PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (1421057)

Clipboard (0)
None

Related Articles

1.  Evaluation of a Minimally Invasive Cell Sampling Device Coupled with Assessment of Trefoil Factor 3 Expression for Diagnosing Barrett's Esophagus: A Multi-Center Case–Control Study 
PLoS Medicine  2015;12(1):e1001780.
Background
Barrett's esophagus (BE) is a commonly undiagnosed condition that predisposes to esophageal adenocarcinoma. Routine endoscopic screening for BE is not recommended because of the burden this would impose on the health care system. The objective of this study was to determine whether a novel approach using a minimally invasive cell sampling device, the Cytosponge, coupled with immunohistochemical staining for the biomarker Trefoil Factor 3 (TFF3), could be used to identify patients who warrant endoscopy to diagnose BE.
Methods and Findings
A case–control study was performed across 11 UK hospitals between July 2011 and December 2013. In total, 1,110 individuals comprising 463 controls with dyspepsia and reflux symptoms and 647 BE cases swallowed a Cytosponge prior to endoscopy. The primary outcome measures were to evaluate the safety, acceptability, and accuracy of the Cytosponge-TFF3 test compared with endoscopy and biopsy.
In all, 1,042 (93.9%) patients successfully swallowed the Cytosponge, and no serious adverse events were attributed to the device. The Cytosponge was rated favorably, using a visual analogue scale, compared with endoscopy (p < 0.001), and patients who were not sedated for endoscopy were more likely to rate the Cytosponge higher than endoscopy (Mann-Whitney test, p < 0.001). The overall sensitivity of the test was 79.9% (95% CI 76.4%–83.0%), increasing to 87.2% (95% CI 83.0%–90.6%) for patients with ≥3 cm of circumferential BE, known to confer a higher cancer risk. The sensitivity increased to 89.7% (95% CI 82.3%–94.8%) in 107 patients who swallowed the device twice during the study course. There was no loss of sensitivity in patients with dysplasia. The specificity for diagnosing BE was 92.4% (95% CI 89.5%–94.7%). The case–control design of the study means that the results are not generalizable to a primary care population. Another limitation is that the acceptability data were limited to a single measure.
Conclusions
The Cytosponge-TFF3 test is safe and acceptable, and has accuracy comparable to other screening tests. This test may be a simple and inexpensive approach to identify patients with reflux symptoms who warrant endoscopy to diagnose BE.
Editors' Summary
Background
Barrett's esophagus is a condition in which the cells lining the esophagus (the tube that transports food from the mouth to the stomach) change and begin to resemble the cells lining the intestines. Although some people with Barrett's esophagus complain of burning indigestion or acid reflux from the stomach into the esophagus, many people have no symptoms or do not seek medical advice, so the condition often remains undiagnosed. Long-term acid reflux (gastroesophageal reflux disease), obesity, and being male are all risk factors for Barrett's esophagus, but the condition's exact cause is unclear. Importantly, people with Barrett's esophagus are more likely to develop esophageal cancer than people with a normal esophagus, especially if a long length (segment) of the esophagus is affected or if the esophagus contains abnormally growing “dysplastic” cells. Although esophageal cancer is rare in the general population, 1%–5% of people with Barrett's esophagus develop this type of cancer; about half of people diagnosed with esophageal cancer die within a year of diagnosis.
Why Was This Study Done?
Early detection and treatment of esophageal cancer increases an affected individual's chances of survival. Thus, experts recommend that people with multiple risk factors for Barrett's esophagus undergo endoscopic screening—a procedure that uses a small camera attached to a long flexible tube to look for esophageal abnormalities. Once diagnosed, patients with Barrett's esophagus generally enter an endoscopic surveillance program so that dysplastic cells can be identified as soon as they appear and removed using endoscopic surgery or “radiofrequency ablation” to prevent cancer development. However, although endoscopic screening of everyone with reflux symptoms for Barrett's esophagus could potentially reduce deaths from esophageal cancer, such screening is not affordable for most health care systems. In this case–control study, the researchers investigate whether a cell sampling device called the Cytosponge coupled with immunohistochemical staining for Trefoil Factor 3 (TFF3, a biomarker of Barrett's esophagus) can be used to identify individuals who warrant endoscopic investigation. A case–control study compares the characteristics of patients with and without a specific disease. The Cytosponge is a small capsule-encased sponge that is attached to a string. The capsule rapidly dissolves in the stomach after being swallowed, and the sponge collects esophageal cells for TFF3 staining when it is retrieved by pulling on the string.
What Did the Researchers Do and Find?
The researchers enrolled 463 individuals attending 11 UK hospitals for investigational endoscopy for dyspepsia and reflux symptoms as controls, and 647 patients with Barrett's esophagus who were attending hospital for monitoring endoscopy. Before undergoing endoscopy, the study participants swallowed a Cytosponge so that the researchers could evaluate the safety, acceptability, and accuracy of the Cytosponge-TFF3 test for the diagnosis of Barrett's esophagus compared with endoscopy. Nearly 94% of the participants swallowed the Cytosponge successfully, there were no adverse effects attributed to the device, and those participants that swallowed the device generally rated the experience as acceptable. The overall sensitivity of the Cytosponge-TFF3 test (its ability to detect true positives) was 79.9%. That is, 79.9% of the individuals with endoscopically diagnosed Barrett's esophagus were identified as having the condition using the new test. The sensitivity of the test was greater among patients who had a longer length of affected esophagus and importantly was not reduced in patients with dysplasia. Compared to endoscopy, the specificity of the Cytosponge-TFF3 test (its ability to detect true negatives) was 92.4%. That is, 92.4% of people unaffected by Barrett's esophagus were correctly identified as being unaffected.
What Do These Findings Mean?
The case–control design of this study means that its results are not generalizable to a primary care population. Also, the study used only a single measure of the acceptability of the Cytosponge-TFF3 test, Nevertheless, these findings indicate that this minimally invasive test for Barrett's esophagus is safe and acceptable, and that its accuracy is similar to that of colorectal cancer and cervical cancer screening tests. The Cytosponge-TFF3 test might, therefore, provide a simple, inexpensive way to identify those patients with reflux symptoms who warrant endoscopy to diagnose Barrett's esophagus, although randomized controlled trials of the test are needed before its routine clinical implementation. Moreover, because most people with Barrett's esophagus never develop esophageal cancer, additional biomarkers ideally need to be added to the test before its routine implementation to identify those individuals who have the greatest risk of esophageal cancer, and thereby avoid overtreatment of Barrett's esophagus.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001780.
The US National Institute of Diabetes and Digestive and Kidney Diseases provides detailed information about Barrett's esophagus and gastroesophageal reflux disease
The US National Cancer Institute provides information for patients and health professionals about esophageal cancer (in English and Spanish)
Cancer Research UK (a non-profit organization) provides detailed information about Barrett's esophagus (including a video about having the Cytosponge test and further information about this study, the BEST2 Study) and about esophageal cancer
The UK National Health Service Choices website has pages on the complications of gastroesophageal reflux and on esophageal cancer (including a real story)
Heartburn Cancer Awareness Support is a non-profit organization that aims to improve public awareness and provides support for people affected by Barrett's esophagus; the organization's website explains the range of initiatives to promote education and awareness as well as highlighting personal stories of those affected by Barrett's esophagus and esophageal cancer
The British Society of Gastroenterology has published guidelines on the diagnosis and management of Barrett's esophagus
The UK National Institute for Health and Care Excellence has published guidelines for gastroesophageal reflux
The Barrett's Esophagus Campaign is a UK-based non-profit organization that supports research into the condition and provides support for people affected by Barrett's esophagus; its website includes personal stories about the condition
In a multi-center case-control study, Rebecca Fitzgerald and colleagues examine whether a minimally invasive cell sampling device could be used to identify patients who warrant endoscopy to diagnose Barrett's esophagus.
doi:10.1371/journal.pmed.1001780
PMCID: PMC4310596  PMID: 25634542
2.  Autofluorescence imaging and magnification endoscopy 
It is well known that angiogenesis is critical in the transition from premalignant to malignant lesions. Consequently, early detection and diagnosis based on morphological changes to the microvessels are crucial. In the last few years, new imaging techniques which utilize the properties of light-tissue interaction have been developed to increase early diagnosis of gastrointestinal (GI) tract neoplasia. We analyzed several “red-flag” endoscopic techniques used to enhance visualization of the vascular pattern of preneoplastic and neoplastic lesions (e.g. trimodal imaging including autofluorescence imaging, magnifying endoscopy and narrow band imaging). These new endoscopic techniques provide better visualization of mucosal microsurface structure and microvascular architecture and may enhance the diagnosis and characterization of mucosal lesions in the GI tract. In the near future, it is expected that trimodal imaging endoscopy will be practiced as a standard endoscopy technique as it is quick, safe and accurate for making a precise diagnosis of gastrointestinal pathology, with an emphasis on the diagnosis of early GI tract cancers. Further large-scale randomized controlled trials comparing these modalities in different patient subpopulations are warranted before their endorsement in the routine practice of GI endoscopy.
doi:10.3748/wjg.v17.i1.9
PMCID: PMC3016686  PMID: 21218078
Angiogenesis; Autofluorescence imaging; Multiband imaging; Narrow band imaging; Zoom endoscopy
3.  Molecular Imaging in Gastrointestinal Endoscopy 
Gastroenterology  2010;138(3):828-33.e1.
Molecular imaging is a rapidly growing new discipline in gastrointestinal endoscopy. It uses the molecular signature of cells for minimally-invasive, targeted imaging of gastrointestinal pathologies. Molecular imaging comprises wide field techniques for the detection of lesions and microscopic techniques for in vivo characterization. Exogenous fluorescent agents serve as molecular beacons and include labeled peptides and antibodies, and probes with tumor-specific activation. Most applications have aimed at improving the detection of gastrointestinal neoplasia with either prototype fluorescence endoscopy or confocal endomicroscopy, and first studies have translated encouraging results from rodent and tissue models to endoscopy in humans. Even with the limitations of the currently used approaches, molecular imaging has the potential to greatly impact on future endoscopy in gastroenterology.
doi:10.1053/j.gastro.2010.01.009
PMCID: PMC3335170  PMID: 20096697
Molecular imaging; endoscopy; confocal endomicroscopy; autofluorescence imaging; cancer; EGFR
4.  State of the art in advanced endoscopic imaging for the detection and evaluation of dysplasia and early cancer of the gastrointestinal tract 
Ideally, endoscopists should be able to detect, characterize, and confirm the nature of a lesion at the bedside, minimizing uncertainties and targeting biopsies and resections only where necessary. However, under conventional white-light inspection – at present, the sole established technique available to most of humanity – premalignant conditions and early cancers can frequently escape detection. In recent years, a range of innovative techniques have entered the endoscopic arena due to their ability to enhance the contrast of diseased tissue regions beyond what is inherently possible with standard white-light endoscopy equipment. The aim of this review is to provide an overview of the state-of-the-art advanced endoscopic imaging techniques available for clinical use that are impacting the way precancerous and neoplastic lesions of the gastrointestinal tract are currently detected and characterized at endoscopy. The basic instrumentation and the physics behind each method, followed by the most influential clinical experience, are described. High-definition endoscopy, with or without optical magnification, has contributed to higher detection rates compared with white-light endoscopy alone and has now replaced ordinary equipment in daily practice. Contrast-enhancement techniques, whether dye-based or computed, have been combined with white-light endoscopy to further improve its accuracy, but histology is still required to clarify the diagnosis. Optical microscopy techniques such as confocal laser endomicroscopy and endocytoscopy enable in vivo histology during endoscopy; however, although of invaluable assistance for tissue characterization, they have not yet made transition between research and clinical use. It is still unknown which approach or combination of techniques offers the best potential. The optimal method will entail the ability to survey wide areas of tissue in concert with the ability to obtain the degree of detailed information provided by microscopic techniques. In this respect, the challenging combination of autofluorescence imaging and confocal endomicroscopy seems promising, and further research is awaited.
Video abstract
doi:10.2147/CEG.S58157
PMCID: PMC4028486  PMID: 24868168
image-enhanced endoscopy; narrowband imaging; autofluorescence imaging; confocal laser endomicroscopy; fluorescence lifetime imaging
5.  Screening for Precancerous Lesions of Upper Gastrointestinal Tract: From the Endoscopists' Viewpoint 
Upper gastrointestinal tract cancers are one of the most important leading causes of cancer death worldwide. Diagnosis at late stages always brings about poor outcome of these malignancies. The early detection of precancerous or early cancerous lesions of gastrointestinal tract is therefore of utmost importance to improve the overall outcome and maintain a good quality of life of patients. The desire of endoscopists to visualize the invisibles under conventional white-light endoscopy has accelerated the advancements in endoscopy technologies. Nowadays, image-enhanced endoscopy which utilizes optical- or dye-based contrasting techniques has been widely applied in endoscopic screening program of gastrointestinal tract malignancies. These contrasting endoscopic technologies not only improve the visualization of early foci missed by conventional endoscopy, but also gain the insight of histopathology and tumor invasiveness, that is so-called optical biopsy. Here, we will review the application of advanced endoscopy technique in screening program of upper gastrointestinal tract cancers.
doi:10.1155/2013/681439
PMCID: PMC3615623  PMID: 23573079
6.  Endoscopy in screening for digestive cancer 
The aim of this study is to describe the role of endoscopy in detection and treatment of neoplastic lesions of the digestive mucosa in asymptomatic persons. Esophageal squamous cell cancer occurs in relation to nutritional deficiency and alcohol or tobacco consumption. Esophageal adenocarcinoma develops in Barrett’s esophagus, and stomach cancer in chronic gastric atrophy with Helicobacter pylori infection. Colorectal cancer is favoured by a high intake in calories, excess weight, low physical activity. In opportunistic or individual screening endoscopy is the primary detection procedure offered to an asymptomatic individual. In organized or mass screening proposed by National Health Authorities to a population, endoscopy is performed only in persons found positive to a filter selection test. The indications of primary upper gastrointestinal endoscopy and colonoscopy in opportunistic screening are increasingly developing over the world. Organized screening trials are proposed in some regions of China at high risk for esophageal cancer; the selection test is cytology of a balloon or sponge scrapping; they are proposed in Japan for stomach cancer with photofluorography as a selection test; and in Europe, America and Japan; for colorectal cancer with the fecal occult blood test as a selection test. Organized screening trials in a country require an evaluation: the benefit of the intervention assessed by its impact on incidence and on the 5 year survival for the concerned tumor site; in addition a number of bias interfering with the evaluation have to be controlled. Drawbacks of screening are in the morbidity of the diagnostic and treatment procedures and in overdetection of none clinically relevant lesions. The strategy of endoscopic screening applies to early cancer and to benign adenomatous precursors of adenocarcinoma. Diagnostic endoscopy is conducted in 2 steps: at first detection of an abnormal area through changes in relief, in color or in the course of superficial capillaries; then characterization of the morphology of the lesion according to the Paris classification and prediction of the risk of malignancy and depth of invasion, with the help of chromoscopy, magnification and image processing with neutrophil bactericidal index or FICE. Then treatment decision offers 3 options according to histologic prediction: abstention, endoscopic resection, surgery. The rigorous quality control of endoscopy will reduce the miss rate of lesions and the occurrence of interval cancer.
doi:10.4253/wjge.v4.i12.518
PMCID: PMC3536848  PMID: 23293721
Esophagus; Stomach; Colon; Adenoma; Adenocarcinoma; Endoscopy; Screening
7.  Indications, stains and techniques in chromoendoscopy 
Early detection of malignancies within the gastrointestinal tract is essential to improve the prognosis and outcome of affected patients. However, conventional white light endoscopy has a miss rate of up to 25% for gastrointestinal pathology, specifically in the context of small and flat lesions within the colon. Chromoendoscopy and other advanced imaging techniques aim at facilitating the visualization and detection of neoplastic lesions and have been applied throughout the gastrointestinal tract. Chromoendoscopy, particularly in combination with magnifying endoscopy has significantly improved means to detect neoplastic lesions in the gastrointestinal mucosa, particularly in ulcerative colitis and Crohn’s colitis. In addition, chromoendoscopy is beneficial in the upper gastrointestinal tract, especially when evaluating Barrett’s oesophagus (BO) for the presence of dysplasia. Furthermore, it also improves characterization, differentiation and diagnosis of endoscopically detected suspicious lesions, and helps to delineate the extent of neoplastic lesions that may be amenable to endoscopic resection. This review discusses the dyes, indications and advanced endoscopic imaging methods used in various chromoendoscopic techniques, and presents a critical overview of the existing evidence supporting their use in current practice with a particular emphasis on the role in inflammatory bowel disease and BO.
doi:10.1093/qjmed/hcs186
PMCID: PMC3550597  PMID: 23097386
8.  International Digestive Endoscopy Network 2012: A Patchwork of Networks for the Future 
Clinical Endoscopy  2012;45(3):209-210.
This special September issue of Clinical Endoscopy will discuss various aspects of diagnostic and therapeutic advancement of gastrointestinal (GI) endoscopy, explaining what is new in digestive endoscopy and why international network should be organized. We proposed an integrated model of international conference based on the putative occurrence of Digestive Endoscopy Networks. In International Digestive Endoscopy Network (IDEN) 2012, role of endoscopy in gastroesophageal reflux disease and Barrett's esophagus, endoscopy beyond submucosa, endoscopic treatment for stricture and leakage in upper GI, how to estimate the invasion depth of early GI cancers, colonoscopy in inflammatory bowel disease (IBD), a look into the bowel beyond colon in IBD, management of complications in therapeutic colonoscopy, revival of endoscopic papllirary balloon dilation, evaluation and tissue acquisition for indeterminate biliopancreatic stricture, updates in the evaluation of pancreatic cystic lesions, issues for tailored endoscopic submucosal dissection (ESD), endoluminal stents, management of upper GI bleeding, endoscopic management of frustrating situations, small bowel exploration, colorectal ESD, valuable tips for frustrating situations in colonoscopy, choosing the right stents for endoscopic stenting of biliary strictures, advanced techniques for pancreaticobiliary visualization, endoscopic ultrasound-guided biliopancreatic drainage, and how we can overcome the obstacles were deeply touched. We hope that IDEN 2012, as the very prestigious endoscopy networks, served as an opportunity to gain some clues for further understanding of endoscopic technologies and to enhance up-and-coming knowledge and their clinical implications from selected 25 peer reviewed articles and 112 invited lectures.
doi:10.5946/ce.2012.45.3.209
PMCID: PMC3429737  PMID: 22977803
IDEN; Network; Digestive endoscopy
9.  INTEGRATED OPTICAL TOOLS FOR MINIMALLY INVASIVE DIAGNOSIS AND TREATMENT AT GASTROINTESTINAL ENDOSCOPY 
Over the past two decades, the bulk of gastrointestinal (GI) endoscopic procedures has shifted away from diagnostic and therapeutic interventions for symptomatic disease toward cancer prevention in asymptomatic patients. This shift has resulted largely from a decrease in the incidence of peptic ulcer disease in the era of antisecretory medications coupled with emerging evidence for the efficacy of endoscopic detection and eradication of dysplasia, a histopathological biomarker widely accepted as a precursor to cancer. This shift has been accompanied by a drive toward minimally-invasive, in situ optical diagnostic technologies that help assess the mucosa for cellular changes that relate to dysplasia. Two competing but complementary approaches have been pursued. The first approach is based on broad-view targeting of “areas of interest” or “red flags.” These broad-view technologies include standard white light endoscopy (WLE), high-definition endoscopy (HD), and “electronic” chromoendoscopy (narrow-band-type imaging). The second approach is based on multiple small area or point-source (meso/micro) measurements, which can be either machine (spectroscopy) or human-interpreted (endomicroscopy, magnification endoscopy), much as histopatholgy slides are. In this paper we present our experience with the development and testing of a set of familiar but “smarter” standard tissue-sampling tools that can be routinely employed during screening/surveillance endoscopy. These tools have been designed to incorporate fiberoptic probes that can mediate spectroscopy or endomicroscopy. We demonstrate the value of such tools by assessing their preliminary performance from several ongoing clinical studies. Our results have shown promise for a new generation of integrated optical tools for a variety of screening/surveillance applications during GI endoscopy. Integrated devices should prove invaluable for dysplasia surveillance strategies that currently result in large numbers of benign biopsies, which are of little clinical consequence, including screening for colorectal polyps and surveillance of “flat” dysplasia such as Barrett’s esophagus and chronic colitis due to inflammatory bowel diseases.
doi:10.1016/j.rcim.2010.06.006
PMCID: PMC2997708  PMID: 21152112
10.  Functional imaging and endoscopy 
The emergence of endoscopy for the diagnosis of gastrointestinal diseases and the treatment of gastrointestinal diseases has brought great changes. The mere observation of anatomy with the imaging mode using modern endoscopy has played a significant role in this regard. However, increasing numbers of endoscopies have exposed additional deficiencies and defects such as anatomically similar diseases. Endoscopy can be used to examine lesions that are difficult to identify and diagnose. Early disease detection requires that substantive changes in biological function should be observed, but in the absence of marked morphological changes, endoscopic detection and diagnosis are difficult. Disease detection requires not only anatomic but also functional imaging to achieve a comprehensive interpretation and understanding. Therefore, we must ask if endoscopic examination can be integrated with both anatomic imaging and functional imaging. In recent years, as molecular biology and medical imaging technology have further developed, more functional imaging methods have emerged. This paper is a review of the literature related to endoscopic optical imaging methods in the hopes of initiating integration of functional imaging and anatomical imaging to yield a new and more effective type of endoscopy.
doi:10.3748/wjg.v17.i38.4277
PMCID: PMC3214702  PMID: 22090783
Endoscopy; Functional imaging; Multi-modal imaging; Optical coherence tomography; Fluorescence molecular imaging; Photoacoustic tomography; Cerenkov luminescence tomography
11.  Ultra high magnification endoscopy: Is seeing really believing? 
Endoscopy is an indispensible diagnostic and therapeutic instrument for gastrointestinal diseases. Endocytoscopy and confocal endomicroscopy are two types of ultra high magnification endoscopy techniques. Standard endoscopy allows for 50 × magnification, whereas endocytoscopy can magnify up to 1400 × and confocal endomicroscopy can magnify up to 1000 ×. These methods open the realm of real time microscopic evaluation of the GI tract, including cellular and subcellular structures. Confocal endomicroscopy has the additional advantage of being able to visualize subsurface structures. The use of high magnification endoscopy in conjunction with standard endoscopy allows for a real-time microscopic assessment of areas with macroscopic abnormalities, providing “virtual biopsies” with valuable information about cellular and subcellular changes. This can minimize the number of biopsies taken at the time of endoscopy. The use of this technology may assist in detecting pre-malignant or malignant changes at an earlier state, allowing for earlier intervention and treatment. High magnification endoscopy has shown promising results in clinical trials for Barrett’s esophagus, esophageal adenocarcinoma, esophageal squamous cell cancer, gastric cancer, celiac disease, colorectal cancer, and inflammatory bowel disease. As the use of high magnification endoscopy techniques increases, the clinical applications will increase as well. Of the two systems, only confocal endomicroscopy is currently commercially available. Like all new technologies there will be an initial learning curve before operators become proficient in obtaining high quality images and discerning abnormal from normal pathology. Validated criteria for the diagnosis of the various gastrointestinal diseases will need to be developed for each method. In this review, the basic principles of both modalities are discussed, along with their clinical applicability and limitations.
doi:10.4253/wjge.v4.i10.462
PMCID: PMC3506956  PMID: 23189217
Endocytoscopy; Confocal endomicroscopy; Confocal laser endomicroscopy; High magnification endoscopy
12.  Recent advances in oesophageal diseases 
Abstract
Dong Y, Qi B, Feng XY, Jiang CM. Meta-analysis of Barrett's esophagus in China. World J Gastroenterol 2013;19(46):8770-8779
The disease pattern of Barrett's esophagus (BE) in China is poorly characterised particularly in comparison with other developed countries. This meta-analysis of 3873 cases of BE collated from 69 clinical studies conducted in 25 provinces between 2000 and 2011 investigated the epidemiology and characteristics of BE in China compared to Western countries. The total endoscopic detection rate of BE was 1.0% (95%CI: 0.1%-1.8%) with an average patient age of 49.07 ± 5.09 years, lower than many Western countries.The authors postulate this may be attributed to environmental risk factor variation, distinct genetics and different medical practice including diagnostic criteria for BE and expertise in endoscopy. This study identified a 1.781 male predominancefor BE in China, consistent with Western reports. Short-segment BE accounted for 80.3% of cases with island type and cardiac type the most common endoscopic (44.8%) and histological (40.0%) manifestations respectively. Of the 1283 BE cases followed up for three to 36 months the incidence of esophageal cancer was 1.418 per 1000 person-years, lower than the incidence reported in Western countries.
Lee HS, Jeon SW. Barrett esophagus in Asia: same disease with different pattern. ClinEndosc 2014;47(1):15-22
Barrett's esophagus (BE) is a common, pre-cancerous condition characterised by intestinal metaplasia of squamous esophageal epithelium usually attributed to chronic gastric acid exposure. This review article explores important differences in the disease pattern of BE between Asian and the Western countries.
Overall the prevalence of BE is lower in Asia compared to the West with a greater proportion of short-segment type. The authors identify great variability in the endoscopic and pathologic diagnostic criteria for BE. Many of the studies in Asian countries did not use a standardised four-quadrant biopsy protocol which may have led to an underestimation of BE prevalence. The review highlights an increasing incidence of esophageal adenocarcinoma in the West but unclear disease trend in Asia with inter-country variability. Similarly in Asian and Western countries BE is associated with the presence of hiatus hernia, advancing age, male gender, alcohol consumption, smoking, abdominal obesity and longer duration of gastro-esophageal reflux disease. The authors postulate that Helicobacter pylori infection, more prevalent in Asia than the West, may have a protective effect on BE.
There is a need for larger, prospective studies to further clarify the disease pattern of BE in Asian countries. Clearly standardisation of the diagnostic process for BE is important to validate the differences in disease trends between Asian and Western countries.
Kiadaliri AA. Gender and social disparities in esophagus cancer incidence in Iran, 2003-2009: a time trend province-level study.Asian Pac J Cancer Prev 2014;15(2):623-7
Esophageal cancer (EC) is a major cause of morbidity and mortality particuarly in Iran where the incidence rate exceeds the global average. An understanding of the factors influencing the province-specific incidence of EC in Iran is important to inform disease-prevention strategies and address health inequalities. This ecological study used cancer registry data to investigate the relationship between gender and social class and the incidence of EC in Iran at province-level between 2003 and 2009. The age standardised incidence rates (ASIR) of EC were greatest in the Northern provinces of Iran, specifically Razavi Khorasan in males and Kordestan in females. Overall the EC incidence did not significantly differ according to gender.
Interestingly, during the study period the ASIR increased by 4.6% per year in females (p=0.08) and 6.5% per year in males (p=0.02). This may reflect increasing rates of establised risk factors for EC including obsesity and gastro-esophageal reflux disease alongside more vigilant recording of new cases. Social class was inversely associated with the ASIR of EC regardless of gender which may be attributed to class differences in risk factor distribution particularly smoking, diet and obesity. An appreciation for the limitations of an epidemiological study is important when interpreting results which should be further evaluated in future studies.
Islami F et al.Determinants of gastroesophageal reflux disease, including hookah smoking and opium use- A cross-sectional analysis of 50,000 individuals. PLoS One 2014;9(2):e89256
Gastroesophageal reflux disease (GERD) is a highly prevalent cause of gastrointestinal symptoms worldwide incurring great cost to the primary and secondary healthcare sectors. An improved understanding of the factors which influence GERD symptoms in low- to medium- income countries may inform public health initiatives. This study analysed prospective data from the Golestan cohort study, primarily established to investigate determinants of upper gastrointestinal cancers, toexplore the risk factors influencing GERD symptoms (regurgitation and/or heartburn) in 50,045 individuals aged 40-75 years in Golestan Province, Iran enrolled between 01/2004 and 06/2008.Of note, 39.12% of individuals denied ever experiencing GERD symptoms. A further 19.89% reported at least once weekly GERD symptoms with 11.83% experiencing daily symptoms. Severe symptoms, defined as disturbing daily work or sleep, were recorded by 11.33% of individuals.
Separately the occurrence of daily GERD symptoms and severe symptoms were inversely associated with male gender (OR 0.36, 95% CI 0.33-0.39 both), level of formal education (p=0.01 and p=0.001 respectively), wealth score (p<0.001 both) and regular nass chewing (OR 0.86, 95% CI 0.75-0.98 and OR 0.87, 95% CI 0.76-0.99 respectively)and were positively associated with body mass index (p<0.001 both), intensity of physical activity (p=0.04 both), cigarette pack years (p<0.001 both), alcohol consumption (OR 1.36, 95% CI 1.13-1.64 and OR 1.53, 95% CI 1.28-1.83 respectively) and opium use (OR 1.82, 95% CI 1.67-1.99 and OR 1.70, 95% CI 1.55-1.87 respectively).In addition hookah smoking had a borderline significant correlation with mild and moderate severity GERD symptoms in individuals who had never smoked cigarettes (OR 1.41, 95% CI 1.00-1.99 and OR 1.25, 95% CI 0.99-1.57 respectively).
Overall this large study contributes useful data to inform the prevention and management of GERD symptoms particularly regarding the use of hookah, opium and nass which was previously unclear.
Barbera M et al. The human squamous oesophagus has widespread capacity for clonal expansion from cells at diverse stages of differentiation. Gut 2014;0:1–9. doi:10.1136/gutjnl-2013-306171
Current knowledge on human esophageal tissue homeostasis and injury repair is derived predominantly from murine models and hence may be inaccurate due to cellular and architectural differences. This study used 3D imaging in conjunction withstaining for cell lineage markers to investigate the cellular mechanisms involved in homeostasis of the normal human squamous esophagus in 10 participants undergoing esophagectomy for esophageal cancer. The self-renewal potential of cell subpopulations was also assessed using in vitro and in vivo assays.
A decreasing gradient of cell proliferation was observed from the inter-papillary basal layer to the tip of the papilla where there was no evidence of mitosis. The expression ofβ1-integrin, a putative stem cell marker, was consistent throughout the basal layer and therefore the entire basal layer can be considered undifferentiated. Quiescent β1-integrin/CD34-positive cells which failed to stain for CD45, S-100 or F4-80were identified at the tip of the papilla suggesting this is an extension of the basal layer. Contrary to previous data, this study found progenitor cells widely distributed in human esophageal tissue and included already differentiated epithelial cells. This insight into esophageal homeostasis may inform future studies exploring the pathological mechanisms underpinning homeostatic disruption in disease states such as Barrett's esophagus.
Papers were prepared by:
Drs Ishfaq Ahmad and Luke Materacki, Department of Medicine, Alexandra Hospital, Redditch, UK
PMCID: PMC4129572  PMID: 25120902
13.  Progress in molecular imaging in endoscopy and endomicroscopy for cancer imaging 
Imaging is an essential tool for effective cancer management. Endoscopes are important medical instruments for performing in vivo imaging in hollow organs. Early detection of cancer can be achieved with surveillance using endoscopy, and has been shown to reduce mortality and to improve outcomes. Recently, great advancements have been made in endoscopic instruments, including new developments in optical designs, light sources, optical fibers, miniature scanners, and multimodal systems, allowing for improved resolution, greater tissue penetration, and multispectral imaging. In addition, progress has been made in the development of highly-specific optical probes, allowing for improved specificity for molecular targets. Integration of these new endoscopic instruments with molecular probes provides a unique opportunity for significantly improving patient outcomes and has potential to further improve early detection, image guided therapy, targeted therapy, and personalized medicine. This work summarizes current and evolving endoscopic technologies, and provides an overview of various promising optical molecular probes.
doi:10.1260/2040-2295.4.1.1
PMCID: PMC4224106  PMID: 23502247
endoscopy; endomicroscopy; optical imaging; molecular probes
14.  Molecular Imaging for Guiding Oncologic Prognosis and Therapy in Esophageal Adenocarcinoma 
Hospital practice (1995)  2011;39(2):97-106.
In the last 30 years, the incidence of esophageal adenocarcinoma has skyrocketed. Sadly, advances in treatment have not followed the same trend, and the prognosis for patients with esophageal adenocarcinoma remains poor with a 5-year survival rate of only 15%. Like most cancers, early detection is the key to improving prognosis, but this outcome has proven difficult in the esophagus for several reasons: 1) patients present with advanced disease because “alarm symptoms” such as dysphagia occur at a late stage, and 2) high-grade dysplasia (HGD) and early adenocarcinoma (ACA) are not visible on routine surveillance endoscopy. Currently, the recommended surveillance strategy involves collection of random biopsies, an imperfect technique that is limited by sampling error and is infrequently used because of the considerable time and cost it requires. Even in patients with biopsy-proven dysplasia, adequate guidance for clinical management decisions is still lacking. Dysplasia alone is not an entirely reliable biomarker for the risk of progression to adenocarcinoma because the natural history of this condition is extremely variable. Clearly, there is a need for additional biomarkers that can better characterize this disease, and thus improve our ability to treat patients on an individual basis. As we better understand the molecular changes that lead to the development of this cancer, new molecular biomarkers are needed to allow for more personalized diagnoses, surveillance and treatment. Targeted agents against EGFR, HER2/neu and VEGF are currently being evaluated for their role in combination chemotherapy for metastatic esophageal adenocarcinoma. As these studies progress, a reliable approach for determining receptor status in individual patients is essential. Molecular imaging uses fluorescent probes that target specific cell surface receptors, and has the potential to evaluate an individual patient’s gene expression profile. By topically applying fluorescent probes to dysplastic epithelium during endoscopy, a variety of receptors can be visualized, and the response to treatment can be monitored in real time. This technique can mitigate the limitations of current surveillance protocols, allow for improved cancer detection, and be used for truly personalized treatment in the future.
doi:10.3810/hp.2011.04.399
PMCID: PMC3227392  PMID: 21576902
15.  Vital-dye enhanced fluorescence imaging of gastrointestinal mucosa: metaplasia, neoplasia, inflammation 
Gastrointestinal Endoscopy  2012;75(4):877-887.
Background
Confocal endomicroscopy has revolutionized endoscopy by offering sub-cellular images of gastrointestinal epithelium; however, field-of-view is limited. There is a need for multi-scale endoscopy platforms that use widefield imaging to better direct placement of high-resolution probes.
Design
Feasibility Study
Objective
This study evaluates the feasibility of a single agent, proflavine hemisulfate, as a contrast medium during both widefield and high resolution imaging to characterize morphologic changes associated with a variety of gastrointestinal conditions.
Setting
U.T. M.D. Anderson Cancer Center (Houston, TX) and Mount Sinai Medical Center (New York, NY)
Patients, Interventions, and Main Outcome Measurements
Surgical specimens were obtained from 15 patients undergoing esophagectomy/colectomy. Proflavine, a vital fluorescent dye, was applied topically. Specimens were imaged with a widefield multispectral microscope and a high-resolution microendoscope. Images were compared to histopathology.
Results
Widefield-fluorescence imaging enhanced visualization of morphology, including the presence and spatial distribution of glands, glandular distortion, atrophy and crowding. High-resolution imaging of widefield-abnormal areas revealed that neoplastic progression corresponded to glandular heterogeneity and nuclear crowding in dysplasia, with glandular effacement in carcinoma. These widefield and high-resolution image features correlated well with histopathology.
Limitations
This imaging approach must be validated in vivo with a larger sample size.
Conclusions
Multi-scale proflavine-enhanced fluorescence imaging can delineate epithelial changes in a variety of gastrointestinal conditions. Distorted glandular features seen with widefield imaging could serve as a critical ‘bridge’ to high-resolution probe placement. An endoscopic platform combining the two modalities with a single vital-dye may facilitate point-of-care decision-making by providing real-time, in vivo diagnoses.
doi:10.1016/j.gie.2011.10.004
PMCID: PMC3336371  PMID: 22301343
fluorescence imaging; Barrett's esophagus; esophageal adenocarcinoma; colonic adenocarcinoma; inflammatory bowel disease
16.  Modern treatment of gastric gastrointestinal stromal tumors 
Gastrointestinal stromal tumors (GIST) are rare mesenchymal smooth muscle sarcomas that can arise anywhere within the gastrointestinal tract. Sporadic mutations within the tyrosine kinase receptors of the interstitial cells of Cajal have been identified as the key molecular step in GIST carcinogenesis. Although many patients are asymptomatic, the most common associated symptoms include: abdominal pain, dyspepsia, gastric outlet obstruction, and anorexia. Rarely, GIST can perforate causing life-threatening hemoperitoneum. Most are ultimately diagnosed on cross-sectional imaging studies (i.e., computed tomography and/or magnetic resonance imaging in combination with upper endoscopy. Endoscopic ultrasonographic localization of these tumors within the smooth muscle layer and acquisition of neoplastic spindle cells harboring mutations in the c-KIT gene is pathognomonic. Curative treatment requires a complete gross resection of the tumor. Both open and minimally invasive operations have been shown to reduce recurrence rates and improve long-term survival. While there is considerable debate over whether GIST can be benign neoplasms, we believe that all GIST have malignant potential, but vary in their propensity to recur after resection and metastasize to distant organ sites. Prognostic factors include location, size (i.e., > 5 cm), grade (> 5-10 mitoses per 50 high power fields and specific mutational events that are still being defined. Adjuvant therapy with tyrosine kinase inhibitors, such as imatinib mesylate, has been shown to reduce the risk of recurrence after one year of therapy. Treatment of locally-advanced or borderline resectable gastric GIST with neoadjuvant imatinib has been shown to induce regression in a minority of patients and stabilization in the majority of cases. This treatment strategy potentially reduces the need for more extensive surgical resections and increases the number of patients eligible for curative therapy. The modern surgical treatment of gastric GIST combines the novel use of targeted therapy and aggressive minimally invasive surgical procedures to provide effective treatment for this lethal, but rare gastrointestinal malignancy.
doi:10.3748/wjg.v18.i46.6720
PMCID: PMC3520160  PMID: 23239909
Gastrointestinal stromal tumors; Laparoscopic resections of gastrointestinal stromal tumors; Imatinib mesylate; Gastrectomy
17.  Esophagitis may not be a Major Precursor Lesion for Esophageal Squamous Cell Carcinoma in a High Incidence Area in North-Eastern Iran 
BACKGROUND
Esophageal squamous cell carcinoma (ESCC) is usually detected in advanced stages resulting in a very poor prognosis. Early diagnosis needs identification of clinically relevant precancerous lesions which could become the target of screening and early treatment. Our aim was to check whether esophagitis could serve as a relevant histological precursor of ESCC in Northern Iran.
METHODS
During 2001–2005, all adult patients who were referred to Atrak clinic for upper gastrointestinal endoscopy and biopsy were enrolled. Atrak clinic is a major center for upper gastrointestinal cancer research in eastern Golestan. All subjects had been complaining of upper GI symptoms and were under further investigation to rule out cancer. Biopsies from the endoscopically normal mid-esophagus and also just above the esophago-gastric junction were obtained in all subjects whose esophagus appeared normal during endoscopy and from endoscopically normal appearing mucosa at the proximal vicinity of any detected mass. Microscopic examinations for the verification of the presence or absence of esophagitis was performed by independant histological examination of the samples by two pathologists. All the discrepant diagnoses were resolved in joint diagnostic sessions.
RESULTS
During the study period 836 patients were enrolled including 419 non cancer patients (endoscopy clinic controls), 387 cancer patients, and 30 subjects with clinical diagnosis of malignancy referred for histological reconfirmation of diagnosis by repeated biopsy. Mild or marked mid-esophagitis was diagnosed in 39 (9.3%), 47 (12.5%) and 12 (40%) of endoscopy clinic controls, cancer patients and those who were suspicious for upper gastrointestinal malignancies.
CONCLUSION
Our observation does not show evidence for esophagitis to be a predisposing factor for ESCC in Gonbad region In North Eastern Iran.
PMCID: PMC4154925  PMID: 25197529
Esophagus; Squamous cell carcinoma; Esophagitis
18.  New aspects of modern endoscopy 
The prognosis for patients with malignancies of the gastrointestinal-tract is strictly dependent on early detection of premalignant and malignant lesions. However, small, flat or depressed neoplastic lesions remain difficult to detect with these technologies thereby limiting their value for polyp and cancer screening. At the same time computer and chip technologies have undergone major technological changes which have greatly improved endoscopic diagnostic investigation. New imaging modalities and techniques are very notable aspects of modern endoscopy. Chromoendoscopy or filter-aided colonoscopy (virtual chromoendoscopy) with high definition endoscopes is able to enhance the detection and characterization of lesions. Finally, confocal laser endomicroscopy provides histological confirmation of the presence of neoplastic changes. The developing techniques around colonoscopy such as the retro-viewing colonoscope, the balloon-colonoscope or the 330-degrees-viewing colonoscope try to enhance the efficacy by reducing the adenoma miss rate in right-sided, non-polypoid lesions. Colon capsule endoscopy is limited to identifying cancer and not necessarily small adenomas. Preliminary attempts have been made to introduce this technique in clinical routine.
doi:10.4253/wjge.v6.i8.334
PMCID: PMC4133412  PMID: 25132916
Modern endoscopy; High definition endoscopy; Virtual chromoendoscopy; Autofluorescence; Endomicroscopy; Molecular imaging
19.  Optical Biopsy: A New Frontier in Endoscopic Detection and Diagnosis 
Endoscopic diagnosis currently relies on the ability of the operator to visualize abnormal patterns in the image created by light reflected from the mucosal surface of the gastrointestinal tract. Advances in fiber optics, light sources, detectors, and molecular biology have led to the development of several novel methods for tissue evaluation in situ. The term “optical biopsy” refers to methods that use the properties of light to enable the operator to make an instant diagnosis at endoscopy, previously possible only by using histological or cytological analysis. Promising imaging techniques include fluorescence endoscopy, optical coherence tomography, confocal microendoscopy, and molecular imaging. Point detection schemes under development include light scattering and Raman spectroscopy. Such advanced diagnostic methods go beyond standard endoscopic techniques by offering improved image resolution, contrast, and tissue penetration and providing biochemical and molecular information about mucosal disease. This review describes the basic biophysics of light-tissue interactions, assesses the strengths and weaknesses of each method, and examines clinical and preclinical evidence for each approach.
doi:10.1053/S1542-3565(04)00345-3
PMCID: PMC2169359  PMID: 15354274
20.  Targeted Endoscopic Imaging 
Summary
Endoscopy has undergone explosive technological growth in over recent years, and with the emergence of targeted imaging, its truly transformative power and impact in medicine lies just over the horizon. Today, our ability to see inside the digestive tract with medical endoscopy is headed toward exciting crossroads. The existing paradigm of making diagnostic decisions based on observing structural changes and identifying anatomical landmarks may soon be replaced by visualizing functional properties and imaging molecular expression. In this novel approach, the presence of intracellular and cell surface targets unique to disease are identified and used to predict the likelihood of mucosal transformation and response to therapy. This strategy can result in the development of new methods for early cancer detection, personalized therapy, and chemoprevention. This targeted approach will require further development of molecular probes and endoscopic instruments, and will need support from the FDA for streamlined regulatory oversight. Overall, this molecular imaging modality promises to significantly broaden the capabilities of the gastroenterologist by providing a new approach to visualize the mucosa of the digestive tract in a manner that has never been seen before.
doi:10.1016/j.giec.2009.02.001
PMCID: PMC3217463  PMID: 19423025
endoscopy; molecular imaging; targets; early detection
21.  Clinical Experience Using a Real Time Autofluorescence Endoscopy System in the Gastrointestinal Tract 
Autofluorescence spectra of neoplastic tissues have been reported to be significantly different from those of normal tissues when excited by blue or violet light. From this concept, a light-induced autofluorescence endoscopic imaging system for gastrointestinal mucosa (LIFE-GI; Xillix, Canada and Olympus, Japan) has been newly developed and the clinical evaluation of the prototype system has been conducted in hospitals in Canada, Netherlands and Japan.
We examined the clinical usefulness of the prototype LIFE-GI system for the detection of gastrointestinal cancer and high and low grade dysplasia. The LIFE-GI system was also applied to the early detection of remnant lesions after endoscopic treatment of early gastric cancer and to the detection of laterally spreading superficial colonic tumors.
This system has potential application for the diagnosis of dysplastic lesions and early cancers in the gastrointestinal tract as an adjunct to ordinary white light endoscopy. This system, which needs no administration of a photosensitive agent, may be suitable as a screening method for the early detection of neoplastic tissues.
doi:10.1155/DTE.5.119
PMCID: PMC2362619  PMID: 18493491
22.  Appropriate use of endoscopy in the diagnosis and treatment of gastrointestinal diseases: up-to-date indications for primary care providers 
The field of endoscopy has revolutionized the diagnosis and treatment of gastrointestinal (GI) diseases in recent years. Besides the ‘traditional’ endoscopic procedures (esophagogastroduodenoscopy, colonoscopy, flexible sigmoidoscopy, and endoscopic retrograde cholangiopancreatography), advances in imaging technology (endoscopic ultrasonography, wireless capsule endoscopy, and double balloon enteroscopy) have allowed GI specialists to detect and manage disorders throughout the digestive system. This article reviews various endoscopic procedures and provides up-to-date endoscopic indications based on the recommendations of American Society for Gastrointestinal Endoscopy and American Cancer Society for primary care providers in order to achieve high-quality and cost-effective care.
doi:10.2147/IJGM.S14555
PMCID: PMC2990396  PMID: 21116340
endoscopy; endoscopic indications; endoscopic procedures; imaging; primary care; gastrointestinal disorders; appropriate use
23.  Indicators of safety compromise in gastrointestinal endoscopy 
The growth in the use of endoscopy to diagnose and treat many gastointestinal disorders, and its central role in cancer screening programs, has led to a significant increase in the number of procedures performed. This growth, however, has also led to many variations in, among others, the provision of services, the choice of sedative medications and the training of providers. The recognition of the significance of quality in endoscopy has prompted several countries, including Canada, to initiate efforts to adopt nationwide quality improvement programs. The Canadian Association of Gastroenterology formed a committee to review endoscopy and quality with the aim of stimulating improvement. This article focuses specifically on patient safety indicators that were developed at a consensus conference aimed at generating a broad range of recommendations for selected endoscopic procedures, which if adopted, could lead to significant changes in how endoscopy services are provided.
INTRODUCTION:
The importance of quality indicators has become increasingly recognized in gastrointestinal endoscopy. Patient safety requires the identification and monitoring of occurrences associated with harm or the potential for harm. The identification of relevant indicators of safety compromise is, therefore, a critical element that is key to the effective implementation of endoscopy quality improvement programs.
OBJECTIVE:
To identify key indicators of safety compromise in gastrointestinal endoscopy.
METHODS:
The Canadian Association of Gastroenterology Safety and Quality Indicators in Endoscopy Consensus Group was formed to address issues of quality in endoscopy. A subcommittee was formed to identify key safety indicators. A systematic literature review was undertaken, and articles pertinent to safety in endoscopy were identified and reviewed. All complications and measures used to document safety were recorded. From this, a preliminary list of 16 indicators was compiled and presented to the 35-person consensus group during a three-day meeting. A revised list of 20 items was subsequently put to the consensus group for vote for inclusion on the final list of safety indicators. Items were retained only if the consensus group highly agreed on their importance.
RESULTS:
A total of 19 indicators of safety compromise were retained and grouped into the three following categories: medication-related – the need for CPR, use of reversal agents, hypoxia, hypotension, hypertension, sedation doses in patients older than 70 years of age, allergic reactions and laryngospasm/bronchospasm; procedure-related early – perforation, immediate postpolypectomy bleeding, need for hospital admission or transfer to emergency department from the gastroenterology unit, instrument impaction, severe persistent abdominal pain requiring evaluation proven to not be perforation; and procedure-related delayed – death within 30 days of procedure, 14-day unplanned hospitalization, 14-day unplanned contact with a health provider, gastrointestinal bleeding within 14 days of procedure, infection or symptomatic metabolic complications.
CONCLUSIONS:
The 19 indicators of safety compromise in endoscopy, identified by a rigorous, evidence-based consensus process, provide clear outcomes to be recorded by all facilities as part of their continuing quality improvement programs.
PMCID: PMC3275408  PMID: 22312605
Digestive system; Endoscopy; Health care; Quality assurance; Surgical complications; Safety
24.  New endoscopic and cytologic tools for cancer surveillance in the digestive tract 
Synopsis
Cancer surveillance is an increasing part of everyday practice in gastrointestinal endoscopy due to the identification of high risk groups from genetic and biomarker testing, genealogic and epidemiologic studies, and the increasing number of cancer survivors. An efficient surveillance program requires a cost-effective means for image-guided cancer detection and biopsy. A laser-based tethered-capsule endoscope with enhanced spectral imaging is introduced for unsedated surveillance of the lower esophagus. An ultrathin version of this same endoscope technology provides a 1.2-mm guidewire with imaging capability and cannula-style tools are proposed for image-guided biopsy. Advanced 3D cell visualization techniques are described for increasing the sensitivity of early cancer diagnosis from hematoxylin-stained cells sampled from the pancreatic and biliary ducts.
doi:10.1016/j.giec.2009.02.002
PMCID: PMC2679952  PMID: 19423026
endoscope; biopsy; image-guided intervention; 3D cytology; cancer surveillance
25.  Optical Molecular Imaging in the Gastrointestinal Tract 
Recent developments in optical molecular imaging allow for real-time identification of morphological and biochemical changes in tissue associated with gastrointestinal neoplasia. This review summarizes widefield and high resolution imaging modalities currently in pre-clinical and clinical evaluation for the detection of colorectal cancer and esophageal cancer. Widefield techniques discussed include high definition white light endoscopy, narrow band imaging, autofluoresence imaging, and chromoendoscopy; high resolution techniques discussed include probe-based confocal laser endomicroscopy, high-resolution microendoscopy, and optical coherence tomography. Finally, new approaches to enhance image contrast using vital dyes and molecular-specific targeted contrast agents are evaluated.
doi:10.1016/j.giec.2013.03.010
PMCID: PMC3746803  PMID: 23735112
optical molecular imaging; white light endoscopy; narrow band imaging; autofluorescence imaging; chromoendoscopy; confocal laser endomicroscopy; high resolution microendoscopy; optical coherence tomography

Results 1-25 (1421057)