Biological therapy for pediatric malignancy: current perspectives.

Biologicals are defined as agents that are either uniquely or partially tumor-specific. Great expectations were raised by the success in agents that target a specific genetic translocation: all-trans retinoic acid, targeting the chronic myeloid leukemia retinoic acid receptor in acute promyelocytic leukemia and imatinib, a small molecule targeting the BCR-ABL translocation in chronic myeloid leukemia (CML). Thus far, the search for similar "druggable" genetic targets in pediatric cancers has not yet resulted in such dramatic results. The rarity of pediatric cancer as well as ethical considerations necessitate that the agents for testing be carefully and rigorously selected. Biologicals present an additional challenge, as they often do not lend themselves to in vitro testing. Early approaches to specific targeting of solid tumors utilized monoclonal antibodies. The microenvironment provides an interesting new biological approach to treating tumors and alteration of the host immune response provides another avenue. Biological agents are a step forward in supportive care to reduce the hematological toxicity of high-dose chemotherapy and to manage the frequent infectious complications.

Recent advances in management of acute myeloid leukemia (AML).

Acute myeloid leukemia (AML) is the most common childhood malignancy. AML has therapeutically been difficult to treat. In 2001, the World Health Organization (WHO), in conjunction with the Society for Hematopathology and the European Association of Hematopathology, published a new classification for myeloid neoplasms. A number of chromosomal abnormalities are used to predict outcome and stratify therapeutic risk groups in children with AML. Recently, alterations in receptor tyrosine kinases, tyrosine phosphatases and in oncogenes such as RAS have been implicated in the pathogenesis of AML. This article aims to review the recent development in diagnosis, treatment and monitoring of AML. Better understanding of the molecular pathogenesis of AML has led to the development of target-specific therapies. Some of the new classes of drugs include monoclonal antibody directed against the CD33 antigen, farnesyltransferase inhibitors (FTI), and FMSlike tyrosine kinase 3 (FLT3) inhibitors. The role of allogenic SCT, particularly whether it should be done during first CR or reserved for second remission, remains the most controversial issue in pediatric AML. There is a need of collaboration with international pediatric cooperative oncology groups and definitive clinical trials in order to establish use of these newer molecules in pediatric populations.