PHILADEPHIA — Acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) are rare myeloid clonal disorders that commonly affect the elderly population and have poor prognosis. Little data is available, however, on the risk of AML/MDS among patients with inflammatory bowel disease (IBD), especially on the effects of thiopurine (TP) therapy.
Corporal Michael J. Crescenz VAMC-led researchers conducted a retrospective cohort study among patients with IBD from a VA data set. Researchers focused on TP exposure: (i) never exposed to TPs, (ii) past TP use (discontinued >6 months ago), (iii) current TP use with a cumulative exposure of <2 years, and (iv) current TP use with a cumulative exposure of ≥2 years.
Thiopurines, including azathioprine, mercaptopurine and thioguanine, are immunomodulating agents often used to maintain corticosteroid-free remission in patients with Crohn’s disease or ulcerative colitis.
Among 56,314 study patients,107 developed AML/MDS. The overall incidence of AML/MDS in the IBD population was 18.7 per 100,000 patient-years, the authors noted in the American Journal of Gastroenterology.1
Results indicated that incidences among those never exposed to TPs, past users of TPs, current users of TPs with a cumulative exposure of <2 years and current users of TPs with a cumulative exposure of ≥2 years were 17.0, 17.7, 30.4, and 30.3 per 100,000 patient-years, respectively.
Further analysis indicated that, compared with those never exposed to TPs, current use of TPs was associated with increased risk (adjusted HR 3.05; 95% CI 1.54-6.06, P = 0.0014 for current use of TPs with a cumulative exposure of <2 years and adjusted HR 2.32; 95% CI 1.22-4.41, P = 0.0101 for current use of TPs with a cumulative exposure of ≥2 years), although past TP exposure was not.
“Among patients with IBD, current TP use was associated with an increased risk of AML/MDS, which reverts to baseline after discontinuation of TP use,” the authors concluded.
- Khan N, Patel D, Trivedi C, Kavani H, Pernes T, Medvedeva E, Lewis J, Xie D, Yang YX. Incidence of Acute Myeloid Leukemia and Myelodysplastic Syndrome in Patients With Inflammatory Bowel Disease and the Impact of Thiopurines on Their Risk. Am J Gastroenterol. 2020 Nov 26. doi: 10.14309/ajg.0000000000001058. Epub ahead of print. PMID: 33252453.