Novel diagnostic and therapeutic techniques for surveillance of dysplasia in patients with inflammatory bowel disease

Colorectal Neoplasia in the Setting of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is associated with an increased risk of colorectal cancer (colorectal adenocarcinoma [CRC]) compared with the general population. IBD-related CRC is related to poorer outcomes than non-IBD-related CRC, and it accounts for 10% to 15% of death in patients with IBD. As such, screening guidelines have been made specific to this population recommending shorter intervals of endoscopic screening to detect dysplasia and CRC relative to the general population. Advances in endoscopic technology allow for improved visualization of dysplasia, which has led to widespread adoption of dye-spray chromoendoscopy with targeted biopsy.

Inflammatory bowel disease-related colorectal cancer: Past, present and future perspectives

Inflammatory bowel disease-related colorectal cancer (IBD-CRC) is one of the most serious complications of IBD contributing to significant mortality in this cohort of patients. IBD is often associated with diet and lifestyle-related gut microbial dysbiosis, the interaction of genetic and environmental factors, leading to chronic gut inflammation. According to the “common ground hypothesis”, microbial dysbiosis and intestinal barrier impairment are at the core of the chronic inflammatory process associated with IBD-CRC. Among the many underlying factors known to increase the risk of IBD-CRC, perhaps the most important factor is chronic persistent inflammation. The persistent inflammation in the colon results in increased proliferation of cells necessary for repair but this also increases the risk of dysplastic changes due to chromosomal and microsatellite instability. Multiple pathways have been identified, regulated by many positive and negative factors involved in the development of cancer, which in this case follows the ‘inflammation-dysplasia-carcinoma’ sequence. Strategies to lower this risk are extremely important to reduce morbidity and mortality due to IBD-CRC, among which colonoscopic surveillance is the most widely accepted and implemented modality, forming part of many national and international guidelines. However, the effectiveness of surveillance in IBD has been a topic of much debate in recent years for multiple reasons — cost-benefit to health systems, resource requirements, and also because of studies showing conflicting long-term data. Our review provides a comprehensive overview of past, present, and future perspectives of IBD-CRC. We explore and analyse evidence from studies over decades and current best practices followed globally. In the future directions section, we cover emerging novel endoscopic techniques and artificial intelligence that could play an important role in managing the risk of IBD-CRC.

[Position paper on endoscopic reporting in IBD]

The complete and reliable documentation of endoscopic findings make up the crucial foundation for the treatment of patients with inflammatory bowel diseases such as Crohn´s disease and ulcerative colitis. These findings are, on the one hand, a prerequisite for therapeutic decisions and, on the other hand, important as a tool for assessing the response to ongoing treatments. Endoscopic reports should, therefore, be recorded according to standardized criteria to ensure that the findings of different endoscopists can be adequately compared and that changes in the course of the disease can be traced back. In consideration of these necessities, fifteen members of the Imaging Working Group of the German Kompetenznetz Darmerkrankungen have created a position paper proposing a structure and specifications for the documentation of endoscopic exams. In addition to the formal report structure, the recommendations address a large number of attributes of acute and chronic inflammatory alterations as well as endoscopically detectable complications, which are explained in detail and illustrated using exemplary images. In addition, more frequently used endoscopic activity indices are presented and their use in everyday clinical practice is discussed.

Inflammatory polyps occur more frequently in inflammatory bowel disease than other colitis patients

BACKGROUND

Colitis is generally considered a risk factor for colon neoplasia. However, not all types of colitis seem to have equal neoplastic transformation potential.

AIM

To determine the prevalence of colorectal polyps in a predominantly African American population with inflammatory bowel disease (IBD) and Non-IBD/Non-Infectious Colitis (NIC).

METHODS

We retrospectively evaluated medical records of 1060 patients previously identified with colitis at Howard University Hospital, based on ICD-10 code. Among these, 485 patients were included in the study: 70 IBD and 415 NIC based on a thorough review of colonoscopy, pathology and clinical reports. Logistic regression analysis was applied to estimate the risk of polyps in patients with IBD compared to those with NIC after adjusting for age and sex. A subgroup analysis within the IBD group was performed.

RESULTS

Of the 485 patients, 415 were NIC and 70 were IBD. Seventy-three percent of the NIC patients and 81% of the IBD patients were African Americans. Forty six percent of IBD and 41% of NIC cases were male. IBD patients were younger than NIC patients (median age of 38 years vs. 50, P < 0.001). The prevalence of all types of polyps was 15.7 and 8.2% in the IBD and NIC groups, respectively (P = 0.045). Among patients with polyps, the prevalence of inflammatory polyps was higher in the IBD group (55%) compared to the NIC group (12%). After adjusting for age, sex and race, odds ratio of inflammatory polyps in IBD patients was 6.0 (P = 0.016). Adenoma prevalence was 4.3% (3/70) in IBD patients and 3.9% (16/415) in the NIC patients (p = 0.75). The anatomic distribution of lesions and colitis shows that polyps occur predominantly in the colitis field regardless of colitis type. More polyps were present in the ulcerative colitis patients when compared to Crohn's disease patients (27% vs. 5%, P < 0.001) within the IBD group.

CONCLUSION

Our study shows that inflammatory polyps are more common in IBD patients when compared to NIC patients. Most polyps were in the same location as the colitis.

Efficacy of various endoscopic modalities in detecting dysplasia in ulcerative colitis: A systematic review and network meta-analysis

BACKGROUND

Longstanding ulcerative colitis (UC) is associated with an increased risk of colonic neoplasia. Various endoscopic modalities, such as chromoendoscopy (CE), narrow band imaging (NBI) and random biopsy have been introduced for surveillance, however, there exists a paucity of direct comparisons between them. We aimed to conduct a network meta-analysis of randomized controlled trials (RCTs) performed for surveillance of neoplasia in UC.

AIM

To provide a comparative evaluation of the efficacy of the above-mentioned various modalities.

METHODS

We searched MEDLINE/PubMed, Web of Science, Embase, Google Scholar and Cochrane Central Registry through May 2016 for RCTs evaluating the efficacy of endoscopic modalities for surveillance of neoplasia in UC. The primary outcomes of interest were dysplasia (low- or high-grade) detection rates per biopsy and per patient, and dysplasia numbers per patient. Studies were simultaneously analyzed using a random-effects network meta-analysis under the Bayesian framework to identify the modality with the highest dysplasia detection rate. The best ranking probability for the dysplasia detection rate was analyzed by surface under the cumulative ranking (SUCRA) technique.

RESULTS

Six prospective RCTs of a total 1038 patients were identified. We identified 4 different modalities; white light (WL) high definition (HD) or standard definition (SD), CE HD, and NBI HD. For dysplasia per biopsy, direct meta-analysis showed superiority of NBI HD over WL HD and CE HD over WL SD. Network meta-analysis demonstrated the rank order of best modality as NBI HD, CE HD, WL HD and WL SD with close SUCRA scores of the first two. For dysplasia per patient, direct meta-analyses showed equivocal results between each modality. Network meta-analysis demonstrated the rank order of best modality as WL HD, NBI HD, CE HD and WL SD with small differences of the SUCRA score among the first two. For dysplasia numbers per patient, direct meta-analysis showed superiority of CE HD over WL SD. Network meta-analysis demonstrated the rank order of best modality as WL HD, NBI HD, CE HD, and WL SD with small differences of the SUCRA score among the first three.

CONCLUSION

We demonstrated that there were small differences among WL HD, NBI HD, and CE HD, while WL SD was inferior, in detecting dysplasia in UC.

Methods of extraction of optical properties from diffuse reflectance measurements of ex-vivo human colon tissue using thin film silicon photodetector arrays

Spatially resolved diffuse reflectance spectroscopy (SRDRS) is a promising technique for characterization of colon tissue. Herein, two methods for extracting the reduced scattering and absorption coefficients ( μ s ' ( λ ) and μ a ( λ ) ) from SRDRS data using lookup tables of simulated diffuse reflectance are reported. Experimental measurements of liquid tissue phantoms performed with a custom multi-pixel silicon SRDRS sensor spanning the 450 - 750 nm wavelength range were used to evaluate the extraction methods, demonstrating that the combined use of spatial and spectral data reduces extraction error compared to use of spectral data alone. Additionally, SRDRS measurements of normal and tumor ex-vivo human colon tissue are presented along with μ s ' ( λ ) and μ a ( λ ) extracted from these measurements.

Management of Inflammatory Bowel Disease-Associated Dysplasia in the Modern Era

This article begins with a brief overview of risk factors for colorectal neoplasia in inflammatory bowel disease to concretize the approach to risk stratification. It then provides an up-to-date review of diagnosis and management of dysplasia in inflammatory bowel disease, which integrates new and emerging data in the field. This is particularly relevant in an era of increased attention to cost- and resource-containment from the health systems vantage point, coupled with a heightened prioritization of patient quality of life and shared decision-making. Also provided is a brief discussion of the status of newer therapeutic techniques, such as endoscopic submucosal dissection.

Endoscopic detection and resection of dysplasia in inflammatory bowel disease-techniques with videos

BACKGROUND

Patients with ulcerative colitis and Crohn's colitis have an increased risk of developing dysplasia and colorectal cancer as compared to the general population; surveillance colonoscopy is recommended in this patient population.

METHODS

This review of the published literature aimed to assess the published evidence.

RESULTS

Detection of dysplasia requires examination of mucosa with targeted biopsies of the visible lesions as well as random biopsies to detect invisible lesions. Newer endoscopic techniques, in particular chromoendoscopy, increase the yield of identifying dysplastic lesions. The surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients International Consensus (SCENIC) guidelines recommends that colonoscopy using chromoendoscopy is the optimal endoscopic surveillance strategy to detect dysplasia. Once dysplastic lesions are discovered on surveillance endoscopic examination, careful and meticulous descriptions of lesions is mandatory to aid in further decision making. Management of dysplastic lesions in inflammatory bowel disease patients depends on endoscopic (morphological) and histologic findings and patient characteristics such as age, general condition of the patient, and patient preferences. Endoscopic mucosal resection, endoscopic submucosal dissection, and surgery are different therapeutic options for colonic dysplastic lesions detected in the setting of inflammatory bowel disease.

CONCLUSIONS

In this review, we discuss the various techniques for endoscopic resection of dysplasia in patients with inflammatory bowel disease. Further research is required to determine the optimal approach to diagnosis and management of dysplasia in patients with inflammatory bowel disease.

Colorectal Cancer in Inflammatory Bowel Disease

Patients with inflammatory bowel disease (IBD) are at significantly increased risk of colorectal cancer (CRC), principally resulting from the pro-neoplastic effects of chronic intestinal inflammation. Epidemiologic studies continue to highlight the increased risk of CRC in IBD. However, the incidence has declined over the past 30 years, attributed to both successful CRC-surveillance programs and improved control of mucosal inflammation. Risk factors that further increase the risk of IBD-related CRC include disease duration, extent and severity, the presence of inflammatory pseudopolyps, coexistent primary sclerosing cholangitis, and a family history of CRC. All major professional societies agree that IBD-CRC surveillance should occur more frequently than in the general population. Yet, guidelines and consensus statements differ on the surveillance schedule and preferred method of surveillance. Improved sensitivity to previously "invisible" flat dysplastic lesions using high definition and chromoendoscopy methods has resulted in many guidelines abandoning requirements for random untargeted biopsies of the colon. While colonic dysplasia remains a worrisome finding, and several clinical scenarios remain best addressed by total proctocolectomy due to concerns of synchronous undetected lesions and the unpredictable tempo of progression to malignancy, better detection techniques have also increased opportunities for endoscopic resection of dysplastic lesions that can be clearly delineated. Finally, the expanding armamentarium of medical options in IBD, including anti-tumor necrosis factor and anti-adhesion biologic therapies, have substantially improved our ability to control severe inflammation and likely reduce the risk of CRC over time.

The role of colorectal endoscopic submucosal dissection in patients with ulcerative colitis

BACKGROUND AND AIM

Patients with ulcerative colitis have an increased risk of colorectal dysplasia. Endoscopic submucosal dissection (ESD) for neoplastic lesions in ulcerative colitis remains controversial. The aim of this study was to clarify the role of ESD in the treatment strategy for ulcerative colitis.

METHODS

We retrospectively investigated 25 patients with ulcerative colitis in clinical remission who underwent colorectal ESD at 2 referral centers. We analyzed short-term and long-term outcomes. Preoperative diagnoses based on biopsy or endoscopy were also compared with the histologic diagnoses of resected specimens.

RESULTS

The mean size of the resected specimens was 34.9 ± 17.1 mm. The mean procedure time for ESD was 71.3 minutes. En bloc resection and R0 resection rates were achieved in 100% (25/25) and 76% (19/25), respectively. Postoperative bleeding and perforation during the procedure occurred in 0% and 4%, respectively. Five patients with noncurative resection underwent additional surgery. During a median 21 months (range, 8-80 months) follow-up, local recurrence did not occur. Metachronous high-grade dysplasia occurred in 1 case (4%). The biopsy predicted a final histologic diagnosis of carcinoma with a sensitivity of 72.2% (95% confidence interval [CI], 46.5-90.3), accuracy of 78.2% (95% CI, 56.3-92.5). The endoscopic findings predicted a final histologic diagnosis of carcinoma with a sensitivity of 72.2% (95% CI, 46.5-90.3), accuracy of 76% (95% CI, 54.9-90.6).

CONCLUSION

ESD for neoplasms in ulcerative colitis is feasible by expert endoscopists and may avoid unnecessary surgery. Because the biopsy and endoscopic findings had relatively low accuracy for the final histology, ESD could have a curative as well as a diagnostic purpose.

Endoscopic Therapeutic Approach for Dysplasia in Inflammatory Bowel Disease

Long-standing intestinal inflammation in patients with inflammatory bowel disease (IBD) induces dysplastic change in the intestinal mucosa and increases the risk of subsequent colorectal cancer. The evolving endoscopic techniques and technologies, including dye spraying methods and high-definition images, have been replacing random biopsies and have been revealed as more practical and efficient for detection of dysplasia in IBD patients. In addition, they have potential usefulness in detailed characterization of lesions and in the assessment of endoscopic resectability. Most dysplastic lesions without an unclear margin, definite ulceration, non-lifting sign, and high index of malignant change with suspicion for lymph node or distant metastases can be removed endoscopically. However, endoscopic resection of dysplasia in chronic IBD patients is usually difficult because it is often complicated by submucosal fibrosis. In patients with dysplasias that demonstrate submucosa fibrosis or a large size (≥20 mm), endoscopic submucosal dissection (ESD) or ESD with snaring (simplified or hybrid ESD) is an alternative option and may avoid a colectomy. However, a standardized endoscopic therapeutic approach for dysplasia in IBD has not been established yet, and dedicated specialized endoscopists with interest in IBD are needed to fully investigate recent emerging techniques and technologies.

DNA Methylation and Mutation of Small Colonic Neoplasms in Ulcerative Colitis and Crohn's Colitis: Implications for Surveillance

BACKGROUND

Stool DNA testing in patients with inflammatory bowel disease (IBD) may detect colorectal cancer and advanced precancers with high sensitivity; less is known about the presence of DNA markers in small IBD lesions, their association with metachronous neoplasia, or contribution to stool test positivity.

METHODS

At a single center in 2 blinded phases, we assayed methylated bone morphogenic protein 3, methylated N-Myc downstream-regulated gene 4, and mutant KRAS in DNA extracted from paraffin-embedded benign lesions, and matched control tissues of patients with IBD, who were followed for subsequent colorectal dysplasia. Stool samples from independent cases and controls with lesions <1 cm or advanced neoplasms were assayed for the same markers.

RESULTS

Among IBD lesions (29 low-grade dysplasia, 19 serrated epithelial change, and 10 sessile serrated adenoma/polyps), the prevalence of methylation was significantly higher than in mucosae from 44 matched IBD controls (P < 0.0001 for methylated bone morphogenic protein 3 or methylated N-Myc downstream-regulated gene 4). KRAS mutations were more abundant in serrated epithelial change than all other groups (P < 0.001). Subsequent dysplasia was not associated with DNA marker levels. In stools, the sensitivity of methylated bone morphogenic protein 3 as a single marker was 60% for all lesions <1 cm, 63% for low-grade dysplasia ≥1 cm and 81% for high-grade dysplasia/colorectal cancer, all at 91% specificity (P < 0.0001).

CONCLUSIONS

Selected DNA markers known to be present in advanced IBD neoplasia can also be detected in both tissues and stools from IBD patients with small adenomas and serrated lesions. Mutant KRAS exfoliated from serrated epithelial change lesions might raise false-positive rates. These findings have relevance to potential future applications of stool DNA testing for IBD surveillance.

Targeted Biopsies Identify Larger Proportions of Patients With Colonic Neoplasia Undergoing High-Definition Colonoscopy, Dye Chromoendoscopy, or Electronic Virtual Chromoendoscopy

BACKGROUND & AIMS

It is unclear what are the best and most appropriate endoscopic procedures for detecting colonic neoplasia in patients with long-term colonic inflammatory bowel disease (IBD). Dye chromoendoscopy (DCE) is the standard used in IBD surveillance colonoscopies. However, studies are needed to determine the optimal endoscopic technique for detecting dysplastic lesions. We investigated current practices used in surveillance colonoscopies by IBD gastroenterologists at a single tertiary center. We also determined the rate of neoplasia detection among different surveillance endoscopic techniques in an analysis of random or targeted biopsies.

METHODS

We collected data on 454 patients with IBD (54.5% male; mean age, 50 y; mean disease duration, 14.5 y; 55.9% with ulcerative colitis, 42.7% with Crohn's disease, and 1.3% with indeterminate colitis) who underwent surveillance colonoscopy from April 2011 through March 2014 at the University of Calgary in Canada. Subjects were examined using white-light standard-definition endoscopy (WLE), high-definition (HD) colonoscopy, virtual electronic chromoendoscopy (VCE), or DCE; random or targeted biopsy specimens were collected. Endoscopic and histologic descriptions with suspected neoplasia were recorded. Rates of neoplasia detection by the different endoscopic procedures were compared using chi-square analysis.

RESULTS

Of the patients analyzed, 27.7% had WLE endoscopy with random collection of biopsy specimens, 27.3% had HD colonoscopy with random collection of biopsy specimens, 14.1% had VCE with random collection of biopsy specimens, 0.9% had DCE with random collection of biopsy specimens, 12.8% had HD colonoscopy with collection of targeted biopsy specimens, 11.9% had VCE with collection of targeted biopsy specimens, and 5.3% had DCE with collection of targeted biopsy specimens. Neoplastic lesions were detected in 8.2% of the procedures performed in the random biopsy group (95% confidence interval, 5.6-11.7) and 19.1% of procedures in the targeted biopsy group (95% confidence interval, 13.4-26.5) (P < .001). Neoplasias were detected in similar proportions of patients by HD colonoscopy, VCE, or DCE, with targeted biopsy collection.

CONCLUSIONS

In a large cohort of IBD patients undergoing surveillance colonoscopy, targeted biopsies identified greater proportions of subjects with neoplasia than random biopsies. Targeted collection of biopsy specimens appears to be sufficient for detecting colonic neoplasia in patients undergoing HD colonoscopy, DCE, or VCE, but not WLE.

Colorectal Cancer in Patients With Inflammatory Bowel Disease: The Need for a Real Surveillance Program

The association between inflammatory bowel disease (IBD) and colorectal cancer (CRC) has been widely shown. This association is responsible for 10% to 15% of deaths in patients with IBD, even if according to some studies, the risk of developing CRC seems to be decreased. An adequate surveillance of patients identified as at-risk patients, might improve the management of IBD-CRC risk. In this article we review the literature data related to IBD-CRC, analyze potential risk factors such as severity of inflammation, duration, and extent of IBD, age at diagnosis, sex, family history of sporadic CRC, and coexistent primary sclerosing cholangitis, and update epidemiology on the basis of new studies. Confirmed risk factors for IBD-CRC are severity, extent, and duration of colitis, the presence of coexistent primary sclerosing cholangitis, and a family history of CRC. Current evidence-based guidelines recommend surveillance colonoscopy for patients with colitis 8 to 10 years after diagnosis, further surveillance is decided on the basis of patient risk factors. The classic white light endoscopy, with random biopsies, is now considered unsatisfactory. The evolution of technology has led to the development of new techniques that promise to increase the effectiveness of the monitoring programs. Chromoendoscopy has already proved highly effective and several guidelines suggest its use with a target biopsy. Confocal endomicroscopy and autofluorescence imaging are currently being tested and for this reason they have not yet been considered as useful in surveillance programs.

Cancer surveillance in ulcerative colitis and Crohn's disease: new strategies

PURPOSE OF REVIEW

Inflammatory bowel disease (IBD) patients have a higher incidence of colon cancer than the general population. Colon cancer surveillance has traditionally involved taking numerous random biopsies to provide sufficient yield to detect dysplasia. Recently, consensus guidelines have been published which promote the use of chromoendoscopy for IBD colon cancer surveillance. This presents a new set of opportunities and challenges in the evaluation and management of dysplasia in IBD.

RECENT FINDINGS

Dysplasia, previously thought to be 'invisible' to the endoscopist, is now considered to be 'visible' in the majority of cases with the advent of the use of high-definition endoscopy and chromoendoscopy. This changes how we manage dysplastic lesions, providing the patient options for endoscopic resection rather than promoting total proctocolectomy.

SUMMARY

Implemention of chromoendoscopy may require additional training for endoscopists unfamiliar with the technique. However, if this proves to be cost-effective and provides a higher sensitivity in dysplasia detection, then widespread education and implementation will be well worth the efforts. To do so, future studies will need to prove its benefits in preventing or reducing colon cancer morbidity and mortality in this high-risk patient population.

Prevention of colorectal cancer: How many tools do we have in our basket?

Prevention is the main strategy in order to reduce colorectal cancer incidence and mortality. It can be accomplished through primary prevention, using measures affecting factors known to confer higher risk of colorectal cancer, or through secondary prevention, aimed at early diagnosis of cancer or preneoplastic lesions in groups of subjects at increased risk of cancer. Although primary prevention should be the goal for future years, because it acts on the probable causes of colorectal cancer, at present it seems that secondary prevention is more effective on colorectal cancer survival, and the approaches which have yielded the most satisfying results, in terms of reduced mortality for cancer, are those aimed at detecting preneoplastic lesions, or cancer at an early stage in selected groups of subjects at average or increased risk of colorectal cancer. These groups are subjects aged 50years or older, affected individuals (gene carriers) or family members of hereditary colorectal cancer syndromes (i.e., Lynch syndrome and familial adenomatous polyposis), and patients with inflammatory bowel diseases. The most effective procedures used, though with some drawbacks, are fecal occult blood tests and colonoscopy. Future research should be addressed to find new approaches that will render preventive strategies more acceptable for the population, and more cost-effective.