**14.5 Exposure to immunomodulators**

Not all studies have attempted to evaluate the risk of lymphoma associated with immunomodulator therapy. The studies which have attempted to make this estimation are heterogenous and frequently there is a lack of distinction between lifetime exposure to these drugs, the cumulative doses received and whether cessation of a drug returns any lymphoma risk back to baseline. The CESAME study group attempted to answer some of these questions (Beaugerie et al., 2009a) by analysing patients who have *continuing*, *discontinued* or *never received* thiopurines. The SIRs for these three groups were 6.86 (95% CI 3.94 to 11.31), 1.44 (95% CI 0.17 to 5.20) and 1.43 (CI 95% 0.53 to 3.12) respectively. This may suggest that discontinuation of thiopurines returns risk to baseline but the results were not statistically significant.
