Prognosis of pediatric-onset inflammatory bowel disease associated with primary sclerosing cholangitis: A population-based study.

To assess whether the prognosis of pediatric-onset inflammatory bowel disease (IBD) is influenced by its association with primary sclerosing cholangitis (PSC) considering medical treatment, bowel resection, risk of cancer, and mortality. A retrospective population-based study was conducted using data from the EPIMAD Registry, one of the most extensive prospective population-based IBD studies globally. Cases (IBD-PSC) were compared with matched controls (matched-IBD). Inclusion criteria were age ≤17 years at IBD diagnosis and follow-up ≥2 years. PSC was confirmed by magnetic resonance cholangiopancreatography and/or histology. Each case was matched to four controls by propensity score (i.e., sex, age, year, and location of IBD at diagnosis). We included 24 cases and 96 controls. Median duration of follow-up was 6.4 years (interquartile range = 3.1-14.3). No significant difference was observed between the two groups in terms of exposure to treatment at 5 years (immunosuppressants, corticosteroids, or antitumor necrosis factor). In IBD-PSC, cancers were 28 times more frequent (standardized incidence ratio = 27.9; 95% confidence interval [CI], 7.0-111.7, p = 0.002), and death was 13 times more frequent (standardized mortality ratio = 13.3; 95% CI, 3.3-53.4, p = 0.010) than in the general population. No increased risk of cancer or mortality was observed in patients with IBD but without PSC compared to the general population. Although the course of IBD is not different, the prognosis of pediatric-onset IBD associated with PSC is significantly worse than that of pediatric-onset IBD without PSC because of increased cancer and mortality rates.