Epidemiology and prognosis in children treated for intracranial tumours in Denmark 1960-1984

Abstract

A total of 911 Danish children under 15 years of age were treated for an intracranial tumour in the 25-five year period 1960-1984. All cases were followed up to the end of 1994 or to emigration or death if one of these came sooner. The mean annual incidence was 32.5 per million children with a slight increase over the 25 years. The male/female ratio was 1.15 and close to the M/F ratio for the entire Danish population of children. Of the tumours, 46% were located in the supratentorial and 54% in the infratentorial compartment, and 94% were verified histologically. In order of frequency the most common types were astrocytomas (all grades, 35%), medulloblastomas (20%), ependymomas (14%), and craniopharyngiomas (5%). Total removal of the tumour was performed in 277 and partial removal, including biopsy, in 490 children. In 57 patients a shunt operation only was performed, and 87 children did not have an operation or died before the correct diagnosis was established. Radiotherapy was administered in 55%. The outcome depended on extent of removal, radiation, location and histology of the tumour. Most (784 or 86%) of the children survived more than 1 month after diagnosis or operation, and 353 children (39% of the whole series, 47% of those alive more than 1 month after diagnosis) were alive at follow-up. Of the survivors 29% had a tumour in the supratentorial midline, 26% one in the lateral part of the supratentorial area, 31% a cerebellar tumour and 13% a IV ventricle tumour. It was possible for 66% of the survivors with supratentorial and 90% of those with infratentorial tumours to lead a normal life. The long-term prognosis was especially good for children with cerebellar and supratentorial astrocytomas and optic chiasma tumours. Children with juvenile cerebellar astrocytoma had the best prognosis: 90% were alive at the end of the follow-up period, as against 20% of those with medulloblastoma and 6% of those with glioblastoma. A comparison of the data from the present series and from a similar Danish series of intracranial tumours in 533 children seen in the years 1935-1959 shows no significant differences in location or histology, a slight increase in annual incidence, and improved survival rates during the 50 years in question.

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

“…Accordingly, one Swedish study (Dreifaldt et al, 2004) also found a greater increase in the incidence rate of benign CNS tumours than of other types of CNS tumours, whereas another Swedish study (Hjalmars et al, 1999) found that the incidence rate increased to a greater extent for grade 3 -4 than for grade 1 -2 astrocytomas. We found the most pronounced increase in the annual incidence rate of slowly growing pilocytic astrocytomas, which have a good prognosis (Gjerris et al, 1998;Fernandez et al, 2003); however, the time between the onset of symptoms and diagnosis of pilocytic astrocytoma remained stable throughout the study, suggesting that earlier detection played only a minor role, if any. Furthermore, the second highest increase in annual incidence rate was for aggressive primitive neuroectodermal tumours, which have a poor prognosis (Lannering et al, 1990;Gjerris et al, 1998;Alston et al, 2003;Viscomi et al, 2003), with only a modest decrease in time between the onset of symptoms and diagnosis during the study period.…”

“…We found the most pronounced increase in the annual incidence rate of slowly growing pilocytic astrocytomas, which have a good prognosis (Gjerris et al, 1998;Fernandez et al, 2003); however, the time between the onset of symptoms and diagnosis of pilocytic astrocytoma remained stable throughout the study, suggesting that earlier detection played only a minor role, if any. Furthermore, the second highest increase in annual incidence rate was for aggressive primitive neuroectodermal tumours, which have a poor prognosis (Lannering et al, 1990;Gjerris et al, 1998;Alston et al, 2003;Viscomi et al, 2003), with only a modest decrease in time between the onset of symptoms and diagnosis during the study period. Finally, the incidences of tumours in all the major morphological subgroups increased, as did that of tumours that were not histologically verified, although they continued to constitute a minor proportion of CNS tumours.…”

“…As suggested by the International Agency for Research of Cancer in 1996, the group of medulloblastomas was expanded to include 'other primitive neuroectodermal tumours' (Kramarova and Stiller, 1996). Tumours that potentially complied with our inclusion criteria were identified in the population-based Danish Cancer Registry (Storm et al, 1997), the population-based Danish Hospital Discharge Registry (Andersen et al, 1999) and a clinical database (Gjerris et al, 1998), established by a collaboration between the major neurosurgical, pathological, paediatric and radiological hospital departments in Denmark and updated through the 1990s. We used wider criteria than those of Birch and Marsden (1987), when we identified potential CNS tumours from the Danish Hospital Discharge Registry and the clinical database, which minimised the risk for overlooking relevant tumours.…”

Primary pediatric brain tumors

“…In the recently reported series of primary pediatric brain tumors in children, supratentorial tumors predominated over infratentorial tumors. 14,16,17 By using chi-square test, statistical comparison of relative incidence of tumors in these series was performed (data not shown). Except choroid plexus tumor and pineal parenchymal tumor, significant statistical difference (P Ͻ 0.05) of relative incidence existed in astrocytic tumor, medulloblastoma, germ cell tumor, craniopharyngioma, ependymoma, and oligodendroglioma.…”

Genetic abnormalities detected in ependymomas by comparative genomic hybridisation

“…They account for only 4 -8% of gliomas, but are the third most common central nervous system (CNS) tumour of childhood, after astrocytomas and medulloblastomas. About 90% of paediatric ependymomas are intracranial, but in adults most are intraspinal (Gilles et al, 1995;Hamilton and Pollack, 1997;Bouffet et al, 1998;Gjerris et al, 1998;Wiestler et al, 2000). The World Health Organisation (WHO) pathological classification (Wiestler et al, 2000) recognises classic (WHO grade 2), anaplastic (grade 3) and myxopapillary (grade 1) variants, plus the subependymoma (grade 1).…”