A Swedish study of 756 rheumatoid arthritis (RA) patients may have found the key to unlock the mystery of why RA patients face 2 times the normal risk of contracting lymphoma. They believe the connection between the 2 diseases lies in the chronic swelling caused by the arthritis. Their study showed that RA patients with moderate swelling were 8 times more likely to develop lymphoma, compared with RA patients with lesser amounts of swelling. Patients with the most severe and prolonged incidents of swelling had a 70-times greater risk of contracting the cancer. Researchers also found that RA patients with pronounced, irreversible joint damage in the hands, feet, and knees were at a greater risk of developing lymphoma.
The researchers found no increase in cancer risk from the use of medications for the treatment of RA?from aspirin to methotrexate. In fact, the risk of lymphoma was significantly lower in RA patients who had received frequent corticosteroid injections in inflamed joints, which indicated a possible lymphoma- protective role of potent antiinflammatory drugs. Researchers agree that a key to preventing the cancer in RA patients is to aggressively treat the swelling associated with the disease.