Screening and surveillance methods for dysplasia in inflammatory bowel disease patients: Where do we stand?

Patients with long-standing ulcerative colitis (UC) and extensive Crohn’s colitis (CC) are at increased risk for dysplasia and colorectal cancer (CRC). Several studies have shown that UC extending proximal to the rectum, CC involving at least 1/3 of the colon, co-existence of primary sclerosing cholangitis, undetermined or unclassified colitis, family history of CRC and young age at diagnosis appear to be independent risk factors for inflammatory bowel disease (IBD) - related CRC. Therefore, screening and surveillance for CRC in IBD patients is highly recommended by international and national guidelines, whilst colonoscopy remains the unequivocal tool in order to detect potentially resectable dysplastic lesions or CRC at an early stage. Although the importance of screening and surveillance is widely proven, there is a controversy regarding the time of the first colonoscopy and the criteria of who should undergo surveillance. In addition, there are different recommendations among scientific societies concerning which endoscopic method is more efficient to detect dysplasia early, as well as the terminology for reporting visible lesions and the management of those lesions. This article concisely presents the main endoscopic methods and techniques performed for detecting dysplasia and CRC surveillance in patients with IBD focusing on their evidence-based accuracy and efficiency, as well as their cost-effectiveness. Finally, newer methods are mentioned, highlighting their applicability in daily endoscopic practice.

Advanced Imaging for Barrett's Esophagus and Early Neoplasia: Surface and Subsurface Imaging for Diagnosis and Management

PURPOSE OF REVIEW

Esophageal adenocarcinoma bears one of the fastest rising incidence of any cancers and generally arises in the setting of gastroesophageal reflux and Barrett's esophagus. However, early detection of neoplasia can be challenging since most patients are asymptomatic until they progress to more advanced and less curable stages, and early dysplastic lesions can be small, multifocal, and difficult to detect. Clearly, new imaging tools are needed in light of sampling error associated with random biopsies, the current standard of practice.

RECENT FINDINGS

Advances in endoscopic imaging including virtual chromoendoscopy, confocal laser endomicroscopy, and subsurface imaging with optical coherence tomography have ushered in a new era for detecting subtle neoplastic lesions. Moreover, in light of esophagus-sparing treatments for neoplastic lesions, such tools are likely to guide ablation and follow-up management. While there is no ideal single imaging modality to facilitate improved detection, staging, ablation, and follow-up of patients with dysplastic Barrett's esophagus, new advances in available technology, the potential for multimodal imaging, and the use of computer-aided diagnosis and biomarkers all hold great promise for improving detection and treatment.

Real-life chromoendoscopy for dysplasia surveillance in ulcerative colitis

AIM

To evaluate the use of chromoendoscopy for surveillance of ulcerative colitis in a real-life community hospital setting.

METHODS

Patients with extensive ulcerative colitis, having disease duration of more than 8 years and who presented between the years of 1999 to 2013, were offered enrolment in this single cohort prospective study. All participants underwent standard bowel preparation with sodium phosphate and chromoendoscopy. Two expert endoscopists, novice to chromoendoscopy, evaluated each segment of the colon with standard-definition colonoscopes after spray application of 0.4% indigo carmine. All observed lesions were recorded and evaluated before being removed and/or biopsied. In addition, nontargeted biopsies were taken from each segment of the colon. The dysplasia detection rate and dysplasia detection yield were ascertained.

RESULTS

A total of 21 neoplastic lesions (2 carcinomas, 4 of high-grade dysplasia and 15 of low-grade dysplasia) and 27 nondysplastic lesions were detected in 16 of the total 67 patients (70% male; median disease duration: 17 years; median age at diagnosis: 25 years; 92% aminosalicylate-treated). The dysplasia detection rate was 10.5% (7/67 patients). The dysplasia detection yield was 20.8% (10/48) for targeted biopsies and 3.5% (11/318) for nontargeted biopsies. The sensitivity and specificity for the macroscopic evaluation of neoplasia using chromoendoscopy were 48% [95% confidence interval (CI): 26%-70%] and 96% (95%CI: 93%-98%), respectively. The positive predictive and negative predictive values were 42% (95%CI: 27%-59%) and 97% (95%CI: 95%-98%), respectively. A total of 19/21 dysplastic lesions were detected in mucosa with histologic inflammation.

CONCLUSION

Chromoendoscopy seems to be of value for dysplasia surveillance of ulcerative colitis in a community hospital setting. The yield of non-targeted biopsies is negligible.

Methylene blue MMX® tablets for chromoendoscopy. Bioavailability, colon staining and safety in healthy volunteers undergoing a full colonoscopy

Methylene blue-MMX® tablets are proposed as an aid for detection and visualisation of adenomas and carcinomas in patients undergoing colonoscopy, by improving their detection rate and highlighting the presence of the intestinal dysplastic lesions. Single total doses of 100 and 200 mg were administered to healthy volunteers undergoing a bowel cleansing preparation and a full colonoscopy to investigate the colonic staining. The pharmacokinetics of methylene blue and the safety after exposure to the tablets were also investigated. With 200 mg, the best staining, assessed as the sum of acceptable and good staining, was achieved in the ascending colon and rectosigmoid (75% subjects each), the transverse and the descending colon (approximately 63% each). Absence of staining or overstaining were reported for no colonic region of interest in any subject. Similar results were observed in the 100 mg dose group. Methylene blue blood concentrations reached a peak (C_max) in a median time (T_max) of 12 h with 100 mg and 16 h with 200 mg. AUC_0-t was 10.7 ± 6.7 μg/mLxh after 100 mg and 25.2 ± 7.4 μg/mLxh after 200 mg. Half-life ranged between 9 and 22 h after the lower dose and between 6 and 26 h after the higher dose. The cumulative urinary excretion was about 28% after 100 mg and about 39% after 200 mg up to 60 h post-dose. The overall frequency of adverse events after single dose of the test product administered along with a bowel cleansing preparation was 39%, but only one was related to the test product: abnormal transaminases. The most frequent adverse event was a transient polyuria (17%). One serious adverse event (gastrointestinal haemorrhage) led the subject to study discontinuation and hospitalisation and another subject withdrew the study due to one adverse event (haematemesis). Either event was not related to methylene blue.

Computer assisted gastric abnormalities detection using hybrid texture descriptors for chromoendoscopy images

BACKGROUND AND OBJECTIVE

The early diagnosis of stomach cancer can be performed by using a proper screening procedure. Chromoendoscopy (CH) is an image-enhanced video endoscopy technique, which is used for inspection of the gastrointestinal-tract by spraying dyes to highlight the gastric mucosal structures. An endoscopy session can end up with generating a large number of video frames. Therefore, inspection of every individual endoscopic-frame is an exhaustive task for the medical experts. In contrast with manual inspection, the automated analysis of gastroenterology images using computer vision based techniques can provide assistance to endoscopist, by finding out abnormal frames from the whole endoscopic sequence.

METHODS

In this paper, we have presented a new feature extraction method named as Gabor-based gray-level co-occurrence matrix (G2LCM) for computer-aided detection of CH abnormal frames. It is a hybrid texture extraction approach which extracts a combination both local and global texture descriptors. Moreover, texture information of a CH image is represented by computing the gray level co-occurrence matrix of Gabor filters responses. Furthermore, the second-order statistics of these co-occurrence matrices are computed to represent images' texture.

RESULTS

The obtained results show the possibility to correctly classifying abnormal from normal frames, with sensitivity, specificity, accuracy, and area under the curve as 91%, 82%, 87% and 0.91 respectively, by using a support vector machine classifier and G2LCM texture features.

CONCLUSION

It is apparent from results that the proposed system can be used for providing aid to the gastroenterologist in the screening of the gastric tract. Ultimately, the time taken by an endoscopic procedure will be sufficiently reduced.

Narrow-Band Imaging: Clinical Application in Gastrointestinal Endoscopy

Narrow-band imaging is an advanced imaging system that applies optic digital methods to enhance endoscopic images and improves visualization of the mucosal surface architecture and microvascular pattern. Narrow-band imaging use has been suggested to be an important adjunctive tool to white-light endoscopy to improve the detection of lesions in the digestive tract. Importantly, it also allows the distinction between benign and malignant lesions, targeting biopsies, prediction of the risk of invasive cancer, delimitation of resection margins, and identification of residual neoplasia in a scar. Thus, in expert hands it is a useful tool that enables the physician to decide on the best treatment (endoscopic or surgical) and management. Current evidence suggests that it should be used routinely for patients at increased risk for digestive neoplastic lesions and could become the standard of care in the near future, at least in referral centers. However, adequate training programs to promote the implementation of narrow-band imaging in daily clinical practice are needed. In this review, we summarize the current scientific evidence on the clinical usefulness of narrow-band imaging in the diagnosis and characterization of digestive tract lesions/cancers and describe the available classification systems.

Detecting dysplasia using white light endoscopy or chromoendoscopy in ulcerative colitis patients without primary sclerosing cholangitis: A systematic review and meta-analysis

BACKGROUND

Endoscopic examinations are a vital diagnostic tool for dysplasia. Establishing the precision of different modes of examination is essential due to the disparate pick-up rates of dysplasia.

OBJECTIVE

The aim of this article was to establish the pick-up rates of dysplastic or cancerous lesions using white light endoscopy (WLE) and random/targeted biopsies, or chromoendoscopy (CE), in patients with ulcerative colitis (UC) without primary sclerosing (PSC) or Crohn's disease (CD).

DATA SOURCES

A systematic review to identify all studies up to November 2017, without language restriction, was conducted from PubMed, the Cochrane Controlled Trials Register (1960-2017), MEDLINE, CINAHL and EMBASE (1981-2017). MeSH and text word terms used included "ulcerative colitis", "dysplasia", "random biopsy", "targeted biopsy", "colonoscopy", "white light", and "chromoendoscopy". Further searches were performed using the bibliographies of these articles.

STUDY SELECTION

All studies reporting on colonoscopy detection rates of dysplasia and cancers in UC without involvement of PSC or CD were included. There was no age restriction to include patients.

DATA EXTRACTION

Outcome data were extracted by 2 authors independently using outcome measures defined a priori. Quality assessment was performed using the Newcastle-Ottawa scales.

DATA SYNTHESIS

Data were extracted and analysed according to meta-analytical techniques using comprehensive meta-analysis. The pooled overall pick-up rate of dysplastic/cancerous lesions on WLE random biopsies was 5.6% [Event rate 0.06 (0.01, 0.23), df = 4, I2 = 94%]. Using a combined random and targeted approach with WLE the incidence was 5.1% [Event rate 0.05 (0.03, 0.09), df = 4, I2 = 96%]. One study reported on CE and found a 7% pick-up rate for dysplastic lesions.

CONCLUSIONS

Endoscopic examination of UC patients without PSC identifies dysplastic or cancerous lesions in 5-7% of cases. WLE and random biopsies may pick-up a similar number of lesions to targeted biopsies, however the number of biopsies may need to be greater to achieve this equivalence. CE has a slightly higher pick-up rate. Further comparative studies are required to strengthen the body of evidence.

Circular stripes were more common in Barrett's esophagus after acetic acid staining

BACKGROUND

The diagnosis of Barrett's esophagus (BE) is disturbed by numerous factors, including correct gastroesophageal junction judgment, the initial location of the Z-line and the biopsy result above it. The acetic acid (AA) could help to diagnose BE better than high resolution imaging technology or magnifying endoscopy, by providing enhanced contrast of different epithelium. We have noticed AA could produce multiple white circular lines, forming circular stripes (CS), at lower esophagus, which hasn't been reported by others. This study aimed to investigate whether the CS is a special marker in BE patients.

METHODS

A total of 47 BE patients and 63 healthy people were enrolled from March 2016 to October 2016, and 2% AA staining had been operated routinely at lower esophagus under high resolution gastroscopy. We observed whether there were CS after AA staining and the images were compared between the two groups.

RESULTS

CS were confirmed in 42 patients (89.36%) in the BE group and 5 (7.94) in the control group ((χ2 = 72.931, P < 0.001)). The average width of CS was 0.76 ± 0.25 cm in BE group, which was similar to that in the control group (0.88 ± 0.11 cm). Villous or punctate or reticular pattern usually existed above or below the CS.

CONCLUSIONS

CS could be found at lower esophagus in most BE patients with AA staining, and this special feature might be valuable in diagnosing, evaluating and following up of BE patients.

Topographic, histological and molecular study of aberrant crypt foci identified in human colon in different clinical groups

Background/Aims

Aberrant crypt foci (ACF) are early microscopic lesions of the colonic mucosa, which can be detected by magnified chromoendoscopy. Herein, we have investigated whether ACF identified in different clinical groups can be differentiated based on their characteristics.

Methods

Macroscopically unremarkable mucosal flaps were collected from 270 fresh colectomies and divided into 3 clinical groups: colorectal carcinoma (group A), disease controls having known pre-neoplastic potential (group Bc), and disease controls without risk of carcinoma development (group Bn). Topographic and histologic analysis, immunohistochemistry, and molecular studies (high-resolution melt curve analysis, real-time polymerase chain reaction, and Sanger sequencing) were conducted for certain neoplasia-associated markers.

Results

ACF were seen in 107 cases, out of which 72 were left colonic ACF and 35 right colonic ACF (67.2% vs. 32.7%, P=0.02). The overall density of left colonic ACF was 0.97/cm, which was greater than the right colonic ACF density of 0.81/cm. Hypercrinia was present in 41 out of 72 left colonic ACF and in 14 out of 35 right colonic ACF (P=0.01). Immunohistochemical expression of p53 was also greater in left colonic ACF than in right colonic ACF (60.5% vs. 38.2%, P=0.03). However, ACF identified among the 3 clinical groups did not show any distinguishing topographic, histological, or genetic changes.

Conclusions

Left colonic ACF appear to be high-risk based on their morphological and prototypic tumor marker signature. ACF identified in different clinical groups do not show significant genotypic or topographic differences. Further detailed genetic studies are required to elucidate them further.

Hypopharyngeal cancer associated with synchronous oesophageal cancer: risk factors and benefits of image-enhanced endoscopic screening

OBJECTIVES

To explore the risk factors associated with the occurrence of synchronous oesophageal cancer in patients with hypopharyngeal cancer, and to investigate the roles of image-enhanced endoscopic screening in the prediction and diagnosis of early oesophageal cancer.

METHODS

The clinical characteristics of patients with hypopharyngeal cancer (n = 160) were analysed. All patients underwent laryngoscopic and gastroscopic examination using image-enhanced endoscopic techniques before treatment.

RESULTS

Of 160 hypopharyngeal cancer patients, 43 (27 per cent) had synchronous oesophageal cancer. Heavy drinking (odds ratio = 4.787, p = 0.029) and local invasion of three or more anatomical sites (odds ratio = 14.391, p = 0.000) were independent risk factors for synchronous oesophageal cancer. Narrow-band imaging laryngoscopy could detect more invaded anatomical sites than ordinary white light endoscopy (t = 8.532, p = 0.000). More early oesophageal cancer cases were detected with Lugol chromoendoscopy than with non-Lugol iodine staining examination (χ2 = 4.925, p = 0.026).

CONCLUSION

Synchronous oesophageal cancer is common in patients with hypopharyngeal cancer. The heavy drinking patients with hypopharyngeal cancer should undergo intensive monitoring. Image-enhanced endoscopic screening is helpful in the prediction and early detection of second primary oesophageal cancer.

Chromoendoscopy, Narrow-Band Imaging or White Light Endoscopy for Neoplasia Detection in Inflammatory Bowel Diseases

BACKGROUND

Studies have confirmed an increased risk of colorectal cancer in patients with ulcerative colitis; hence, surveillance is recommended. Optional modalities include white light endoscopy (WLE) or dye-spray chromoendoscopy. However, narrow-band imaging (NBI) is still not considered comparable to chromoendoscopy.

AIM

The aim of this study was to compare the diagnostic yield (DY) of WLE, chromoendoscopy, NBI for detection of neoplasia in patients with inflammatory bowel disease (IBD) by performing a meta-analysis of the existing literature.

METHODS

We searched databases for prospective studies. For each modality, we performed comparative per-lesion analysis (any neoplasia detection) and per-patient analysis (patient with neoplastic lesions). Meta-analysis was performed using fixed-effect model unless heterogeneity was high. Odds ratios (ORs) with 95% CIs were calculated and pooled.

RESULTS

Five studies compared chromoendoscopy to WLE. Chromoendoscopy (n = 361) was superior to WLE (n = 358) with per-patient analysis OR 2.05 (95% CI 1.26, 3.35) and per-lesion analysis OR 2.79 (95% CI 2.08, 3.73). High-definition (HD) chromoendoscopy was superior to HD-WLE with per-lesion analysis OR 2.48 (95% CI 1.55, 3.97). In four studies comparing NBI to WLE (n = 305), no difference was found in per-patient analysis OR 0.97 (95% CI 0.62, 1.53) and per-lesion analysis OR 0.94 (95% CI 0.63, 1.4). In two studies comparing CE to NBI (n = 104), no difference was found in per-patient analysis OR 1.0 (95% CI 0.51, 1.95) and per-lesion analysis OR 1.29 (95% CI 0.69, 2.41).

CONCLUSION

Chromoendoscopy is superior to WLE for detection of dysplasia in IBD, even with HD endoscopy. No difference in DY could be demonstrated for NBI in comparison with other modalities.

Role of Advanced Endoscopic Imaging Techniques in the Management of Inflammatory Bowel Disease

Endoscopy plays a crucial role in the management of inflammatory bowel disease (IBD) in terms of diagnosis, monitoring of mucosal status, and surveillance of colitis-associated neoplasia. Mucosal healing evaluated by endoscopy has been recognized as the target of treatment in the era of powerful biologics therapy. The optimal modality for identifying dysplasia in IBD has yet to be well defined. Increasing progress has recently been made in endoscopic technologies to more accurately assess mucosal inflammation and more effectively detect dysplasia. Here we review the data of advanced endoscopic imaging techniques such as chromoendoscopy, virtual chromoendoscopy, endocytoscopy, and confocal laser endomicroscopy in the management of IBD.

Endoscopic diagnosis and treatment of early esophageal squamous neoplasia

Esophageal cancer is one of the leading causes of cancer-related death and is associated with high morbidity and mortality. It carries a poor prognosis as more than half of patients present with advanced and unresectable disease. One contributing factor is the increased risk of lymph node metastases at early stages of disease. As such, it is essential to detect squamous cell neoplasia (SCN) at an early stage. In order to risk stratify lesions, endoscopists must be able to perform image enhanced endoscopy including magnification and Lugol’s chromoendoscopy. The assessment of both the horizontal extent and depth of any lesion is also of utmost importance prior to treatment. Endoscopic mucosal resection and submucosal dissection remain the standard of care with literature supportive their respective use. Radiofrequency ablation and other endoscopic treatments are currently available although should not be considered first line at this time. Our objective is to review the current options for the endoscopic diagnosis and treatment of esophageal SCN.

Use and barriers to chromoendoscopy for dysplasia surveillance in inflammatory bowel disease

Traditionally, patients with inflammatory bowel disease (IBD) have been thought to be at increased risk of developing colitis-associated colorectal cancer. Although there are recent data suggesting that rates of colitis-associated cancer in IBD patients is declining, current guidelines still recommend regular dysplasia surveillance for early detection and prevention of neoplasia in patients with IBD. White-light endoscopy with random biopsies has been the traditional approach for dysplasia detection; however, newer technologies and approaches have emerged. One method, dye-based chromoendoscopy, has the potential to detect more dysplasia. However, longitudinal data to showing a benefit in morbidity or mortality from the use of chromoendoscopy are still lacking. Many societies have included recommendation on the use of chromoendoscopy with targeted biopsies as a method of surveillance for colitis - associated colorectal cancer. This narrative review seeks to outline data on dysplasia detection as well as barriers to the implementation of dye-based chromoendoscopy for the prevention and early detection of colitis-associated colorectal cancer.

Endoscopic Surveillance in Long-standing Colitis

OPINION STATEMENT

There is a relative increase in the risk of colon cancer in patients with inflammatory bowel disease (IBD) affecting the colon, and endoscopic surveillance is advocated to mitigate this risk. The current standard practice is to survey this high-risk patient population using colonoscopy. Chromoendoscopy with targeted biopsies has emerged as the colonoscopy modality recommended by the major societies to optimize dysplasia detection. Studies over the past year support the improved yield from targeted as compared to random biopsies and improved dysplasia detection from chromoendoscopy as compared to white light endoscopy. Ongoing efforts should focus on the implementation of chromoendoscopy as the primary modality for colorectal cancer surveillance in IBD. Our review will describe current status and provide an update on the recent literature on surveillance colonoscopy in patients with IBD.

Role of new endoscopic techniques in inflammatory bowel disease management: Has the change come?

Despite significant therapeutic progress in recent years, inflammatory bowel disease (IBD), which includes Crohn’s disease and ulcerative colitis, remains a challenge regarding its pathogenesis and long-term complications. New concepts have emerged in the management of this disease, such as the “treat-to-target” concept, in which mucosal healing plays a key role in the evolution of IBD, the risk of recurrence and the need for surgery. Endoscopy is essential for the assessment of mucosal inflammation and plays a pivotal role in the analysis of mucosal healing in patients with IBD. Endoscopy is also essential in the detection of dysplasia and in the identification of the risk of colon cancer. The current surveillance strategy for dysplasia in IBD patients indicates white-light endoscopy with non-targeted biopsies. The new chromoendoscopy techniques provide substantial benefits for both clinicians and patients. Narrow-band imaging (NBI) has similar rates of dysplastic lesion detection as white-light endoscopy, and it seems that NBI identifies more adenoma-like lesions. Because it is used instinctively by many endoscopists, the combination of these two techniques might improve the rate of dysplasia detection. Flexible spectral imaging color enhancement can help differentiate dysplastic and non-dysplastic lesions and can also predict the risk of recurrence, which allows us to modulate the treatment to gain better control of the disease. The combination of non-invasive serum and stool biomarkers with endoscopy will improve the monitoring and limit the evolution of IBD because it enables the use of a personalized approach to each patient based on that patient’s history and risk factors.

Endoscopic recommendations for colorectal cancer screening and surveillance in patients with inflammatory bowel disease: Review of general recommendations

Screening for colorectal cancer (CRC) in patients with inflammatory bowel disease (IBD) is recommended by all scientific societies. However, there are differences in the recommendations they make regarding screening and surveillance. We address a series of questions that come up in the daily clinical practice of a physician. The first two questions that are raised are: (1) Who should be offered screening for CRC? and (2) When should the first colonoscopy be performed? The next step is to decide who should undergo endoscopic surveillance and at what intervals they should be performed. Chromoendoscopy is emerging as the recommended endoscopic technique for screening and surveillance. The terminology for describing lesions detected with endoscopy is also changing. The management of visible lesions or non-visible dysplasia is also a motive for the review. We end the review by addressing the follow-up for endoscopically resected lesions. These questions often cannot be answered easily due to the varying degrees of evidence available; therefore, we have made some general recommendations based on those made by the various guidelines and consensuses. The first screening colonoscopy should be offered 8 years after a IBD diagnosis and we recommend that patients be stratified according to the individual risk for each for endoscopic surveillance intervals.

The Role of Chromoendoscopy in Evaluating Colorectal Dysplasia

Chromoendoscopy pertains to image-enhanced endoscopic techniques such as dye-based chromoendoscopy and electronic chromoendoscopy using narrow-band imaging, flexible spectral imaging color enhancement, and i-scan. Dye-based chromoendoscopy has been demonstrated to improve colorectal dysplasia detection in high-risk patients with long-term inflammatory bowel disease, and electronic chromoendoscopy techniques have been shown to improve characterization of diminutive colorectal lesions, allowing for optical diagnosis during a colonoscopy examination. This article reviews endoscopic imaging using chromoendoscopy techniques for colorectal dysplasia evaluation.

Past and current trends in endoscopic diagnosis for early stage gastric cancer in Japan

Methodology for the diagnosis and staging of early gastric cancer (EGC) has improved in Japan since the development of the gastro-camera and determination of a definition of EGC. Imaging technology has been steadily evolving in the endoscopy field. Improvements in the resolution of standard endoscopy images used in screening and surveillance provide greater opportunities to find gastric cancer earlier. Image enhancement endoscopy (IEE), such as narrow band imaging (NBI), highlights mucosal structures and vascularity. In particular, when NBI is used with magnifying endoscopy, it reveals fine details of subtle superficial abnormalities of EGC that are difficult to recognize using standard white light endoscopy. IEE-assisted magnifying endoscopy has improved the accuracy of the differentiation of superficial gastric cancer as well as delineation of the diseased mucosa. The advanced imaging technology enables precise assessment of the risk of lymph node metastasis of EGC and is widely used to determine indications for endoscopic treatment. It is not an overstatement to say that this has become the basis for the current development and dissemination of endoscopic treatments. Moreover, the resolution of endoscopic imaging has been upgraded to the microscopy level by the development of endomicroscopy, including endocytoscopy and confocal laser endomicroscopy. Endomicroscopy allows real-time histological analysis of living tissue during routine endoscopy and may reduce the number of biopsies needed to reach the correct diagnosis, minimizing the risk of sampling errors.

Changing Paradigms in Detection of Dysplasia and Management of Patients With Inflammatory Bowel Disease: Is Colectomy Still Necessary?

This review chronicles the evolution of dysplasia detection and management in inflammatory bowel disease since 1925, the year the first case report of colitis-related colorectal cancer was published. We conclude that colorectal cancer prevention and dysplasia management for patients with inflammatory bowel disease has changed since this first case report, from somewhat hopeless to hopeful.

Endoluminal Diagnosis of Early Gastric Cancer and Its Precursors: Bridging the Gap Between Endoscopy and Pathology

Although dye-based and image-enhanced endoscopic techniques have revolutionized endoscopic diagnosis, conventional white light endoscopy still plays an important role in the diagnosis of early gastric cancer (EGC) during routine endoscopy. Chromoendoscopy reveals morphological characteristics of the mucosal lesions by enhancing mucosal contrast, while narrow-band imaging (NBI) facilitates detailed evaluation of the vascular architecture and surface features. Positive diagnostic findings of EGC on white light imaging and indigo carmine chromoendoscopy are a sharply demarcated lesion and irregularity in surface morphology or color. Magnifying NBI further improves diagnostic accuracy of white light imaging and chromoendoscopy. We review our approach to the endoscopic diagnosis of (pre-)malignant lesions in the stomach and discuss in detail novel endoscopic microvascular architectural patterns which further leverage diagnostic biopsy yield. We expect that further improvement of endoscopic techniques and correlative studies will close the gap between endoscopy and pathology.

Evidence based review of the impact of image enhanced endoscopy in the diagnosis of gastric disorders

Gastric cancer is the third most common cause of cancer-related death. Advanced stages of gastric cancers generally have grim prognosis. But, good prognosis can be achieved if such cancers are detected, diagnosed and resected at early stages. However, early gastric cancers and its precursors often produce only subtle mucosal changes and therefore quite commonly remain elusive at the conventional examination with white light endoscopy. Image-enhanced endoscopy makes mucosal lesions more conspicuous and can therefore potentially yield earlier and more accurate diagnoses. Recent years have seen growing work of research in support of various types of image enhanced endoscopy (IEE) techniques (e.g., dye-chromoendoscopy; magnification endoscopy; narrow-band imaging; flexible spectral imaging color enhancement; and I-SCAN) for a variety of gastric pathologies. In this review, we will examine the evidence for the utilization of various IEE techniques in the diagnosis of gastric disorders.

Surveillance of patients with inflammatory bowel disease

Patients with inflammatory bowel disease involving the colon are at increased risk for developing colorectal cancer. Colonoscopy surveillance is important to identify and treat IBD associated dysplasia. The SCENIC consensus provides evidence-based recommendations for optimal surveillance and management of dysplasia in IBD. Chromoendoscopy, with the surface application of dyes to enhance mucosal visualization, is the superior endoscopic surveillance strategy to detect dysplasia. Most dysplasia is visible, and can be endoscopically resected. Future studies should determine the effect of new surveillance strategies on the incidence of CRC and mortality in patients with IBD.

A low-cost method for chromoendoscopy for surveillance in ulcerative colitis

The risk of colorectal cancer in Indian patients with long-standing ulcerative colitis is high and similar to that in the West. Surveillance for dysplasia in these patients is therefore important. Recent studies and guidelines suggest an increasing role for chromoendoscopy-guided biopsy in surveillance for dysplasia. We report our experience with the technique of chromoendoscopy and an economical method of performing it. Reconstituting indigo carmine from a powder form rather than the dyes available commercially is a better economical alternative and should help make chromoendoscopy the standard of care for dysplasia surveillance across the country.

FICE vs Narrow Band Imaging for In Vivo Histologic Diagnosis of Polyps

BACKGROUND AND OBJECTIVES

Gastrointestinal cancers are the most frequently occurring cancers worldwide. Diagnosis and removal of polyps during screening endoscopy decreases the prevalence of colon cancer and cancer-related mortality, and it is considered to be the gold standard in gastrointestinal system cancer prevention. Technological innovations in endoscopy have led to revolutionary developments in many areas. Flexible spectral imaging color enhancement (FICE) and narrow-band imaging (NBI) are forms of digital chromoendoscopy and enhance the endoscopic images without the need for a dye. This study seeks to evaluate the efficacy of FICE and NBI on polyp screening and real-time histologic diagnosis with endoscopy and to compare them.

METHODS

A total of 134 patients (male/female = 72/62) and 161 polyps were evaluated with FICE or NBI, and real-time histologic diagnosis predictions were classified as neoplastic or nonneoplastic, according to Kudo's pit pattern classification. Pathological results and real-time endoscopic diagnoses were statistically interpreted for both FICE and NBI. Positive predictive value, negative predictive value, sensitivity, specificity, and accuracy rates were calculated and compared for both modalities.

RESULTS

When both systems were compared, the negative predictive value of NBI was found to be higher than that of FICE statistically (P < .001). Specificity and positive predictive value in the FICE group were higher than in the NBI group, but the difference was not statistically significant (P = .082 and P = .153, respectively).

CONCLUSIONS

Aside from being safe in polyp detection, digital chromoendoscopy also helps the endoscopist in selecting the type of simultaneous intervention (eg, polypectomy, endomucosal resection, or submucosal dissection) by enabling endoscopic histologic diagnosis.