The agency said the drugs -- Enbrel, Humira and Remicade -- are being reviewed for a possible association with development of lymphoma and other cancers in children and young adults treated for juvenile idiopathic arthritis and Crohn's disease.

The drugs suppress the immune system by blocking the activity of TNF, a substance in the body that can cause inflammation and lead to immune system-related diseases.

The FDA said it has asked the makers of the TNF blockers to supply information about all cases of cancer reported in children and young adults taking TNF blockers.

While the review is ongoing, FDA advises doctors to weigh the possible association with lymphoma and other cancers against the benefits of treatment when prescribing TNF blockers to children and young adults.

Enbrel is manufactured by Amgen and Wyeth Pharmaceuticals, Humira is produced by Abbott Laboratories (NYSE:ABT) and Remicade is manufactured by Centocor Inc.