WASHINGTON – Federal regulators are investigating whether a group of arthritis drugs made by Abbott Laboratories, Schering-Plough Corp. and other companies heighten the risk of cancer in youngsters.

The Food and Drug Administration said Wednesday it has received 30 reports of children and young adults developing cancer while taking the drugs over the last 10 years.

The drugs include Abbott Labs' Humira, Schering-Plough's Remicade, and Enbrel, which is marketed by Amgen Inc. and Wyeth. They are prescribed to children with arthritis to block a chemical that causes inflammation. The drugs also are used to treat children with the intestinal disorder Crohn's disease.

Calls placed to the companies were not immediately returned Wednesday morning.

FDA said the drugs' labeling already warns of a potential association with cancer, but the agency's investigation will focus on risks to younger patients.

The agency has asked drug makers to provide all information about children who developed cancer while taking the medications. Regulators will report the findings of their review by November.