OP12 The incidence and disease course of perianal Crohn’s disease: A Danish nationwide cohort study
M.D. Wewer1, M. Zhao2, A. Nordholm-Carstensen3, J.B. Seidelin1, J. Burisch2
1Department of Gastroenterology, Herlev Gentofte University Hospital, Herlev, Denmark, 2Gastrounit- Medical Division, Amager Hvidovre University Hospital, Hvidovre, Denmark, 3Digestive Disease Center, Bispebjerg Hospital, Copenhagen, Denmark
Background
Perianal Crohn’s disease (pCD) has a major negative impact on patients’ quality of life and is complex to treat. Despite its putative high frequency and burden for patients, only a few studies have investigated the incidence, disease course and associated cancer-risk in a population-based setting. The aim was to assess the incidence and course of pCD in adult patients with CD within a 19-year period. Specifically, describing changes in medical and surgical management as well as rates of cancer.
Methods
The cohort comprised all individuals >18 years diagnosed with CD in Denmark between 1 January 1997 and 31 December 2015. Patients were identified in the National Patient Registry. Chi-square test, Mann–Whitney–Wilcoxon test and multivariate Cox regression analysis were used.
Results
A total of 1,697/9,739 (17%) patients with CD were found to have pCD. Perianal fistulas were the most common manifestation accounting for 943 (56%) cases. The onset of pCD before CD diagnosis occurred in 32%. The overall incidence of pCD was 20/1,000 patient-years. The incidence of pCD remained stable over time. More patients with pCD were treated with immunomodulators (70%) and biologics (35%) than those without pCD (51%,
Conclusion
In this nationwide study, 17% of the CD patients developed pCD. The continuing high incidence of pCD suggests a limited disease-modifying effect of biologics. Patients with pCD were at increased risk of undergoing major surgery compared with non-pCD patients. The risk of rectal or anal cancer was increased in patients with pCD compared with non-IBD matched controls. These findings encourage surveillance of rectal and anal cancer.