Risk and Clinical Characteristics of Lymphoma in Korean Patients With Inflammatory Bowel Diseases

Abstract

Studies of lymphoma risk in Western inflammatory bowel disease (IBD) patients show conflicting results; however, none have examined the lymphoma risk and clinical characteristics of Asian IBD patients. Patients with lymphoma were identified in an IBD database from 3 tertiary referral centers in Seoul, Korea. The standardized incidence ratio (SIR) of lymphoma was estimated using data from the Korea Central Cancer Registry of the National Cancer Center. The risk of lymphoma in relation to specific medications was also explored. Seven cases of lymphoma (0.1%) were identified in 6585 IBD patients. The median age at lymphoma diagnosis was 43 years (range, 33 to 70 y) and the median duration of IBD at lymphoma diagnosis was 96.1 months (range, 15.1 to 171.6 mo). Three patients had underlying ulcerative colitis and 4 had Crohn's disease (CD). Non-Hodgkin lymphoma was diagnosed in 5 patients (71.4%) and Hodgkin disease (HD) in 2 patients (28.6%). The SIR of lymphoma was 2.03 [95% confidence interval (CI), 0.81-4.18] in the entire IBD patients. Both the SIR of lymphoma in CD patients (9.31; 95% CI, 1.13-33.62) and the SIR of HD (13.16; 95% CI, 1.59-47.53) in IBD patients were increased. The SIR of lymphoma in patients who were exposed to thiopurines was 5.93 (95% CI, 1.61-15.18). The risk of lymphoma in CD patients and the risk of HD in IBD patients seem to be increased in Korea. Thiopurine may be related with the risk of lymphoma in Korean IBD patients.