Prognosis of lymphoma in patients following treatment with 6-mercaptopurine/azathioprine for inflammatory bowel disease

Abstract

Background: 6-Mercaptopurine (6-MP) and azathioprine (AZA) are effective for induction and maintenance therapy of Crohn's disease (CD) and ulcerative colitis (UC). There is an increased risk of lymphoma in patients with inflammatory bowel disease (IBD) treated with 6-MP/AZA. Little, however, is known about the prognosis of IBD patients treated with 6-MP/AZA who develop lymphoma. Methods: We conducted a retrospective review of 8780 records from three tertiary IBD centers and the records of 600 lymphoma patients from an academic Hematology and Oncology Center. The primary endpoint variable was survival of IBD patients with a lymphoma diagnosis treated or not treated with 6-MP/AZA. A secondary endpoint was the relative survival rate (by gender, race, and ethnicity) extrapolated from the Surveillance Epidemiology and End Results (SEER) database, computed for each subject. Results: Fourteen IBD patients were diagnosed with lymphoma. Twelve had CD and two had UC. Seven patients had treatment with 6-MP/AZA and seven had not. Two patients who received 6-MP/AZA died (both 1 year after diagnosis) and two patients who had not received 6-MP/AZA died (one after 2 years, another 3 years after diagnosis), all from lymphoma. Survival at last follow-up was similar to expected survival based on extrapolated SEER data for both 6-MP/AZA treated and untreated patients. Conclusions: We found no differences of survival with lymphoma between IBD patients and expected survival for the general population. Also, the prognosis for those IBD patients treated with 6-MP/AZA was not worse than lymphoma patients not treated with 6-MP/AZA. Statistical analysis, however, was limited by the small sample size and heterogeneity of the patients studied. (Inflamm Bowel Dis 2012) Copyright © 2012 Crohn's & Colitis Foundation of America, Inc.