Inflammatory polyarthritis ups risk of lymphoma

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Inflammatory polyarthritis ups risk of lymphoma

Fri May 5, 2006 1:44 PM ET

NEW YORK (Reuters Health) - The risk of lymphoma (cancer of the

blood) appears to be more than twice as high in people with

inflammatory polyarthritis relative to that seen in the general

population, UK researchers report. Inflammatory polyarthritis is a

form of rheumatoid arthritis involving two or more joints.

There are conflicting data on the association between rheumatoid

arthritis and lymphoma and the possible influence of arthritis

treatments that suppress the immune system, Dr. Alan J. Silman of The

Medical School, Manchester and colleagues note.

To investigate further, the researchers conducted a prospective

cohort study involving 2105 patients with new-onset inflammatory

polyarthritis.

Over a median of 8.4 years, there were 11 cases of non-Hodgkin's

lymphoma -- cancer involving the lymph nodes. Six of these cases were

large B-cell lymphoma -- the most common type of lymph node cancer in

adults.

Individuals with inflammatory polyarthritis were 2.4 times more

likely to have lymphoma than the general population.

The incidence was higher in patients with rheumatoid arthritis and

those who reported taking disease modifying anti-rheumatic drugs. The

highest risk was seen in patients treated with methotrexate.

These data, the researchers point out, " stress the need for an

appropriate control cohort for comparison of the long term adverse of

novel drugs for rheumatic diseases. "

SOURCE: ls of Rheumatic Disease, May 2006.