The debate continues.
According to a study presented at the annual meeting of the American College of Rheumatology, and contrary to many previous studies, anti–tumor necrosis factor (TNF) therapy does not increase the risk of lymphoma in patients with rheumatoid arthritis.
This study was presented by Dr. Kimme L. Hyrich of the arthritis research UK epidemiology unit at the University of Manchester.
Dr. Hyrich and colleagues looked at patients from the British Society for Rheumatology Rheumatoid Arthritis Register (BSRBR-RA), a prospective registry of RA patients taking biologic drugs, recruited between 2001 and 2009. The treatment group included just under 12,000 patients who had received anti–tumor necrosis factor therapy, including infliximab (Remicade), etanercept (Enbrel), or adalimumab (Humira). They were compared to a control group consisting of 3,465 patients who were treated only with non-biologic disease modifying anti-rheumatic drugs (DMARDs).
Patients were followed until 30 September 2010, their first lymphoma, or death— whichever came first. A full 95% of cancers were detected by having been flagged in the national cancer database.
The research team found a total of 84 incident lymphomas over the study period. The majority of lymphomas found were diagnosed as diffuse large B-cell lymphoma—the most frequently diagnosed NHL among the general population.
-- 64 lymphomas were found in the anti-TNF cohort, including 9 cases of Hodgkin's lymphoma.
-- 20 lymphomas were found in the DMARD control group, including 5 cases of Hodgkin's.
While initially it appears that there is a greater incidence of lymphoma among anti-TNF users with RA, following adjustment for baseline age, gender, disease activity score, health assessment questionnaire results, disease duration, smoking, and current or previous cyclophosphamide use, that greater incidence nearly vanishes.
Dr. Hyrich commented:
"The challenge in studying whether therapies for rheumatoid arthritis (RA) patients can increase the risk of lymphoma is the knowledge that the disease itself has been associated with this outcome. It’s possible that with immunosuppression, we may see an increased risk of lymphoma, but equally, if we can control the disease activity that has been associated with this outcome, it’s possible that we actually can see a decrease in lymphoma risk over time."
Source: Oncology Practice