Surveillance in inflammatory bowel disease: chromoendoscopy and digital mucosal enhancement

Endoscopic surveillance of colorectal cancer in inflammatory bowel diseases: a review of the literature

INTRODUCTION

The risk of colorectal cancer (CRC) in patients with inflammatory bowel diseases (IBD) is higher compared to the general population and it is related to the type, severity, duration, and extension of the disease.

AREAS COVERED

This review aims to highlight current evidence from the literature supporting the role of endoscopic surveillance of CRC in patients with IBD.

EXPERT OPINION

Even in the absence of randomized controlled trials (RCTs), evidence from the literature supports the effectiveness of endoscopic surveillance in reducing IBD-related CRC incidence and mortality. As a consequence, current guidelines recommend colonoscopy 8-10 years after disease or symptom onset in all patients with ulcerative colitis (UC) and Crohn's disease (CD) involving at least one-third of the colon and agree on the necessity of annual surveillance in high-risk patients. Nevertheless, an overall agreement on the optimal intervals for surveillance of low-intermediate risk patients is absent and 2-5 year intervals have been proposed. In the near future, further studies are needed to assess the most effective intervals and tailor the surveillance based on the personal risk profile. Additionally, further efforts should be made to evaluate the role of noninvasive tests as primary screening, thus avoiding unnecessary colonoscopies.

Endoscopic surveillance strategies for dysplasia in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disorder with an increased risk of colorectal cancer (CRC). This has led to the implementation of surveillance programmes to minimise this risk. Overall, these proactive programmes in association with better medical therapies have reduced the incidence of CRC in this population. Specific populations remain at increased risk, such as younger age at diagnosis, primary sclerosing cholangitis, colonic strictures and pseudopolyps. The majority of gastrointestinal international societies favour chromoendoscopy with targeted biopsies or random biopsies. The aim of this review is to present the current literature on dysplasia surveillance, the methodology and endoscopic technology available to assess dysplasia in UC.

An Update on Surveillance in Ulcerative Colitis

PURPOSE OF REVIEW

Patients with long-standing ulcerative colitis have an increased risk for the development of colorectal cancer (CRC). Colitis-related dysplasia appears to confer the greatest risk. Colonoscopic surveillance to detect dysplasia has been advocated by gastrointestinal societies. The aim of surveillance is the reduction of mortality and morbidity of CRC through detection and resection of dysplasia or detecting CRC at an earlier and potentially curable stage. Traditional surveillance has relied on mucosal assessment with targeted biopsy of visible lesions and random biopsy sampling on the premise that dysplasia was not visible at endoscopy. Advances in optical technology permitting increased detection of dysplasia and evidence that most dysplasia is visible has had practice-changing implications.

RECENT FINDINGS

Emerging evidence favours chromoendoscopy (CE) for dysplasia detection and is gaining wider acceptance through recent international (International Consensus Statement on Surveillance and Management of Dysplasia in Inflammatory Bowel Disease (SCENIC)) recommendations and endorsed by many gastrointestinal societies. Adoption of CE as the gold standard of surveillance has been met with by scepticism, from conflicting data, operational barriers and the need to understand the true impact of increasingly higher dysplasia detection on overall CRC mortality. Valid debate notwithstanding, implementation of a risk stratification protocol that includes CE is an effective approach allowing earlier detection of dysplasia and colorectal neoplasia, determination of surveillance intervals with appropriate allocation of resources and limiting morbidity from CRC and colonoscopy itself. Further prospective data should define the true and long-term impact of dysplasia detection with modern techniques.

Advanced imaging in colonoscopy: contemporary approach to dysplasia surveillance in inflammatory bowel disease

Inflammatory bowel disease (IBD) (ulcerative colitis (UC) and Crohn's disease (CD)) is a chronic relapsing/remitting condition characterised by intestinal inflammation. One of the main concerns in patients with longstanding ulcerative and Crohn's colitis is development of colonic dysplasia and colorectal cancer (CRC), a risk higher than that of the general population. Colonoscopy surveillance programmes have been developed by major societies worldwide to improve early dysplasia detection and treatment, thus preventing progression to colorectal cancer. Colonoscopy is an imperfect tool as lesions can be missed, an issue even more relevant to colitic patients, where mucosal inspection and lesion recognition may prove challenging. Extensive research has been undertaken on performance improvement in this area while technical advances in optical imaging, such as high-definition, have made their way into modern endoscopy units. Techniques and technologies available to enhance optical diagnosis of dysplasia in inflammatory bowel disease are reviewed in this paper, focusing on those that are realistic, widely available and feasible for everyday practice.

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.

Colorectal cancer in patients with inflammatory bowel disease: the true impact of the risk

Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of colorectal cancer (CRC). The association between IBD and CRC is well supported, but reported risk estimates vary widely. Although recent evidence from population-based studies reports a decline in risk, CRC accounts for 10-15% of all deaths in IBD. The potential causes of recent epidemiological trends and the real magnitude of risk of CRC in IBD are subjects of debate. The molecular pathway leading to CRC differs from the classic adenoma-to-CRC sequence. Chronic inflammation contributes to the development of low- and high-grade dysplasia which may further convert into CRC. Patients with a young age at onset, long-standing and extensive colitis with severe inflammatory burden, a family history of sporadic CRC, and concomitant primary sclerosing cholangitis are at greatest risk. The CRC risk in patients with colonic Crohn's disease is similar to that of ulcerative colitis. IBD-associated CRC can frequently be detected at late stages and at a younger age. The long-term prognosis of CRC may be poorer in patients with IBD than in those with sporadic CRC. Regular surveillance colonoscopies may permit earlier detection of CRC, with a corresponding improved prognosis. The interval between surveillance colonoscopies is dependent on each patient's personal risk profile.