Epidemiologic studies in a population-based childhood cancer registry in Northeast Hungary

Abstract

Reports on the patterns of childhood cancer incidence are rare in Eastern Europe. To compare incidence rates and trends with international data, we processed records of the regional childhood cancer registry of Northeast Hungary. Our computerized database contains population-based information on childhood cancer cases (<15 years) diagnosed in residents of two counties of Hungary: leukaemias from 1973, non-CNS solid tumours from 1978, and CNS tumours from 1984. After a retrospective evaluation of completeness of ascertainment, descriptive epidemiologic analyses were performed for the years of operation of the registry. Age-standardized annual incidence rates and age-specific incidences were calculated. Trends were evaluated in linear regression analysis. The distribution of major histologic groups was similar to those observed in the Western countries with the exception that central nervous system tumours account for a higher percentage (27.3%). Average age-standardized annual incidence rates were as follows: all types of cancer: 120.7 per million; leukaemia: 37.3; CNS tumours: 31.6; lymphomas: 12.2; sympathetic nervous system tumours: 12.5; kidney tumours: 8.8. Significant increases were observed in incidence of leukaemia (average annual percent change AAPC: 0.7%), acute lymphoblastic leukaemia (AAPC: 1.9%), and all cancer groups (AAPC: 2.6%), but not in acute non-lymphocytic leukaemia or in CNS tumours. The strongest increases in cancer incidence were detected in the age group of 10-14 years (AAPC: 4.4%) and in infants (AAPC: 12.9%). Incidences and trends are in accordance with the data in the latest literature, however, the contribution of CNS tumours and the rate of increase in total cancer incidence proved to be higher. Further detailed genetic and environmental studies of cancer registries may shed light on the etiology of the observed differences whether they represent a pattern specific for this region.