Cancer in children and adolescents in Europe: developments over 20 years and future challenges.

This special issue contains 18 articles describing population-based analyses of incidence and survival for cancer among children and adolescents in Europe over the period 1978-1997. The analyses were derived from the large database of the ACCIS project (Automated Childhood Cancer Information System), which was built through collaboration of 62 population-based cancer registries in 19 European countries. Data on 88,465 cancers in children and 15,369 in adolescents (age 15-19 yrs) were included in the various analyses, making this the largest database on cancer in these age-groups in the world. National data were grouped into five European regions to allow comparisons of incidence and survival, for all cancers and by tumour type, including analysis of trends in both over time. This overview paper focuses on the comparability of the data from multiple registries and describes the potential confounding factors. Age-standardised annual incidence rates of many, but not all, cancers in children and adolescents are clearly rising. There are geographical differences in survival for the majority of tumour types. Survival rates increased for nearly all types of cancer in children and adolescents. The implications of these findings for aetiological factors and treatment delivery for cancer in children and adolescents are discussed.