FAQ

Azathioprine and Mercaptopurine

DOES TAKING THIOPURINES INCREASE THE RISK OF CANCER?

People with IBD treated with thiopurines are at increased risk of cancer due to the drugs making the body’s tissues more susceptible and reducing the number of immune cells available to fight cancer. Studies suggest the overall risk of cancer for people taking thiopurines is increased, with the greatest risks for nonmelanoma skin cancers (which are generally not life-threatening) and lymphoma (a type of cancer affecting the lymph glands).

The skin cancer risk may persist after treatment has stopped so you will always need to use sun protection. However the risk of lymphoma appears to diminish once treatment is stopped. When weighing up these risks of cancer you should bear in mind that research shows no overall increase in mortality among people with IBD exposed to thiopurines.

References