Rheumatoid arthritis, treatment with corticosteroids, and risk of malignant lymphomas - results from a case-control study
- Karin Hellgren ( )
- Johan Askling ( )
- Published Online First 12 May 2009
Objective: Benefits and risks of corticosteroid treatment in rheumatoid arthritis (RA) are debated. Patients with RA are at increased risk of malignant lymphomas. In a large case-control study of risk factors for lymphoma in RA, we recently reported that steroid treatment was associated with decreased lymphoma risk. This study sought to further assess the nature of this association.
Methods: In a cohort of 74,651 patients with RA, we identified 378 cases with lymphoma and 378 matched RA controls, and abstracted information on inflammatory activity and different aspects of steroid treatment (duration, therapeutic strategy and mode of administration) from their medical records. Lymphomas were reclassified (WHO classification) and examined for Epstein-Barr virus. Relative risks were assessed as adjusted odds ratios (OR) through conditional logistic regression.
Results: A total duration of oral steroid treatment less than two years was not associated with lymphoma risk (OR=0.87; 95% confidence interval [CI] 0.51-1.5), whereas total treatment longer than two years was associated with a lower lymphoma risk (OR= 0.43; 95% CI 0.26-0.72). RA duration at the initiation of oral steroids did not affect lymphoma risk. Intra-articular steroids were associated with a reduced lymphoma risk, but only when used as swift flare therapy (OR= 0.22; 95% CI 0.13-0.37). Analyses by lymphoma subtype showed a reduced risk of diffuse large B-cell lymphoma (crude OR=0.59; 95% CI 0.37-0.94).
Conclusion: In this RA population, use of steroids was associated with reduced lymphoma risk. Whether this association is a generic effect of steroids or specific to the studied population remains unknown.