Registration quality and descriptive epidemiology of childhood brain tumours in Scotland 1975-90

Abstract

S_nary Children (0-14 years) with malignant brain and central nervous system (CNS) tumours (ICD9 191 and 192) were listed from the Scottish Cancer Registration Scheme for the years 1975-90. These cases formed the basis for validation and verification procedures aimed at providing a complete and accurate data set for epidemiological analyses. A variety of data sources were cross-checked to optimise ascertainment, and resulting from this 5.7% of validated cases were found on the cancer registry with diagnostic codes outside the ICD-9 range [191][192]. A further 8.4% were newly registered cases. Analyses were conducted on the validated data set showing a significant temporal increase in incidence rates over the 16 year study period with an average annual percentage change of + 2.6%. Large-scale geographical heterogeneity was also found, with a particularly high incidence in the Fife and Lothian areas and a low incidence in Grampian. Examination of associations with socioeconomic status, using the Carstairs deprivation index, revealed a rising trend in incidence strongly linked to areas with increasing levels of affluence. Our results suggest that for studies of childhood CNS tumours validation of cancer registry data is necessary and large-scale geographical variation and socioeconomic factors should be taken into account in any investigation of distribution in small geographical areas.Recent technological advances in a range of diagnostic techniques have made the identification of tumours in the brain and central nervous system potentially more complete and accurate. However, temporal trends in the incidence of brain tumours are sparsely documented for children and young people, and international variation shows inconsistent trends (Davis et al., 1990, Mao et al., 1991. Suggested increases in incidence must be interpreted in relation to the impact of improved diagnostic techniques on the ascertainment of cases.As a preliminary to a geographical study investigating the incidence of childhood cancer near nuclear facilities in Scotland, a validation exercise was initiated to provide an optimal data set in terms of completeness and accuracy. This involved cross-checking of alternative sources of ascertainment, validation of diagnosis and verification of case details. As part of this exercise the incidence and pathology of central nervous system (CNS) tumours in children in Scotland between 1975 and have been reviewed.The main source of data for the study was the Scottish National Cancer Registration Scheme (SMR6). The two aims of this paper are to assess the completeness and accuracy of the original cancer registration data for childhood CNS tumours and, for the validated data set, to describe the incidence and broad geographical distribution in Scotland. For each cancer registration and potential new case a form was created showing initial diagnosis and case details and was passed to the collaborating pathologist (J.W.I.). The form was structured in order to permit the pathologists to indicate whether or not a par...

Increasing incidence of childhood tumours of the central nervous system in Denmark, 1980–1996

“…Overall, these findings agree with those of most previous studies (Blair and Birch, 1994;McKinney et al, 1994;Bunin et al, 1996;Gurney et al, 1996;Hjalmars et al, 1999;McNally et al, 2001;Dreifaldt et al, 2004), although differences have been found. Thus, a British study showed a stable rate of ependymomas (McNally et al, 2001), one study in the USA showed a stable rate of primitive neuroectodermal tumours (Gurney et al, 1996) and another study in the USA, spanning 21 years, showed that increases in the incidence rates of various morphological subgroups depends on the period studied .…”

“…Cases were identified from a nationwide, clinical CNS tumour database and two independent population-based registers, both of which benefit from mandatory registration, resulting in virtually complete case ascertainment. In addition, use of medical records, including reports on pathology and neuroimaging, ensured better validity of the diagnoses than cancer registry data alone (McKinney et al, 1994;Thorsteinsson et al, 2005). Furthermore, the same persons coded all the tumours according to the ICD-O to ensure consistent coding practice.…”

“…Increasing incidence rates of central nervous system (CNS) tumours in children have been reported for several populations in countries where incident cancer cases are registered routinely, that is, in Australia, Italy, Sweden, the United Kingdom and the USA (Mosso et al, 1992;McKinney et al, 1994;Giles et al, 1995;Bunin et al, 1996;Gurney et al, 1996;Hjalmars et al, 1999;McNally et al, 2001;Dreifaldt et al, 2004). It is uncertain whether these increases are owing to improved diagnostic methods, changes in cancer registration procedures or changes in tumour classification practices, or whether the increases are biologically real and owing to changes in environmental or lifestyle factors (Black, 1998;Smith et al, 1998;Forman, 1999;Schechter, 1999;Varner, 1999).…”

“…In contrast, the increase in the incidence rate of childhood CNS tumours in the United Kingdom occurred mostly before the introduction of MRI (McKinney et al, 1994;McNally et al, 2001). In the USA, the increase in childhood CNS tumour incidence rate occurred within a few years during the mid-1980s, when MRI became widespread (Steinberg, 1986;Smith et al, 1998), and was preceded and followed by relatively stable rates (Gurney et al, 1996;Smith et al, 1998); at the same time, a slight but steady decrease in specific mortality from CNS tumours in childhood was registered .…”

Epidemiology of childhood brain tumours in Yorkshire, UK, 1974-95: geographical distribution and changing patterns of occurrence

“…The oxerall incidence of CNS tumours in York-shire (28.0 per million) is similar to that previouslI reported for Britain (27.0) and Scotland (29.0) (McKinnev et al 1994 (Miltenburg et al 1996) and 36 and 31 for boys and girls respectixely in the USA (Dexesa et al 1995).…”