No Cancer Risk from Arthritis Drugs?
Study Fails to Find Increased Risk From Newer Type Rheumatoid Arthritis Drugs
Aug. 31, 2006 -- Concerns that the newer rheumatoid arthritis drugs used to treat the sickest patients increase cancer risk aren't supported, according to a new study.
The findings should reassure patients who take Enbrel, Remicade, or Humira. All of these drugs are so-called biologics -- meaning they are derived from living organisms. They are known as necrosis factor (TNF)-blocking biologics.
"If there is a [cancer] risk, this study supports the conclusion that it is a small one," says researcher Soko Setoguchi, MD, DrPh, of Harvard Medical School's Brigham and Women's Hospital.
Lymphoma Risk Well Known
Rheumatoid arthritisarthritis patients do have a higher than normal risk for developing certain cancers, especially cancers known as lymphomas.
But it has been unclear if this elevated risk is due to the disease itself, or to the drugs used to treat it.
Studies examining the highly effective TNF-blocking drugs have been mixed. A widely-reported analysis by researchers from the Mayo Clinic published late last spring found a threefold increase in cancer risk among patients who took Remicade and Humira. That analysis didn't look at Enbrel.
The Mayo Clinic research weighed data from nine studies that compared biologic treatments to placebo.
In the newly published study, Setoguchi and colleagues compared the biologic drugs to the traditional rheumatoid arthritis drug, methotrexate.
Drugs like methotrexate are known as disease-modifying antirheumatic drugs. They slow down rheumatoid arthritis and improve quality of life for most people.
In the Harvard study, 1,152 patients took a TNF-blocking biologic, while 7,306 took methotrexate.
The patients were all 65 or older. They were identified through insurance databases in New Jersey, Pennsylvania, and British Columbia, Canada.
Even though the biologic users tended to have more severe rheumatoid arthritis than those who took methotrexate, the researchers found no significant difference in cancer risk between the two groups.
The biologic users were followed for an average of 2.6 years, compared to 4.2 years for patients taking methotrexate. Setoguchi tells WebMD the researchers will continue to follow study subjects.
"We will need longer follow-up with a larger number of patients to provide precise answers," she says. "Until then, this issue [cancer risk] should be part of the decision-making process for patients who consider taking these drugs."