raman spectra along with the absence of a suitable instant classifier are the main obstacles to its adoption in clinical practice. This study aims to address these issues by developing a real-time automated classification pipeline coupled with a user-friendly application tailored for non-spectroscopists. First, in addition to routine colonoscopy, 377 subjects underwent in vivo acquisitions of Raman spectra of healthy tissue, adenomatous polyps, or cancerous tissue, which were conducted using a custom-made microprobe. The spectra were then loaded into the pipeline and pre-processed in several steps, including standard normal variate transformation and finite impulse response filtration. The quality of the pre-processed spectral data was checked based on their signal-to-noise ratio before the suitable spectra were decomposed and classified using a combination of principal component analysis and a support vector machine, respectively. After five-fold cross-validation, the developed classifier exhibited 100% sensitivity toward adenocarcinoma and adenomatous polyps. The overall accuracy was 96.9% and 79.2% for adenocarcinoma and adenomatous polyps respectively. In addition, an application with a graphical user interface was developed to facilitate the use of our data pipeline by medical professionals in a clinical environment. Overall, the combination of supervised and unsupervised machine learning with algorithmic pre-processing of in vivo Raman spectra appears to be a viable way of reducing the relatively large number of biopsies currently needed to definitively diagnose colorectal cancer.

Frequency of colorectal surveillance colonoscopies for adenomatous polyps: systematic review and meta-analysis

BACKGROUND AND AIM

The purpose of this study was to assess evidence on the frequency of polyp surveillance colonoscopies performed earlier than the recommended follow-up intervals in clinical practice guidelines.

METHODS

A systematic review was performed based on electronic searches in PubMed and Embase. Research articles, letters to the editors, and review articles, published before April 2022, were included. Studies that focused on the intervals of polyp surveillance in adult populations were selected. The Risk Of Bias In Non-randomized Studies of Exposure (ROBINS-E) was used to assess the risk of bias. A meta-analysis was performed with Forest plots to illustrate the results.

RESULTS

In total, 16 studies, comprising 11 172 patients from Australia, Europe, and North America, were included for analysis. The quality of the studies was moderate. Overall, 38% (95% CI: 30-47%) of colonoscopies were undertaken earlier than their respective national clinical guidelines. In risk-stratified surveillance, 10 studies contained data relating to low-risk polyp surveillance intervals and 30% (95% CI: 29-31%) of colonoscopies were performed earlier than recommended. Eight studies contained data relating to intermediate-risk polyp surveillance and 15% (95% CI: 14-17%) of colonoscopies were performed earlier than recommended. One study showed that 6% (95% CI: 4-10%) of colonoscopies performed for high-risk polyp surveillance were performed earlier than recommended.

CONCLUSIONS

A significant proportion of polyp surveillance was performed earlier than the guidelines suggested. This provides evidence of the potential overuse of healthcare resources and the opportunity to improve hospital efficiency.

Endoscopic differential diagnosis between foveolar-type gastric adenoma and gastric hyperplastic polyps in Helicobacter pylori-naïve patients

BACKGROUND

Foveolar-type gastric adenoma (FGA) occurs in Helicobacter pylori (Hp)-naïve individuals and morphologically mimics Hp-naïve gastric hyperplastic polyp (HpN-GHP). FGA is often difficult to distinguish from HpN-GHP even by biopsy, due to its low-grade histologic atypia. We conducted a retrospective study to create an endoscopic diagnostic index.

METHODS

We analyzed 51 FGAs in 41 patients and 36 HpN-GHPs in 24 patients. All lesions were photographed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). Three experts and three non-experts reviewed the WLE and WLE+NBIME images to assess six items for lesion diagnosis. We analyzed correlations between the diagnostic items and histologic features and compared the diagnostic accuracy between modalities. We created a composite diagnostic index and calculated its accuracy and consistency.

RESULTS

FGAs more frequently showed the following features vs. HpN-GHPs: bright-red color (94.1% vs. 44.4%), peripheral hyperplasia (58.8% vs. 8.3%), papillary/gyrus-like microstructure (96.1% vs. 33.3%), visible capillaries (70.6% vs. 38.9%), and demarcation line (98.0% vs. 41.7%) (P < 0.05). White-zone thickening was seen only in HpN-GHPs (52.8%). Diagnostic accuracy (mean, WLE vs. WLE+NBIME) was 90.8 ± 1.1% vs. 93.5 ± 2.4% (P = 0.15) for experts and 88.5 ± 3.0% vs. 86.6 ± 3.5% (P = 0.51) for non-experts. When satisfying the four criteria (bright-red color, papillary/gyrus-like microstructure, demarcation line, and absent white-zone thickening), sensitivity and specificity for FGA were 90.2% and 94.4%, respectively, with a kappa value of ≥ 0.6 for interobserver diagnostic agreement.

CONCLUSIONS

Composite diagnostic index contributes to the reproducible, accurate, preoperative differential diagnosis of FGA and HpN-GHP.

Older Age at First Screening Colonoscopy is Associated With an Increased Risk of Colorectal Adenomas and Cancer

INTRODUCTION

The goal of colorectal cancer (CRC) screening is to detect precancerous polyps before cancer development or identification of cancer at an early stage. Guidelines have recommended screening colonoscopy to start at age 45. Our aim was to determine the impact of delays in performing the first screening colonoscopy on the risk of adenoma or CRC detection.

METHODS

We analyzed colonoscopy and histopathology data of average CRC risk patients who had their first screening colonoscopy between 2010 and 2017. Univariate and multivariable logistic regression was performed to determine the association between demographic variables and the risk of adenomas or CRC.

RESULTS

A total of 1155 average risk patients underwent their initial screening colonoscopy during the study period. Median age was 54 years (range of 45-87) and 58.2% were females. In multivariable analysis, older age at first screening colonoscopy was significantly associated with the detection of adenomatous polyps (odds ratio 1.05, 95% confidence interval 1.04-1.07, P <0.001) and CRC (odds ratio 1.11, 95% confidence interval 1.06-1.16, P <0.001). The association between age and risk of adenomatous polyps (F-test 35.43, P =0.0019) and CRC (F-test 36.94, P =0.0017) fit an exponential growth model. It was estimated that the detection rate doubled every 14.20 years and 4.75 years for adenomas and CRC, respectively.

CONCLUSION

We found that older age at the initial performance of a screening colonoscopy was associated with increased detection of adenomatous polyps and CRC. This work highlights the need for guideline adherence for the prevention of CRC development.

Elevated Adenomatous Polyp Detection Rate Among Alaska Native and American Indian People in Interior Alaska, 2018-2022

OBJECTIVES

Colorectal cancer (CRC) incidence and mortality are twice as high among Alaska Native people as among non-Hispanic White people in the United States; as such, colonoscopy is a recommended screening test for Alaska Native people. Adenoma detection rate (ADR) is measured in patients at average risk of CRC undergoing initial screening colonoscopy and reflects the prevalence of precancerous polyps in a screened population. We evaluated the ADR among Alaska Native people living in Interior Alaska.

METHODS

This project evaluated the ADR among Alaska Native and American Indian adults aged ≥40 years (N = 460) living in Interior Alaska, using a retrospective medical record review of patients referred for screening colonoscopy from February 1, 2018, through March 31, 2022. The main outcome measure was ADR, stratified by age and sex.

RESULTS

The ADR was 45.0% overall: 43.0% among women and 47.1% among men. Among patients aged ≥50 years, the ADR was 67.1%: 62.7% among women and 70.7% among men. Among patients aged 40-49 years, the ADR was 34.4%: 35.3% among women and 33.3% among men.

CONCLUSIONS

Measured ADR was high among Alaska Native men and women aged ≥50 years in Interior Alaska and in all age groups that were screened. These findings have implications for which CRC screening methods, intervals, and age to begin screening are most appropriate for Alaska Native people, as well as the need for future research on the pathology, etiology, and natural history of CRC in this population.

A New Risk-Scoring System for Colorectal Cancer and Polyp Screening by Turkish Colorectal Cancer and Polyp Study Group

BACKGROUND

Colorectal cancer is one of the most commonly diagnosed types of cancer worldwide. An early diagnosis and detection of colon cancer and polyp can reduce mortality and morbidity from colorectal cancer. Even though there are a variety of options in screen- ing tests, the question remains on which test is the most effective for the early detection of colorectal cancer. In this prospective study, we aimed to develop a simple, useful, effective, and reliable scoring system to detect colon polyp and colorectal cancer.

METHODS

We enrolled 6508 subjects over the age of 18 from 16 centers, with colonoscopy screening. The age, smoking status, alcohol consumption, body mass index, polyp incidence, polyp size, number and localization, and pathologic findings were recorded.

RESULTS

The age, male gender, obesity, smoking, and family history were found as independent risk factors for adenomatous polyp. We have developed a new scoring system which can be used for these factors. With a score of 4 or above, we found the following: sensitivity 81%, specificity 40%, positive predictive value 25.68%, and negative predictive value 89.84%, for adenomatous polyp detection; and sensitivity 96%, specificity 39%, positive predictive value 3.35%, negative predictive value 99.29%, for colorectal cancer detection.

CONCLUSION

Even though the first colorectal cancer screening worldwide is generally performed for individuals over 50 years of age, we recommend that screening for colorectal cancer might begin for those under 50 years of age as well. Individuals with a score ≥ 4 must be included in the screening tests for colorectal cancer.

The role of "Prominin - 1" marker in adenomatous colorectal polyps

&lt;b&gt;Introduction:&lt;/b&gt; Adenomatous polyps are pivotal to the development of colorectal cancer. The risk of colorectal carcinogenesis can be reduced through polypectomy and close surveillance of the disease. Early-stage polyps can be detected and removed endoscopically, therefore, reducing the incidence of carcinoma. The identification of CSC in colon polyps allows for assessment of their potential malignancy. Therefore, it is very relevant to study the prognostic significance of the prevalence of stem cells in colorectal polyps in early detection and prevention of cancer. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Method:&lt;/b&gt; Previously pathologically evaluated adenomatous tumors (60M, 40F) at Azerbaijan Medical University were reevaluated in Meram Medical Faculty Pathology Department. Hematoxylin-Eosin-stained slides were examined and cases with and without dysplasia were determined. New sections were taken from paraffin blocs. Prominin-1 staining was performed immunohistochemically on these sections. Stained slides were examined by an image analysis system. Prominin-1-positive cells were automatically counted with the same image analysis system. The cases that developed malignancy after polypectomy were determined. The relationship between CD133 expression of dysplasia and malignancy was statistically analyzed. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Results:&lt;/b&gt; Statistically significant prominin-1 expression was detected in cases with dysplasia and malignancy. &lt;/br&gt;&lt;/br&gt; &lt;b&gt; Conclusion:&lt;/b&gt; The investigation of prominin-1 expression in colorectal polyps may be important to determine malignancy development.

The Sulfur Microbial Diet Is Associated With Increased Risk of Early-Onset Colorectal Cancer Precursors

BACKGROUND & AIMS

Diet may contribute to the increasing incidence of colorectal cancer (CRC) before age 50 (early-onset CRC). Microbial metabolism of dietary sulfur produces hydrogen sulfide (H2S), a gastrointestinal carcinogen that cannot be easily measured at scale. As a result, evidence supporting its role in early neoplasia is lacking.

METHODS

We evaluated long-term adherence to the sulfur microbial diet, a dietary index defined a priori based on increased abundance of 43 bacterial species involved with sulfur metabolism, with risk of CRC precursors among 59,013 individuals who underwent lower endoscopy in the Nurses' Health Study II (1991-2015), a prospective cohort study with dietary assessment every 4 years through validated food frequency questionnaires and an assessment of dietary intake during adolescence in 1998. The sulfur microbial diet was characterized by intake high in processed meats, foods previously linked to CRC development, and low in mixed vegetables and legumes. Multivariable logistic regression for clustered data was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

We documented 2911 cases of early-onset adenoma. After adjusting for established risk factors, higher sulfur microbial diet scores were associated with increased risk for early-onset adenomas (ORquartile [Q]4 vs Q1, 1.31; 95% CI, 1.10-1.56, Ptrend = .02), but not serrated lesions. Compared with the lowest, women in the highest quartile of sulfur microbial diet scores had significantly increased risk of early-onset adenomas with greater malignant potential (ORQ4 vs Q1, 1.65 for villous/tubulovillous histology; 95% CI, 1.12-2.43; Ptrend = .04). Similar trends for early-onset adenoma were observed based on diet consumed during adolescence. In contrast, no clear association for adenomas was identified after age 50.

CONCLUSIONS

Our findings in a cohort of young women support a role for dietary interactions with gut sulfur-metabolizing bacteria in early-onset colorectal carcinogenesis, possibly beginning in adolescence.

Serrated polyps: innocent or guilty?

Serrated lesions represent a group of lesions with different genetic and biological features causing important clinical repercussions. Three types of serrated lesions are identified: hyperplastic, sessile adenomas (with and without dysplasia) and traditional serrated adenomas. Such lesions are now recognized as precancerous lesions.The carcinogenic process of serrated lesions follows a pathway including: alterations concerning activation of mitogen and protein kinase regulating the extracellular signal of other intracellular kinases (MAPK-ERK), inhibition of the apoptosis and hypermethylation of DNA and instability of microsatellites. Like for adenomatous polyps, the risk factors for serrated lesions are environmental factors, related to lifestyle and diet. The cancerogenic risk is increased by excessive alcohol consumption, obesity and poor intake of folate. When a high number of colorectal polyps with architecture serrated is diagnosed, it could be considered as serrated polyposis syndrome (SPS). According the most recent ESGE guidelines, the diagnostic criteria of the SPS, are: at least 5 polyps resected proximal to the sigmoid colon, 2 of which> 10 mm, or >20 serrated lesions of any size distributed in the entire colon. This condition presents a high risk for personal and/or familiar CRC, for this reason a regular screening colonoscopy should be performed in these patients and in their first-degree relatives.

Screening and prevention of colorectal cancer

Mortality from colorectal cancer is reduced through screening and early detection; moreover, removal of neoplastic lesions can reduce cancer incidence. While understanding of the risk factors, pathogenesis, and precursor lesions of colorectal cancer has advanced, the cause of the recent increase in cancer among young adults is largely unknown. Multiple invasive, semi- and non-invasive screening modalities have emerged over the past decade. The current emphasis on quality of colonoscopy has improved the effectiveness of screening and prevention, and the role of new technologies in detection of neoplasia, such as artificial intelligence, is rapidly emerging. The overall screening rates in the US, however, are suboptimal, and few interventions have been shown to increase screening uptake. This review provides an overview of colorectal cancer, the current status of screening efforts, and the tools available to reduce mortality from colorectal cancer.

Colorectal Cancer Screening and Postpolypectomy Surveillance

CASE SUMMARY

A healthy 52-year-old woman without any family history presents for a health maintenance appointment and opts for a fecal immunochemical test for colorectal cancer screening after reviewing her options. After a positive result, she is referred for colonoscopy. She is found to have 3 small (<10 mm) polyps that are completely resected via snare polypectomy and return as tubular adenomas on histologic examination. It is recommended that she return for repeat colonoscopy in 3 years, at which point she has a normal examination with excellent preparation by an experienced endoscopist and is given the option to return to her average-risk screening interval.

[Comparative prevalence of adenomatous polyps in people aged 45 to 49 years and in people over 50 years of age in a Colombian population: a case-control study]

INTRODUCTION

Colon and rectal cancer (CRC) is the third most frequent cancer and the fourth cause of cancer death in the world. In Colombia, it is the third leading cause of death from cancer. The most accepted recommendation is to do colonoscopy screening in people 50 to 75 years old. However, recently the American Cancer Association (ACS) has recommended starting screening from the age of 45. In our environment there are no studies on the prevalence of adenomatous polyps in children under 50 years of age.

OBJECTIVE

To compare the prevalence of adenomatous polyps during screening colonoscopy in people aged 45-49 years (cases) and compare it with that of people aged 50 to 75 years (control).

MATERIALS AND METHODS

Case-control studies. The data were collected prospectively during the period from January 2018 to November 2019 at the gastroenterology and digestive endoscopy center of Bogotá Colombia.

RESULTS

490 patients were included, 119 cases and 371 controls, case: control ratio was 1: 3. The prevalence of polyps in cases 36.7% and in controls (42.5%) p=0.279. Adenomatous polyps were detected in 18.5% (95% CI 12.4-26.6) of the cases and 32.4% (95% CI 27.7-37.2) of the controls (p=0.004).

CONCLUSION

The prevalence of polyps during screening colonoscopy in people aged 45-49 years is similar to that expected in screening colonoscopies of people between 50-75 years. This finding would favor screening colonoscopy from 45 years of age.

The inflammatory microenvironment in screen-detected premaligant adenomatous polyps: early results from the integrated technologies for improved polyp surveillance (INCISE) project

INTRODUCTION

Around 40% of patients who attend colonoscopy following a positive stool screening test have adenomatous polyps. Identifying which patients have a higher propensity for malignant transformation is currently poorly understood. The aim of the present study was to assess whether the type and intensity of inflammatory infiltrate differ between screen-detected adenomas with high-grade dysplasia (HGD) and low-grade dysplasia (LGD).

METHODS

A representative sample of 207 polyps from 134 individuals were included from a database of all patients with adenomas detected through the first round of the Scottish Bowel Screening Programme in NHS Greater Glasgow and Clyde (April 2009-April 2011). Inflammatory cell phenotype infiltrate was assessed by immunohistochemistry for CD3+, CD8+, CD45+ and CD68+ in a semi-quantitative manner at 20× resolution. Immune-cell infiltrate was graded as absent, weak, moderate or strong. Patient and polyp characteristics and inflammatory infiltrate were then compared between HGD and LGD polyps.

RESULTS

CD3+ infiltrate was significantly higher in HGD polyps compared to LGD polyps (74 vs. 69%; P < 0.05). CD8+ infiltrate was significantly higher in HGD polyps compared to LGD polyps (36 vs. 13%; P < 0.001) whereas CD45+ infiltrate was not significantly different (69 vs. 64%; P = 0.401). There was no significant difference in CD68+ infiltrate (P = 0.540) or total inflammatory cell infiltrate (calculated from CD3+ and CD68+) (P = 0.226).

CONCLUSIONS

This study reports an increase in CD3+ and CD8+ infiltrate in HGD colonic adenomas when compared to LGD adenomas. It may therefore have a use in the prognostic stratification and treatment of dysplastic polyps.

Self-reported Metabolic Risk Factor Associations with Adenomatous, Sessile Serrated, and Synchronous Adenomatous and Sessile Serrated Polyps

Studies have found a positive association between metabolic risk factors, such as obesity and diabetes, and adenomatous polyps (AP). However, fewer studies have assessed the association between sessile serrated polyps (SSP) or synchronous diagnosis of APs and SSPs (synch polyps). Study participants (N = 1,370; ages 40-85) undergoing screening colonoscopy were enrolled between August 2016 and February 2020. Self-reported metabolic risk factors, including diabetes, hypertension, hyperlipidemia, and overweight/obesity, were evaluated for associations with new diagnoses of APs, SSPs, and synch polyps at the present colonoscopy. Average participant age was 60.73 ± 8.63 (SD) years; 56.7% were female and 90.9% white. In an assessment of individual metabolic risk factors, adjusted for age, sex, race, and smoking status, increased body mass index (BMI; overweight or obese vs. normal BMI of <25 kg/m2) was associated with an increased odds for new onset of colon APs (P trend < 0.001) as was a diagnosis of diabetes [adjusted conditional OR (aCOR) = 1.59 (1.10-2.29)]. No associations were seen between the metabolic risk factors and onset of SSPs. Being obese or hypertensive each increased the odds of new onset of synch polyps with aCOR values of 2.09 (1.01-4.32) and 1.79 (1.06-3.02), respectively. Self-reported risk factors may help assess polyp type risk. Because SSPs and synch polyps are rare, larger studies are needed to improve our understanding of the contribution of these factors to polyp risk. These data lead us to hypothesize that differences in observed metabolic risk factors between polyp types reflect select metabolic impact on pathways to colorectal cancer. PREVENTION RELEVANCE: Self-reported medical history provides valuable insight into polyp risk, potentially enabling the use of larger retrospective studies of colonoscopy populations to assess knowledge gaps. More aggressive colonoscopy screening, critical to colorectal cancer prevention, may be considered in populations of individuals with metabolic risk factors and modifiable lifestyle risk factors.

Artificial intelligence-based endoscopic diagnosis of colorectal polyps using residual networks

Convolutional neural networks (CNNs) are widely used for artificial intelligence (AI)-based image classification. Residual network (ResNet) is a new technology that facilitates the accuracy of image classification by CNN-based AI. In this study, we developed a novel AI model combined with ResNet to diagnose colorectal polyps. In total, 127,610 images consisting of 62,510 images with adenomatous polyps, 30,443 with non-adenomatous hyperplastic polyps, and 34,657 with healthy colorectal normal mucosa were subjected to deep learning after annotation. Each validation process was performed using 12,761 stored images of colorectal polyps by a 10-fold cross validation. The efficacy of the ResNet system was evaluated by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy. The sensitivity, specificity, PPV, NPV, and diagnostic accuracy for adenomatous polyps at WLIs were 98.8%, 94.3%, 90.5%, 87.4%, and 92.8%, respectively. Similar results were obtained for adenomatous polyps at narrow-band imagings (NBIs) and chromoendoscopy images (CEIs) (NBIs vs. CEIs: sensitivity, 94.9% vs. 98.2%; specificity, 93.9% vs. 85.8%; PPV, 92.5% vs. 81.7%; NPV, 93.5% vs. 99.9%; and overall accuracy, 91.5% vs. 90.1%). The ResNet model is a powerful tool that can be used for AI-based accurate diagnosis of colorectal polyps.

Incidence of Colorectal Cancer and Adenomatous Polyps After a Two-Step Screening in Isfahan Province, Iran in 2018

PURPOSE

The aim of this study was to estimate the incidence of colorectal cancers in Iran. The results of this study are based on a screening program that is being implemented in Isfahan province.

MATERIAL AND METHODS

In this study, about 137,000 people were screened for colorectal cancer and adenomatous polyps in 2 steps during the year 2018.

RESULTS

Based on the findings of this study, the incidence of adenomatous polyps was reported to be 389 (95% CI, 365-422) per 100,000 population. The incidence of adenomatous polyps was reported to be 483 (95% CI, 446-520) and 316 (95% CI, 286-346) in men and women, respectively (p < 0.001). Also, the incidence of colorectal cancer was reported to be 33 (95% CI, 23-42) per 100,000 population. The incidence of colorectal cancer in men and women was reported to be 41 (95% CI, 30-51) and 26 (95% CI, 17-34), respectively, indicating a statistically non-significant difference (p = 0.29).

CONCLUSION

Based on the result of this study, despite a low participation rate of the target population in the screening program, the incidence of adenomatous polyps and colorectal cancer is relatively high in the average-risk population.

[Clinicopathological features of the colorectal serrated adenoma and analysis on influencing factors of malignancy]

Objective: Serrated adenoma is recognized as a precancerous lesion of colorectal cancer, and the serrated pathway is considered as an important pathway that can independently develop into colorectal cancer. However, little is known about the related risk factors of carcinogenesis of serrated adenoma. The purpose of this study was to analyze the distribution characteristics and potential malignant factors of serrated adenoma in the colon and rectum. Methods: A retrospective case-control study was conducted to collect the clinical data of patients with serrated adenoma who underwent colonoscopy and were pathologically diagnosed in the Cancer Hospital of Chinese Academy of Medical Sciences from April 2017 to July 2019, and exclude patients with two or more pathological types of lesions. The clinical characteristics of serrated adenoma were summarized, and univariate and logistic multivariate regression analysis was conducted to explore the influencing factors for serrated adenoma to develop malignant transformation. Results: Among 28 730 patients undergoing colonoscopy, 311 (1.08%) were found with 372 serrated adenomas, among which 22 (5.9%) were sessile serrated adenomas/polyps, 84 (22.6%) were traditional serrated adenomas, and 266 (71.5%) were unclassified serrated adenomas according to WHO classification. The pathological results showed that 106 (28.5%) lesions were non-dysplasia, 228 (61.3%) lesions were low grade intraepithelial neoplasia, and 38 (10.2%) lesions were high grade intraepithelial neoplasia or cancer. There were 204 (54.8%) lesions with long-axis diameter <10 mm and 168 (45.2%) lesions with length long-axis ≥ 10 mm. 238 (64.0%) lesions were found in the left side colon and rectum and 134 (36.0%) lesions in the right side colon. Gross classification under endoscopy: 16 flat type lesions (4.3%), 174 sessile lesions (46.8%), 117 semi-pedunculated lesions (31.5%), 59 pedunculated lesions (15.9%). Narrow-band imaging international colorectal endoscopic (NICE) classification: 85 (22.8%) type I lesions, 280 (75.3%) type II lesions, 4 (1.1%) type III lesions. Univariate analysis showed that lesion size, lesion location, lesion site and different WHO classifications were associated with malignant transformation of colorectal serrated adenoma (all P<0.05). For the serrated adenomas with different NICE classifications, there were statistically significant differences in the distribution of malignant lesions among groups (P=0.001). Multivariate analysis showed that the long-axis diameter of the lesion ≥10 mm (OR=6.699, 95% CI: 2.843-15.786) and the lesion locating in the left side colorectum (OR=2.657, 95% CI: 1.042-6.775) were independent risk factors for malignant transformation. Conclusions: Serrated adenomas mainly locate in the left side colon and rectum, and are prone to malignant transformation when the lesions are ≥10 mm in long-axis diameter or left-sided.

Impact of endoscopic sedation on gastric polyp detection: A one-center retrospective observational study

Sedation esophagogastroduodenoscopy (EGD) has become more prevalent in many countries. However, owing to the limitation of health insurance payment for sedation EGD in Taiwan, non-sedation EGD still accounts for the majority of cases. This study was aimed to explore the differences between the sedation and non-sedation groups in terms of endoscopic findings, such as detection rate of gastric polyp of any size, number of detected gastric polyps, and location of the gastric polyps detected.We enrolled 10,940 patients who underwent EGD between January 1, 2016 and December 31, 2016 at the Tri-Service General Hospital; among the patients, 1900 received intravenous sedation (IVS) and 9040 did not. The data reviewed included demographics, parameters of the polyp (number, size, and location), and pathology.Compared with the non-sedation group, the sedation group had a higher overall polyp detection rate (P < .001); a greater number of detected polyps (Odds ratio 1.50, P = .007); and a higher detection rate of smaller polyps, such as fundic gland polyp, and hyperplastic polyp (P < .001). Among the pathological findings, gastric neuroendocrine tumor (NET) was detected using EGD in 2 cases and manifested as small polyps (<0.05 cm), and it showed significantly better detection rates in the sedation EGD group than in the non-sedation EGD group (P = .002).Sedation EGD could enhance a patients willingness and cooperation during EGD. Furthermore, sedation EGD increased the detection rates of small gastric polyps and was more likely to enable identification of unusual findings, such as gastric NET.

Short Term Outcomes of Using Fecal Immunochemical Test for a Pilot Colorectal Cancer Screening Program. A Single Center Study on 3024 Consecutive Patients

Background: In Romania, colorectal cancer does not benefit yet from a national screening program. In order to decrease the harm and burden of colorectal cancer (CRC), opportunistic programs relying on endoscopy has been adopted by each centre according to its capacity. A colorectal cancer (CRC) screening programme based on faecal immunochemical test (FIT) was launched at Ponderas Academic Hospital (PAH) in 2019. Aim: The present study analyses the outcomes after the first 1500 tests in the PAH-FIT-CRC Screening Program. We have also aimed to compare the efficiency of the FIT testing program with the screening colonoscopies performed in our Center, withing the same time interval (2019). Methods: The test was recommended in asymptomatic patients over 45 years, and it was followed by a colonoscopy when the test results were positive. Furthermore, we performed a retrospective observational study gathering data from all the consecutive patients prospectively included in the respective databases of our hospital, comparing the efficacy of the two colorectal cancer screening methods (FIT versus colonoscopy). Results: Between 01.01.2019 and 01.01.2020, 1524 screening colonoscopies were performed, and the resulting data were compared with those obtained in the FIT group (1500 FIT tests freely distributed). In the screening colonoscopy group, the polyp detection rate was 38.98% and 22 (1.44%) adenocarcinomas were identified. In the FIT group, the FIT uptake rate was 71% with a positivity rate of 21.7%. The colonoscopy compliance rate for positive FIT patients was 29.4%, with only 2 adenocarcinomas detected. Conclusions: Following data analysis, the need for improvement of uptake rate and colonoscopy compliance rate was suggested, due to the lower acceptance of FIT tests and colonoscopies, especially among men. Moreover, special efforts should be made in order to improve quality indicators for screening colonoscopies (especially adenoma detection rate) with the purpose of decreasing interval CRC.

Evaluation of Fecal M2PK as a Diagnostic Marker in Colorectal Cancer

BACKGROUND

Invasive colonoscopy is the gold standard for patients at risk for colorectal cancer. However, the need for non-invasive and specific markers is required.

OBJECTIVE

To evaluate the sensitivity of the glycolytic pyruvate kinase isoenzyme type M2 dimer (M2PK) as a diagnostic biomarker for colorectal cancer (CRC) and adenomatous colorectal polyps (CRP) screening.

DESIGN

Case-control.

PATIENTS

Twenty patients with CRC, 20 patients with CRP (lack criteria for colonic cancer by biopsy), and 20 normal subjects.

OUTCOME

Complete blood count (CBC), erythrocyte sedimentation rate (ESR), tumor markers: carcino embryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9), fecal occult blood test (FOBT), and fecal M2PK. Pelvic and abdominal ultrasound (US), colonoscopy, and a histopathological examination.

RESULTS

Only weight loss and cachexia were significantly associated with CRC than CRP or control groups. M2PK was the most sensitive and specific test in differentiating CRC from CRP and the control subjects (sensitivity = 75%, specificity = 100%).

LIMITATIONS

(1) The selection of cases for three well-matched groups, as to perform colonoscopy in well-prepared cases and conditions. (2) Replicates in more than 20 cases for confirmation at the expense of enrolling new patients. (3) The cost associated with tumor markers analysis.

CONCLUSION

Fecal M2PK can be used as a precolonoscopy screening test for CRC patients, and is superior to other tumor markers, and in indicating the progress of colorectal adenomas > 1 cm. Thus being cost-effective and easy-to-perform test, it is a feasible tool to preselect patients who require colonoscopy.

Interval Colorectal Cancer in Inflammatory Bowel Disease: The Role of Guideline Adherence

BACKGROUND

Factors associated with interval colorectal cancer (CRC) development in the inflammatory bowel disease (IBD) population remain unclear.

AIMS

Among a cohort of patients with interval CRC, we aimed to evaluate IBD characteristics, colonoscopy quality indicators, and surveillance guideline adherence.

METHODS

We performed a retrospective review of IBD- and non-IBD-associated interval CRCs diagnosed between January 2007 and December 2014 within a large US healthcare system. We evaluated risk factors for CRC among patients with IBD. We assessed adherence to surveillance guidelines according to the American Society for Gastrointestinal Endoscopy (IBD surveillance) and the US Multi-Society Task Force on Colorectal Cancer (polyp surveillance). We compared colonoscopy quality measures between patients with and without IBD.

RESULTS

Among 5345 cases of colonic adenocarcinoma, we detected 15 IBD-associated cases of interval CRC and 230 non-IBD-associated cases of interval CRC. Compared to patients without IBD, IBD patients were younger (54.5 vs. 70.4 years; p < 0.0001) and experienced a shorter interval between index colonoscopy and CRC diagnosis (20.7 vs. 35.1 months; p = 0.0009). Fifty three percent (8/15) of interval CRCs in IBD patients were detected within surveillance guidelines. All IBD patients with interval CRC detected after guideline surveillance interval had high-risk features, including active inflammation, previous low-grade or indefinite dysplasia, multiple pseudopolyps on index colonoscopy, or a first-degree relative with CRC. There were no differences in colonoscopy quality measures between patients with and without IBD.

CONCLUSIONS

This study stresses the importance of strict short-interval surveillance for IBD patients with high-risk features, including active inflammation on index colonoscopy.

Panchromoendoscopy Increases Detection of Polyps in Patients With Serrated Polyposis Syndrome

BACKGROUND & AIMS

Serrated polyposis syndrome (SPS), characterized by multiple and/or large proximal serrated lesions, increases the risk of colorectal cancer. Serrated lesions often are missed during colonoscopy but panchromoendoscopy can increase their detection in an average-risk population. We performed a randomized controlled study to determine the efficacy of panchromoendoscopy in detection of polyps in patients with SPS.

METHODS

Patients with SPS (n = 86 patients) underwent tandem high-definition (HD) colonoscopies from February 2015 through July 2016 at 7 centers in Spain. Patients were assigned randomly to groups that received 2 HD white-light endoscopy examinations (HD-WLE group; n = 43) or HD-WLE followed by 0.4% indigo carmine panchromoendoscopy (HD-CE group; n = 43). For each procedure, polyps detected were described, removed, and analyzed by histology. The primary outcome was additional polyp detection rate, defined as the number of polyps detected during the second inspection divided by the total number of polyps detected during the first and the second examination.

RESULTS

A total of 774 polyps were detected (362 in the HD-WLE group and 412 in the HD-CE group); 54.2% were hyperplastic, 13.8% were adenomas, and 10.9% were sessile serrated polyps. There was a significantly higher additional polyp detection rate in the HD-CE group (0.39; 95% CI, 0.35-0.44) than in the HD-WLE group (0.22; 95% CI, 0.18-0.27) (P < .001). A higher additional rate of serrated lesions proximal to the sigmoid colon were detected in the second inspection with HD-CE (0.40; 95% CI, 0.33-0.47) than with HD-WLE (0.24; 95% CI, 0.19-0.31) (P = .001). Detection of adenomas and serrated lesions greater than 10 mm did not differ significantly between groups. In a multivariate logistic regression analysis, only use of HD-CE was associated independently with increased polyp detection throughout the colon.

CONCLUSIONS

In a randomized controlled trial, we found that panchromoendoscopy increases detection of polyps (mostly of small serrated lesions) and should be considered the standard of care in patients with SPS. Studies are needed to determine the effects of this strategy on the incidence of advanced neoplasia during long-term follow-up evaluation. ClinicalTrials.gov no: NCT03476434.

Impact of moderate versus deep sedation on adenoma detection rate in index average-risk screening colonoscopies

BACKGROUND AND AIMS

The debate between moderate sedation versus deep sedation for index average-risk screening colonoscopies is well known to gastroenterologists. Ensuring the best of all metrics to perform quality colonoscopies for colon cancer prevention is paramount for both patients and physicians alike, because colon cancer remains the leading cause of cancer death and is the most-used screening tool in the United States. The aim of this study was to determine if moderate sedation versus deep sedation affects outcomes of adenoma detection rate (ADR) or polyp detection rate (PDR) in index, average-risk colonoscopies for colon cancer screening.

METHODS

A retrospective, single, tertiary care outpatient center study of 585 healthy average-risk patients who underwent index screening colonoscopy between June 1, 2015 to December 31, 2015 (moderate sedation only) and June 1, 2016,to December 31, 2016 (deep sedation only) was performed after Institutional Review Board approval. Demographic data and polyp details were collected to determine ADR and PDR. Patients who were not average risk were excluded from the study.

RESULTS

A total of 585 index average-risk screening colonoscopies were included in this study with 57.7% moderate sedation and 42.2% deep sedation. Neither ADR nor PDR was significantly different between the 2 groups (44.1% vs 38.5% [P = .18] and 71.9% vs 67.6% [P = .27], respectively).

CONCLUSIONS

In index average-risk screening colonoscopies, deep sedation appears to have no benefit compared with moderate sedation for ADR and PDR.

Mucosal microbiota of intestinal polyps reveals putative biomarkers of colorectal cancer

The human intestine retains a complex microbial ecosystem, which performs crucial functions that impact on host health. Several studies have indicated that intestinal dysbiosis may impact on the establishment of life-threatening intestinal diseases such as colorectal cancer. An adenomatous polyp is the result of abnormal tissue growth, which is benign but is considered to be associated with a high risk of developing colorectal cancer, based on its grade of dysplasia. Development of diagnostic tools that are based on surveying the gut microbiota and are aimed at early detection of colorectal cancer represent highly desirable target. For this purpose, we performed a pilot study in which we applied a metataxonomic analysis based on 16S rRNA gene sequencing approach to unveil the composition of microbial communities of intestinal polyps. Moreover, we performed a meta-analysis involving the reconstructed microbiota composition of adenomatous polyps and publicly available metagenomics datasets of colorectal cancer. These analyses allowed the identification of microbial taxa such as Faecalibacterium, Bacteroides and Romboutsia, which appear to be depleted in cancerogenic mucosa as well as in adenomatous polyps, thus representing novel microbial biomarkers associated with early tumor formation. Furthermore, an absolute quantification of Fusubacterium nucleatum in polyps further compounded the important role of this microorganism as a valuable putative microbial biomarker for early diagnosis of colorectal cancer.

Risk of Colorectal Polyps and Malignancies Among Predominantly Rural Hispanics

Colorectal cancer is the fourth most frequently diagnosed cancer. However, due to variations in diet, it was hypothesized that risk of adenomatous or hyperplastic polyps or malignancies would be lower among Hispanics. Participants (n = 1671) underwent a colonoscopy. Results were grouped into one of four groups: normal, hyperplastic polyps only, adenomatous polyps, and malignancies. As expected, Hispanics had a lower risk of hyperplastic (p = .031, OR = 0.47) and adenomatous polyps (p = .031, OR = 0.66) than non-Hispanic Whites. Comparison between malignancies was not possible as no Hispanics had a malignancy. Contrary to expectations, risk of hyperplastic and adenomatous polyps and malignancies were no different between non-Hispanic Blacks and Whites. Among rural and mostly rural populations, Hispanics had a lower risk of hyperplastic and adenomatous polyps.

Assessment of colon polyp morphology: Is education effective?

AIM

To determine the inter-observer variability for colon polyp morphology and to identify whether education can improve agreement among observers.

METHODS

For purposes of the tests, we recorded colonoscopy video clips that included scenes visualizing the polyps. A total of 15 endoscopists and 15 nurses participated in the study. Participants watched 60 video clips of the polyp morphology scenes and then estimated polyp morphology (pre-test). After education for 20 min, participants performed a second test in which the order of 60 video clips was changed (post-test). To determine if the effectiveness of education was sustained, four months later, a third, follow-up test was performed with the same participants.

RESULTS

The overall Fleiss’ kappa value of the inter-observer agreement was 0.510 in the pre-test, 0.618 in the post-test, and 0.580 in the follow-up test. The overall diagnostic accuracy of the estimation for polyp morphology in the pre-, post-, and follow-up tests was 0.662, 0.797, and 0.761, respectively. After education, the inter-observer agreement and diagnostic accuracy of all participants improved. However, after four months, the inter-observer agreement and diagnostic accuracy of expert groups were markedly decreased, and those of beginner and nurse groups remained similar to pre-test levels.

CONCLUSION

The education program used in this study can improve inter-observer agreement and diagnostic accuracy in assessing the morphology of colon polyps; it is especially effective when first learning endoscopy.

Sex-influenced association of non-alcoholic fatty liver disease with colorectal adenomatous and hyperplastic polyps

AIM

To investigate the relationship between non-alcoholic fatty liver disease (NAFLD) and colorectal adenomatous and hyperplastic polyps.

METHODS

A retrospective cross-sectional study was conducted on 3686 individuals undergoing health checkups (2430 males and 1256 females). All subjects underwent laboratory testing, abdominal ultrasonography, colonoscopy, and an interview to ascertain the baseline characteristics and general state of health. Multinomial logistic regression analysis was performed to examine the association between NAFLD and the prevalence of colorectal adenomatous and hyperplastic polyps. Furthermore, the relationship was analyzed in different sex groups. Subgroup analysis was performed based on number, size, and location of colorectal polyps.

RESULTS

The prevalence of colorectal polyps was 38.8% in males (16.2% for adenomatous polyps and 9.8% for hyperplastic polyps) and 19.3% in females (8.4% for adenomatous polyps and 3.9% for hyperplastic polyps). When adjusting for confounding variables, NAFLD was significantly associated with the prevalence of adenomatous polyps (OR = 1.28, 95%CI: 1.05-1.51, P < 0.05) and hyperplastic polyps (OR = 1.35, 95%CI: 1.01-1.82, P < 0.05). However, upon analyzing adenomatous and hyperplastic polyps in different sex groups, the significant association remained in males (OR = 1.53, 95%CI: 1.18-2.00, P < 0.05; OR = 1.42, 95%CI: 1.04-1.95, P < 0.05) but not in females (OR = 0.44, 95%CI: 0.18-1.04, P > 0.05; OR = 1.18, 95%CI: 0.50-2.78, P > 0.05).

CONCLUSION

NAFLD is specifically associated with an increased risk of colorectal adenomatous and hyperplastic polyps in men. However, NAFLD may not be a significant factor in the prevalence of colorectal polyps in women.

New endoscopes and add-on devices to improve colonoscopy performance

Colonoscopy is the gold standard for colorectal cancer prevention; however, it is still an imperfect modality. Precancerous lesions can be lost during screening examinations, thus increasing the risk of interval cancer. A variety of factors either patient-, or endoscopist dependent or even the procedure itself may contribute to loss of lesions. Sophisticated modalities including advanced technology endoscopes and add-on devices have been developed in an effort to eliminate colonoscopy's drawbacks and maximize its ability to detect potentially culprit polyps. Novel colonoscopes aim to widen the field of view. They incorporate more than one cameras enabling simultaneous image transmission. In that way the field of view can expand up to 330°. On the other hand a plethora of add-on devices attachable on the standard colonoscope promise to detect lesions in the proximal aspect of colonic folds either by offering a retrograde view of the lumen or by straightening the haustral folds during withdrawal. In this minireview we discuss how these recent advances affect colonoscopy performance by improving its quality indicators (cecal intubation rate, adenoma detection rate) and other metrics (polyp detection rate, adenomas per colonoscopy, polyp/adenoma miss rate) associated with examination's outcomes.

Massive Gastric Juvenile Polyposis: A Clinicopathologic Study Using SMAD4 Immunohistochemistry

OBJECTIVES

Juvenile polyps involving the stomach are uncommon. Massive gastric juvenile polyposis is even rarer.

METHODS

We describe the clinicopathologic features of nine cases of massive gastric juvenile polyposis.

RESULTS

All patients had anemia; four had hypoalbuminemia. The polyps were composed predominantly of dilated crypts lined by columnar epithelium and abundant edematous stroma with mixed inflammatory infiltrates. One patient had a poorly differentiated adenocarcinoma, arising in juvenile polyp-associated intraepithelial neoplasia. A second patient had a well-differentiated intramucosal adenocarcinoma arising in a juvenile polyp with high-grade dysplasia. Three of our cases had polyposis restricted to the stomach. Six (66.6%) had loss of SMAD4 immunoreactivity, making them subject to severe bleeding and hypoproteinemia, as well as developing severe dysplasia or adenocarcinoma.

CONCLUSIONS

SMAD4 immunohistochemstry is a helpful ancillary diagnostic test in cases of suspected juvenile polyposis syndrome involving the stomach.

[THE PROGNOSTIC FACTORS ANALYSIS FOR THE REPEATED DEVELOPMENT OF GASTRIC POLYPS AFTER ENDOSCOPIC POLYPECTOMY]

There were analyzed the results of treatment of 1450 patients, to whom in surgical departments of Lugansk Regional Clinical Hospital the elective endoscopic polypectomy for solitary and multiple gastric polyps, premalignant changes, was conducted. The unfavorable prognosis signs, trustworthily impacting the gastric polyps reoccurring, were considered: quantity of gastric polyps, their dimensions, localization and presence of mucosal erosions. Reoccurrence of majority of the polyps in gastric antrum may be due to microcirculatory disorders, present in their mucosa.

Diagnostic Potential of Cell-Free and Exosomal MicroRNAs in the Identification of Patients with High-Risk Colorectal Adenomas

BACKGROUND

Although there is a growing interest in developing circulating microRNA (miRNA) as noninvasive diagnostic biomarkers for the detection of high-risk colorectal adenomas and early-stage CRCs, but the comparative diagnostic significance of serum vs. exosomal miRNAs remains unexplored.

METHODS

Based upon published literature, we performed an initial discovery step by investigating the expression of a miRNA panel in 20 normal colonic mucosa, 27 adenomas, and 19 CRC tissues. We performed subsequent validation by quantifying expression of candidate miRNAs in total serum and in exosomes from 26 adenoma patients and 47 healthy controls, and evaluated their clinical significance and potential diagnostic value in colorectal adenomas.

RESULTS

We observed that the expression of four miRNAs, miR-21, miR-29a, miR-92a, and miR-135b, was significantly higher in colorectal adenomas vs. normal colonic mucosa. During validation, expression of miR-21, miR-29a and miR-92a in serum was significantly higher in adenomas vs. healthy controls, significantly correlated with adenoma size and total adenoma number within the colorectum, and significantly discriminated patients with advanced adenomas. In contrast, although exosomal miR-21 and miR-29a levels in adenoma patients were significantly higher than those of healthy volunteers, only exosomal miR-21 significantly correlated with adenoma size and total adenoma number, and could discriminate patients with high-risk adenomas.

CONCLUSION

Compared to exosomal miRNAs, serum levels of miR-21, miR-29a and miR-92a are superior diagnostic biomarkers in patients with high-risk adenomatous polyps.

Simultaneous fingerprint and high-wavenumber fiber-optic Raman spectroscopy enhances real-time in vivo diagnosis of adenomatous polyps during colonoscopy

Colorectal cancer can be prevented if detected early (e.g., precancerous polyps-adenoma). Endoscopic differential diagnosis of hyperplastic polyps (that have little or no risk of malignant transformation) and adenomas (that have prominent malignant latency) remains an unambiguous clinical challenge. Raman spectroscopy is an optical vibrational technique capable of probing biomolecular changes of tissue associated with neoplastic transformation. This work aims to apply a fiber-optic simultaneous fingerprint (FP) and high wavenumber (HW) Raman spectroscopy technique for real-time in vivo assessment of adenomatous polyps during clinical colonoscopy. We have developed a fiber-optic Raman endoscopic technique capable of simultaneously acquiring both the FP (i.e., 800-1800 cm(-1)) and HW (i.e., 2800-3600 cm(-1)) Raman spectra from colorectal tissue subsurface (<200 µm) for real-time assessment of colorectal carcinogenesis. In vivo FP/HW Raman spectra were acquired from 50 patients with 17 colorectal polyps during clinical colonoscopy. Prominent Raman spectral differences (p < 0.001) were found between hyperplastic (n = 118 spectra), adenoma (n = 184 spectra) that could be attributed to changes in inter- and intra-cellular proteins, lipids, DNA and water structures and conformations. Simultaneous FP/HW Raman endoscopy provides a diagnostic sensitivity of 90.9% and specificity of 83.3% for differentiating adenoma from hyperplastic polyps, which is superior to either the FP or HW Raman technique alone. This study shows that simultaneous FP/HW Raman spectroscopy technique has the potential to be a clinically powerful tool for improving early diagnosis of adenomatous polyps in vivo during colonoscopic examination.

Correlation between Faecal Tumour M2 Pyruvate Kinase and Colonoscopy for the Detection of Adenomatous Neoplasia in a Secondary Care Cohort

BACKGROUND AND AIMS

Colorectal cancer screening programmes that target detection and excision of adenomatous colonic polyps have been shown to reduce colorectal cancer related mortality. Many screening programmes include an initial faecal occult blood test (FOBt) prior to colonoscopy. To refine the selection of patients for colonoscopy other faecal-based diagnostic tools have been proposed, including tumour M2-pyruvate kinase (tM2-PK). To determine whether tM2-PK quantification may have a role in diverse settings we have assessed the assay in a cohort of patients derived from both the England bowel cancer screening programme (BCSP) and symptomatic individuals presenting to secondary care.

METHOD

Patients undergoing colonoscopy provided faecal samples prior to bowel preparation. Faecal tM2-PK concentrations were measured by ELISA. Sensitivity, specificity, positive predictive value, negative predictive value and ROC analyses were calculated.

RESULTS

Ninety-six patients returned faecal samples: 50 of these with adenomas and 7 with cancer. Median age was 68. Median faecal tM2-PK concentration was 3.8 U/mL for individuals without neoplastic findings at colonoscopy, 7.7 U/mL in those with adenomas and 24.4 U/mL in subjects with colorectal cancer (both, p=0.01). ROC analysis demonstrated an AUROC of 0.66 (sensitivity 72.4%, specificity 48.7%, positive predictive value 67.7%, negative predictive value 36.7%). Amongst BCSP patients with a prior positive FOBt faecal tM2-PK was more abundant (median 6.4 U/mL, p=0.03) and its diagnostic accuracy was greater (AUROC 0.82).

CONCLUSION

Our findings confirm that faecal tM2-PK ELISA may have utility as an adjunct to FOBt in a screening context, but do not support its use in symptomatic patients.

Nonampullary duodenal adenoma: Current understanding of its diagnosis, pathogenesis, and clinical management

Nonampullary duodenal adenomas are relatively common in familial adenomatous polyposis (FAP), but nonampullary sporadic duodenal adenomas (SDAs) are rare. Emerging evidence shows that duodenal adenomas, regardless of their anatomic location and whether they are sporadic or FAP-related, share morphologic and molecular features with colorectal adenomas. The available data suggest that duodenal adenomas develop to duodenal adenocarcinomas via similar mechanisms. The optimal approach for management of duodenal adenomas remains to be determined. The techniques for endoscopic resection of duodenal adenoma include snare polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and argon plasma coagulation ablation. EMR may facilitate removal of large duodenal polyps. Although several studies have reported cases of successful ESD for duodenal adenomas, the procedure is technically difficult to perform safely because of the anatomical properties of the duodenum. Although current clinical practice recommends endoscopic resection of all large duodenal adenomas in patients with FAP, endoscopic treatment is usually insufficient to guarantee a polyp-free duodenum. Surgery is indicated for FAP patients with severe polyposis or nonampullary SDAs or FAP-related polyps not amenable to endoscopic resection. Further studies are needed to develop newer endoscopic techniques to guide diagnostic and therapeutic decisions for future management of nonampullary duodenal adenomas.

Obesity and Colorectal Cancer

There is strong evidence that modifiable lifestyle factors such as obesity play a key role in colorectal carcinogenesis. Epidemiologic data have consistently reported a positive association between obesity and colorectal cancer. The relative risk associated with general obesity (as assessed by BMI) is higher in men than in women and for cancer of the colon than for cancer of the rectum. Abdominal obesity (as assessed by waist circumference (WC) or waist-to-hip ratio) is associated with an increased risk of colorectal cancer in both sexes, with stronger associations for cancer of the colon than for cancer of the rectum. Plausible biological mechanisms include insulin resistance, hyperinsulinemia, chronic inflammation, altered levels of growth factors, adipocytokines and steroid hormones. In addition to its effect on colorectal cancer incidence, obesity may play a role in colorectal cancer recurrence, treatment outcomes and survival. Understanding the effects of childhood and adolescent obesity and weight change over the life course in relation to future risk of colorectal cancer is incomplete but essential for targeted preventive recommendations. This chapter summarizes the current evidence on the relationship between obesity and colorectal cancer and colorectal adenoma, a common precursor lesion.

Race and Prevalence of Large Bowel Polyps Among the Low-Income and Uninsured in South Carolina

BACKGROUND

Compared to whites, blacks have higher colorectal cancer incidence and mortality rates and are at greater risk for early-onset disease. The reasons for this racial disparity are poorly understood, but one contributing factor could be differences in access to high-quality screening and medical care.

AIMS

The present study was carried out to assess whether a racial difference in prevalence of large bowel polyps persists within a poor and uninsured population (n = 233, 124 blacks, 91 whites, 18 other) undergoing screening colonoscopy.

METHODS

Eligible patients were uninsured, asymptomatic, had no personal history of colorectal neoplasia, and were between the ages 45-64 years (blacks) or 50-64 years (whites, other). We examined the prevalence of any adenoma (conventional, serrated) and then difference in adenoma/polyp type by race and age categories.

RESULTS

Prevalence for ≥1 adenoma was 37 % (95 % CI 31-43 %) for all races combined and 36 % in blacks <50 years, 38 % in blacks ≥50 years, and 35 % in whites. When stratified by race, blacks had a higher prevalence of large conventional proximal neoplasia (8 %) compared to whites (2 %) (p value = 0.06) but a lower prevalence of any serrated-like (blacks 18 %, whites 32 %; p value = 0.02) and sessile serrated adenomas/polyps (blacks 2 %, whites 8 % Chi-square p value; p = 0.05).

CONCLUSIONS

Within this uninsured population, the overall prevalence of adenomas was high and nearly equal by race, but the racial differences observed between serrated and conventional polyp types emphasize the importance of taking polyp type into account in future research on this topic.

Interval colorectal carcinoma: An unsolved debate

Colorectal carcinoma (CRC), as the third most common new cancer diagnosis, poses a significant health risk to the population. Interval CRCs are those that appear after a negative screening test or examination. The development of interval CRCs has been shown to be multifactorial: location of exam-academic institution versus community hospital, experience of the endoscopist, quality of the procedure, age of the patient, flat versus polypoid neoplasia, genetics, hereditary gastrointestinal neoplasia, and most significantly missed or incompletely excised lesions. The rate of interval CRCs has decreased in the last decade, which has been ascribed to an increased understanding of interval disease and technological advances in the screening of high risk individuals. In this article, we aim to review the literature with regard to the multifactorial nature of interval CRCs and provide the most recent developments regarding this important gastrointestinal entity.

[THE BIOMARKERS FOR TIMELY DIAGNOSTICS OF COLORECTAL CANCER]

The colorectal cancer (CC) is one of the most widespread type of cancer all over the world. It is confirmed that the screening procedures intended for timely detection of CC and adenomatous polyps, significantly decrease mortality. The colonoscopy and analysis offeces for occult blood are widely applied as screening procedures. However, they have a number of shortcomings. The studies of the last decade revealed number of genetic and epigenetic markers potentially permitting revealing patients with CC at early stages of development of disease. The article analyzes CC-specific microRNA and their possible interactions with different transcriptional factors. These factors, being integrated into the structure of so called network s with direct signal propagation, ensure special stability of all regulatory system. The derangement of functioning of these networks quite often results in pathological alterations.

The prevalence and associated factors of colorectal neoplasms in acromegaly: a single center based study

PURPOSE

Colorectal neoplasms are well known to be a complication in cases of acromegaly; however, data on the prevalence of colorectal neoplasms in Asian patients with acromegaly are limited. Further, the factors associated with colorectal neoplasms in cases of acromegaly are controversial. Therefore, we aimed to clarify the prevalence of and factors associated with colorectal neoplasms in Japanese patients with acromegaly in a single center.

METHODS

We analyzed consecutive 57 patients who had undergone full-length colonoscopy at the time of diagnosis at Kobe University Hospital between 1986 and 2012.

RESULTS

Of the 57 patients, 22 (38.6%), 18 (31.6%) and 3 (5.3%) patients were diagnosed with hyperplastic polyps, adenomas, and adenocarcinomas, respectively and the prevalence was significantly higher than in a historical control group, Chinese patients with irritable bowel syndrome (The odds ratio was 4.0, 8.7, and 17.5, respectively). The prevalence of adenocarcinomas was also significantly higher in these patients than in the general Japanese population (odds ratio 14.5). Patients with acromegaly who had colorectal neoplasms had longer disease duration than those without colorectal neoplasms. Of note, the area under the growth hormone (GH) concentration-time curve (GH AUC) during the oral glucose tolerance test was significantly higher in patients with adenocarcinomas than in those with no colonic lesion or those with hyperplastic polyps.

CONCLUSION

Japanese patients with acromegaly exhibited an increased risk of colorectal neoplasms, especially colorectal adenocarcinomas. An increased GH AUC was associated with an increased risk for colon adenocarcinomas in patients with acromegaly.

Discovery of a 29-gene panel in peripheral blood mononuclear cells for the detection of colorectal cancer and adenomas using high throughput real-time PCR

Colorectal cancer (CRC) is the second leading cause of cancer-related death in developed countries. Early detection of CRC leads to decreased CRC mortality. A blood-based CRC screening test is highly desirable due to limited invasiveness and high acceptance rate among patients compared to currently used fecal occult blood testing and colonoscopy. Here we describe the discovery and validation of a 29-gene panel in peripheral blood mononuclear cells (PBMC) for the detection of CRC and adenomatous polyps (AP). Blood samples were prospectively collected from a multicenter, case-control clinical study. First, we profiled 93 samples with 667 candidate and 3 reference genes by high throughput real-time PCR (OpenArray system). After analysis, 160 genes were retained and tested again on 51 additional samples. Low expressed and unstable genes were discarded resulting in a final dataset of 144 samples profiled with 140 genes. To define which genes, alone or in combinations had the highest potential to discriminate AP and/or CRC from controls, data were analyzed by a combination of univariate and multivariate methods. A list of 29 potentially discriminant genes was compiled and evaluated for its predictive accuracy by penalized logistic regression and bootstrap. This method discriminated AP >1cm and CRC from controls with a sensitivity of 59% and 75%, respectively, with 91% specificity. The behavior of the 29-gene panel was validated with a LightCycler 480 real-time PCR platform, commonly adopted by clinical laboratories. In this work we identified a 29-gene panel expressed in PBMC that can be used for developing a novel minimally-invasive test for accurate detection of AP and CRC using a standard real-time PCR platform.

Trainee colonoscopists fulfil quality standards for the detection of adenomatous polyps

BACKGROUND

The detection of adenomatous lesions is a major indicator for quality and competence in colonoscopy. Little is known about adenoma detection rates (ADR) of endoscopy trainees. The aim of our study was to investigate the performance of trainee colonoscopists in detecting adenomas and to depict the shape of adenoma detection learning curves during apprenticeship.

METHODS

We retrospectively investigated a prospectively maintained database of a single tertiary referral center to reveal colonoscopies performed by trainee endoscopists during 2001 and 2013. Colonoscopy reports were chronologically retrieved and separately analyzed for each trainee. Using cumulative curves, courses of trainee's Adenoma detection rates (ADR) during apprenticeship were displayed. Additionally, procedural data including cecal intubation rate and occurrence of complications were assessed.

RESULTS

We retrospectively analyzed 4354 colonoscopies conducted by 10 trainee endoscopists (TE). A median number of 371 investigations were performed by each apprentice. Group ADR was 23%. No significant difference between aggregated ADRs at the beginning (23%) and at the end (22%) of apprenticeship could be determined (p = 0.70). However, individual learning curves showed considerable different slopes. Personal ADR values ranged between 17% and 31%. Overall cecum intubation rate was 99.0 %. Complication rates were low and fulfilled quality requirements recommended in guidelines.

CONCLUSION

From the beginning of education, trainee colonoscopists are capable to provide high-quality investigations considering the detection of adenomas as a benchmark quality indicator. Nevertheless, performance differs markedly between investigators. Therefore, individual detection rates should be reviewed regularly to reveal further need for training.

Body mass index and colon cancer screening: The road ahead

Screening for colorectal cancer (CRC) has been associated with a decreased incidence and mortality from CRC. However, patient adherence to screening is less than desirable and resources are limited even in developed countries. Better identification of individuals at a higher risk could result in improved screening efforts. Over the past few years, formulas have been developed to predict the likelihood of developing advanced colonic neoplasia in susceptible individuals but have yet to be utilized in mass screening practices. These models use a number of clinical factors that have been associated with colonic neoplasia including the body mass index (BMI). Advances in our understanding of the mechanisms by which obesity contributes to colonic neoplasia as well as clinical studies on this subject have proven the association between BMI and colonic neoplasia. However, there are still controversies on this subject as some studies have arrived at different conclusions on the influence of BMI by gender. Future studies should aim at resolving these discrepancies in order to improve the efficiency of screening strategies.

[Application of double balloon enteroscopy in diagnosis of small bowel diseases]

INTRODUCTION

Double balloon enteroscopy (DBE) is one of the newest among endoscopic techniques used in diagnosis of the digestive tract diseases--particularly in small bowel's lesions.

MATERIALS AND METHODS

The retrospective analysis of patients' data from 2008 to 2012 in the Department of Digestive Tract Diseases, UM was made. Case histories were analised and evaluated for sex, age, clinical symptoms, results of additional examinations and indications. The course of the examination, its result, complications and role in final diagnosis were also checked.

RESULTS

During the analysed period DBE was attempted 71 times DBE among 42 patients (17 women and 25 men; the age was 44.5 years ± 17.5 years). The most frequent indication for DBE was occult gastrointestinal bleeding--34 patients (80.9%). Among the other patients, the clinical image suggested Crohn's disease (4 cases--9.5%), suspicion of small bowel's neoplasm (2 patients--4.8%), familiar adenomatous polyposis with a need to make polypectomy (1 case--2.4%) and state after bariatric surgery to extract moved gastric balloon (1 patient--2.4%). Small bowel's lesions were detected in 21 patients (50%)--8 polyps, 8--aphthaes and inflammatory changes, 3--vascular lesions, 2--smoothing villi. In four cases the polypectomy was made. The anaesthetic complications appeared with two patients (4,8%). Complications being a result of performed DBE was observed in one case (2.4%).

CONCLUSIONS

Double balloon enteroscopy is safe endoscopic procedure and it plays a key role in diagnosis of patients with gastrointestinal bleeding.

Rare combination of familial adenomatous polyposis and gallbladder polyps

Familial adenomatous polyposis is associated with a high incidence of malignancies in the upper gastrointestinal tract (particularly ampullary adenocarcinomas). However, few reports have described a correlation between familial adenomatous polyposis and gallbladder neoplasms. We present a case of a 60-year-old woman with familial adenomatous polyposis who presented with an elevated mass in the neck of the gallbladder (measuring 16 mm × 8 mm in diameter) and multiple small cholecystic polyps. She had undergone a total colectomy for ascending colon cancer associated with familial adenomatous polyposis 22 years previously. The patient underwent laparoscopic cholecystectomy under a preoperative diagnosis of multifocal gallbladder polyps. Pathologic examination of the resected gallbladder revealed more than 70 adenomatous lesions, a feature consistent with adenoma of the gallbladder. This case suggests a requirement for long-term surveillance of the biliary system in addition to the gastrointestinal tract in patients with familial adenomatous polyposis.

Predictive gene signatures: molecular markers distinguishing colon adenomatous polyp and carcinoma

Cancers exhibit abnormal molecular signatures associated with disease initiation and progression. Molecular signatures could improve cancer screening, detection, drug development and selection of appropriate drug therapies for individual patients. Typically only very small amounts of tissue are available from patients for analysis and biopsy samples exhibit broad heterogeneity that cannot be captured using a single marker. This report details application of an in-house custom designed GenomeLab System multiplex gene expression assay, the hCellMarkerPlex, to assess predictive gene signatures of normal, adenomatous polyp and carcinoma colon tissue using archived tissue bank material. The hCellMarkerPlex incorporates twenty-one gene markers: epithelial (EZR, KRT18, NOX1, SLC9A2), proliferation (PCNA, CCND1, MS4A12), differentiation (B4GANLT2, CDX1, CDX2), apoptotic (CASP3, NOX1, NTN1), fibroblast (FSP1, COL1A1), structural (ACTG2, CNN1, DES), gene transcription (HDAC1), stem cell (LGR5), endothelial (VWF) and mucin production (MUC2). Gene signatures distinguished normal, adenomatous polyp and carcinoma. Individual gene targets significantly contributing to molecular tissue types, classifier genes, were further characterised using real-time PCR, in-situ hybridisation and immunohistochemistry revealing aberrant epithelial expression of MS4A12, LGR5 CDX2, NOX1 and SLC9A2 prior to development of carcinoma. Identified gene signatures identify aberrant epithelial expression of genes prior to cancer development using in-house custom designed gene expression multiplex assays. This approach may be used to assist in objective classification of disease initiation, staging, progression and therapeutic responses using biopsy material.

Two rare gastric hamartomatous inverted polyp cases suggest the pathogenesis of growth

Gastric hamartomatous inverted polyps (GHIP) are difficult to diagnose accurately because of inversion into the submucosal layer. GHIP are diagnosed using the pathological characteristics of the tumor, including the fibroblast cells, smooth muscle, nerve components, glandular hyperplasia, and cystic gland dilatation. Although Peutz-Jeghers syndrome, juvenile polyposis, and Cowden disease are hereditary, it is rare to encounter 2 cases of monostotic and asymptomatic gastric hamartomas. The pathogeneses of hamartomatous inverted polyps and inverted hyperplastic polyps remain controversial because of the paucity of reported cases. There are 3 hypotheses regarding the pathogenesis of complete gastric inverted polyps. Based on our experience with 2 successive, rare GHIP cases, we affirm the hypothesis that after a hamartomatous change occurs in the submucosal layer, some of these components are exposed to the gastric mucosa and, consequently, form a hypertrophic lesion. In Case 1, our hypothesis explains why a tiny hypertrophic change was first detected on the top of the submucosal tumor using a detailed narrow band imaging-magnified endoscopy. There was no confirmation that the milky white mucous and calcification structures were exuding directly from the biopsy site like Case 1, and in Case 2 the presence of this mucous was indirectly confirmed during an endoscopic submucosal dissection (ESD). Regarding the pathogenesis of GHIP, a submucosal hamartomatous change may occur prior to the growth of hypertrophic portions. An en bloc resection using ESD is recommended for treatment.

18F-FDG PET/CT imaging for a gastrointestinal mantle cell lymphoma with multiple lymphomatous polyposis

Multiple lymphomatous polyposis (MLP) is an uncommon type of gastrointestinal lymphoma characterized by the presence of multiple polyps along the gastrointestinal tract. Most of this entity is in fact considered the counterpart of gastrointestinal tract involvement for mantle cell lymphoma (MCL). To our knowledge, there have been no reports on [fluorine-18]-fluorodeoxy-glucose (¹⁸F-FDG)-positron emission tomography (PET)/computed tomography (CT) imaging for gastrointestinal MCL with MLP. We present the results of ¹⁸F-FDG PET/CT imaging in a patient with gastrointestinal tract involvement of MCL showing continuous MLP from the stomach to the rectum and intestinal intussusception. FDG-PET/CT findings were false negative in typical MLP spreading widely over the gastrointestinal tract, but uptake was noted in large lesions with deep infiltration considered atypical as MLP. On FDG-PET/CT imaging, the Ki-67 proliferative index, which is a cell proliferation marker, showed neither correlation with the presence of uptake nor the maximum standardized uptake value.