Malignant diseases in childhood and adolescence
Overall, cancer in a person younger than 20 years is rare in Europe. It accounts for only 1 % of all childhood diseases. Nevertheless, cancer ist one of the most frequent mortal diseases in childhood and adolescence. According to statistical data provided by the German Childhood Cancer Registry, about 1.800 young patients under 15 years of age are newly affected each year. Leukaemias are the most frequent malignant diseases in children and adolescents (32 %), followed by tumours of the central nervous system (brain tumours, 25 %), which also represent the most frequent solid tumours in childhood. Lymphomas account for about 11 % of all cancers, followed by neuroblastoma (about 7 %) and nephroblastoma, also known as Wilms tumour (5 %).
Children are not "little adults". Therefore, cancer in the young differs from cancer in adults regarding incidence, types, biology and causes. While exposure to certain dietary, lifestyle and environmental factors appear to play a major role in the development of cancers in adults, only a few risk factors, such as ionising radiation and a mother's exposure to X-rays during pregnancy, have been identified for the paediatric population, and these account for only a small proportion of patients. Many childhood cancers are more successfully treated than cancers in adults. This is partly related to the fact that in general, children tolerate treatment better than adults. It may also be explained by the types of cells involved, since the relatively faster growth of cancer in children makes them more sensitive to most forms of treatment.
The different cancer types differ a lot between age groups: While carcinomas are rare in the paediatric population (1 % of all cancers), they account more than 90 % of malignancies in adults.
