Colorectal Cancer in IBD: David Rubin, MD, on Natural History and Prevention

The cumulative risk of developing colorectal cancer among patients with inflammatory bowel disease (IBD), including those with ulcerative colitis (UC), has been steadily declining, and more cases are being diagnosed at earlier stages, largely due to improved understanding of risk and prognostic factors, better medical therapies, and advanced diagnostic tools, David Rubin, MD, told the audience at the Advances in Inflammatory Bowel Diseases regional meeting.

Dr Rubin is the Joseph B Kirsner Professor In Medicine, and chief of Gastroenterology, Hepatology, and Nutrition at the University of Chicago School of Medicine.

The approach to colorectal cancer prevention in IBD has evolved over time to focus on secondary prevention through augmented imaging techniques, such as high-definition scopes and electronic or dye-spray chromoendoscopy, he noted. Through a regular schedule of colonoscopies, early dysplasia can be detected and discrete lesions removed.

When unresectable neoplasia or recurrent neoplasia is found, or a patient’s cumulative risks are unacceptable, surgery is an option, Dr Rubin said, noting that total colectomy is not always required and for some patients, segmental resection is possible. However, he stressed, "We're not trying to save the colon; we're trying to save the patient."

Prognostic factors that place patients with IBD at high risk are extensive disease; low-grade dysplasia; comorbid primary sclerosing cholangitis; a family history of CRC; postinflammatory polyps; and stricturing disease. Patients with UC have a higher risk of developing dysplasia than do patients with Crohn disease.

Certain risk factors are modifiable, including increased inflammatory activity; backwash ileitis; pseudopolyps; prior dysplasia; and the presence of a mass or stricture. Others, however, are immutable, including male gender; younger age at diagnosis; longer duration of disease; a family history of CRC; PSC; and greater extent of colonic involvement.

The American College of Gastroenterology and the American Gastroenterology Association have developed specific recommendations for performing endoscopic surveillance in UC, Dr Rubin noted. The first and most important remains control of inflammation. “Control of inflammation is the most effective primary prevention for colorectal cancer among patients with IBD,” he stressed.

Both societies recommend the use of high-definition endoscopes; with these scopes, virtual chromoendoscopy, or narrow-band imaging, is suitable. Dye-spray chromoendoscopy is recommended when only standard definition scopes are available or when the patient has a history of dysplasia. “With high-definition equipment, white light with or without virtual chromo is sufficient to find dysplasia,” Dr Rubin noted. 

All suspicious areas should be targeted, he said. “Endoscopic resection is preferred over biopsies, but perilesion biopsies are not needed if a complete resection is performed.” 

One important advance in best practices for dysplasia in IBD is the movement away from random biopsies and surgery, he added. However, there are times when nontargeted biopsies are advisable, such as to assess the extent of disease; assessing disease activity; and for neoplasia, when visualization is suboptimal, to clarify the presence of chronic colitis near a detected lesion, and for less experienced endoscopists. Nontargeted biopsies should be performed with white light and without virtual or actual chromo, Dr Rubin said.

Following an exam negative for findings of dysplasia, the interval for follow-up will depend on risk factors, Dr Rubin stated. When a patient shows moderate to severe inflammation, has PSC or a family history of CRC in a first-degree relative under age 50, has dense pseudopolyposis, and has a history of invisible dysplasia or higher-risk visible within the past 5 years, the interval should be 1 year.  

For patients with mild inflammation, family history of CRC but not of a first-degree relative, shows features of previous severe colitis, and has a history of invisible dysplasia or higher-risk visible more than 5 prior, the interval can be extended to 2 to 3 years.

A 5-year interval may be appropriate for a patient with IBD who is in continuous remission with mucosal healing, has had 2 or more consecutive exams that showed no dysplasia, and has a minimal historical extent of colitis.

Colectomy may be indicated among male patients as well as patients with PSC; a family history of CRC; a long duration of disease; significant inflammation over time and at the last exam; and those who are willing and able to follow the physician’s recommendations.

Total colectomy is not always needed, Dr Rubin stated. Segmental colectomy for dysplasia may be appropriate when there is remission of disease in the distal colon or rectum, there is a single lesion or focus of dysplasia, and the patient is able and willing to do follow-ups for active surveillance. The segmental colectomy may also be preferred among older patients who need to retain their rectum to maintain continence.

While several options for primary prevention of dysplasia and CRC have been examined, from prophylactic colectomy to use of statins, “The one area that might make sense is control of inflammation over time,” Dr Rubin emphasized.

The key best practices for detecting and controlling dysplasia among patients with IBD, Dr Rubin outlined, are to “understand individual risks for your patient, including (especially) chronic inflammation; set surveillance intervals based on the absence of dysplasia and remission status on last exam, except among patients with PSC; use high-definition white-light and narrow-band imaging exams, which are as good as dye-spray for most colonoscopic surveillance exams; understand the new nomenclature for neoplasia in IBD; and perform targeted biopsies in most patients.

There is no currently available primary chemoprotection, Dr Rubin said. “Control of inflammation is the most effective primary prevention. Treat your patients to deep remission.”

--Rebecca Mashaw

Rubin, DT. Dysplasia in IBD: Best Practices. Presented at: Advances in Inflammatory Bowel Diseases regional meeting. April 1, 2023. Baltimore, Maryland.