TNF Blockers May Raise Lymphoma Risk in Rheumatoid Arthritis Patients

April 22, 2005

NEW YORK APR 19, 2005 (Reuters Health) - Although use of TNF blockers

does not increase the overall tumor risk in patients with rheumatoid

arthritis, it may heighten the risk of lymphoma, according to a new

report. Still, given the small patient numbers, further research is

needed to confirm these findings.

Previous reports have linked rheumatoid arthritis with an elevated risk

of lymphoid malignancies. Data from clinical trials has not supported

an association with TNF blocker use, but these studies have suffered

from various methodologic issues.

To investigate this subject further, Dr. P. Geborek, from Lund

University Hospital in Sweden, and colleagues analyzed data from 757

patients in southern Sweden who were treated with etanercept or

infliximab between February 1999 and December 2002. The comparison

group consisted of 800 patients who were treated with conventional

antirheumatic agents.

The researchers' findings appear in the April 19th issue of the ls

of the Rheumatic Diseases.

During 1603 person-years at risk, 16 tumors, including 5 lymphomas,

were detected in the TNF blocker group. In the comparison group, 69

tumors, including 2 lymphomas, were identified during 3948

person-years.

On proportional hazard analysis, TNF blocker-treated patients were

nearly five times more likely to develop lymphoma, the investigators

note.

Based on the cancer rates expected in southern Sweden, there was a rise

in overall tumor risk in the comparison group, mostly due to an

increase in smoking-related cancers. By contrast, TNF blocker-treated

patients showed no increase in overall tumor risk.

The study is " welcome as it is the first direct attempt to investigate

the relationship between disease severity, use of anti-TNF-alpha

agents, and risk of lymphoma in patients with rheumatoid arthritis, "

Dr. J. P. lin and colleagues, from the Manchester University

Medical School in the UK, note in a related editorial. Still, further

research is needed before any firm conclusions can be reached, they

add.

SOURCFE:

* ls of the Rheumatic Diseases 2005;64:657-658,699-703.

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