NEW YORK (Reuters Health) - 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.
This small increased risk was accounted for entirely by those who began anti-TNF treatment before 2002.
Although the reason or reasons for this are not clear, the researchers offered several possibilities. One is that patients who started on anti-TNF drugs when they first became available were by some measures already at higher risk for developing lymphoma.
In any case, the team notes, the study "points to the need for protracted follow-up of the safety profile of biological agents."
SOURCE: Annals of the Rheumatic Diseases, May 2009.
This is good news Lynn. Such a tiny increase! Thanks! It is good news! Especially since the article said that the increase was accounted for entirely by those who began anti-TNF treatment before 2002.