What's new in pediatric oncology? Epidemiology, treatment principles and prognosis in childhood malignancies.

The proportion of malignancies in children differs from that in adults: Leukemias and malignant lymphomas predominate with a total of 50%, followed by tumors of the nervous system, of the kidneys, and of connective and supportive tissue. Most of these diseases respond well to cytostatic therapy. Therefore chemotherapy occupies a major role in the curative concepts for nearly all childhood malignancies. Its objective is the destruction of micrometastases as well as the reduction of primary tumor mass in inoperable cases, and it often helps to limit the extent of radical surgery. Radiotherapy, too, can be reduced under the influence of cytostatic therapy. In nearly all childhood cancers, prognosis has improved substantially over the past 10 to 15 years. Today, our aim is not the mere limited survival, but a definitive cure. Modern strategies have raised the cure rates of Hodgkin's disease to 90%, of Wilms' tumor, acute lymphoblastic leukemia and non- Hodgkin lymphomas to 70-75%, of soft tissue sarcomas and osteosarcomas to about 50%, and of acute myelogenous leukemia, neuroblastoma and medulloblastoma to 30-35%. Centralized management of childhood cancers in specially staffed hospitals is mandatory on account of their relative low frequency, the risks of chemotherapy, and the high staff workload.