P1125 Incidence and Neoplastic Risk Associated with Colonic Stricture in Pediatric-Onset Crohn's Disease: A Population-based Study

Abstract

Abstract Background The identification of colonic stricture in patients with Crohn's disease (CD) often leads to surgery due to concerns about associated neoplasia. Nevertheless, information regarding the neoplastic risk associated to colonic stricture is still limited. The objective of this study was to assess both the incidence of colonic stricture in pediatric-onset CD and the associated neoplastic risk at the population-based level. Methods All patients diagnosed with CD before age 17 between 1988 and 2011, and included in a population-based registry, were followed until 2013. Colonic stricture was defined as a narrowing of the digestive lumen observed on endoscopic or radiological examination. Excluded were stricture in the ileocaecal valve, anal canal, or low rectum. Univariate risk factors for colonic stricture were explored using Cox proportional hazards models with time-dependent variables, and a multivariable Cox model analysis was performed. Results A total of 1,007 patients diagnosed with CD between 1988 and 2011 were included. Median age at diagnosis was 14.5 years [IQR: 12.0-16.1]. Throughout the follow-up period (median follow-up, 8.8 years [4.6-14.2]), patients were predominantly exposed to 5-aminosalicylates (88.1%), immunosuppressants (70.6%), and biologics (47.9%). Colonic stricture was diagnosed in 52 patients, including 11 at CD diagnosis. The cumulative incidence of colonic stricture in CD was 2.9% [1.8%-4.0%] at 5 years. The overall incidence rate of colonic stricture in CD was 5.4 cases/1000 person-years, 95% CI [4.1-7.1]. In multivariable analysis, an increased risk of colonic stricture was observed during periods of active disease (HR = 2.62, [1.40-4.89], p<0.01). Conversely, the absence of colonic involvement at diagnosis (HR = 0.18, [0.04, 0.80], p<0.05) or treatment with aminosalicylates (HR = 0.39, [0.19-0.79], p<0.05) was associated with a lower risk of colonic stricture. After a median follow-up of 6.4 [2.4-12.7] years, colonic stricture surgical resection was performed in 29 patients (55.8%). Colon adenocarcinoma was detected in one patient (1.9%) within 6 months after the diagnosis of colonic stricture. Conclusion In this population-based study of pediatric-onset Crohn's disease, 52 patients (5%) experienced colonic stricture, with a 2.9% incidence rate observed after 5 years of follow-up. Additionally, one patient (2%) presented with an associated adenocarcinoma.