USC Health Now

Q. I’ve heard that some medications for rheumatoid arthritis (RA) cause lymphoma. Is this true?

A. “Clinicians have known for a long time that patients with autoimmune diseases such as RA may have a five to 20 percent increased risk of developing blood cancer,” says Ann Mohrbacher, M.D., associate professor of clinical hematology at the Keck School of Medicine of USC and USC/Norris hematologist. “However, it’s difficult to know if the disease itself causes the increased risk or if it is the medications.” Mohrbacher explains that with autoimmune diseases like rheumatoid arthritis, the body attacks its own cells. Coupled with potent prescription drugs, the immune system is more vulnerable to abnormal cells, such as cancer. “Side effects for these types of drugs for advanced diseases are common,” notes Mohrbacher. If you are being treated for RA, follow through with routine screenings and check-ups, advises Mohrbacher. If you are suddenly suffering from night sweats, enlarged lymph nodes or unexplained weight loss when being treated for RA, let your physician know immediately. “It’s important to keep in mind that only a small percentage of patients with RA get lymphoma—less than one percent,” says Mohrbacher.