DEAR DR. ROACH: I’m 72 years old, and I have been prescribed azathioprine for rheumatoid arthritis (RA). I have only mild discomfort in my hands and wrist, which came on suddenly. While researching this medicine, I saw that the extended use of it increases the risk of lymphoma. My brother has been treated for lymphoma for 12 years, and my sister has leukopenia.
When questioned about this, my rheumatologist said that this history in my family doesn’t necessarily increase my odds of getting lymphoma. My doctor also said that once I start the medication for RA, I would have to stay on it forever. What is your opinion of this medication and of my taking it with only mild symptoms of RA at this point, especially if I am at an increased risk of developing this cancer or any other illness as a result of this medicine? — R.C.S. ANSWER: Having a family member with lymphoma does increase your risk of getting lymphoma, which is an uncommon condition. About 2% of the population will develop lymphoma in their lifetime, with the percentage raising to 3.6% in people who have a first-degree relative with the condition; a same-sex sibling is particularly at risk.
Azathioprine does reduce the activity of the immune system, which is good for treating autoimmune diseases like RA. However, immune-suppressing drugs do put people at risk for infections and cancers. A physician must always balance the benefits of treating a serious disease like RA against the risk of serious infections and cancers.
RA can be much worse than mild hand and wrist discomfort; it’s a multisystem disease that can affect the heart and lungs. I have seen joints destroyed by RA in the days before effective therapy was available. In the case of lymphoma, azathioprine does increase the risk. However, the increase in risk is small — approximately 1 additional case of lymphoma among 100 people in 10 years.
The familial risk is separate from the risk of azathioprine, so maybe this is what your rheumatologist meant. Both your family history and the azathioprine increase your risk of lymphoma, but family history does not make the azathioprine risk worse than it would be without your family history.
