The Food and Drug Administration has asked manufacturers of tumor necrosis factor blockers to enhance their follow-up of pediatric and young adult patients who develop malignancies while on these treatments.The agency also is advising health care professionals to "remain vigilant" for malignancies in these patients, according to a statement issued by the FDA Nov. 4.Manufacturers of TNF blockers have been asked by the FDA to report cases of malignancies in children, adolescents, and adults aged 30...