(RxWiki News) Fear that the treatment for one condition might cause another condition, like cancer, could prevent people from taking needed medications. But should this be a concern for lupus patients?
A recent study has found that medications taken for lupus do not appear to increase a person's risk of blood cancer. Lupus is a disease that causes the body's immune system to attack healthy tissues, like joints, kidneys and the brain.
Medications for lupus are called immunosuppressants. They reduce the immune response in a person so that the body doesn't attack itself.
This study showed there is no evidence of a higher risk of blood cancer among those taking immunosuppressant medications.
"Follow your rheumatologist's recommendations."
The study, led by Sasha Bernatsky, MD, PhD, of the Division of Clinical Epidemiology, Research at the Institute of the McGill University Health Centre in Canada, looked at the risk of a certain blood cancer in those with lupus.
The researchers identified 75 patients with lupus who also had lymphoma, (mostly non-Hodgkin's lymphoma, except three patients), and 4,961 lupus patients without lymphoma.
Lymphoma is a blood cancer resulting from an uncontrollable growth of lymphocytes, a type of blood cell that fights infections. Most (54 cases) of the lymphomas of patients in this study came from the B-cell line. The other came from T-cells or were not identified.
The risk of lymphoma was higher in men with lupus than in women with lupus. This pattern of a higher risk for males is also seen in the general population.
In those with cancer, patients developed lymphoma an average of 12.4 years after being diagnosed with lupus.
Among those with lymphoma, 56 percent (42 individuals) had never taken any immunosuppressants for their lupus. Among the lupus patients without lymphoma, 48 percent had never taken immunosuppressants.
The only immunosuppressive drug that was taken by a higher percentage of lymphoma patients than non-cancer patients was cyclophosphamide. While 15 of the 75 lymphoma patients (20 percent) had been exposed to cyclophosphamide, only 16.8 percent of the non-cancer lupus patients had taken this medication.
However, statistically, this percentage difference could have been due to chance.
In addition to treating lupus, cyclophosphamide can also be used to treat Hodgkin's lymphoma and several other conditions.
After making adjustments for different patient demographics and characteristics, the researchers found the risk for lymphoma among lupus patients who had taken cyclophosphamide was still very low. In one year, only one in 1,000 lupus patients who had taken cyclophosphamide might develop lymphoma.
The researchers also did not find any link between the symptoms or progression of lupus with a risk of developing lymphoma.
"Our findings do not clearly substantiate that medication exposures drive most of the lymphoma risk in [lupus]," the researchers wrote.
"In fact, many of the lymphoma cases were not exposed to any immunosuppressant medications before the onset of the malignancy. In addition, we found no clear relationship between SLE [systemic lupus erythematosus] disease activity and lymphoma risk."
The study was published January 8 in the journal Annals of the Rheumatic Diseases. The research was funded by the National Institutes of Health and the Canadian Institutes of Health Research. The authors declared no conflicts of interest.