Non-Hodgkin's lymphoma--meta-analyses of the effects of corticosteroids and non-steroidal anti-inflammatories.

OBJECTIVE Recent research has focused on the effects of corticosteroids and non-steroidal anti-inflammatory drugs/agents (NSAIDs) on non-Hodgkin's lymphoma (NHL) risk, with inconclusive results. We conducted meta-analyses of data published to date, to ascertain the over-all association between NHL and corticosteroid use, and between NHL and NSAID use. METHODS Literature searches were performed to find studies assessing the effects of corticosteroids and/or NSAIDs on NHL risk. We analysed nine case-control studies and one cohort study of the effect of corticosteroids and/or NSAIDs on NHL risk. We performed a formal meta-analysis using summary measures from these studies. RESULTS The studies contributed 6897 NHL cases and 8881 controls for the corticosteroid analyses, and 5794 NHL cases and 34,707 controls for the NSAID analyses. There was no heterogeneity of the odds ratio (OR) estimates. The overall OR for the effect of corticosteroid exposure on NHL occurrence was not suggestive of an increased risk [OR 1.09, 95% confidence interval (CI) 0.96-1.24]. Similarly, the OR for the effect of NSAIDs on NHL occurrence did not support an increased risk (OR 0.93, 95% CI 0.74-1.14). CONCLUSIONS Our meta-analyses suggest little evidence that corticosteroid or NSAID exposures are themselves risk factors for NHL. Early data linking corticosteroids and/or NSAIDs with NHL may reflect an underlying increased risk of lymphoma in patient populations that use these medications (i.e. autoimmune diseases such as rheumatoid arthritis), and may point to the importance of disease activity in driving NHL risk in these populations.