P090 Risk of cancer in pediatric onset inflammatory bowel disease: A nationwide cohort study 1977-2014

Abstract

BACKGROUND: The prognosis of pediatric onset inflammatory bowel disease (IBD) remains uncertain. We examined the overall and site-specific cancer risk among pediatric onset IBD patients as compared to non-IBD individuals from the general population. METHODS: Based on diagnoses from the Danish National Patient Register, we established a nationwide cohort (1977–2014) including all individuals with an IBD diagnosis before the age of 18 (n = 4,221) and 42,210 randomly selected age and sex matched individuals from the general population. The risk of cancer was determined by using Cox proportional hazard regression. RESULTS: During 59,563 person-years of follow-up, 126 of 4,221 pediatric onset IBD patients developed cancer (2.1 cases per 1,000 person-years) as compared to 554 of 42,210 non-IBD individuals (1.0 case per 1,000 person-years). Accordingly, the hazard ratio (HR) of any cancer was 2.16 (95% CI, 1.77–2.62). When examining site-specific cancers, the risk was significantly increased for non-melanoma skin: HR, 2.21 (95% CI, 1.41–3.46), liver: HR, 32.83 (95% CI, 9.23–116.78), small bowel, mouth, upper gastrointestinal: HR, 8.4 (95% CI, 2.70–26.14) and colorectal cancer: HR, 18.26 (95% CI, 9.16–36.39). Males with pediatric onset IBD had a significantly higher risk of cancer than females: HR, 3.17 (95% CI, 2.33–4.29) vs 1.71 (95% CI, 1.32–2.21). A slightly higher risk of cancer was observed for Crohn's disease patients than for ulcerative colitis patients: HR, 2.45 (95% CI, 1.82–3.30) vs 1.96 (95% CI, 1.51–2.55). CONCLUSION(S): In this nationwide cohort study, individuals with pediatric IBD had significantly increased risk of cancer, especially liver, small bowel, mouth, upper gastrointestinal, and colorectal cancer, but absolute numbers were low. The impact of chronic inflammation, respectively, IBD treatments on cancer risk in early onset IBD merits further investigation.