Cyclophosphamide treatment of rheumatoid arthritis (RA) is associated with an increased risk of hematologic malignancy, according to a report from Canada in the February 25th issue of the Archives of Internal Medicine.
"Some drugs (specifically, cyclophosphamide) do play a role in some of the hematologic malignancies that arise in autoimmune diseases like RA and lupus," Dr. Sasha Bernatsky told Reuters Health. "However, some drugs, like methotrexate, don't seem to be associated with a great risk of these cancers."
Dr. Bernatsky from McGill University Health Centre in Montreal, Quebec, and colleagues assessed the risk in RA of hematologic malignancy associated with exposure to disease-modifying antirheumatic drugs (DMARDs). They used database information on 23,810 patients with rheumatoid arthritis treated with DMARDS from 1980 through 2003. During that time, 619 patients developed hematologic malignancies.
After adjustments for other DMARD use and other factors, only cyclophosphamide was associated with a significantly increased risk for hematologic malignancy, with a relative risk of 1.84, the authors report.
Methotrexate, azathioprine, antimalarial agents, and anti-TNF agents were not associated with a significantly increased risk in the adjusted analysis, the researchers note.
Lymphoma, leukemia, and multiple myeloma were the most frequently noted specific types of hematologic malignancies.
"Obviously, a drug like cyclophosphamide, with severe potential adverse effects, should be used only when necessary," Dr. Bernatsky said. "However, at the present time cyclophosphamide remains an important option for very severe autoimmune disease manifestations (e.g., severe vasculitis or lupus nephritis)."
Arch Intern Med 2008;168:378-381.
Good Lord thats a stupid study!