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World Journal of Gastrointestinal... May 2023Colonoscopy and polypectomy remain the gold standard investigation for the detection and prevention of colorectal cancer. Halting the progression of colonic adenoma... (Review)
Review
Colonoscopy and polypectomy remain the gold standard investigation for the detection and prevention of colorectal cancer. Halting the progression of colonic adenoma through adequate detection of pre-cancerous lesions interrupts the progression to carcinoma. The adenoma detection rate is a key performance indicator. Increasing adenoma detection rates are associated with reducing rates of interval colorectal cancer. Endoscopists with high baseline adenoma detection rate have a meticulous technique during colonoscopy withdrawal that improves their adenoma detection. This minireview article summarizes the evidence on the following simple operator techniques and their effects on the adenoma detection rate; minimum withdrawal times, dynamic patient position change and proximal colon retroflexion.
PubMed: 37274557
DOI: 10.4253/wjge.v15.i5.354 -
Cancers Jul 2021Colorectal cancer (CRC) develops from pre-cancerous cellular lesions in the gut epithelium, known as polyps. Polyps themselves arise through the accumulation of... (Review)
Review
Colorectal cancer (CRC) develops from pre-cancerous cellular lesions in the gut epithelium, known as polyps. Polyps themselves arise through the accumulation of mutations that disrupt the function of key tumour suppressor genes, activate proto-oncogenes and allow proliferation in an environment where immune control has been compromised. Consequently, colonoscopic surveillance and polypectomy are central pillars of cancer control strategies. Recent advances in genomic sequencing technologies have enhanced our knowledge of key driver mutations in polyp lesions that likely contribute to CRC. In accordance with the prognostic significance of Immunoscores for CRC survival, there is also a likely role for early immunological changes in polyps, including an increase in regulatory T cells and a decrease in mature dendritic cell numbers. Gut microbiotas are under increasing research interest for their potential contribution to CRC evolution, and changes in the gut microbiome have been reported from analyses of adenomas. Given that early changes to molecular components of bowel polyps may have a direct impact on cancer development and/or act as indicators of early disease, we review the molecular landscape of colorectal polyps, with an emphasis on immunological and microbial alterations occurring in the gut and propose the potential clinical utility of these data.
PubMed: 34298598
DOI: 10.3390/cancers13143382 -
Frontiers in Medicine 2018Postpolypectomy bleeding and incomplete polyp removal are important complication and quality concerns of colonoscopy for colon cancer prevention. We investigated if...
Postpolypectomy bleeding and incomplete polyp removal are important complication and quality concerns of colonoscopy for colon cancer prevention. We investigated if endoscopic mucosal stripping (EMS) as a technical modification of traditional cold snare polypectomy to avoid submucosal injury during removal of non-pedunculated colon polyps could prevent postpolypectomy bleeding and facilitate complete polyp removal. This is an Internal Review Board exemption-granted retrospective analysis of 5,142 colonoscopies with snare polypectomy performed by one of the authors (ZJC) at Minnesota Gastroenterology ambulatory endoscopy centers during a 12-year period divided into pre-EMS era (2005-2012, = 2,973) and EMS era (2013-2016, = 2169) with systemic adoption of EMS starting 2013. Change in postpolypectomy bleeding rate before and after EMS adoption and EMS polypectomy completeness were evaluated. Zero postpolypectomy bleeding case was found during EMS era (rate 0%) compared with 10 bleeding cases during pre-EMS era (rate 0.336%). This difference was statistically significant ( = 0.0055) and remained so after excluding 2 bleeding cases of pedunculated polyps ( = 0.012). All bleeding cases involved hot snare polypectomy. Histological examination of the involved polyps showed substantial submucosal vascular damage in contrast to a remarkable paucity of submucosa in comparable advanced polyps removed using EMS. Both biopsy and follow-up colonoscopy examination of the polypectomy sites confirmed that EMS more completely removed non-pedunculated advanced polyps. EMS polypectomy was effective in preventing postpolypectomy bleeding and facilitated complete polyp removal.
PubMed: 30467544
DOI: 10.3389/fmed.2018.00312 -
World Journal of Gastroenterology Jul 2013Despite multiple efforts aimed at early detection through screening, colon cancer remains the third leading cause of cancer-related deaths in the United States, with an... (Review)
Review
Despite multiple efforts aimed at early detection through screening, colon cancer remains the third leading cause of cancer-related deaths in the United States, with an estimated 51000 deaths during 2013 alone. The goal remains to identify and remove benign neoplastic polyps prior to becoming invasive cancers. Polypoid lesions of the colon vary widely from hyperplastic, hamartomatous and inflammatory to neoplastic adenomatous growths. Although these lesions are all benign, they are common, with up to one-quarter of patients over 60 years old will develop pre-malignant adenomatous polyps. Colonoscopy is the most effective screening tool to detect polyps and colon cancer, although several studies have demonstrated missed polyp rates from 6%-29%, largely due to variations in polyp size. This number can be as high as 40%, even with advanced (> 1 cm) adenomas. Other factors including sub-optimal bowel preparation, experience of the endoscopist, and patient anatomical variations all affect the detection rate. Additional challenges in decision-making exist when dealing with more advanced, and typically larger, polyps that have traditionally required formal resection. In this brief review, we will explore the recent advances in polyp detection and therapeutic options.
Topics: Adenoma; Colonic Neoplasms; Colonic Polyps; Colonoscopy; Humans; Intestinal Mucosa; Laparoscopy; Precancerous Conditions; Recurrence; Treatment Outcome
PubMed: 23885138
DOI: 10.3748/wjg.v19.i27.4277 -
World Journal of Gastroenterology Mar 2015In recent years, a second pathway for colonic carcinogenesis, distinct from the adenomatous pathway, has been explored. This is referred to as serrated pathway and... (Review)
Review
In recent years, a second pathway for colonic carcinogenesis, distinct from the adenomatous pathway, has been explored. This is referred to as serrated pathway and includes three types of polyp, characterised by a serrated appearance of the crypts: hyperplastic polyps (HP), sessile serrated adenomas (SSA) or lesions, and traditional serrated adenomas. Each lesion has its own genetic, as well as macroscopic and microscopic morphological features. Because of their flat aspect, their detection is easier with chromoendoscopy (carmin indigo or narrow-band imaging). However, as we show in this review, the distinction between SSA and HP is quite difficult. It is now recommended to resect in one piece as it is possible the serrated polyps with a control in a delay depending on the presence or not of dysplasia. These different types of lesion are described in detail in the present review in general population, in polyposis and in inflammatory bowel diseases patients. This review highlights the need to improve characterization and understanding of this way of colorectal cancerogenesis.
Topics: Adenomatous Polyps; Chromogenic Compounds; Colonic Neoplasms; Colonic Polyps; Colonoscopy; Diagnosis, Differential; Humans; Hyperplasia; Microscopy; Narrow Band Imaging; Precancerous Conditions; Predictive Value of Tests; Prognosis
PubMed: 25780286
DOI: 10.3748/wjg.v21.i10.2896 -
United European Gastroenterology Journal Jun 2021Artificial intelligence (AI) using deep learning methods for polyp detection (CADe) and characterization (CADx) is on the verge of clinical application. CADe already... (Review)
Review
BACKGROUND
Artificial intelligence (AI) using deep learning methods for polyp detection (CADe) and characterization (CADx) is on the verge of clinical application. CADe already implied its potential use in randomized controlled trials. Further efforts are needed to take CADx to the next level of development.
AIM
This work aims to give an overview of the current status of AI in colonoscopy, without going into too much technical detail.
METHODS
A literature search to identify important studies exploring the use of AI in colonoscopy was performed.
RESULTS
This review focuses on AI performance in screening colonoscopy summarizing the first prospective trials for CADe, the state of research in CADx as well as current limitations of those systems and legal issues.
Topics: Adenoma; Artificial Intelligence; Clinical Trials as Topic; Colonic Neoplasms; Colonic Polyps; Colonoscopy; Deep Learning; Diagnosis, Computer-Assisted; Humans; Precancerous Conditions; Quality Improvement; Randomized Controlled Trials as Topic
PubMed: 34617420
DOI: 10.1002/ueg2.12108 -
Journal of Carcinogenesis 2014Colorectal cancer (CRC) is an important cause of mortality and morbidity in North America. Screening using a fecal occult blood test, flexible sigmoidoscopy, or... (Review)
Review
Colorectal cancer (CRC) is an important cause of mortality and morbidity in North America. Screening using a fecal occult blood test, flexible sigmoidoscopy, or colonoscopy reduces CRC mortality through the detection and treatment of precancerous polyps and early stage CRC. Although CRC screening participation has increased in recent years, large inequities still exist. Minorities, new immigrants, and those with lower levels of education or income are much less likely to be screened. This review provides an overview of the commonly used tests for CRC screening, disparities in CRC screening, and promising methods at the individual, provider, and system levels to reduce these disparities. Overall, to achieve high CRC participation rates and reduce the burden of CRC in the population, a multi-faceted approach that uses strategies at all levels to reduce CRC screening disparities is urgently required.
PubMed: 25506266
DOI: 10.4103/1477-3163.144576 -
Cancers Dec 2021Colorectal cancer (CRC) is the third and second cancer for incidence and mortality worldwide, respectively, and is becoming prevalent in developing countries. Most CRCs... (Review)
Review
Colorectal cancer (CRC) is the third and second cancer for incidence and mortality worldwide, respectively, and is becoming prevalent in developing countries. Most CRCs derive from polyps, especially adenomatous polyps, which can gradually transform into CRC. The family of Matrix Metalloproteinases (MMPs) plays a critical role in the initiation and progression of CRC. Prominent MMPs, including MMP-1, MMP-2, MMP-7, MMP-8, MMP-9, MMP-12, MMP-13, MMP-14, and MMP-21, have been detected in CRC patients, and the expression of most of them correlates with a poor prognosis. Moreover, many studies have explored the inhibition of MMPs and targeted therapy for CRC, but there is not enough information about the role of MMPs in polyp malignancy. In this review, we discuss the role of MMPs in colorectal cancer and its pathogenesis.
PubMed: 34944846
DOI: 10.3390/cancers13246226 -
World Journal of Gastroenterology Sep 2016It is currently known that colorectal cancers (CRC) arise from 3 different pathways: the adenoma to carcinoma chromosomal instability pathway (50%-70%); the mutator... (Review)
Review
It is currently known that colorectal cancers (CRC) arise from 3 different pathways: the adenoma to carcinoma chromosomal instability pathway (50%-70%); the mutator "Lynch syndrome" route (3%-5%); and the serrated pathway (30%-35%). The World Health Organization has classified serrated polyps into three types of lesions: hyperplastic polyps (HP), sessile serrated adenomas/polyps (SSA/P) and traditional serrated adenomas (TSA), the latter two strongly associated with development of CRCs. HPs do not cause cancer and TSAs are rare. SSA/P appear to be the responsible precursor lesion for the development of cancers through the serrated pathway. Both HPs and SSA/Ps appear morphologically similar. SSA/P are difficult to detect. The margins are normally inconspicuous. En bloc resection of these polyps can hence be troublesome. A careful examination of borders, submucosal injection of a dye solution (for larger lesions) and resection of a rim of normal tissue around the lesion may ensure total eradication of these lesions.
Topics: Adenoma; Colonic Neoplasms; Colonic Polyps; Colonoscopy; Colorectal Neoplasms; Disease Progression; Endoscopy; Gastrointestinal Neoplasms; Humans; Hyperplasia; Practice Guidelines as Topic; Precancerous Conditions; Societies, Medical
PubMed: 27678358
DOI: 10.3748/wjg.v22.i34.7754 -
World Journal of Gastroenterology Mar 2014Colonoscopy is the principal investigative procedure for colorectal neoplasms because it can detect and remove most precancerous lesions. The effectiveness of... (Review)
Review
Colonoscopy is the principal investigative procedure for colorectal neoplasms because it can detect and remove most precancerous lesions. The effectiveness of colonoscopy depends on the quality of the examination. Bowel preparation is an essential part of high-quality colonoscopies because only an optimal colonic cleansing allows the colonoscopist to clearly view the entire colonic mucosa and to identify any polyps or other lesions. Suboptimal bowel preparation not only prolongs the overall procedure time, decreases the cecal intubation rate, and increases the costs associated with colonoscopy but also increases the risk of missing polyps or adenomas during the colonoscopy. Therefore, a repeat examination or a shorter colonoscopy follow-up interval may be suitable strategies for a patient with suboptimal bowel preparation.
Topics: Adenoma; Cathartics; Colonic Neoplasms; Colonic Polyps; Colonoscopy; Humans
PubMed: 24659866
DOI: 10.3748/wjg.v20.i11.2746