The arthritis drugs known as TNF-blockers do not seem to markedly increase the chances of developing malignant lymphoma, according to the results of a Swedish study.
TNF is a natural inflammatory compound that was originally identified as an anti-tumor substance. While blocking TNF often greatly improves rheumatoid arthritis, there has been concern that doing so might allow cancers to develop.
Dr. J. Askling of the Karolinska University Hospital and colleagues used data from two large Swedish registries to identify nearly 68,000 patients with rheumatoid arthritis. Of these subjects, about 6600 started anti-TNF therapy between 1998 and 2006.
Malignant lymphomas occurred in 26 patients on anti-TNF therapy and in 336 of those not treated with these agents, the researchers report in the Annals of the Rheumatic Diseases.
They calculate that the risk of developing malignant lymphoma was 1.35-fold higher for rheumatoid arthritis patients given TNF-blockers compared to those who were not.
SOURCE: Annals of the Rheumatic Diseases, May 2009.
