Malignant lymphoma proves to be a difficult adversary in rheumatoid arthritis, despite TNFi therapy, a study shows.
The increased risk of malignant lymphoma in rheumatoid arthritis (RA) patients has been well established. Despite the use of treatments that have been proven to control rheumatoid arthritis disease activity, it doesn’t appear to have made an impact in the prevalence of lymphoma among RA patients, a new study shows.
The study, published in Arthritis and Rheumatology, examines the risk of lymphoma in patients diagnosed with RA between2007 and 2012. “The risk of lymphoma in contemporary RA does not seem to have decreased,” the researchers wrote.
It is thought that perhaps the inflammatory process associated with rheumatoid arthritis is associated with the development of lymphoma, but in this study, researchers found that treatment with methotrexate and TNFi agents “did not predict future lymphoma risk.”
Patients with rheumatoid arthritis are at increased risk of malignant lymphomas with a strong correlation with RA disease severity. The introduction of biologics in recent decades has changed the treatment landscape so this study was undertaken to assess whether lymphoma risk remains increased, and if so, it to explore risk predictors and lymphoma subtypes.
This study included 12,656 RA cases from the Swedish Rheumatology Quality Register 1997 – 2012. Overall, the hazard ratio for lymphoma was increased in RA to 1.6 (95% confidence interval [95% CI] 1.2–2.1). With RA disease duration, the risks did not appear to have declined over successive calendar years of RA diagnosis. Neither the use of methotrexate the first year after diagnosis or the use of TNFi increased lymphoma risk (HR 0.9 [95% CI 0.4–1.9]). However, the use of oral corticosteroids the first year after an RA diagnosis was associated with a reduced risk (HR 0.5 [95% CI 0.3–0.9]). Inflammatory activity during the first year after RA diagnosis did not predict future lymphoma risk. Chronic lymphocytic leukemia occurred less frequently, and Hodgkin’s lymphoma occurred more frequently, in RA patients than in the general population.
“We found that the overall increase in risk of lymphoma in contemporary and incident RA patients remains largely at the same magnitude as that reported in historical RA cohorts (8,10,11,13,14). Whereas the risk increased with longer RA duration, we did not demonstrate any trend toward decreasing risk over successive calendar periods of RA diagnosis, although we acknowledge the collinearity of these 2 factors,” researchers wrote.
K. Hellgren, E. Baecklund, C. Backlin, et al. "Rheumatoid Arthritis and Risk of Malignant Lymphoma," Arthritis and Rheumatology. Vol. 69, No. 4, April 2017, pp 700–708. DOI 10.1002/art.40017