Incidence of childhood cancer in Latin America and the Caribbean: coverage, patterns, and time trends.

Objective: To provide a comprehensive overview of geographical patterns (2001-2010) and time trends (1993-2012) of cancer incidence in children aged 0-19 years in Latin America and the Caribbean (LAC) and interpret the findings in the context of global patterns. Methods: Geographical variations in 2001-2010 and incidence trends over 1993-2012 in the population of LAC younger than 20 years were described using the database of the third volume of the International Incidence of Childhood Cancer study containing comparable data. Age-specific incidence per million person-years (ASR) was calculated for population subgroups and age-standardized (WSR) using the world standard population. Results: Overall, 36 744 unique cases were included in this study. In 2001-2010 the overall WSR in age 0-14 years was 132.6. The most frequent were leukemia (WSR 48.7), central nervous system neoplasms (WSR 23.0), and lymphoma (WSR 16.6). The overall ASR in age group 15-19 years was 152.3 with lymphoma ranking first (ASR 30.2). Incidence was higher in males than in females, and higher in South America than in Central America and the Caribbean. Compared with global data LAC incidence was lower overall, except for leukemia and lymphoma at age 0-14 years and the other and unspecified tumors at any age. Overall incidence at age 0-19 years increased by 1.0% per year (95% CI [0.6, 1.3]) over 1993-2012. The included registries covered 16% of population aged 0-14 years and 10% of population aged 15-19 years. Conclusions: The observed patterns provide a baseline to assess the status and evolution of childhood cancer occurrence in the region. Extended and sustained support of cancer registration is required to improve representativeness and timeliness of data for childhood cancer control in LAC.

Subsequent cancers within 5 years from initial diagnosis of childhood cancer. Patterns and risks in the population of Great Britain.

BACKGROUND: Patterns and risks of subsequent primary tumours (SPTs) among long-term survivors of childhood cancer have been extensively described, but much less is known about early SPTs (ESPTs) occurring within 5 years after initial diagnosis. PROCEDURE: We carried out a population-based study of ESPTs following childhood cancer throughout Britain, using the National Registry of Childhood Tumours. The full study series comprised all ESPTs occurring among 56,620 children whose initial cancer diagnosis was in the period 1971-2010. Frequencies of ESPT were calculated for the entire cohort. For analyses of risk, follow-up began 92 days after initial diagnosis. RESULTS: ESPT developed in 0.4% of children overall, 0.52% of those initially diagnosed at age less than 1 year and 0.38% of those diagnosed at age 1-14 years. Standardised incidence ratio (SIR) was 7.7 (95% confidence interval [CI]: 6.7-8.9), overall 9.5 (95% CI: 7.1-12.5) for children initially diagnosed in 1981-1990 and 6.5-7.5 for those from earlier and later decades. SIR by type of first cancer ranged from 4.4 (95% CI: 1.8-9.1) for Wilms tumour to 13.1 (95% CI: 7.7-21.0) for non-Hodgkin lymphoma. SIR by type of ESPT ranged from 2.0 (95% CI: 1.0-3.4) for acute lymphoblastic leukaemia to 66.6 (95% CI: 52.3-83.6) for acute myeloid leukaemia. Predisposition syndromes were known to be implicated in 21% of children with ESPT and suspected in another 5%. CONCLUSIONS: This study provides an overview of the patterns and risks of ESPTs in a large population where many children received therapy that is still in widespread use. Further research will be needed to monitor and understand changes in risk as childhood cancer treatment continues to evolve.

International variation in childhood cancer mortality rates from 2001 to 2015: Comparison of trends in the International Cancer Benchmarking Partnership countries.

Despite improved survival rates, cancer remains one of the most common causes of childhood death. The International Cancer Benchmarking Partnership (ICBP) showed variation in cancer survival for adults. We aimed to assess and compare trends over time in cancer mortality between children, adolescents and young adults (AYAs) and adults in the six countries involved in the ICBP: United Kingdom, Denmark, Australia, Canada, Norway and Sweden. Trends in mortality between 2001 and 2015 in the six original ICBP countries were examined. Age standardised mortality rates (ASR per million) were calculated for all cancers, leukaemia, malignant and benign central nervous system (CNS) tumours, and non-CNS solid tumours. ASRs were reported for children (age 0-14 years), AYAs aged 15 to 39 years and adults aged 40 years and above. Average annual percentage change (AAPC) in mortality rates per country were estimated using Joinpoint regression. For all cancers combined, significant temporal reductions were observed in all countries and all age groups. However, the overall AAPC was greater for children (-2.9; 95% confidence interval = -4.0 to -1.7) compared to AYAs (-1.8; -2.1 to -1.5) and adults aged >40 years (-1.5; -1.6 to -1.4). This pattern was mirrored for leukaemia, CNS tumours and non-CNS solid tumours, with the difference being most pronounced for leukaemia: AAPC for children -4.6 (-6.1 to -3.1) vs AYAs -3.2 (-4.2 to -2.1) and over 40s -1.1 (-1.3 to -0.8). AAPCs varied between countries in children for all cancers except leukaemia, and in adults over 40 for all cancers combined, but not in subgroups. Improvements in cancer mortality rates in ICBP countries have been most marked among children aged 0 to 14 in comparison to 15 to 39 and over 40 year olds. This may reflect better care, including centralised service provision, treatment protocols and higher trial recruitment rates in children compared to older patients.

Incidence, prevalence and survival in patients with Langerhans cell histiocytosis: A national registry study from England, 2013-2019.

This analysis is the largest population-based study to date to provide contemporary and comprehensive epidemiological estimates of all third edition of the International Classification of Diseases for Oncology (ICD-O-3) coded Langerhans cell histiocytosis (LCH) from England. People of all ages were identified from the National Cancer Registration Dataset using ICD-O-3 morphologies 9751-9754 for neoplasms diagnosed in 2013-2019. A total of 658 patients were identified, of whom 324 (49%) were children aged <15 years. The age-standardised incidence rate was 4.46 (95% confidence interval [CI] 3.99-4.98) per million children and 1.06 (95% CI 0.94-1.18) per million adults aged ≥15 years. Prevalence of LCH was 9.95 (95% CI 9.14-10.81) per million persons at the end of 2019. The 1-year overall survival (OS) was 99% (95% CI 97%-100%) for children and 90% (95% CI 87%-93%) for adults. Those aged ≥60 years had poorer OS than those aged <15 years (hazard ratio [HR] 22.12, 95% CI 7.10-68.94; p < 0.001). People in deprived areas had lower OS than those in the least deprived areas (HR 5.36, 95% CI 1.16-24.87; p = 0.03). There will inevitably be other environmental factors and associations yet to be identified, and the continued standardised data collection will allow further evaluation of data over time. This will be increasingly important with developments in LCH management following the large collaborative international trials such as LCH IV.

Does the morphology of cutaneous melanoma help to explain the international differences in survival? Results from 1 578 482 adults diagnosed during 2000-2014 in 59 countries (CONCORD-3).

BACKGROUND: CONCORD-3 highlighted wide disparities in population-based 5-year net survival for cutaneous melanoma during 2000-2014. Clinical evidence suggests marked international differences in the proportion of lethal acral and nodular subtypes of cutaneous melanoma. OBJECTIVES: We aimed to assess whether the differences in morphology may explain global variation in survival. METHODS: Patients with melanoma were grouped into the following seven morphological categories: malignant melanoma, not otherwise specified (International Classification of Diseases for Oncology, third revision morphology code 8720), superficial spreading melanoma (8743), lentigo maligna melanoma (8742), nodular melanoma (8721), acral lentiginous melanoma (8744), desmoplastic melanoma (8745) and other morphologies (8722-8723, 8726-8727, 8730, 8740-8741, 8746, 8761, 8770-8774, 8780). We estimated net survival using the nonparametric Pohar Perme estimator, correcting for background mortality by single year of age, sex and calendar year in each country or region. All-ages survival estimates were standardized using the International Cancer Survival Standard weights. We fitted a flexible parametric model to estimate the effect of morphology on the hazard of death. RESULTS: Worldwide, the proportion of nodular melanoma ranged between 7% and 13%. Acral lentiginous melanoma accounted for less than 2% of all registrations but was more common in Asia (6%) and Central and South America (7%). Overall, 36% of tumours were classified as superficial spreading melanoma. During 2010-2014, age-standardized 5-year net survival for superficial spreading melanoma was 95% or higher in Oceania, North America and most European countries, but was only 71% in Taiwan. Survival for acral lentiginous melanoma ranged between 66% and 95%. Nodular melanoma had the poorest prognosis in all countries. The multivariable analysis of data from registries with complete information on stage and morphology found that sex, age and stage at diagnosis only partially explain the higher risk of death for nodular and acral lentiginous subtypes. CONCLUSIONS: This study provides the broadest picture of distribution and population-based survival trends for the main morphological subtypes of cutaneous melanoma in 59 countries. The poorer prognosis for nodular and acral lentiginous melanomas, more frequent in Asia and Latin America, suggests the need for health policies aimed at specific populations to improve awareness, early diagnosis and access to treatment. What is already known about this topic? The histopathological features of cutaneous melanoma vary markedly worldwide. The proportion of melanomas with the more aggressive acral lentiginous or nodular histological subtypes is higher in populations with predominantly dark skin than in populations with predominantly fair skin. What does this study add? We aimed to assess the extent to which these differences in morphology may explain international variation in survival when all histological subtypes are combined. This study provides, for the first time, international comparisons of population-based survival at 5 years for the main histological subtypes of melanoma for over 1.5 million adults diagnosed during 2000-2014. This study highlights the less favourable distribution of histological subtypes in Asia and Central and South America, and the poorer prognosis for nodular and acral lentiginous melanomas. We found that later stage at diagnosis does not fully explain the higher excess risk of death for nodular and acral lentiginous melanoma compared with superficial spreading melanoma.

Severity of COVID-19 in children with cancer: Report from the United Kingdom Paediatric Coronavirus Cancer Monitoring Project.

BACKGROUND: Children with cancer are frequently immunocompromised. While children are generally thought to be at less risk of severe SARS-CoV-2 infection than adults, comprehensive population-based evidence for the risk in children with cancer is unavailable. We aimed to produce evidence of the incidence and outcomes from SARS-CoV-2 in children with cancer attending all hospitals treating this population across the UK. METHODS: Retrospective and prospective observational study of all children in the UK under 16 diagnosed with cancer through data collection from all hospitals providing cancer care to this population. Eligible patients tested positive for SARS-CoV-2 on reverse transcription polymerase chain reaction (RT-PCR). The primary end-point was death, discharge or end of active care for COVID-19 for those remaining in hospital. RESULTS: Between 12 March 2020 and 31 July 2020, 54 cases were identified: 15 (28%) were asymptomatic, 34 (63%) had mild infections and 5 (10%) moderate, severe or critical infections. No patients died and only three patients required intensive care support due to COVID-19. Estimated incidence of hospital identified SARS-CoV-2 infection in children with cancer under 16 was 3%. CONCLUSIONS: Children with cancer with SARS-CoV-2 infection do not appear at increased risk of severe infection compared to the general paediatric population. This is reassuring and supports the continued delivery of standard treatment.

Incidence of childhood renal tumours: An international population-based study.

Malignant renal tumours represent 5% of childhood cancers and include types with likely different aetiology: Wilms tumour (WT), rhabdoid renal tumour, kidney sarcomas and renal carcinomas. WT is the most common renal tumour in children, previously shown to vary internationally and with ethnicity. Using the comprehensive database of the International Incidence of Childhood Cancer study (IICC), we analysed global variations and time trends in incidence of renal tumour types in children (age 0-14 years) and adolescents (age 15-19 years). The results were presented by 14 world regions, and five ethnic groups in the US. We included 15 320 renal tumours in children and 800 in adolescents reported to the 163 contributing registries during 2001-2010. In children, age-standardised incidence rate (ASR) of renal tumours was 8.3 per million (95% confidence interval, CI = 8.1, 8.4); it was the highest in North America and Europe (9-10 per million) and the lowest in most Asian regions (4-5 per million). In the US, Blacks had the highest ASR (10.9 per million, 95% CI = 10.2, 11.6) and Asian and Pacific Islanders the lowest (4.4 per million, 95% CI = 3.6, 5.1). In adolescents, age-specific incidence rate of renal tumours was 1.4 per million (95% CI = 1.3, 1.5). WT accounted for over 90% of all renal tumours in each age from 1 to 7 years and the proportion of renal carcinomas increased gradually with age. From 1996 to 2010, incidence remained mostly stable for WT (average annual percent change, AAPC = 0.1) and increased for renal carcinomas in children (AAPC = 3.7) and adolescents (AAPC = 3.2). Our findings warrant further monitoring.

Case-control study of paternal occupational exposures and childhood bone tumours and soft-tissue sarcomas in Great Britain, 1962-2010.

BACKGROUND: This nationwide study investigated associations between paternal occupational exposure and childhood bone tumours and soft- tissue sarcomas. METHODS: The UK National Registry of Childhood Tumours provided cases of childhood sarcomas born and diagnosed in Great Britain, 1962-2010. Control births, unaffected by childhood cancer, were matched on sex, birth period and birth registration sub-district. Fathers' occupations were assigned to one or more of 33 exposure groups and coded for occupational social class. RESULTS: We analysed 5,369 childhood sarcoma cases and 5380 controls. Total bone tumours, total soft-tissue sarcomas and the subgroups osteosarcoma, rhabdomyosarcoma and Ewing Sarcoma Family of Tumours (ESFT) were considered separately. Significant positive associations were seen between rhabdomyosarcoma and paternal exposure to EMFs (odds ratio = 1.67, CI = 1.22-2.28) and also for ESFT and textile dust (1.93, 1.01-3.63). There were putative protective effects on total bone tumours of paternal dermal exposure to hydrocarbons, metal, metal working or oil mists. CONCLUSIONS: Despite the large size and freedom from bias of this study, our results should be interpreted with caution. Many significance tests were undertaken, and chance findings are to be expected. Nevertheless, our finding of associations between ESFT and paternal exposure to textile dust may support related suggestions in the literature.

Case-control study of paternal occupational exposures and childhood lymphoma in Great Britain, 1962-2010.

BACKGROUND: This nationwide study investigates associations between paternal occupational exposure and childhood lymphoma. METHODS: The UK National Registry of Childhood Tumours provided cases of childhood lymphoma born and diagnosed in Great Britain 1962-2010. Control births, unaffected by childhood cancer, were matched on sex, birth period and birth registration sub-district. Fathers' occupations were assigned to one or more of 33 exposure groups and also coded for occupational social class. RESULTS: We analysed 5033 childhood lymphoma cases and 4990 controls. Total lymphoma and the subgroups Hodgkin, Burkitt and non-Hodgkin lymphoma were considered separately. No one exposure was significantly associated with increased risk within all subgroups and for total lymphoma. However, exposure to "ceramics and glass" was significantly associated with increased risk of total lymphoma, Hodgkin and non-Hodgkin lymphoma. Paternal lead exposure was associated with Burkitt lymphoma and exposure to metal fumes was associated with Hodgkin lymphoma. CONCLUSIONS: This study provides no support for previous suggestions of an association between childhood lymphoma and paternal occupational exposure to pesticides, solvents/hydrocarbons or infections potentially transmitted by father's social contacts. An association with exposure to "ceramics and glass" was noted for the two major lymphoma subtypes together comprising 80% of total lymphoma.

Global surveillance of trends in cancer survival 2000-14 (CONCORD-3): analysis of individual records for 37 513 025 patients diagnosed with one of 18 cancers from 322 population-based registries in 71 countries.

BACKGROUND: In 2015, the second cycle of the CONCORD programme established global surveillance of cancer survival as a metric of the effectiveness of health systems and to inform global policy on cancer control. CONCORD-3 updates the worldwide surveillance of cancer survival to 2014. METHODS: CONCORD-3 includes individual records for 37·5 million patients diagnosed with cancer during the 15-year period 2000-14. Data were provided by 322 population-based cancer registries in 71 countries and territories, 47 of which provided data with 100% population coverage. The study includes 18 cancers or groups of cancers: oesophagus, stomach, colon, rectum, liver, pancreas, lung, breast (women), cervix, ovary, prostate, and melanoma of the skin in adults, and brain tumours, leukaemias, and lymphomas in both adults and children. Standardised quality control procedures were applied; errors were rectified by the registry concerned. We estimated 5-year net survival. Estimates were age-standardised with the International Cancer Survival Standard weights. FINDINGS: For most cancers, 5-year net survival remains among the highest in the world in the USA and Canada, in Australia and New Zealand, and in Finland, Iceland, Norway, and Sweden. For many cancers, Denmark is closing the survival gap with the other Nordic countries. Survival trends are generally increasing, even for some of the more lethal cancers: in some countries, survival has increased by up to 5% for cancers of the liver, pancreas, and lung. For women diagnosed during 2010-14, 5-year survival for breast cancer is now 89·5% in Australia and 90·2% in the USA, but international differences remain very wide, with levels as low as 66·1% in India. For gastrointestinal cancers, the highest levels of 5-year survival are seen in southeast Asia: in South Korea for cancers of the stomach (68·9%), colon (71·8%), and rectum (71·1%); in Japan for oesophageal cancer (36·0%); and in Taiwan for liver cancer (27·9%). By contrast, in the same world region, survival is generally lower than elsewhere for melanoma of the skin (59·9% in South Korea, 52·1% in Taiwan, and 49·6% in China), and for both lymphoid malignancies (52·5%, 50·5%, and 38·3%) and myeloid malignancies (45·9%, 33·4%, and 24·8%). For children diagnosed during 2010-14, 5-year survival for acute lymphoblastic leukaemia ranged from 49·8% in Ecuador to 95·2% in Finland. 5-year survival from brain tumours in children is higher than for adults but the global range is very wide (from 28·9% in Brazil to nearly 80% in Sweden and Denmark). INTERPRETATION: The CONCORD programme enables timely comparisons of the overall effectiveness of health systems in providing care for 18 cancers that collectively represent 75% of all cancers diagnosed worldwide every year. It contributes to the evidence base for global policy on cancer control. Since 2017, the Organisation for Economic Co-operation and Development has used findings from the CONCORD programme as the official benchmark of cancer survival, among their indicators of the quality of health care in 48 countries worldwide. Governments must recognise population-based cancer registries as key policy tools that can be used to evaluate both the impact of cancer prevention strategies and the effectiveness of health systems for all patients diagnosed with cancer. FUNDING: American Cancer Society; Centers for Disease Control and Prevention; Swiss Re; Swiss Cancer Research foundation; Swiss Cancer League; Institut National du Cancer; La Ligue Contre le Cancer; Rossy Family Foundation; US National Cancer Institute; and the Susan G Komen Foundation.

Incidence of childhood CNS tumours in Britain and variation in rates by definition of malignant behaviour: population-based study.

BACKGROUND: Intracranial and intraspinal tumours are the most numerous solid tumours in children. Some recently defined subtypes are relatively frequent in childhood. Many cancer registries routinely ascertain CNS tumours of all behaviours, while others only cover malignant neoplasms. Some behaviour codes have changed between revisions of the International Classification of Diseases for Oncology, including pilocytic astrocytoma, downgraded to uncertain behaviour in ICD-O-3. METHODS: We used data from the population-based National Registry of Childhood Tumours, which routinely included non-malignant CNS tumours, to document the occurrence of CNS tumours among children aged < 15 years in Great Britain during 2001-2010 and to document the descriptive epidemiology of childhood CNS tumours over the 40-year period 1971-2010, during which several new entities were accommodated in successive editions of the WHO Classification and revisions of ICD-O. Eligible cases were all those with a diagnosis included in Groups III (CNS tumours) and Xa (CNS germ-cell tumours) of the International Classification of Childhood Cancer, Third Edition. The population at risk was derived from annual mid-year estimates by sex and single year of age compiled by the Office for National Statistics and its predecessors. Incidence rates were calculated for age groups 0, 1-4, 5-9 and 10-14 years, and age-standardised rates were calculated using the weights of the world standard population. RESULTS: Age-standardised incidence in 2001-10 was 40.1 per million. Astrocytomas accounted for 41%, embryonal tumours for 17%, other gliomas for 10%, ependymomas for 7%, rarer subtypes for 20% and unspecified tumours for 5%. Incidence of tumours classified as malignant and non-malignant by ICD-O-3 increased by 30 and 137% respectively between 1971-75 and 2006-10. CONCLUSIONS: Total incidence was similar to that in other large western countries. Deficits of some, predominantly low-grade, tumours or differences in their age distribution compared with the United States and Nordic countries are compatible with delayed diagnosis. Complete registration regardless of tumour behaviour is essential for assessing burden of disease and changes over time. This is particularly important for pilocytic astrocytoma, because of its recent downgrading to non-malignant and time trends in the proportion of astrocytomas with specified subtype.

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 cancer incidence and survival in Japan and England: A population-based study (1993-2010).

The present study aimed to compare cancer incidence and trends in survival for children diagnosed in Japan and England, using population-based cancer registry data. The analysis was based on 5192 children with cancer (age 0-14 years) from 6 prefectural cancer registries in Japan and 21 295 children diagnosed in England during 1993-2010. Differences in incidence rates between the 2 countries were measured with Poisson regression models. Overall survival was estimated using the Kaplan-Meier method. Incidence rates for Hodgkin lymphoma, renal tumors and Ewing sarcomas in England were more than twice as high as those in Japan. Incidence of germ cell tumors, hepatic tumors, neuroblastoma and acute myeloid leukemia (AML) was higher in Japan than in England. Incidence of all cancers combined decreased in Japan throughout the period 1993 to 2010, which was mainly explained by a decrease in registration of neuroblastoma in infants. For many cancers, 5-year survival improved in both countries. The improvement in survival in chronic myeloid leukemia (CML) was particularly dramatic in both countries. However, 5-year survival remained less than 80% in 2005-2008 in both countries for AML, brain tumors, soft tissue sarcomas, malignant bone tumors and neuroblastoma (age 1-14 years). There were significant differences in incidence of several cancers between countries, suggesting variation in genetic susceptibility and possibly environmental factors. The decrease in incidence for all cancers combined in Japan was related to the cessation of the national screening program for neuroblastoma. The large improvement in survival in CML coincided with the introduction of effective therapy (imatinib).

Childhood cancer research in Oxford II: The Childhood Cancer Research Group.

BACKGROUND: We summarise the work of the Childhood Cancer Research Group, particularly in relation to the UK National Registry of Childhood Tumours (NRCT). METHODS: The Group was responsible for setting up and maintaining the NRCT. This registry was based on notifications from regional cancer registries, specialist children's tumour registries, paediatric oncologists and clinical trials organisers. For a large sample of cases, data on controls matched by date and place of birth were also collected. RESULTS: Significant achievements of the Group include: studies of aetiology and of genetic epidemiology; proposals for, and participation in, international comparative studies of these diseases and on a classification system specifically for childhood cancer; the initial development of, and major contributions to, follow-up studies of the health of long-term survivors; the enhancement of cancer registration records by the addition of clinical data and of birth records. The Group made substantial contributions to the UK government's Committee on Medical Aspects of Radiation in the Environment. CONCLUSION: An important part of the ethos of the Group was to work in collaboration with many other organisations and individuals, both nationally and internationally: many of the Group's achievements described here were the result of such collaborations.

Childhood cancer research in oxford III: The work of CCRG on ionising radiation.

BACKGROUND: High doses of ionising radiation are a known cause of childhood cancer and great public and professional interest attaches to possible links between childhood cancer and lower doses, particularly of man-made radiation. This paper describes work done by the Childhood Cancer Research Group (CCRG) on this topic METHODS: Most UK investigations have made use of the National Registry of Childhood Tumours and associated controls. Epidemiological investigations have included national incidence and mortality analyses, geographical investigations, record linkage and case-control studies. Dosimetric studies use biokinetic and dosimetric modelling. RESULTS: This paper reviews the work of the CCRG on the association between exposure to ionising radiation and childhood cancer, 1975-2014. CONCLUSION: The work of CCRG has been influential in developing understanding of the causes of 'clusters' of childhood cancer and the risks arising from exposure to ionising radiation both natural and man-made. Some clusters around nuclear installations have certainly been observed, but ionising radiation does not seem to be a plausible cause. The group's work has also been instrumental in discounting the hypothesis that paternal preconception irradiation was a cause of childhood cancers and has demonstrated an increased leukaemia risk for children exposed to higher levels of natural gamma-ray radiation.

International incidence of childhood cancer, 2001-10: a population-based registry study.

BACKGROUND: Cancer is a major cause of death in children worldwide, and the recorded incidence tends to increase with time. Internationally comparable data on childhood cancer incidence in the past two decades are scarce. This study aimed to provide internationally comparable local data on the incidence of childhood cancer to promote research of causes and implementation of childhood cancer control. METHODS: This population-based registry study, devised by the International Agency for Research on Cancer in collaboration with the International Association of Cancer Registries, collected data on all malignancies and non-malignant neoplasms of the CNS diagnosed before age 20 years in populations covered by high-quality cancer registries with complete data for 2001-10. Incidence rates per million person-years for the 0-14 years and 0-19 years age groups were age-adjusted using the world standard population to provide age-standardised incidence rates (WSRs), using the age-specific incidence rates (ASR) for individual age groups (0-4 years, 5-9 years, 10-14 years, and 15-19 years). All rates were reported for 19 geographical areas or ethnicities by sex, age group, and cancer type. The regional WSRs for children aged 0-14 years were compared with comparable data obtained in the 1980s. FINDINGS: Of 532 invited cancer registries, 153 registries from 62 countries, departments, and territories met quality standards, and contributed data for the entire decade of 2001-10. 385 509 incident cases in children aged 0-19 years occurring in 2·64 billion person-years were included. The overall WSR was 140·6 per million person-years in children aged 0-14 years (based on 284 649 cases), and the most common cancers were leukaemia (WSR 46·4), followed by CNS tumours (WSR 28·2), and lymphomas (WSR 15·2). In children aged 15-19 years (based on 100 860 cases), the ASR was 185·3 per million person-years, the most common being lymphomas (ASR 41·8) and the group of epithelial tumours and melanoma (ASR 39·5). Incidence varied considerably between and within the described regions, and by cancer type, sex, age, and racial and ethnic group. Since the 1980s, the global WSR of registered cancers in children aged 0-14 years has increased from 124·0 (95% CI 123·3-124·7) to 140·6 (140·1-141·1) per million person-years. INTERPRETATION: This unique global source of childhood cancer incidence will be used for aetiological research and to inform public health policy, potentially contributing towards attaining several targets of the Sustainable Development Goals. The observed geographical, racial and ethnic, age, sex, and temporal variations require constant monitoring and research. FUNDING: International Agency for Research on Cancer and the Union for International Cancer Control.

Burden and centralised treatment in Europe of rare tumours: results of RARECAREnet-a population-based study.

BACKGROUND: Rare cancers pose challenges for diagnosis, treatments, and clinical decision making. Information about rare cancers is scant. The RARECARE project defined rare cancers as those with an annual incidence of less than six per 100 000 people in European Union (EU). We updated the estimates of the burden of rare cancers in Europe, their time trends in incidence and survival, and provide information about centralisation of treatments in seven European countries. METHODS: We analysed data from 94 cancer registries for more than 2 million rare cancer diagnoses, to estimate European incidence and survival in 2000-07 and the corresponding time trends during 1995-2007. Incidence was calculated as the number of new cases divided by the corresponding total person-years in the population. 5-year relative survival was calculated by the Ederer-2 method. Seven registries (Belgium, Bulgaria, Finland, Ireland, the Netherlands, Slovenia, and the Navarra region in Spain) provided additional data for hospitals treating about 220 000 cases diagnosed in 2000-07. We also calculated hospital volume admission as the number of treatments provided by each hospital rare cancer group sharing the same referral pattern. FINDINGS: Rare cancers accounted for 24% of all cancers diagnosed in the EU during 2000-07. The overall incidence rose annually by 0.5% (99·8% CI 0·3-0·8). 5-year relative survival for all rare cancers was 48·5% (95% CI 48·4 to 48·6), compared with 63·4% (95% CI 63·3 to 63·4) for all common cancers. 5-year relative survival increased (overall 2·9%, 95% CI 2·7 to 3·2), from 1999-2001 to 2007-09, and for most rare cancers, with the largest increases for haematological tumours and sarcomas. The amount of centralisation of rare cancer treatment varied widely between cancers and between countries. The Netherlands and Slovenia had the highest treatment volumes. INTERPRETATION: Our study benefits from the largest pool of population-based registries to estimate incidence and survival of about 200 rare cancers. Incidence trends can be explained by changes in known risk factors, improved diagnosis, and registration problems. Survival could be improved by early diagnosis, new treatments, and improved case management. The centralisation of treatment could be improved in the seven European countries we studied. FUNDING: The European Commission (Chafea).

Cancer risk among children born after assisted conception.

BACKGROUND: Accurate population-based data are needed on the incidence of cancer in children born after assisted conception. METHODS: We linked data on all children born in Britain between 1992 and 2008 after assisted conception without donor involvement with data from the United Kingdom National Registry of Childhood Tumours to determine the number of children in whom cancer developed before 15 years of age. Cohort cancer rates were compared with population-based rates in Britain over the same period, with stratification for potential mediating and moderating factors, including sex, age at diagnosis, birth weight, singleton versus multiple birth, parity, parental age, type of assisted conception, and cause of parental infertility. RESULTS: The cohort consisted of 106,013 children born after assisted conception (700,705 person-years of observation). The average duration of follow-up was 6.6 years. Overall, 108 cancers were identified, as compared with 109.7 expected cancers (standardized incidence ratio, 0.98; 95% confidence interval [CI], 0.81 to 1.19; P=0.87). Assisted conception was not associated with an increased risk of leukemia, neuroblastoma, retinoblastoma, central nervous system tumors, or renal or germ-cell tumors. It was associated with an increased risk of hepatoblastoma (standardized incidence ratio, 3.64; 95% CI, 1.34 to 7.93; P=0.02; absolute excess risk, 6.21 cases per 1 million person-years) and rhabdomyosarcoma (standardized incidence ratio, 2.62; 95% CI, 1.26 to 4.82; P=0.02; absolute excess risk, 8.82 cases per 1 million person-years), with hepatoblastoma developing in 6 children and rhabdomyosarcoma in 10 children. The excess risk of hepatoblastoma was associated with low birth weight. CONCLUSIONS: There was no increase in the overall risk of cancer among British children born after assisted conception during the 17-year study period. Increased risks of hepatoblastoma and rhabdomyosarcoma were detected, but the absolute risks were small. (Funded by Cancer Research UK and others.).