Damian McNamara

March 18, 2016

AMSTERDAM — New predictors will help find the one in 20 people with ulcerative colitis who will go on to develop colorectal neoplasia, according to a large retrospective cohort study.

"The problem with cancer surveillance in ulcerative colitis is the higher relative risk of developing cancer, compared with the general population, although the absolute risk remains quite small," said Ryan Choi, MD, from St. Mark's Hospital in London, United Kingdom.

"The vast majority of these patients never progress to cancer," but it would be nice to be able to identify those who will, he explained.

Dr Choi presented the study findings, along with some practical guidance, here at the European Crohn's and Colitis Organisation 2016 Congress.

"Largest and Longest Study"

Dr Choi and his colleagues evaluated 6957 colonoscopies in 987 patients enrolled in the ulcerative colitis surveillance program at St. Mark's. All had histologically confirmed extensive ulcerative colitis and had undergone at least two surveillance colonoscopies.

Ninety-seven patients (9.8%) developed colorectal neoplasia from 2003 to 2013.

On univariate analysis, the investigators identified seven predictors of colorectal neoplasia, including mean ulcerative colitis severity score (hazard ratio [HR], 3.55) and chronicity score (HR, 1.29). On multivariate analysis, five predictors remained.

Table. Predictors of Colorectal Neoplasia on Multivariate Analysis

Predictor Hazard Ratio
Colonic stricture 3.30
Presence of primary sclerosing cholangitis 2.20
Mean severity of inflammation 2.05
Unusual endoscopy colonic findings 1.80
Inflammation chronicity on histology 1.18

 

"Severity and, importantly, chronicity of microscopic inflammation were the most important risk factors for colorectal neoplasia," Dr Choi said.

This suggests that inflammation data could be used to stratify patients by risk, but "using inflammation scores in practice is difficult," he pointed out.

The investigators used colonoscopy data to rate the severity of each patient's inflammation on a scale of 0 to 3. And they used the proportion of positive histologic inflammation findings over time to calculate a chronicity of inflammation score.

But these patients underwent numerous procedures, and "we have to take into account a patient's entire surveillance history" when calculating scores, Dr Choi told Medscape Medical News. Therefore, this method is "not practical to use."

Taking the Long View

Dr Choi tried to find a more clinically practical alternative.

Basing inflammation severity on only the most recent procedure simplified the assessment, but this was not significant after adjustment for chronicity and other confounders, and did not reveal chronicity over time.

He recommended that physicians take a long-term look, when feasible, and found that a more practical approach — basing the calculation of severity and chronicity scores on the previous three or four colonoscopies conducted over the most recent 5 or 10 years. With this strategy, "the predictive powers were similar to those of scores calculated from all colonoscopies that patients underwent," said Dr Choi.

Macroscopic features of chronicity seen on endoscopy — such as tubular, featureless, or shortened colon — could also help to identify high-risk patients, he explained.

After the presentation, a member of the audience asked whether the risk for dysplasia could be reduced if active inflammation was treated.

"It is important that we treat these patients. I didn't show it here, but having a higher proportion of normal or quiescent disease in histology was a significant protective factor, inversely proportional to the chronicity," Dr Choi replied.

The detection of colorectal neoplasia depends in part on the duration of disease activity and the frequency of colonoscopies, said session comoderator Marina Shapina, MD, from Moscow.

"We need to monitor disease activity" for all people with ulcerative colitis, but particularly for asymptomatic people with histology or endoscopic findings at disease onset, she told Medscape Medical News.

She also suggested routine fecal occult test monitoring every 6 to 12 months in this population, with a more invasive colonoscopy to confirm any potentially relevant findings.

The study was funded through a Derek Willoughby Clinical Scientist Award for Inflammatory Research. Dr Choi and Dr Shapina have disclosed no relevant financial relationships.

European Crohn's and Colitis Organisation (ECCO) 2016 Congress: Abstract OP012. Presented March 18, 2016.

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