DOP094 Cancer in elderly-onset inflammatory bowel disease: A population-based study

The ageing of the population makes elderly-onset inflammatory bowel diseases (IBD) a rising problem. Risk of cancer is unknown in this population. We studied this risk in a populationbased cohort of patients with IBD. Patients and methods: In a French population-based cohort, we identified 841 IBD patients >60 years of age at diagnosis from 1988 to 2006, including 367 Crohn's disease (CD) and 472 ulcerative colitis (UC)1. We compared incidence of cancer among patients with IBD with that observed in the French Network of populationbased Cancer Registries (FRANCIM). Only cancers occurring after IBD diagnosis were taken into account. Confidence interval (CI) was estimated assuming a Poisson specific law for rare events. Results were expressed using the standardized ratios of incidence (SIR) and their CI 95%. Results: After a median follow-up of 6 years [2-11], 103 (12.3%) patients with IBD including 42 CD and 61 UC developed a cancer corresponding to a SIR of 1.00 [0.83-1.21]. Eleven patients (1.3%) developed at least 2 cancers.There was no increased risk of colorectal cancer in IBD (SIR=1.06 [0.65-1.72], CD (SIR=1.15 [0.54-2.40] and UC (SIR=0.99 [0.52-1.91] without significant protective role of 5-ASA (HR=0.7 [0.2-2.6]). An increased risk of malignant lymphoproliferative disorders was found in IBD (SIR=2.71 [1.415.20] and in UC (SIR=3.05 [1.37-6.79]) but not in CD (SIR=2.21 [0.71-6.86]). An increased risk of extraintestinal tumors was observed only for the liver in CD (SIR=3.25 [1.04-4.07]). Immunomodulator exposure (n=26) was not associated with an increased risk of cancer (SIR=0.75 [0.43-1.29]) nor with any specific risk including malignant lymphoproliferative disorders (SIR=1.89 [0.26-13.44]). Only 2 patients of this cohort received biotherapy. Conclusions: There is no increased risk for developing intestinal cancer among patients with elderly-onset IBD in this population-based cohort. There is an increased risk of developing malignant lymphoproliferative disorders in UC and an increased risk for developing liver cancer in CD. These data reinforce the peculiarity of elderly-onset IBD as compared with younger age at onset IBD1. 1 Charpentier C et al. Gut 2013