Increased histologic inflammation is an independent risk factor for nonconventional dysplasia in ulcerative colitis

Several types of nonconventional dysplasia have been described in inflammatory bowel disease. Hypermucinous, goblet cell-deficient, and crypt cell dysplasias are considered high-risk subtypes, as they often have molecular features of advanced neoplasia (e.g. aneuploidy) and are more frequently associated with advanced neoplasia than conventional dysplasia. This study investigated if increased colonic inflammation is a risk factor for nonconventional dysplasia.

A cohort of 125 patients with ulcerative colitis (UC)-associated dysplasia were analyzed and compared with 50 control UC patients without a history of neoplasia. For each patient, all biopsies prior to the initial detection of dysplasia were scored using a 4-point inflammatory activity score. Both mean and maximum scores from all biopsies taken during each colonoscopy were derived. Inflammation burden was calculated by multiplying the average maximum score between each pair of surveillance episodes by length of surveillance interval in years. The average scores of all colonoscopies were used to calculate overall mean, maximum, and inflammation burden scores. In multivariate analyses, higher maximum (odds ratio [OR] 3.4) and inflammation burden (OR 4.2) scores were significantly associated with the detection of dysplasia (P < 0.05). Similarly, higher mean and maximum scores increased the odds of nonconventional dysplasia by 2.7 and 4.9, respectively (P < 0.05). There was a stronger association between these two scores and high-risk subtypes (ORs 4.0 and 7.5, respectively, P < 0.05).

The risk of nonconventional dysplasia is significantly associated with increased colonic inflammation, which may contribute to its higher rates of aneuploidy and malignancy.