Thiopurines in IBD Linked with Myeloid Disorders

Summary and Comment |
August 26, 2014

Thiopurines in IBD Linked with Myeloid Disorders

  1. Douglas K. Rex, MD

Patients exposed to thiopurines had a sevenfold increased risk for myeloid leukemia or myelodysplastic syndrome, although the absolute risk was low.

  1. Douglas K. Rex, MD

Recent study findings have strengthened the evidence of a positive association between thiopurine use in patients with inflammatory bowel disease (IBD) and risks for lymphoma and nonmelanoma skin cancers (basal cell carcinoma and squamous cell carcinoma). Alternately, in recent studies, cancer risks associated with anti–tumor necrosis factor agents seem lower than previously observed.

The current study is derived from a French nationwide observational cohort of 19,486 patients with IBD. During 49,736 person-years of follow-up, five patients were diagnosed with incident myeloid disorders (2 with acute myeloid leukemia and 3 with myelodysplastic syndrome). Four of the five patients had been exposed to thiopurines, including three with past exposure and one with ongoing treatment. Patients with past exposure to thiopurines had an increased risk for these disorders (standardized incidence ratio, 6.98).

The risks for myeloid disorders in patients receiving ongoing thiopurine treatment (SIR, 1.54) and those never exposed to thiopurines (SIR, 0.59) were not significantly different compared with the general population. The duration of thiopurine treatment in the patients with myeloid disorders was uncertain.


This study seems to add to the risks associated with thiopurines, although the absolute risk for myeloid disorders remains low, at about 1 per 10,000 patient-years of follow-up.

Editor Disclosures at Time of Publication

  • Disclosures for Douglas K. Rex, MD at time of publication Consultant / Advisory board Given Imaging; Olympus Corporation America; Exact Sciences; Endo Aid Speaker’s bureau Boston Scientific; Braintree Laboratories; Ferring Pharmaceuticals; Olympus America Grant / Research support CDC; Olympus America; Boston Medical Center Editorial boards World Journal of Gastroenterology; The Journal of Clinical Gastroenterology; Techniques in Gastrointestinal Endoscopy; Gastroenterology & Hepatology; Expert Review of Gastroenterology & Hepatology; Medscape Gastroenterology; World Journal of Gastrointestinal Pharmacology and Therapeutics; Annals of Gastroenterology & Hepatology; World Journal of Gastrointestinal Oncology; Comparative Effectiveness Research; Journal of Anesthesia & Clinical Research; Gastroenterology; World Journal of Gastrointestinal Pathophysiology; Gastroenterology Research and Practice; GI & Hepatology News; Gastroenterology Report; Clinical Epidemiology Reviews; JSM Gastroenterology and Hepatology Leadership positions in professional societies American Society for Gastrointestinal Endoscopy (Councilor); US Multi-Society Task Forces (AGA, ACG, ASGE) (Chair)


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