Paediatric inflammatory bowel disease (PIBD; which encompasses Crohn’s disease (CD), ulcerative colitis (UC) and IBD-unclassified (IBD-U)) has an increased overall risk of mortality and malignancy compared to the general population however this is not fully characterized in children. Scotland has a population of 5.5 million people and one of the highest PIBD prevalences worldwide; we aim to present long-term nationwide PIBD cancer and mortality data.

We identified all PIBD patients within paediatric care who developed cancer or died between 01.01.2003 - 30.11.22. Accurate case accrual was ensured through review of the yearly national PIBD in Scotland audit (PISA) data and a follow-up questionnaire to each regional centre. Electronic medical records were reviewed retrospectively.

10 patients were included in the analysis. 6 patients (100% male, all CD) were diagnosed with malignancy with a median age at cancer diagnosis of 16.7 yrs (IQR 13.2 – 17.5) and a median disease duration prior to diagnosis of 3.0 yrs (IQR: 1.5 – 3.1). These included 2 cases of acute myeloid leukaemia, 3 Hodgkin’s Lymphoma and 1 Non-Hodgkin’s Lymphoma. No patients had a family history of cancer or primary sclerosing cholangitis. 5/6 (83%) received an immunomodulator or anti-TNF within the past 3 months and all patients had been exposed during their disease course. 4/6 (67%) are currently in remission, 1/6 (17%) is receiving treatment and 1/6 (17%) died.

5 patients died, including 1 cancer patient, (80% female, 2 UC, 2 CD, 1 IBDU) with a median age at death of 11.9 years (12.2 years (IQR: 11.7 – 18.0). 2/6 (33%) likely died as a direct consequence of their disease (1 late surgical complication and 1 thiopurine associated malignancy).

Death and malignancy are a rare but significant consequence of PIBD. While causation cannot be proved, six cases of malignancies associated with thiopurine/anti-TNF use were observed over a 20 year period.