Childhood and Adolescent Central Nervous System Tumours in Spain: Incidence and Survival over 20 Years: A Historical Baseline for Current Assessment

BACKGROUND

Central nervous system (CNS) neoplasms are highly frequent solid tumours in children and adolescents. While some studies have shown a rise in their incidence in Europe, others have not. Survival remains limited. We addressed two questions about these tumours in Spain: (1) Is incidence increasing? and (2) Has survival improved?

METHODS

This population-based study included 1635 children and 328 adolescents from 11 population-based cancer registries with International Classification of Childhood Cancer Group III tumours, incident in 1983-2007. Age-specific and age-standardised (world population) incidence rates (ASRws) were calculated. Incidence time trends were characterised using annual percent change (APC) obtained with Joinpoint. Cases from 1991 to 2005 (1171) were included in Kaplan-Meier survival analyses, and the results were evaluated with log-rank and log-rank for trend tests. Children's survival was age-standardised using: (1) the age distribution of cases and the corresponding trends assessed with Joinpoint; and (2) European weights for comparison with Europe.

RESULTS

ASRw 1983-2007: children: 32.7 cases/106; adolescents: 23.5 cases/106. The overall incidence of all tumours increased across 1983-2007 in children and adolescents. Considering change points, the APCs were: (1) children: 1983-1993, 4.3%^ (1.1; 7.7); 1993-2007, -0.2% (-1.9; 1.6); (2) adolescents: 1983-2004: 2.9%^ (0.9; 4.9); 2004-2007: -7.7% (-40; 41.9). For malignant tumours, the trends were not significant. 5-year survival was 65% (1991-2005), with no significant trends (except for non-malignant tumours).

CONCLUSIONS

CNS tumour incidence in Spain was found to be similar to that in Europe. Rises in incidence may be mostly attributable to changes in the registration of non-malignant tumours. The overall malignant CNS tumour trend was compatible with reports for Southern Europe. Survival was lower than in Europe, without improvement over time. We provide a baseline for assessing current paediatric oncology achievements and incidence in respect of childhood and adolescent CNS tumours.

Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000-2014 (CONCORD-3)

BACKGROUND

Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.

METHODS

We analyzed individual data for adults (15-99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000-2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.

RESULTS

The study included 556,237 adults. In 2010-2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%-38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000-2004 and 2005-2009. These improvements were more noticeable among adults diagnosed aged 40-70 years than among younger adults.

CONCLUSIONS

To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines.

Neuroblastoma in Spain: Linking the national clinical database and epidemiological registries - A study by the Joint Action on Rare Cancers

PURPOSE

Linkage between clinical databases and population-based cancer registries may serve to evaluate European Reference Networks' (ERNs) activity, by monitoring the proportion of patients benefiting from these and their impact on survival at a population level. To test this, a study targeting neuroblastoma (Nb) was conducted in Spain by the European Joint Action on Rare Cancers.

MATERIAL AND METHODS

Subjects: Nb cases, incident 1999-2017, aged < 15 years. Linkage included: Spanish Neuroblastoma Clinical Database (NbCDB) (1217 cases); Spanish Registry of Childhood Tumours (RETI) (1514 cases); and 10 regional population-based registries (RPBCRs) which cover 33% of the childhood population (332 cases). Linkage was semiautomatic. We estimated completeness, incidence, contribution, deficit, and 5-year survival in the databases and specific subsets.

RESULTS

National completeness estimates for RETI and NbCDB were 91% and 72% respectively, using the Spanish RPBCRs on International Incidence of Childhood Cancer (https://iicc.iarc.fr/) as reference. RPBCRs' specific contribution was 1.6%. Linkage required manual crossover in 54% of the semiautomatic matches. Five-year survival was 74% (0-14 years) and 90% (0-18 months).

CONCLUSIONS

All three databases were incomplete as regards Spain as a whole and should therefore be combined to achieve full childhood cancer registration. A unique personal patient identifier could facilitate such linkage. Most children have access to Nb clinical trials. Consolidated interconnections between the national registry and clinical registries (including ERNs and paediatric oncology clinical groups) should be established to evaluate outcomes.

The histology of brain tumours for 67,331 children and 671,085 adults diagnosed in 60 countries during 2000-2014: a global, population-based study (CONCORD-3)

INTRODUCTION

Global variations in survival for brain tumours are very wide when all histological types are considered together. Appraisal of international differences should be informed by the distribution of histology, but little is known beyond Europe and North America.

PATIENTS AND METHODS

The source for the analysis was the CONCORD data base, a programme of global surveillance of cancer survival trends, which includes the tumour records of individual patients from more than 300 population-based cancer registries. We considered all patients aged 0-99 years who were diagnosed with a primary brain tumour during 2000-2014, whether malignant or non-malignant. We presented the histology distribution of these tumours, for patients diagnosed during 2000-2004, 2005-2009, and 2010-2014.

RESULTS

Records were submitted from 60 countries on five continents, 67,331 for children and 671,085 for adults. After exclusion of irrelevant morphology codes, the final study population comprised 60,783 children and 602,112 adults. Only 59 of 60 countries covered in CONCORD-3 were included, because none of the Mexican records were eligible. We defined 12 histology groups for children, and 11 histology groups for adults. In children (0-14 years), the proportion of low-grade astrocytomas ranged between 6% and 50%. Medulloblastoma was the most common sub-type in countries where low-grade astrocytoma was less commonly reported. In adults (15-99 years), the proportion of glioblastomas varied between 9% and 69%. International comparisons were made difficult by wide differences in the proportion of tumours with unspecified histology, which accounted for up to 52% of diagnoses in children and up to 65% in adults.

CONCLUSIONS

To our knowledge, this is the first account of the global histology distribution of brain tumours, in children and adults. Our findings provide insights into the practices and the quality of cancer registration worldwide.

Changing geographical patterns and trends in cancer incidence in children and adolescents in Europe, 1991-2010 (Automated Childhood Cancer Information System): a population-based study

BACKGROUND

A deceleration in the increase in cancer incidence in children and adolescents has been reported in several national and regional studies in Europe. Based on a large database representing 1·3 billion person-years over the period 1991-2010, we provide a consolidated report on cancer incidence trends at ages 0-19 years.

METHODS

We invited all population-based cancer registries operating in European countries to participate in this population-based registry study. We requested a listing of individual records of cancer cases, including sex, age, date of birth, date of cancer diagnosis, tumour sequence number, primary site, morphology, behaviour, and the most valid basis of diagnosis. We also requested population counts in each calendar year by sex and age for the registration area, from official national sources, and specific information about the covered area and registration practices. An eligible registry could become a contributor if it provided quality data for all complete calendar years in the period 1991-2010. Incidence rates and the average annual percentage change with 95% CIs were reported for all cancers and major diagnostic groups, by region and overall, separately for children (age 0-14 years) and adolescents (age 15-19 years). We examined and quantified the stability of the trends with joinpoint analyses.

FINDINGS

For the years 1991-2010, 53 registries in 19 countries contributed a total of 180 335 unique cases. We excluded 15 162 (8·4%) of 180 335 cases due to differing practices of registration, and considered the quality indicators for the 165 173 cases included to be satisfactory. The average annual age-standardised incidence was 137·5 (95% CI 136·7-138·3) per million person-years and incidence increased significantly by 0·54% (0·44-0·65) per year in children (age 0-14 years) with no change in trend. In adolescents, the combined European incidence was 176·2 (174·4-178·0) per million person-years based on all 35 138 eligible cases and increased significantly by 0·96% (0·73-1·19) per year, although recent changes in rates among adolescents suggest a deceleration in this increasing trend. We observed temporal variations in trends by age group, geographical region, and diagnostic group. The combined age-standardised incidence of leukaemia based on 48 458 cases in children was 46·9 (46·5-47·3) per million person-years and increased significantly by 0·66% (0·48-0·84) per year. The average overall incidence of leukaemia in adolescents was 23·6 (22·9-24·3) per million person-years, based on 4702 cases, and the average annual change was 0·93% (0·49-1·37). We also observed increasing incidence of lymphoma in adolescents (average annual change 1·04% [0·65-1·44], malignant CNS tumours in children (average annual change 0·49% [0·20-0·77]), and other tumours in both children (average annual change 0·56 [0·40-0·72]) and adolescents (average annual change 1·17 [0·82-1·53]).

INTERPRETATION

Improvements in the diagnosis and registration of cancers over time could partly explain the observed increase in incidence, although some changes in underlying putative risk factors cannot be excluded. Cancer incidence trends in this young population require continued monitoring at an international level.

FUNDING

Federal Ministry of Health of the Federal German Government, the European Union's Seventh Framework Programme, and International Agency for Research on Cancer.

Childhood and adolescent lymphoma in Spain: incidence and survival trends over 20 years

BACKGROUND

Lymphoma is the third most common malignancy in children (0-14 years) and the first in adolescents (15-19 years). This population-based study-the largest ever done in Spain-analyses incidence and survival of lymphomas among Spanish children and adolescents.

PATIENTS AND METHODS

1664 lymphoma cases (1983-2007) for incidence and 1030 for survival (1991-2005) followed until 31/12/2010, were provided by 11 cancer registries. Age-adjusted incidence rates (ASRw) to the world standard population were obtained; incidence trends were modelled using the Joinpoint programme, observed survival (OS) was estimated with Kaplan-Meier and trends tested with a log-rank test. Results are presented according to the International Classification of Childhood Cancer-3.

RESULTS

In Spain, the ASRw_0-14 for lymphomas was 17.5 per 1.000.000 child-years and 50.0 the specific rate for adolescents. Overall incidence increased significantly during 1983-1997 with no increases thereafter. Patients over 9 years old showed significant rising trends for all subtypes, except for Burkitt lymphoma (BL) in adolescents. During 2001-2005 (age 0-19 years), 5-year OS was 94 (90-98), 73 (64-83) and 86 (78-94) for Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL) and BL, respectively. No improvement in survival was found. The incidence in Spain was higher than overall European rates, but within the range of that in Southern Europe. Comparing OS in Spain 1991-1995 and 2001-2005 with results for Europe of the Automated Childhood Cancer Information System (ACCIS) (1988-1997) and the European cancer registry-based study on survival and care of cancer patients (EUROCARE) (2000-2007), it was similar for HL and lower for NHL and BL.

CONCLUSIONS

Systematic monitoring and analysis of lymphoma paediatric data would provide clinical and epidemiological information to improve the health care of these patients and the outcomes for these malignancies in Spain.

Worldwide comparison of survival from childhood leukaemia for 1995-2009, by subtype, age, and sex (CONCORD-2): a population-based study of individual data for 89 828 children from 198 registries in 53 countries

BACKGROUND

Global inequalities in access to health care are reflected in differences in cancer survival. The CONCORD programme was designed to assess worldwide differences and trends in population-based cancer survival. In this population-based study, we aimed to estimate survival inequalities globally for several subtypes of childhood leukaemia.

METHODS

Cancer registries participating in CONCORD were asked to submit tumour registrations for all children aged 0-14 years who were diagnosed with leukaemia between Jan 1, 1995, and Dec 31, 2009, and followed up until Dec 31, 2009. Haematological malignancies were defined by morphology codes in the International Classification of Diseases for Oncology, third revision. We excluded data from registries from which the data were judged to be less reliable, or included only lymphomas, and data from countries in which data for fewer than ten children were available for analysis. We also excluded records because of a missing date of birth, diagnosis, or last known vital status. We estimated 5-year net survival (ie, the probability of surviving at least 5 years after diagnosis, after controlling for deaths from other causes [background mortality]) for children by calendar period of diagnosis (1995-99, 2000-04, and 2005-09), sex, and age at diagnosis (<1, 1-4, 5-9, and 10-14 years, inclusive) using appropriate life tables. We estimated age-standardised net survival for international comparison of survival trends for precursor-cell acute lymphoblastic leukaemia (ALL) and acute myeloid leukaemia (AML).

FINDINGS

We analysed data from 89 828 children from 198 registries in 53 countries. During 1995-99, 5-year age-standardised net survival for all lymphoid leukaemias combined ranged from 10·6% (95% CI 3·1-18·2) in the Chinese registries to 86·8% (81·6-92·0) in Austria. International differences in 5-year survival for childhood leukaemia were still large as recently as 2005-09, when age-standardised survival for lymphoid leukaemias ranged from 52·4% (95% CI 42·8-61·9) in Cali, Colombia, to 91·6% (89·5-93·6) in the German registries, and for AML ranged from 33·3% (18·9-47·7) in Bulgaria to 78·2% (72·0-84·3) in German registries. Survival from precursor-cell ALL was very close to that of all lymphoid leukaemias combined, with similar variation. In most countries, survival from AML improved more than survival from ALL between 2000-04 and 2005-09. Survival for each type of leukaemia varied markedly with age: survival was highest for children aged 1-4 and 5-9 years, and lowest for infants (younger than 1 year). There was no systematic difference in survival between boys and girls.

INTERPRETATION

Global inequalities in survival from childhood leukaemia have narrowed with time but remain very wide for both ALL and AML. These results provide useful information for health policy makers on the effectiveness of health-care systems and for cancer policy makers to reduce inequalities in childhood cancer survival.

FUNDING

Canadian Partnership Against Cancer, Cancer Focus Northern Ireland, Cancer Institute New South Wales, Cancer Research UK, US Centers for Disease Control and Prevention, Swiss Re, Swiss Cancer Research foundation, Swiss Cancer League, and the University of Kentucky.

Incidence Patterns and Trends of non-Central Nervous System Solid Tumours in Children and Adolescents. A Collaborative Study of the Spanish Population Based Cancer Registries

Objective: To describe incidence patterns and trends in children (0-14 years) and adolescents (15-19 age-range) with solid tumours, except those of central nervous system (CNS), in Spain.

Methods: Cases were drawn from eleven Spanish population-based cancer registries. Incidence was estimated for the period 1983-2007 and trends were evaluated using Joinpoint regression analysis.

Results: The studied tumour groups accounted for 36% of total childhood cancers and 47.6% of those diagnosed in adolescence with annual rates per million of 53.5 and 89.3 respectively. In children 0 to 14 years of age, Neuroblastoma (NB) was the commonest (7.8%) followed by Soft-tissue sarcomas (STS) (6.3%), bone tumours (BT) (6.2%) and renal tumours (RT) (4.5%). NB was the most frequently diagnosed tumour before the 5th birthday, while STS and BT were the commonest at 5-9 years of age, and BT and Carcinoma and other epithelial tumours (COET) at 10-14. COET presented the highest incidence in adolescents, followed by germ-cell tumours (GCT), BT and STS. These four diagnostic groups accounted for 94% of total non-CNS solid tumours, in adolescents. Overall incidence rates increased significantly in children up to 1996 with an annual percentage change (APC) of 2.6% (95%CI: 1.7; 3.6). NB and COET showed significant time trend (APCs: 1.4% and 3.8% respectively) while other tumour groups such as RT, STS, BT or GCT had no significant changes over time. A significant increase was present in NB under the age of 5 and in BT and STS in children aged 10-14 years. In adolescents there were significant increases for all tumours combined (APC=2.7; 95%CI: 1.8-3.6) and for STS, GCT and COET (APCs: 3.2%, 4.4% and 3.5% respectively), while other tumour groups such as hepatic tumours, BT or thyroid carcinomas showed a decreasing trend or no increase.

Conclusions: Overall, the incidence of the studied cancers in children increased along the period 1983-1996 with no posterior significant rise, while the incidence in adolescents increased significantly over the whole period 1983-2007. Several specific tumour groups showed significant rises or decrements in childhood or adolescence, although the small number of cases precludes showing significant trends or inflexion points.

Registration of childhood cancer: Moving towards pan-European coverage?

Cancer is relatively rare in childhood, but it contributes considerably to childhood mortality, years of life lost per person and late effects in survivors. Large populations need to be covered to set up meaningful studies of these rare conditions. Cancer registries ensure cancer surveillance, thus providing the basis for research as well as policy decisions. In this paper we examine coverage of childhood population by cancer registries in Europe and encourage national cancer registration. Over 200 cancer registries in various stages of development were identified as collecting data on childhood cancer patients in Europe. They cover 52% of the childhood population in the World Health Organisation (WHO) European region and 83% in the European Union (EU). More than 80% of this coverage is ensured by nationwide data collection, which is ongoing in 29 European countries. Overall coverage of the childhood population could increase to around 98%, if the recently established cancer registries start producing results and others improve their quality and dissemination plans. Paediatric cancer registries are being established with increasing frequency even in the areas covered by general cancer registries, and they tend to be national. Compared with regional registration, national cancer registries are more cost-effective, record larger number of cases, they can achieve higher completeness, less biased incidence and survival estimates and they are conditioned for national and international research. National registration of childhood cancer should be the rule in Europe, so that accurate regional, nation-wide and international statistics can provide solid baselines for research, clinical practice and public health policy. Governmental support and stakeholders' involvement are indispensable to guarantee optimal data quality and completeness.

Childhood cancer survival in Europe 1999-2007: results of EUROCARE-5--a population-based study

BACKGROUND

Survival and cure rates for childhood cancers in Europe have greatly improved over the past 40 years and are mostly good, although not in all European countries. The EUROCARE-5 survival study estimates survival of children diagnosed with cancer between 2000 and 2007, assesses whether survival differences among European countries have changed, and investigates changes from 1999 to 2007.

METHODS

We analysed survival data for 157,499 children (age 0-14 years) diagnosed between Jan 1, 1978 and Dec 31, 2007. They came from 74 population-based cancer registries in 29 countries. We calculated observed, country-weighted 1-year, 3-year, and 5-year survival for major cancers and all cancers combined. For comparison between countries, we used the corrected group prognosis method to provide survival probabilities adjusted for multiple confounders (sex, age, period of diagnosis, and, for all cancers combined without CNS cancers, casemix). Age-adjusted survival differences by area and calendar period were calculated with period analysis and were given for all cancers combined and the major cancers.

FINDINGS

We analysed 59,579 cases. For all cancers combined for children diagnosed in 2000-07, 1-year survival was 90.6% (95% CI 90.2-90.9), 3-year survival was 81.0 % (95% CI 80.5-81.4), and 5-year survival was 77.9% (95% CI 77.4-78.3). For all cancers combined, 5-year survival rose from 76.1% (74.4-77.7) for 1999-2001, to 79.1% (77.3-80.7) for 2005-07 (hazard ratio 0.973, 95% CI 0.965-0.982, p<0.0001). The greatest improvements were in eastern Europe, where 5-year survival rose from 65.2% (95% CI 63.1-67.3) in 1999-2001, to 70.2% (67.9-72.3) in 2005-07. Europe-wide average yearly change in mortality (hazard ratio) was 0.939 (95% CI 0.919-0.960) for acute lymphoid leukaemia, 0.959 (0.933-0.986) for acute myeloid leukaemia, and 0.940 (0.897-0.984) for non-Hodgkin lymphoma. Mortality for all of Europe did not change significantly for Hodgkin's lymphoma, Burkitt's lymphoma, CNS tumours, neuroblastoma, Wilms' tumour, Ewing's sarcoma, osteosarcoma, and rhabdomyosarcoma. Disparities for 5-year survival persisted between countries and regions, ranging from 70% to 82% (for 2005-07).

INTERPRETATION

Several reasons might explain persisting inequalities. The lack of health-care resources is probably most important, especially in some eastern European countries with limited drug supply, lack of specialised centres with multidisciplinary teams, delayed diagnosis and treatment, poor management of treatment, and drug toxicity. In the short term, cross-border care and collaborative programmes could help to narrow the survival gaps in Europe.

FUNDING

Italian Ministry of Health, European Commission, Compagnia di San Paolo Foundation.

Survival and cure trends for European children, adolescents and young adults diagnosed with acute lymphoblastic leukemia from 1982 to 2002

Proportion cured is a potentially more informative cancer outcome measurement than 5-year survival. We present population-based estimates of cure for young patients diagnosed with acute lymphoblastic leukemia in Europe from 1982 to 2002. Thirty-five European cancer registries provided data. Survival was estimated by age, period of diagnosis and European region, and used as input for parametric cure models, which assume cured patients have the same mortality as the general population. For acute lymphoblastic leukemia diagnosed in 1-14 year olds in 2000-2002, over 77% were estimated cured. The proportion cured improved significantly over the study period: an impressive 26-58% in infants (up to 1 year), 70-90% in 1-4 year olds, 63-86% in 5-9 year olds, 52-77% in 10-14 year olds, and 44-50% in 15-24 year olds. Regional variations in proportion cured reduced over time for 1-14 year-olds, but persisted in infants and 15-24 year olds. Five-year survival was always slightly higher than proportion cured. Considerable proportions of young patients were estimated cured of acute lymphoblastic leukemia. Nevertheless, a small excess risk of death persisted beyond five years after diagnosis when patients remained at risk for late treatment effects, late relapses and second primaries.

Survival of European children and young adults with cancer diagnosed 1995-2002

This study analyses survival in 40,392 children (age 0-14 years) and 30,187 adolescents/young adults (age 15-24 years) diagnosed with cancer between 1995 and 2002. The cases were from 83 European population-based cancer registries in 23 countries participating in EUROCARE-4. Five-year survival in countries and in regional groupings of countries was compared for all cancers combined and for major cancers. Survival for 15 rare cancers in children was also analysed. Five-year survival for all cancers combined was 81% in children and 87% in adolescents/young adults. Between-country survival differences narrowed for both children and adolescents/young adults. Relative risk of death reduced significantly, by 8% in children and by 13% in adolescents/young adults, from 1995-1999 to 2000-2002. Survival improved significantly over time for acute lymphoid leukaemia and primitive neuroectodermal tumours in children and for non-Hodgkin lymphoma in adolescents/young adults. Cancer survival in patients <25 years is poorly documented in Eastern European countries. Complete cancer registration should be a priority for these countries as an essential part of a policy for effective cancer control in Europe.

Family cancer history and risk of brain tumors in children: results of the SEARCH international brain tumor study

OBJECTIVE

To examine whether childhood brain tumors (CBTs) are associated with a family history of brain tumors or other cancers in an international case-control study.

METHODS

Cancers in children's first- and second-degree relatives were ascertained by interview with parents of 620 children with astroglial tumors, 255 with primitive neuroectodermal tumors, 324 with other CBTs, and 2,218 controls from Australia, Canada, France, Israel, Italy, Spain, and the US. These were used with histories of neurofibromatosis or tuberous sclerosis to exclude in subanalyses children with Li-Fraumeni or other hereditary syndromes predisposing to brain tumors.

RESULTS

A first- or second-degree relative of 4% of children with astroglial tumors, 6% with PNET, 5% with other CBTs, and 5% of controls had had a brain tumor. Any potential differences were statistically non-significant, including when focusing on relatives diagnosed in childhood. In the US, where anatomical sites of relatives' other cancers were known, CBT occurrence was not associated with any other specific site. Results were not markedly altered by exclusion of children with hereditary syndromes.

CONCLUSION

Consistent with most prior studies using these methods, we observed no strong relationship between CBT occurrence and cancers in family members.

Up-to-date monitoring of childhood cancer long-term survival in Europe: central nervous system tumours

BACKGROUND

Tumours of the central nervous system (CNS) account for 15-20% of all malignant childhood tumours in developed countries. Steady improvement of survival of children with CNS tumours has been reported for the past decades. However, these results, obtained by cohort analysis of survival, do not reflect the full extent of recent improvement.

METHODS

Using selected registries from the database of the Automated Childhood Cancer Information System (ACCIS), we calculated period survival estimates for the years 1995-99 for children diagnosed with a malignant CNS tumour.

RESULTS

The overall 10-year period survival estimate for the years 1995-99 was 59% for children with all CNS tumours combined, 73% for children with astrocytoma, 53% for children with ependymoma and 45% for children with primitive neuroectodermal tumours. On average, estimates derived by cohort analysis (pertaining to children diagnosed in 1985-89) were around 4% units lower. Region-specific analysis revealed that recent progress was largest in Eastern Europe, where prognosis nevertheless remained lower than in other European regions. In Northern and Southern Europe, 10-year survival remained essentially unchanged.

CONCLUSION

Although period survival of children with CNS tumours is higher than previously reported cohort survival, their long-term prognosis remains modest compared to other childhood malignancies.

Childhood soft tissue sarcomas incidence and survival in European children (1978-1997): report from the Automated Childhood Cancer Information System project

This population-based study is based on 5802 cases of soft tissue sarcomas (STS) in children aged 0-14 years extracted from the database of the Automated Childhood Cancer Information System (ACCIS) and registered in population-based cancer registries in Europe for the period 1978-1997. STS represent almost 8% of neoplasms in children, almost half of whom are less than 5 years at diagnosis. Rhabdomyosarcoma is the most frequent childhood STS (50%). During 1988-1997 the age-standardised incidence of STS in Europe was 9.1 per million children, lowest in the West and East and highest in the North. The incidence of STS increased almost 2% per year over the period 1978-1997, attributable mostly to increase in genito-urinary rhabdomyosarcoma. Prognosis of children with STS was related to age and site of tumour. Five-year survival of children with STS increased from 46% in 1978-1977 to 66% in 1993-1997, reaching 74% in the North for those diagnosed in 1993-1997. This improvement is ascribed to therapy advances.

Childhood central nervous system tumours – incidence and survival in Europe (1978–1997): Report from Automated Childhood Cancer Information System project

This paper describes the incidence and survival of childhood central nervous system (CNS) tumours in Europe for the period 1978-1997. A total of 19,531 cases, aged 0-14 years, from the ACCIS database were analysed by five regions: the British Isles, East, North, South, and West. Overall age-standardised incidence rate (ASR) of CNS tumours in Europe (1988-1997) was 29.9 per million, with the highest rates in the North. Astrocytoma (ASR=11.8), primitive neuroectodermal tumours (PNET) (ASR=6.5) and ependymoma (ASR=3.4) were the most frequent types. Incidence increased significantly during 1978-1997, on average by 1.7% per year. Diagnostic methods may partially explain incidence rates and trends, although a role of variations in risk factors cannot be excluded. Overall 5-year survival was 64% and varied between 72% in the North and 53% in the East. PNET had the poorest prognosis (49%) and astrocytoma the best (75%). Survival has improved by 29% since late 1970s. The positive trends were seen in all regions, although the interregional differences persisted, as a reflection of the different healthcare systems.

Beauty product-related exposures and childhood brain tumors in seven countries: results from the SEARCH International Brain Tumor Study

Data from 1218 cases of childhood brain tumors (CBT) diagnosed between 1976 and 1994 and 2223 matched controls from the general population were included in an analysis of maternal beauty product exposure and beauty-related employment in 9 centers in 7 countries. A 50% increased odds ratio (OR) [95% confidence interval (CI) = 1.0-2.1] for CBT was observed among children of mothers who were exposed via personal use of and/or possible ambient contact with beauty products during the 5 years preceding the index child's birth compared with children of mothers never exposed to beauty products during this time period. Overall maternal personal use of hair-coloring agents in the month before or during the pregnancy of the index child's birth was not associated with CBT (OR = 1.0, CI = 0.83-1.3) or with astroglial (OR = 1.1, CI = 0.85-1.4), PNET (OR = 1.0, CI = 0.71-1.5) and other glial subtypes (OR = 1.0, CI = 0.62-1.0). Similarly, no statistically increased ORs or discernable pattern of risk estimates were observed for period of use or for number of applications per year for maternal personal use of hair-coloring agents overall or by histologic type. Among children born on or after 1980, increased ORs for CBT were associated with maternal non-work-related exposure to any beauty products (OR = 2.6, CI = 1.2-5.9), hair-dyes (OR = 11, CI = 1.2-90), and hair sprays (OR = 3.4, CI = 1.0-11). No overall increased OR for CBT was observed among children of mothers employed in beauty-related jobs during the 5 years preceding the index child's birth compared with those who reported no beauty-related employment. In general, other specific beauty product-related exposures were not associated with increased ORs for CBT. Data from our study provide little evidence of an increased risk for CBT with mothers' exposures to beauty products.

Parental exposure to polycyclic aromatic hydrocarbons and the risk of childhood brain tumors: The SEARCH International Childhood Brain Tumor Study

Experimental evidence suggests that parental exposure to polycyclic aromatic hydrocarbons (PAH), which occurs primarily through tobacco smoke, occupational exposure, and air pollution, could increase the risk of cancer during childhood. Population-based case-control studies carried out in seven countries as part of the SEARCH Program compared data for 1,218 cases of childhood brain tumors and 2,223 controls (1976-1994). Parental occupational exposure to PAH during the 5-year period before birth was estimated with a job exposure matrix. Risk estimates were adjusted for child's age, sex, and study center. Paternal preconceptional occupational exposure to PAH was associated with increased risks of all childhood brain tumors (odds ratio (OR) = 1.3, 95% confidence interval: 1.1, 1.6) and astroglial tumors (OR = 1.4, 95% confidence interval: 1.1, 1.7). However, there was no trend of increasing risk with predicted level of exposure. Paternal smoking alone (OR = 1.4) was also associated with the risk of astroglial tumors in comparison with nonsmoking, non-occupationally-exposed fathers. Risks for paternal occupational exposure were higher, with (OR = 1.6) or without (OR = 1.7) smoking. Maternal occupational exposure to PAH before conception or during pregnancy was rare, and this exposure was not associated with any type of childhood brain tumor. This large study supports the hypothesis that paternal preconceptional exposure to PAH increases the risk of brain tumors in humans.

Childhood cancer survival in Europe

BACKGROUND

EUROCARE-3 collected data from 45 population-based cancer registries in 20 countries on 24 620 European children aged from 0 to 14 years diagnosed with malignancy in the period 1990-1994.

METHODS

Five-year survival between countries was compared for all malignancies and for the major diagnostic categories, adjusting for age, and estimated average European survival weighting for differences in childhood populations.

RESULTS

For all cancers combined, survival variation was large (45% in Estonia to 90% in Iceland), and was generally low (60-70%) in eastern Europe and high (> or =75%) in Switzerland, Germany and the Nordic countries (except Denmark). The Nordic countries had the highest survival for four of the seven major tumour types: nephroblastoma (92%), acute lymphoid leukaemia (85%), CNS tumours (73%) and acute non-lymphocytic leukaemia (62%). The eastern countries had lowest survival: 89% for Hodgkin's disease, 71% for nephroblastoma, 68% for acute lymphoid leukaemia, 61% for non-Hodgkin's lymphoma, 57% for central nervous system (CNS) tumours and 29% for acute non-lymphocytic leukaemia.

CONCLUSIONS

The Nordic countries represent a survival gold standard to which other countries can aspire. Since most childhood cancers respond well to treatment, survival differences are attributable to differences in access (including referral and timely diagnosis) and use of modern treatments; however, the obstacles to access and application of standard treatments probably vary markedly with country.

Farm-related exposures and childhood brain tumours in seven countries: results from the SEARCH International Brain Tumour Study

A total of 1218 cases of childhood brain tumours (CBT) and 2223 control subjects from the general population were included in a population-based case-control study conducted in nine centres in seven countries. Mothers were asked about farm- or agriculture-related exposures. Significantly elevated odds ratios (OR) for CBT were associated with children's personal and maternal prenatal exposure while living on a farm with pigs (child OR = 1.7, mother OR = 2.3), horses (child OR = 1.6, mother OR = 1.8), dogs (child OR = 1.5, mother OR = 1.5) and cats (child OR = 1.5, mother OR = 1.7). Children who were exposed to pigs, horses and cats combined, while living on a farm, had a threefold elevated OR for CBT. Increased ORs for primitive neuroectodermal tumours (PNET) were associated with children's farm exposure to dogs (OR = 1.9) and cats (OR = 2.2), and maternal farm exposure to pigs (OR = 4.2). The OR for CBT was elevated (OR = 2.3) for children of mothers who had preconception/prenatal farm- or agriculture-related employment involving potential contact with animals, relative to no farm- or agriculture-related employment. In particular, increased ORs for CBT were observed for children of mothers who were employed as general farmers (OR = 4.1) or general farm workers (OR = 3.8). During the 5 years preceding the index child's birth, maternal exposures were related to CBT, relative to no maternal exposure to agricultural chemicals or animal products: fertilisers (OR = 1.8), pesticides (OR = 2.0), animal manure (OR = 2.0) and unprocessed wool (OR = 3.0). Our findings suggest that various farm-related exposures are positively associated with CBT and warrant further investigation into the public health importance of these associations.

Parental occupations and childhood brain tumors: results of an international case-control study

OBJECTIVE

To evaluate the role of parental occupations in the etiology of childhood brain tumors (CBT).

METHODS

Population-based case-control studies were conducted concurrently in seven countries under the coordination of the International Agency for Research on Cancer, gathering 1,218 cases and 2,223 controls. We report here the findings related to parental occupations during the 5-year period before the child's birth. Risk estimates related to a number of paternal and maternal occupations were obtained by unconditional logistic regression adjusted for age, sex, year of birth, and center, for all types of CBT combined and for the subgroups of astroglial, primitive neuroectodermal tumors (PNET), and other glial tumors.

RESULTS

An increased risk in relation with agricultural work was seen for all CBT combined and for other glial tumors. Increased risks for all tumors and PNET were seen for paternal occupation as an electrician; the same pattern held for maternal occupation when children under 5 were selected. Paternal occupation as a driver or mechanic, and maternal work in an environment related to motor-vehicles were associated with an increased risk for all CBT and astroglial tumors. More case mothers compared to control mothers were employed in the textile industry.

CONCLUSION

Our study reinforces previous findings relative to the role of parental work in agriculture, electricity, or motor-vehicle related occupations and maternal work in the textile industry. It does not confirm previous associations with work environments including aerospace, the chemical industry, or the food industry, or with maternal occupation as a hairdresser, a nurse, or a sewing machinist, and paternal occupation as a welder.

SEARCH international case-control study of childhood brain tumours: role of index pregnancy and birth, and mother's reproductive history

A series of co-ordinated population-based case-control studies of childhood brain tumours (CBT) was undertaken under the auspices of the Surveillance of Environmental Aspects Related to Cancer in Humans (SEARCH) programme of the International Agency for Research on Cancer (IARC) to evaluate, inter alia, the risk in relation to characteristics of the index pregnancy and birth, and maternal reproductive history. Subjects comprised 1218 cases aged 0-19 years and 2223 controls. Risk estimates were calculated by unconditional logistic regression, adjusted for age, sex, centre and mother's years of schooling, for all types of CBT combined as well as for four groups defined by histopathology (astrologlial tumours, primitive neuroectodermal tumours of the brain, 'other glial' tumours and 'other histological types') and for five age groups (0-1, 0-4, 5-9, 10-14, 15-19 years). Use of anaesthetic 'gas' was associated with an increased risk of CBT (OR = 1.5, 95% CI [1.1, 2.0]), apparent in children aged 0-4 years (OR = 2.4, 95% CI [1.4, 4.1]) and for astroglial tumours (OR = 1.6, 95% CI [1.1, 2.2]) with non-significantly increased relative risks for each of the other histological groups. However, not all centre-specific relative risks were elevated. No other aspect of the index pregnancy, delivery and early neonatal period or of the mother's previous reproductive history was associated with risk for CBT.

Population density and childhood leukaemia: results of the EUROCLUS Study

The EUROCLUS study assembled incidence data for 13,551 cases of childhood leukaemia (CL) diagnosed between 1980 and 1989 in 17 countries (or regions of countries). These were referenced by location at diagnosis to small census areas of which there were 25,723 in the study area. Population counts, surface area and, hence, population density were available for all these small areas. Previous analyses have shown limited extra-Poisson variation (EPV) of case counts within small areas; this is most pronounced in areas of intermediate population density (150-499 persons/km2). In this study, the data set was examined in more detail for evidence that variations in incidence and EPV of CL are associated with population density. Incidence showed a curvilinear association with population density and was highest in areas which were somewhat more densely populated (500-750 persons/km2), where the incidence rate ratio relative to areas having > or = 1000 persons/km2 was 1.16 (95% confidence interval 1.07-1.26) and the P value for quadratic trend across eight strata of population density was 0.02. Incidence in these areas is uniformly elevated and showed no evidence of heterogeneity (i.e. EPV). Statistically significant evidence of EPV was evident amongst some of the areas previously classified as intermediate density areas (specifically, those with a density of 250-499 persons/km2, P < 0.001 for CL). These results were interpreted in terms of the current aetiological hypotheses for CL which propose that exposure to localised epidemics of one or more common infectious agent may contribute to the development of leukaemia. They suggest that such epidemics arise regularly in moderately densely populated areas and also sporadically in areas which are somewhat less densely populated. Although other interpretations are possible, these results may assist in the identification of characteristics which infectious agents must possess if direct or indirect causes of CL.

Prenatal vitamin supplementation and risk of childhood brain tumors

An international case-control study of primary pediatric brain tumors included interviews with mothers of cases diagnosed from 1976 to 1994 and mothers of population controls. Data are available on maternal vitamin use during pregnancy for 1,051 cases and for 1,919 controls from 8 geographic areas in North America, Europe and Israel. While risk estimates varied by study center, combined results suggest that maternal supplementation for 2 trimesters decreased risk of brain tumor [odds ratio (OR) = 0.7; 95% confidence interval (CI) = 0.5, 0.9], with a trend of less risk with longer duration of use (p trend = 0.0007). The greatest risk reduction was among children diagnosed under 5 years of age whose mothers used supplements during all 3 trimesters (OR = 0.5; CI = 0.3, 0.8). This effect did not vary by histology and was seen for supplementation during pregnancy rather than during the month before pregnancy or while breastfeeding. Our findings are largely driven by data from the United States, where most mothers took vitamins. The proportion of control mothers who took vitamins during pregnancy varied markedly from 3% in Israel and in France, 21% in Italy, 33% in Canada and 52% in Spain to 86-92% at the 3 U.S. centers. The composition of the various multivitamin compounds taken also varied: daily dose of vitamin C ranged from 0 to 600 mg; vitamin E from 0 to 70 mg; vitamin A from 0 to 30,000 IU; and folate from 0 to 2,000 micrograms. Mothers also took individual micronutrient supplements (e.g., vitamin C tablets), but most mothers who took these also took multivitamins, making it impossible to determine the potential independent effects of these micronutrients.

Prenatal vitamin supplementation and pediatric brain tumors: huge international variation in use and possible reduction in risk

An international case-control study of primary pediatric brain tumors included interviews with mothers of cases diagnosed from 1976-1994 and mothers of population controls. Data are available on maternal vitamin use during pregnancy for 1051 cases and for 1919 controls in eight geographic areas of North America, Europe and Israel. While risk estimates varied by study center, combined results suggest that maternal supplementation for two trimesters may decrease risk of brain tumor [odds ratio (OR)=0.7; 95% confidence interval (CI)=0.5-0.9], with a trend toward less risk with longer duration of use (P trend= 0.0007). The greatest risk reduction was among children diagnosed under 5 years of age whose mothers used supplements during all three trimesters (OR=0.5; CI=0.3- 0.8). This effect did not vary by histology and was seen for supplementation during pregnancy rather than during the month before pregnancy or while breast feeding. These findings are largely driven by data from the US, where most mothers took vitamins. The proportion of control mothers who took vitamins during pregnancy varied tremendously, from 3% in Israel and in France through 21% in Italy, 33% in Canada, 52% in Spain to 86-92% at the three US centers. The composition of the various multivitamin compounds taken also varied: daily dose of vitamin C ranged from 0 up to 600 mg; vitamin E from 0 to 70 mg; vitamin A from 0 to 30,000 IU and folate from 0 to 2000 mg. Mothers also took individual micronutrient supplements (e.g., vitamin C tablets), but most mothers who took these also took multivitamins, making it impossible to determine potential independent effects of these micronutrients.

Results from an international case-control study of childhood brain tumors: the role of prenatal vitamin supplementation

An international case-control study of primary pediatric brain tumors included interviews with mothers of cases diagnosed from 1976 to 1994 and mothers of population controls. Data are available on maternal vitamin use during pregnancy for 1051 cases and 1919 controls from eight geographic areas in North America, Europe, and Israel. Although risk estimates varied by study center, combined results suggest that maternal supplementation for two trimesters may decrease risk of brain tumor (odds ratio [OR] 0.7, 95% confidence interval [CI] 0.5-0.9), with a trend of less risk with longer duration of use (p trend = 0.0007). The greatest risk reduction was among children diagnosed under 5 years of age whose mothers used supplements during all three trimesters (OR 0.5, CI 0.3-0.8). This effect did not vary by histology and was seen for supplementation during pregnancy rather than during the month before pregnancy or while breast feeding. These findings are largely driven by data from the United States, where most mothers took vitamins. The proportion of control mothers who took vitamins during pregnancy varied tremendously: from 3% in Israel and France, 21% in Italy, 33% in Canada, 52% in Spain and 86 to 92% at the three U.S. centers. The composition of the various multivitamin compounds taken also varied: the daily dose of vitamin C ranged from 0 to 600 mg, vitamin E ranged from 0 to 70 mg, vitamin A ranged from 0 to 30,000 IU, and folate ranged from 0 to 2000 micrograms. Mothers also took individual micronutrient supplements (e.g., vitamin C tablets), but most mothers who took these also took multivitamins, making it impossible to determine potential independent effects of these micronutrients.

Spatial clustering of childhood leukaemia: summary results from the EUROCLUS project

The interpretation of reports of clusters of childhood leukaemia is difficult, first because little is known about the causes of the disease, and second because there is insufficient information on whether cases show a generalized tendency to cluster geographically. The EUROCLUS project is a European collaborative study whose primary objective is to determine whether the residence locations of cases at diagnosis show a general tendency towards spatial clustering. The second objective is to interpret any patterns observed and, in particular, to see if clustering can be explained in terms of either infectious agents or environmental hazards as aetiological agents. The spatial distribution of 13351 cases of childhood leukaemia diagnosed in 17 countries between 1980 and 1989 has been analysed using the Potthoff-Whittinghill method. The overall results show statistically significant evidence of clustering of total childhood leukaemia within small census areas (P=0.03) but the magnitude of the clustering is small (extra-Poisson component of variance (%) = 1.7 with 90% confidence interval 0.2-3.1). The clustering is most marked in areas that have intermediate population density (150-499 persons km[-2]). It cannot be attributed to any specific age group at diagnosis or cell type and involves spatial aggregation of cases of different ages and cell types. The results indicate that intense clusters are a rare phenomenon that merit careful investigation, although aetiological insights are more likely to come from investigation of large numbers of cases. We present a method for detecting clustering that is simple and readily available to cancer registries and similar groups.

Spatial temporal patterns in childhood leukaemia: further evidence for an infectious origin. EUROCLUS project

The EUROCLUS project included information on residence at diagnosis for 13351 cases of childhood leukaemia diagnosed in the period 1980-89 in defined geographical regions in 17 countries. A formal algorithm permits identification of small census areas as containing case excesses. The present analysis examines spatial-temporal patterns of the cases (n = 970) within these clustered areas. The objectives were, first, to compare these results with those from an analysis conducted for UK data for the period 1966-83, and, second, to extend them to consider infant leukaemias. A modification of the Knox test investigates, within the small areas, temporal overlap between cases in a subgroup of interest at a putative critical time and all other cases at any time between birth and diagnosis. Critical times were specified in advance as follows: for cases of acute lymphoblastic leukaemia aged 2-4 years, the 18-month period preceding diagnosis; for cases of total leukaemia aged 5-14 years, 1 year before to 1 year after birth; and for infant cases (diagnosed < 1 year), 1 year before to 6 months after birth. Each of the analyses found evidence of excess space-time overlap compared with that expected; these were 10% (P = 0.005), 15% (P= 0.0002) and 26% (P= 0.03) respectively. The results are interpreted in terms of an infectious origin of childhood leukaemia.

Parental occupation, occupational exposure to solvents and polycyclic aromatic hydrocarbons and risk of childhood brain tumors (Italy, France, Spain)

The role of parental occupational exposure in childhood brain tumors was investigated in a population-based case-control study grouping 251 cases and 601 controls from three European centers: Milan (Italy), Paris (France), and Valencia (Spain). Parental occupational exposure to solvents and polycyclic aromatic hydrocarbons (PAH) during the five-year period before birth was estimated using a job-exposure matrix developed earlier in the same countries. Odds ratios (OR) of brain tumors for each occupation and occupational exposure were estimated by logistic regression, adjusting for child's age, gender, exposure to tobacco smoke and ionizing radiation, mother's age and years of schooling, and center. The risk of childhood brain tumors rose when fathers worked in agriculture (OR = 2.2, 95 percent confidence interval [CI] = 1.0-4.7) and motor-vehicle-related occupations. In the latter group, the risk increased for primitive neuroectodermal tumors in particular (OR = 2.7, CI = 1.1-6.6). Astroglial tumors were more frequent among children of mothers in health services (OR = 2.2, CI = 1.0-4.9). Paternal exposure to PAHs was associated with an increased, but not dose-related, risk of primitive neuroectodermal tumors (OR = 2.0, CI = 1.0-4.0), and maternal exposure to solvents at a high level was associated with an increased risk of both astroglial (OR = 2.3, CI = 0.9-5.8) and primitive neuroectodermal tumors (OR = 3.2, CI = 1.0-10.3).