The Food and Drug Administration (FDA) is reviewing the safety of TNF blockers, drugs used to treat autoimmune diseases such as Crohn's, to determine if they are associated with an increased risk of cancer in children and young adults.

What are TNF blockers?

TNF, or tumor necrosis factor, is a naturally occurring protein in the body and may play a role in inflammatory diseases, such as Crohn's and Juvenile Rheumatoid Arthritis. TNF blockers are a relatively new class of drug produced from natural, living sources, such as proteins, cells or tissues. They suppress the immune system by targeting the proteins that trigger inflammation during an immune response.

There are four TNF blockers currently used for treating inflammatory diseases: Remicade, Enbrel, Humira and Cimzia. In both subjective and objective measurements, TNF blockers clearly help manage symptoms and suppress disease progression.

Why the safety review?

Between 1998 and April 2008, physicians reported 30 cases of cancer in children and young adults who took TNF blockers while under the age of 18. The children simultaneously all received other immune-suppressing medication, which have known cancer risk factors.

Concerns about the link between TNF blockers and cancer risk are not new. In an earlier study by the Mayo Clinic, researchers found that patients taking high doses of Humera or Remicade had three times the risk of developing skin, gastrointestinal, breast and lung cancers and lymphoma. These medications carry warnings that using them may increase your risk of cancer.

The FDA has requested additional studies to shed more light on this possible link. Studies of drugs already approved and in use are standard and provide a way to collect long-term safety and effectiveness information. Because cancers, for example, can take a long time to develop, researchers may not detect all risks in the studies they conduct before submitting drugs to the FDA to approve.

Should you be concerned?

Currently, researchers and the FDA believe the benefits of TNF blockers in treating Inflammatory Bowel Diseases outweigh the risks. They don't believe many physicians will change the way they prescribe TNF Blockers, although it's certainly something they should keep in mind when evaluating treatment options, especially with children.

If you have a child with Crohn's disease and are concerned about the possible link between TNF blockers and an increased risk of developing cancer, discuss this treatment option with your child's physician.