Inflammation is an independent risk factor for colonic neoplasia in patients with ulcerative colitis: a case-control study

Background & aims: An association between inflammatory activity and colorectal neoplasia (CRN) has been documented in patients with ulcerative colitis (UC). However, previous studies did not address the duration of inflammation or the effects of therapy on risk for CRN. We investigated the effects of inflammation, therapies, and characteristics of patients with UC on their risk for CRN.

Methods: We collected data from 141 patients with UC without CRN (controls) and 59 matched patients with UC who developed CRN (cases), comparing disease extent and duration and patients' ages. We used a new 6-point histologic inflammatory activity (HIA) scale to score biopsy fragments (n = 4449). Information on medications, smoking status, primary sclerosing cholangitis, and family history of CRN were collected from the University of Chicago Inflammatory Bowel Disease Endoscopy Database. Relationships between HIA, clinical features, and CRN were assessed by conditional logistic regression.

Results: Cases and controls were similar in numbers of procedures and biopsies, exposure to steroids or mesalamine, smoking status, and family history of CRN. They differed in proportion of men vs women, exposure to immune modulators, and primary sclerosing cholangitis prevalence. In univariate analysis, HIA was positively associated with CRN (odds ratio [OR], 2.56 per unit increase; P = .001), whereas immune modulators (including azathioprine, 6-mercaptopurine, and methotrexate) reduced the risk for CRN (OR, 0.35; P < .01). HIA was also associated with CRN in multivariate analysis (OR, 3.68; P = .001).

Conclusions: In a case-control study, we associated increased inflammation with CRN in patients with UC. Use of immune modulators reduced the risk for CRN, indicating that these drugs have chemoprotective effects. On the basis of these data, we propose new stratified surveillance and treatment strategies to prevent and detect CRN in patients with UC.