No Clear Link Found Between Lupus Treatments and Lymphoma Risk

By Dr. Sasha Bernatsky

Dr. Sasha Bernatsky

Lymphoma risk in people with lupus has been a topic of considerable interest – both among people with lupus and in the lupus research community—because of concerns about the potential increased risk from immunosuppressive treatments. Researchers like me have been working to understand this potential link.

For our most recent study, Dr. Ann Clarke of McGill University, Dr. Rosalind Ramsey-Goldman of Northwestern University, and I have been working with lupus investigators all over the world (endorsed by the Systemic Lupus International Collaborating Clinics, SLICC, and the Canadian Network for Improved Outcomes in SLE, CaNIOS). We set out to explore independent or unique contributions of treatments versus disease activity as risk factors for lymphoma.

In the study, published in the January issue of the Annals of Rheumatic Diseases, we found no clear indication that the occurrence of lymphoma is mostly driven by drug treatments for lupus. Also no clear association was observed between disease activity and lymphoma risk.

Treatments we studied included cyclophosphamide, azathioprine, methotrexate, mycophenolate, anti-malarial drugs (e.g. Plaquenil), and steroids (e.g. prednisone).

Lymphomas are cancers of the immune system, the body's disease-fighting center that includes the lymph nodes, spleen, thymus gland, and bone marrow. Our study included nearly 5,000 cancer-free lupus patients, comparing these to 75 lupus patients with lymphoma. The lymphoma cases occurred an average of 12 years after the lupus diagnosis.

Most of the lymphomas observed in lupus patients were of the non-Hodgkin’s type, and most cases involved B cells- a category of white blood cells that are a vital part of the body’s immune system and which make antibodies to fight bacteria and viruses.

It’s interesting to note another welcome finding of a different study by my team—a finding we are now investigating further: patients with lupus have a decreased risk of breast cancer.

Sasha Bernatsky, MD, FRCPC, PhD, is an Assistant Professor in the Department of Medicine at McGill University in Montreal, Canada. Her study, “Lymphoma risk in systemic lupus: effects of disease activity versus treatment,” appeared in the January issue of the Annals of the Rheumatic Diseases.