Publication Date:
2013-11-15
Description:
Background A meta-analysis by our group has shown an elevated risk of lymphoma with thiopurine therapy for IBD (Kandiel 2005 Gut). It summed referral data and population (pop) data, but the risk of lymphoma in referral centers may be skewed higher due to referral bias (Ang 2006 PMID 16531538). Since a previous meta-analysis presented in 2012 (Kotlyar 2012, DDW), there have been two large population based studies published (Pasternak 2013 Am J of Epidemiol, Abbas 2013 Gastroenterology). The latter study reported on a nationwide database of patients from the Veterans Affairs (VA) Hospitals from the United States. Aims Calculate the standard incidence rate of lymphoma in pts exposed to AZA/6-MP in population cohort studies and contrast these results to referral center studies. Methods We searched MEDLINE and the Cochrane Database for: “lymphoproliferative and thiopurines”; and “azathioprine and lymphoma”. Included citations were IBD cohort studies, evaluated cancer as an outcome, and pts. received AZA and/or 6-MP. Additionally a comprehensive search of the literature and abstracts from international meetings (2005-2013) was done. In our study additional data were extracted from the Spanish collaborative registry ENEIDA. Pooled standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were estimated. CIs assumed a Poisson distribution. To examine for heterogeneity, the deviance statistic from Poisson regression models was examined. Results There were 507 citations, and fifteen citations were included. Two studies (Korelitz and Kinlen) were obtained from Kandiel 2005, and Lewis 2001 was replaced by Armstrong 2010 as data were of the GPRD database. In referral studies (n=7), the SIR = 6.47 (95% CI: 3.77-10.36). In pop studies (n=8), the SIR = 2.27 (95% CI: 1.76-2.88). Overall the SIR was = 2.61 (95% CI: 2.08-3.23). Data from referral centers did not show significant heterogeneity (p=0.052), while pop studies did show significant heterogeneity (p=0.003). Results between referral and pop centers showed a significant difference (p
Print ISSN:
0006-4971
Electronic ISSN:
1528-0020
Topics:
Biology
,
Medicine
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