Childhood malignancies in the EUROCARE study: the database and the methodsof survival analysis

This paper describes the database of children with cancer in the EUROCARE s tudy and the methodology used to analyse and report survival. This is the f irst systematic evaluation of survival after childhood cancer on a large sc ale in Europe: approximately 45 000 cases were included, diagnosed between 1978 and 1992 (34 814 cases diagnosed in 1975-1389 and an additional set of 9495 cases diagnosed in 1990-1992) and followed-up until 1995. Data were p rovided from 34 population-based registries (four specialised for childhood cancer registrations and one specialised registry for childhood leukaemia) in 17 countries of Europe (where there was national coverage in 10 countri es). Quality of the data was fairly good, given the general differences amo ng the countries and their health systems, thereby allowing for comparisons between them. Among cases diagnosed in 1978-1989, overall 2.0% were lost t o follow-up, 91.8% were microscopically diagnosed and 93.4% of alive cases had at least 5 years of observation. Survival proportions (observed surviva l) were calculated for each of the countries involved, by age group (0: 1-4 , 5-9, 10-14 years), gender, different time periods and selected diagnostic groups. Age-standardised cumulative survival rates and European averages ( weighted and pooled) were also computed. Cox regression models were used to evaluate geographical and temporal differences. The EUROCARE database repr esents a unique source of information on survival of childhood cancer patie nts in Europe, intercountry differences and time trends in survival. (C) 20 01 Elsevier Science Ltd. All rights reserved.