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Little MP, Bazyka D, de Gonzalez AB, Brenner AV, Chumak VV, Cullings HM, Daniels RD, French B, Grant E, Hamada N, Hauptmann M, Kendall GM, Laurier D, Lee C, Lee WJ, Linet MS, Mabuchi K, Morton LM, Muirhead CR, Preston DL, Rajaraman P, Richardson DB, Sakata R, Samet JM, Simon SL, Sugiyama H, Wakeford R, Zablotska LB. A Historical Survey of Key Epidemiological Studies of Ionizing Radiation Exposure. Radiat Res 2024; 202:432-487. [PMID: 39021204 PMCID: PMC11316622 DOI: 10.1667/rade-24-00021.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 04/23/2024] [Indexed: 07/20/2024]
Abstract
In this article we review the history of key epidemiological studies of populations exposed to ionizing radiation. We highlight historical and recent findings regarding radiation-associated risks for incidence and mortality of cancer and non-cancer outcomes with emphasis on study design and methods of exposure assessment and dose estimation along with brief consideration of sources of bias for a few of the more important studies. We examine the findings from the epidemiological studies of the Japanese atomic bomb survivors, persons exposed to radiation for diagnostic or therapeutic purposes, those exposed to environmental sources including Chornobyl and other reactor accidents, and occupationally exposed cohorts. We also summarize results of pooled studies. These summaries are necessarily brief, but we provide references to more detailed information. We discuss possible future directions of study, to include assessment of susceptible populations, and possible new populations, data sources, study designs and methods of analysis.
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Affiliation(s)
- Mark P. Little
- Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892-9778, USA
- Faculty of Health and Life Sciences, Oxford Brookes University, Headington Campus, Oxford, OX3 0BP, UK
| | - Dimitry Bazyka
- National Research Center for Radiation Medicine, Hematology and Oncology, 53 Melnikov Street, Kyiv 04050, Ukraine
| | | | - Alina V. Brenner
- Radiation Effects Research Foundation, 5-2 Hijiyama Park, Minami-ku, Hiroshima 732-0815, Japan
| | - Vadim V. Chumak
- National Research Center for Radiation Medicine, Hematology and Oncology, 53 Melnikov Street, Kyiv 04050, Ukraine
| | - Harry M. Cullings
- Radiation Effects Research Foundation, 5-2 Hijiyama Park, Minami-ku, Hiroshima 732-0815, Japan
| | - Robert D. Daniels
- National Institute for Occupational Safety and Health, Cincinnati, OH, USA
| | - Benjamin French
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Eric Grant
- Radiation Effects Research Foundation, 5-2 Hijiyama Park, Minami-ku, Hiroshima 732-0815, Japan
| | - Nobuyuki Hamada
- Biology and Environmental Chemistry Division, Sustainable System Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Chiba 270-1194, Japan
| | - Michael Hauptmann
- Institute of Biostatistics and Registry Research, Brandenburg Medical School Theodor Fontane, 16816 Neuruppin, Germany
| | - Gerald M. Kendall
- Cancer Epidemiology Unit, Nuffield Department of Population Health, University of Oxford, Richard Doll Building, Old Road Campus, Headington, Oxford, OX3 7LF, UK
| | - Dominique Laurier
- Institute for Radiological Protection and Nuclear Safety, Fontenay aux Roses France
| | - Choonsik Lee
- Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892-9778, USA
| | - Won Jin Lee
- Department of Preventive Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Martha S. Linet
- Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892-9778, USA
| | - Kiyohiko Mabuchi
- Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892-9778, USA
| | - Lindsay M. Morton
- Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892-9778, USA
| | | | | | - Preetha Rajaraman
- Radiation Effects Research Foundation, 5-2 Hijiyama Park, Minami-ku, Hiroshima 732-0815, Japan
| | - David B. Richardson
- Environmental and Occupational Health, 653 East Peltason, University California, Irvine, Irvine, CA 92697-3957 USA
| | - Ritsu Sakata
- Radiation Effects Research Foundation, 5-2 Hijiyama Park, Minami-ku, Hiroshima 732-0815, Japan
| | - Jonathan M. Samet
- Department of Epidemiology, Colorado School of Public Health, Aurora, Colorado, USA
| | - Steven L. Simon
- Radiation Epidemiology Branch, National Cancer Institute, Bethesda, MD 20892-9778, USA
| | - Hiromi Sugiyama
- Radiation Effects Research Foundation, 5-2 Hijiyama Park, Minami-ku, Hiroshima 732-0815, Japan
| | - Richard Wakeford
- Centre for Occupational and Environmental Health, The University of Manchester, Ellen Wilkinson Building, Oxford Road, Manchester, M13 9PL, UK
| | - Lydia B. Zablotska
- Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, 550 16 Street, 2 floor, San Francisco, CA 94143, USA
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Desai S, Guddati AK. Bimodal Age Distribution in Cancer Incidence. World J Oncol 2022; 13:329-336. [PMID: 36660209 PMCID: PMC9822681 DOI: 10.14740/wjon1424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 11/05/2022] [Indexed: 12/26/2022] Open
Abstract
Cancer is caused by accumulation of genetic changes which include activation of protooncogenes and loss of tumor suppressor genes. The age-specific incidence of cancer in general increases with advancing age. However, some cancers exhibit a bimodal distribution. Commonly recognized cancers with bimodal age distribution include acute lymphoblastic leukemia, osteosarcoma, Hodgkin's lymphoma, germ cell tumors and breast cancer. Delayed infection hypothesis has been used to provide explanation for the early childhood peak in leukemias and lymphomas, whereas the peak at an older age is associated with accumulation of protooncogenes and weakened immune system. Further genetic analysis and histopathological variations point to distinctly different cancers, varying genetically and histologically, which are often combined under a single category of cancers. Tumor characteristics and age distribution of these cancers varies also by population groups and has further implications on cancer screening methods. Although significant advances have been made to explain the bimodal nature of such cancers, the specific genetic mechanisms for each age distribution remain to be elucidated. Further distinction among the different cancer subtypes may lead to improvements in individual risk assessments, prevention and enhancement of treatment strategies.
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Affiliation(s)
- Shreya Desai
- Division of Hematology/Oncology, Georgia Cancer Center, Augusta University, Augusta, GA 30912, USA
| | - Achuta K. Guddati
- Division of Hematology/Oncology, Georgia Cancer Center, Augusta University, Augusta, GA 30912, USA,Corresponding Author: Achuta Kumar Guddati, Division of Hematology/Oncology, Georgia Cancer Center, Augusta University, Augusta, GA 30909, USA.
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The Authors Respond. Epidemiology 2019; 30:e26-e27. [PMID: 30985530 DOI: 10.1097/ede.0000000000001018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Re. The Association Between Childhood Leukemia and Population Mixing: An Artifact of Focusing on Clusters? Epidemiology 2019; 30:e26. [PMID: 30985535 DOI: 10.1097/ede.0000000000001017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hwee J, Tait C, Sung L, Kwong JC, Sutradhar R, Pole JD. A systematic review and meta-analysis of the association between childhood infections and the risk of childhood acute lymphoblastic leukaemia. Br J Cancer 2017; 118:127-137. [PMID: 29065105 PMCID: PMC5765221 DOI: 10.1038/bjc.2017.360] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/19/2017] [Accepted: 09/21/2017] [Indexed: 01/02/2023] Open
Abstract
Background: To determine whether childhood infections were associated with the development of childhood acute lymphoblastic leukaemia (ALL). Methods: We included studies that assessed any infection in childhood prior to the diagnosis of ALL in children aged 0–19 years compared to children without cancer. The primary analysis synthesised any infection against the odds of ALL, and secondary analyses assessed the frequency, severity, timing of infections, and specific infectious agents against the odds of ALL. Subgroup analyses by data source were investigated. Results: In our primary analysis of 12 496 children with ALL and 2 356 288 children without ALL from 38 studies, we found that any infection was not associated with ALL (odds ratio (OR)=1.10, 95% CI: 0.95–1.28). Among studies with laboratory-confirmed infections, the presence of infections increased the odds of ALL by 2.4-fold (OR=2.42, 95% CI: 1.54–3.82). Frequency, severity, and timing of infection were not associated with ALL. Conclusions: The hypothesis put forward by Greaves and others about an infectious aetiology are neither confirmed nor refuted and the overall evidence remains inadequate for good judgement. The qualitative difference in the subgroup effects require further study, and future research will need to address the challenges in measuring infectious exposures.
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Affiliation(s)
- Jeremiah Hwee
- Dalla Lana School of Public Health, University of Toronto, Health Sciences Building, 155 College Street, Toronto, ON, Canada
| | - Christopher Tait
- Dalla Lana School of Public Health, University of Toronto, Health Sciences Building, 155 College Street, Toronto, ON, Canada
| | - Lillian Sung
- Division of Haematology/Oncology, Department of Pediatrics, The Hospital for Sick Children, 555 University Avenue, Toronto, ON, Canada.,Program in Child Health Evaluative Sciences, The Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street, Toronto, ON, Canada.,Institute of Health Policy, Management and Evaluation, University of Toronto, Health Sciences Building, 155 College Street, Toronto, ON, Canada
| | - Jeffrey C Kwong
- Dalla Lana School of Public Health, University of Toronto, Health Sciences Building, 155 College Street, Toronto, ON, Canada.,Institute for Clinical Evaluative Sciences, 2075 Bayview Avenue, Toronto, ON, Canada.,Department of Family and Community Medicine, University of Toronto, Toronto, ON Canada.,Public Health Ontario, Toronto, ON, Canada.,Toronto Western Family Health Team, University Health Network, Toronto, ON, Canada
| | - Rinku Sutradhar
- Dalla Lana School of Public Health, University of Toronto, Health Sciences Building, 155 College Street, Toronto, ON, Canada.,Institute for Clinical Evaluative Sciences, 2075 Bayview Avenue, Toronto, ON, Canada
| | - Jason D Pole
- Dalla Lana School of Public Health, University of Toronto, Health Sciences Building, 155 College Street, Toronto, ON, Canada.,Pediatric Oncology Group of Ontario, 480 University Avenue, Suite 1014, Toronto, ON, Canada
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Umweltbelastung und Krebsrisiko im Kindesalter. Monatsschr Kinderheilkd 2017. [DOI: 10.1007/s00112-017-0281-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Mueller W, Gilham C. Childhood leukemia and proximity to nuclear power plants: A systematic review and meta-analysis. J Cancer Policy 2015. [DOI: 10.1016/j.jcpo.2015.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Comment on 'Residential distance at birth from overhead high-voltage powerlines: childhood cancer risk in Britain 1962-2008'. Br J Cancer 2014; 111:2199-200. [PMID: 25386860 PMCID: PMC4260017 DOI: 10.1038/bjc.2014.334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Abstract
Acute lymphoblastic leukaemia occurs in both children and adults but its incidence peaks between 2 and 5 years of age. Causation is multifactorial and exogenous or endogenous exposures, genetic susceptibility, and chance have roles. Survival in paediatric acute lymphoblastic leukaemia has improved to roughly 90% in trials with risk stratification by biological features of leukaemic cells and response to treatment, treatment modification based on patients' pharmacodynamics and pharmacogenomics, and improved supportive care. However, innovative approaches are needed to further improve survival while reducing adverse effects. Prognosis remains poor in infants and adults. Genome-wide profiling of germline and leukaemic cell DNA has identified novel submicroscopic structural genetic changes and sequence mutations that contribute to leukaemogenesis, define new disease subtypes, affect responsiveness to treatment, and might provide novel prognostic markers and therapeutic targets for personalised medicine.
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Affiliation(s)
- Hiroto Inaba
- Department of Oncology, St Jude Children's Research Hospital and University of Tennessee Health Science Center, Memphis, TN 38105, USA.
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Kinlen LJ. An examination, with a meta-analysis, of studies of childhood leukaemia in relation to population mixing. Br J Cancer 2012; 107:1163-8. [PMID: 22955857 PMCID: PMC3461174 DOI: 10.1038/bjc.2012.402] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background: Marked influxes of people into rural areas, termed rural population mixing (PM), have been associated with excesses of childhood leukaemia (CL), consistent with mini-epidemics of a mainly immunising, subclinical infection to which CL is a rare response. For such situations of rural PM would promote contacts between infected and susceptible individuals, the latter tending to have a higher than average prevalence in rural or isolated areas. Confusion has arisen from some workers applying the term PM to non-rural situations lacking known recent change. Methods: Available PM studies using the original definition of influxes were examined, a meta-analysis carried out of studies of CL in relation to exposure to high levels of rural PM, and also a detailed analysis by age group. Results: The meta-analysis of 17 studies shows a significant CL excess in association with rural PM: overall relative risk (RR) at ages 0–14: 1.57; 95% confidence interval 1.44–1.72; at 0–4 years 1.72 (1.54–1.91). This contrasts with the absence of an excess of CL in similarly exposed urban areas (RR 1.00; 0.93–1.07), pointing to a high level of immunity there. The mixed results of studies using other definitions of PM were summarised. The excess associated with rural PM below age 2 years (RR 1.51; 1.17, 1.92) was not appreciably different from that at later childhood ages. Conclusion: Much of the inconsistency among studies ostensibly about CL and PM reflects the use of definitions other than that originally proposed. The broad similarity of the CL excess below age 2 with that at older childhood ages is inconsistent with the Greaves’ delayed infection hypothesis, since any infection underlying the former is difficult to consider as delayed.
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Affiliation(s)
- L J Kinlen
- Cancer Epidemiology Unit, University of Oxford, Richard Doll Building, Headington, Oxford OX3 7LF, UK.
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Wiemels J. Perspectives on the causes of childhood leukemia. Chem Biol Interact 2012; 196:59-67. [PMID: 22326931 PMCID: PMC3839796 DOI: 10.1016/j.cbi.2012.01.007] [Citation(s) in RCA: 158] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 01/05/2012] [Accepted: 01/24/2012] [Indexed: 12/22/2022]
Abstract
Acute leukemia is the most common cancer in children but the causes of the disease in the majority of cases are not known. About 80% are precursor-B cell in origin (CD19+, CD10+), and this immunophenotype has increased in incidence over the past several decades in the Western world. Part of this increase may be due to the introduction of new chemical exposures into the child's environment including parental smoking, pesticides, traffic fumes, paint and household chemicals. However, much of the increase in leukemia rates is likely linked to altered patterns of infection during early childhood development, mirroring causal pathways responsible for a similarly increased incidence of other childhood-diagnosed immune-related illnesses including allergy, asthma, and type 1 diabetes. Factors linked to childhood leukemia that are likely surrogates for immune stimulation include exposure to childcare settings, parity status and birth order, vaccination history, and population mixing. In case-control studies, acute lymphoblastic leukemia (ALL) is consistently inversely associated with greater exposure to infections, via daycare and later birth order. New evidence suggests also that children who contract leukemia may harbor a congenital defect in immune responder status, as indicated by lower levels of the immunosuppressive cytokine IL-10 at birth in children who grow up to contract leukemia, as well as higher need for clinical care for infections within the first year of life despite having lower levels of exposure to infections. One manifestation of this phenomenon may be leukemia clusters which tend to appear as a leukemia "outbreak" among populations with low herd immunity to a new infection. Critical answers to the etiology of childhood leukemia will require incorporating new tools into traditional epidemiologic approaches - including the classification of leukemia at a molecular scale, better exposure assessments at all points in a child's life, a comprehensive understanding of genetic risk factors, and an appraisal of the interplay between infectious exposures and the status of immune response in individuals.
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Affiliation(s)
- Joseph Wiemels
- Department of Epidemiology and Biostatistics, University of California San Francisco, Helen Diller Cancer Center Research Building, 1450 3rd Street, HD274, San Francisco, CA 94158, United States.
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Kulkarni K, Stobart K, Witol A, Rosychuk RJ. Leukemia and lymphoma incidence in children in Alberta, Canada: a population-based 22-year retrospective study. Pediatr Hematol Oncol 2011; 28:649-60. [PMID: 21981741 DOI: 10.3109/08880018.2011.613091] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
There is a paucity of published literature on the epidemiology of childhood acute leukemias and lymphomas in Canada. This study was designed to describe children and youth (age <20 years) diagnosed with acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), Hodgkin lymphoma (HL), and non-Hodgkin lymphoma (NHL) in Alberta, Canada, during 22 fiscal years. The Alberta Cancer Registry was used to extract data all ALL, AML, HL, and NHL cases diagnosed between April 1, 1982, and March 31, 2004. Population data for Alberta were also obtained. Descriptive statistics and cluster detection tests were used. During 22 years, 525, 117, 257, and 111 children (total = 1010) were diagnosed with ALL, AML, HL, and NHL, respectively. The median ages at diagnosis were 4, 11, 16, and 12 years for ALL, AML, HL, and NHL, respectively. The majority were male for ALL (287/525, 55%), AML (64/117, 55%), and NHL (81/111, 73%), and female for HL (133/257, 52%). The crude rates per 100,000 children were variable, without significant trends, over time and for each diagnosis; the median annual rates, per 100,000 children, were 3.00 (ranging from 1.87 to 3.75) for ALL, 0.62 (ranging from 0.26 to 1.27) for AML, 1.42 (ranging from 0.76 to 2.67) for HL, and 0.54 (ranging from 0.24 to 1.40) for NHL. A few potential spatiotemporal clusters were identified. They are likely due to small number of cases and plausibly clinically insignificant. Overall, childhood leukemia and lymphoma rates in Alberta have remained relatively stable, with no clear epidemiological trends and no significant spatiotemporal clustering. Further investigations are warranted to see if such stability continues and if spatiotemporal patterns arise from longer studies and studies in larger geographic regions with a larger sample size, whilst analyzing for other causal/associated factors, individual susceptibilities, and disease outcomes.
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Affiliation(s)
- Ketan Kulkarni
- Department of Pediatrics , Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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Mobbs SF, Muirhead CR, Harrison JD. Risks from ionising radiation: an HPA viewpoint paper for Safegrounds. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2011; 31:289-307. [PMID: 21865619 DOI: 10.1088/0952-4746/31/3/r01] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Safegrounds is a forum for developing and disseminating good practice guidance on the management of radioactively contaminated land on nuclear and defence sites in the UK. This review has been provided to Safegrounds as a summary of the basis for current radiation risk estimates and the International Commission on Radiological Protection (ICRP) protection system, in a form that will be accessible to a wide range of stakeholders. Safegrounds has also received viewpoint papers from other members who contend that the ICRP methodology results in substantial underestimates of risk, particularly for internal emitters. There is an extensive literature on the risks of radiation exposure, regularly reviewed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and other expert groups. These data provide a sound basis for the system of protection recommended by ICRP. The available epidemiological and experimental evidence supports the application of cancer risk estimates derived for acute, high dose, external exposures to low dose exposures to external and internal sources. In the context of radioactively contaminated land on nuclear and defence sites, the national standards for the cleaning up of land and for waste disposal correspond to very low doses, two orders of magnitude less than average annual doses in the UK from natural background radiation (10-20 µSv compared with 2-3 mSv). Risks at such very low doses can only be estimated on the basis of observations after exposure of population groups at much higher doses. The estimated risks at these very low doses, while uncertain, are as likely to be overestimates as underestimates.
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Affiliation(s)
- S F Mobbs
- Health Protection Agency, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxon, UK.
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Francis SS, Selvin S, Yang W, Buffler PA, Wiemels JL. Unusual space-time patterning of the Fallon, Nevada leukemia cluster: Evidence of an infectious etiology. Chem Biol Interact 2011; 196:102-9. [PMID: 21352818 DOI: 10.1016/j.cbi.2011.02.019] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 02/12/2011] [Accepted: 02/16/2011] [Indexed: 02/07/2023]
Abstract
The town of Fallon within Churchill County, Nevada exhibited an unusually high incidence of childhood leukemia during the years 1997-2003. We examined the temporal and spatial patterning of the leukemia case homes in comparison to the distribution of the general population at risk, other cancer incidence, and features of land use. Leukemia cases were predominantly diagnosed during the early to mid summer, exhibiting a seasonal bias. Leukemia cases lived outside of the "developed/urban" area of Fallon, predominantly in the "agriculture/pasture" region of Churchill County, circumscribing downtown Fallon. This pattern was different from the distribution of the underlying population (p-value<0.01) and different from the distribution of other cancers, which were evenly distributed when compared to the population (p-value=0.74). The unusual space-time patterning of childhood leukemia is consistent with the involvement of an infectious disease. A possible mode of transmission for such an infectious disease is by means of a vector, and mosquitoes are abundant in Churchill County outside of the urban area of Fallon. This region harbors a US Navy base, and a temporally concordant increase in military wide childhood leukemia rates suggests the base a possible source of the virus. Taken together, our current understanding of the etiology of childhood leukemia, the rural structure combined with temporal and geospatial patterning of these leukemia cases, and the high degree of population mixing in Fallon, suggest a possible infectious cause.
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Affiliation(s)
- Stephen S Francis
- Division of Epidemiology, School of Public Health, University of California, Berkeley, CA, United States
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Kinlen L. Childhood leukaemia, nuclear sites, and population mixing. Br J Cancer 2011; 104:12-8. [PMID: 21063418 PMCID: PMC3039801 DOI: 10.1038/sj.bjc.6605982] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 10/12/2010] [Accepted: 10/13/2010] [Indexed: 11/23/2022] Open
Abstract
The excess of childhood leukaemia (CL) in Seascale, near the Sellafield nuclear reprocessing site in rural NW England, suggested that an epidemic of an underlying infection, to which CL is a rare response, is promoted by marked population mixing (PM) in rural areas, in which the prevalence of susceptibles is higher than average. This hypothesis has been confirmed by 12 studies in non-radiation situations. Of the five established CL excesses near nuclear sites, four are associated with significant PM; in the fifth, the Krummel power station in Germany, the subject has not been thoroughly investigated.
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Affiliation(s)
- L Kinlen
- Cancer Epidemiology Unit, University of Oxford, Richard Doll Building, Headington, Oxford, OX3 7LF, UK.
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Mahjour SB, Ghaffarpasand F, Fattahi MJ, Ghaderi A, Fotouhi Ghiam A, Karimi M. Seroprevalence of Human Herpes Simplex, Hepatitis B and Epstein-Barr Viruses in Children with Acute Lymphoblastic Leukemia in Southern Iran. Pathol Oncol Res 2010; 16:579-82. [DOI: 10.1007/s12253-010-9258-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Accepted: 03/01/2010] [Indexed: 12/27/2022]
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Abstract
The acute leukaemias account for about 30% of all malignancy seen in childhood across the Western world. A peak incidence of precursor B cell ALL has emerged as socio-economic conditions have improved in countries worldwide. From twin studies and the use of neonatal blood spots it has been possible to back track the first initiating genetic events within critical haemopoietic cells to foetal development in utero for most precursor B cell ALL and some cases of AML. These events may occur as part of normal foetal development. Whether other factors (environmental or constitutional) are involved to increase the chance of these first genetic changes happening is unclear. For some leukaemias (e.g. infant MLL positive ALL) the first event appears adequate to create a malignant clone but for the majority of ALL and AML further 'genetic' changes are required, probably postnatal. Many environmental factors have been proposed as causative for leukaemia but only ionising irradiation and certain chemicals, e.g. benzene and cytotoxics (alkylators and topoisomerase II inhibitors) have been confirmed and then principally for acute myeloid leukaemia. It appears increasingly likely that delayed, dysregulated responses to 'common' infectious agents play a major part in the conversion of pre-leukaemic clones into overt precursor B cell ALL, the most common form of childhood leukaemia. Constitutional polymorphic alleleic variants in immune response genes (especially the HLA Class II proteins) and cytokines may play a role in determining the type of immune response. High penetrance germ-line mutations are involved in only about 5% of childhood leukaemias (more in AML than ALL). There is little evidence to support any role of viral transformation in causation, unlike in animals. Other environmental factors for which some evidence exists include non-ionising electromagnetic radiation and electric fields, although their mode of action in leukaemogenesis remains unclear. There is no single cause for childhood leukaemia and for most individuals a combination of factors appears to be necessary; all involving gene-environment interactions. To date few clear preventative measures have emerged, except the complete avoidance of first trimester X-rays in pregnancy; a healthy diet with adequate oral folic acid intake both preconception and early in pregnancy; and the early exposure of children to other children outside the home to facilitate stimulation and maturation of the natural immune system. Here then are clear echoes of the "hygiene hypothesis" regarding the initiation of allergies, autoimmune disease and type I diabetes mellitus in children and young people.
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Urayama KY, Buffler PA, Gallagher ER, Ayoob JM, Ma X. A meta-analysis of the association between day-care attendance and childhood acute lymphoblastic leukaemia. Int J Epidemiol 2010; 39:718-32. [PMID: 20110276 PMCID: PMC2878455 DOI: 10.1093/ije/dyp378] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background Childhood acute lymphoblastic leukaemia (ALL) may be the result of a rare response to common infection(s) acquired by personal contact with infected individuals. A meta-analysis was conducted to examine the relationship between day-care attendance and risk of childhood ALL, specifically to address whether early-life exposure to infection is protective against ALL. Methods Searches of the PubMed database and bibliographies of publications on childhood leukaemia and infections were conducted. Observational studies of any size or location and published in English resulted in the inclusion of 14 case–control studies. Results The combined odds ratio (OR) based on the random effects model indicated that day-care attendance is associated with a reduced risk of ALL [OR = 0.76, 95% confidence interval (CI): 0.67, 0.87]. In subgroup analyses evaluating the influence of timing of exposure, a similarly reduced effect was observed for both day-care attendance occurring early in life (≤2 years of age) (OR = 0.79, 95% CI: 0.65, 0.95) and day-care attendance with unspecified timing (anytime prior to diagnosis) (OR = 0.81, 95% CI: 0.70, 0.94). Similar findings were observed with seven studies in which common ALL were analysed separately. The reduced risk estimates persisted in sensitivity analyses that examined the sources of study heterogeneity. Conclusions This analysis provides strong support for an association between exposure to common infections in early childhood and a reduced risk of ALL. Implications of a ‘hygiene’-related aetiology suggest that some form of prophylactic intervention in infancy may be possible.
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Affiliation(s)
- Kevin Y Urayama
- School of Public Health, University of California, Berkeley, CA 94720, USA.
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Increasing steroid hormone receptors expression defines breast cancer subtypes non responsive to preoperative chemotherapy. Breast Cancer Res Treat 2008; 116:359-69. [DOI: 10.1007/s10549-008-0223-y] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2008] [Accepted: 10/02/2008] [Indexed: 12/26/2022]
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Law GR, Feltbower RG, Taylor JC, Parslow RC, Gilthorpe MS, Boyle P, McKinney PA. What do epidemiologists mean by 'population mixing'? Pediatr Blood Cancer 2008; 51:155-60. [PMID: 18421720 DOI: 10.1002/pbc.21570] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
There is growing evidence that some chronic diseases are caused, or promoted, by infectious disease. 'Population mixing' has been used as a proxy for the range and dose of infectious agents circulating in a community. Given the speculation over the role of population mixing in many chronic diseases, we review the various methods used for measuring population mixing, and provide a classification of these. We recommend that authors fulfill two criteria in publications: measures are demonstrably associated with the putative risk factors for which population-mixing is acting as a proxy and fundamental characteristics of the chosen measures are clearly defined.
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Affiliation(s)
- Graham R Law
- Biostatistics Unit, University of Leeds, Leeds, UK
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Clark BR, Ferketich AK, Fisher JL, Ruymann FB, Harris RE, Wilkins JR. Evidence of population mixing based on the geographical distribution of childhood leukemia in Ohio. Pediatr Blood Cancer 2007; 49:797-802. [PMID: 17366525 DOI: 10.1002/pbc.21181] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND This ecologic study examined the geographic distribution of childhood leukemias in Ohio, 1996-2000, among children aged 0-19 for evidence that population mixing may be a factor. PROCEDURE (1) State incidence rates were compared to Surveillance, Epidemiology and End Results (SEER) rates for each year and for the 5-year period, 1996-2000; (2) incidence rates for each of Ohio's 88 counties were compared to statewide rates; and (3) county incidence rates were compared based on population density, population growth, and rural/urban locale. SEER*Stat version 5.0 was used to derive age-specific and 0-19 age-adjusted rates. Expected values, standardized incidence ratios (SIRs), and Poisson P-values were calculated with Excel using the indirect method of standardization. RESULTS Of the 585 cases, 73.3% were acute lymphocytic leukemia (ALL), 16.6% acute myelogenous leukemia (AML), 3.2% acute monocytic leukemia (AMoL), and 2.6% chronic myelogenous leukemia (CML). Rates for total leukemia burden were significantly below national levels for all races (P = 0.00001), likely due to poor ascertainment of cases. Yearly incidence rates for 1996-2000 were stable for ALL and AML; CML rates declined over the period. Based on 2000 Census and intercensal population estimates for 1996-2000, statistically higher rates for ALL were noted for counties experiencing >10% population change 1990-2000 (P < 0.05), especially for ages 1-4 (P < 0.03) in counties with 10-20% growth. Counties 67.9-99.2% urban experienced fewer than expected cases of AML + AMoL (P < 0.06). CONCLUSION Data support Kinlen's theory of population mixing and warrant further studies in Ohio, the US and other countries.
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Affiliation(s)
- Brenda R Clark
- Division of Health Behavior and Health Promotion, School of Public Health, The Ohio State University, Ohio 43210, USA.
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Gustafsson B, Huang W, Bogdanovic G, Gauffin F, Nordgren A, Talekar G, Ornelles DA, Gooding LR. Adenovirus DNA is detected at increased frequency in Guthrie cards from children who develop acute lymphoblastic leukaemia. Br J Cancer 2007; 97:992-4. [PMID: 17876329 PMCID: PMC2360426 DOI: 10.1038/sj.bjc.6603983] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Epidemiological evidence suggests that childhood acute lymphoblastic leukaemia (ALL) may be initiated by an in infection in utero. Adenovirus DNA was detected in 13 of 49 neonatal blood spots from ALL patients but only in 3 of 47 controls (P=0.012) suggesting a correlation between prenatal adenovirus infection and the development of ALL
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Affiliation(s)
- B Gustafsson
- Department of Pediatrics, Karolinska University Hospital, Karolinska Institutet, Stockholm, Sweden.
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Li CK, Zee B, Lee J, Chik KW, Ha SY, Lee V. Impact of SARS on development of childhood acute lymphoblastic leukaemia. Leukemia 2007; 21:1353-6. [PMID: 17579654 PMCID: PMC7099337 DOI: 10.1038/sj.leu.2404729] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- C K Li
- Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - B Zee
- Centre for Clinical Trials, School of Public Health, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - J Lee
- Centre for Clinical Trials and Department of Clinical Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - K W Chik
- Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - S Y Ha
- Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, China
| | - V Lee
- Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
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Sheppard PR, Toepfer P, Schumacher E, Rhodes K, Ridenour G, Witten ML. Morphological and chemical characteristics of airborne tungsten particles of Fallon, Nevada. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2007; 13:296-303. [PMID: 17637079 DOI: 10.1017/s1431927607070237] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Accepted: 01/17/2007] [Indexed: 05/16/2023]
Abstract
Morphological and chemical characteristics were determined for airborne tungsten particles in Fallon, Nevada, a town that is distinguishable environmentally by elevated airborne tungsten and cobalt. From samples of airborne dust collected previously at six different places in Fallon, tungsten-rich dust particles were isolated and analyzed with automated electron microprobe and wavelength-dispersive spectrometry. Representative W particles were further analyzed using transmission electron microscopy. Morphologically, Fallon W particles are angular and small, with minimum and maximum sizes of < or = 1 microm and 5.9 microm in diameter, respectively. The number and size of tungsten-rich particles decrease in Fallon with distance from a hard-metal facility located near the center of town. Chemically, Fallon airborne W particles include mixtures of tungsten with cobalt plus other metals such as chromium, iron, and copper. No W-rich particles were identifiable as CaWO4 (scheelite) or MnWO4 (huebnerite). From d-spacings, Fallon particles are most consistent with identification as tungsten carbide. Based on these multiple lines of evidence, airborne W particles in Fallon are anthropogenic in origin, not natural. The hard-metal facility in Fallon processes finely powdered W and W-Co, and further investigation using tracer particles is recommended to definitively identify the source of Fallon's airborne tungsten.
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Affiliation(s)
- Paul R Sheppard
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona 85721, USA.
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Sheppard PR, Speakman RJ, Ridenour G, Witten ML. Temporal variability of tungsten and cobalt in Fallon, Nevada. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115:715-9. [PMID: 17520058 PMCID: PMC1867993 DOI: 10.1289/ehp.9451] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Accepted: 02/20/2007] [Indexed: 04/14/2023]
Abstract
BACKGROUND Since 1997, Fallon, Nevada, has experienced a cluster of childhood leukemia that has been declared "one of the most unique clusters of childhood cancer ever reported." Multiple environmental studies have shown airborne tungsten and cobalt to be elevated within Fallon, but the question remains: Have these metals changed through time in correspondence with the onset of the leukemia cluster? METHODS We used dendrochemistry, the study of element concentrations through time in tree rings, in Fallon to assess temporal variability of airborne tungsten and cobalt since the late 1980s. The techniques used in Fallon were also tested in a different town (Sweet Home, OR) that has airborne tungsten from a known source. RESULTS The Sweet Home test case confirms the accuracy of dendrochemistry for showing temporal variability of environmental tungsten. Given that dendrochemistry works for tungsten, tree-ring chemistry shows that tungsten increased in Fallon relative to nearby comparison towns beginning by the mid-1990s, slightly before the onset of the cluster, and cobalt has been high throughout the last approximately 15 years. Other metals do not show trends through time in Fallon. DISCUSSION Results in Fallon suggest a temporal correspondence between the onset of excessive childhood leukemia and elevated levels of tungsten and cobalt. Although environmental data alone cannot directly link childhood leukemia with exposure to metals, research by others has shown that combined exposure to tungsten and cobalt can be carcinogenic to humans. CONCLUSION Continued biomedical research is warranted to directly test for linkage between childhood leukemia and tungsten and cobalt.
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Affiliation(s)
- Paul R Sheppard
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona 85721, USA.
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Martinez JC, Cook JL. High-Risk Cutaneous Squamous Cell Carcinoma without Palpable Lymphadenopathy: Is There a Therapeutic Role for Elective Neck Dissection? Dermatol Surg 2007; 33:410-20. [PMID: 17430374 DOI: 10.1111/j.1524-4725.2007.33087.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE The beneficial role of elective neck dissection (END) in the management of high-risk cutaneous squamous cell carcinoma (CSCC) of the head and neck remains unproven. Some surgical specialists suggest that END may be beneficial for patients with clinically node-negative (N0) high-risk CSCC, but there are few data to support this claim. We reviewed the available literature regarding the use of END in the management of both CSCC and head and neck SCC (HNSCC). METHODOLOGY The available medical literature pertaining to END in both CSCC and HNSCC was reviewed using PubMed and Ovid Medline searches. RESULTS Many surgical specialists recommend that END be routinely performed in patients with N0 HNSCC when the risk of occult metastases is estimated to exceed 20%; however, patients who undergo END have no proven survival benefit over those who are initially staged as N0 and undergo therapeutic neck dissection (TND) after the development of apparent regional disease. There is a lack of data regarding the proper management of regional nodal basins in patients with N0 CSCC. In the absence of evidence-based data, the cutaneous surgeon must rely on clinical judgment to guide the management of patients with N0 high-risk CSCC of the head and neck. CONCLUSIONS Appropriate work-up for occult nodal disease may occasionally be warranted in patients with high-risk CSCC. END may play a role in only a very limited number of patients with high-risk CSCC.
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Little J, McLaughlin J, Miller A. Leukaemia in young children living in the vicinity of nuclear power plants. Int J Cancer 2007; 122:x-xi. [DOI: 10.1002/ijc.23347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Swanson J, Vincent T, Kroll M, Draper G. Power-frequency electric and magnetic fields in the light of Draper et al. 2005. Ann N Y Acad Sci 2006; 1076:318-30. [PMID: 17119212 DOI: 10.1196/annals.1371.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Power-frequency electric and magnetic fields are produced wherever electricity is used; exposure is ubiquitous. Epidemiologic studies find an association between children living in homes with the highest magnetic fields and childhood leukemia, but bias is a possible alternative to a causal explanation. A new study, Draper et al., looks at residence close to high-voltage power lines, one source of exposure to such fields, and its design avoids any obvious bias. It finds elevated childhood leukemia rates, but extending too far from the power lines to be straightforwardly compatible with the existing literature. This leads to an examination of alternative explanations: magnetic fields, other physical factors, such as corona ions, the characteristics of the areas power lines pass through, bias, and chance. The conclusion is that there is currently no single preferred explanation, but that this is a serious body of science that needs further work until an explanation is found.
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Kroll ME, Draper GJ, Stiller CA, Murphy MFG. RESPONSE: Re: Childhood Leukemia Incidence in Britain, 1974–2000: Time Trends and Possible Relation to Influenza Epidemics. J Natl Cancer Inst 2006. [DOI: 10.1093/jnci/djj472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Abstract
Much evidence has accumulated that childhood leukaemia (CL) is a rare response to a common, but unidentified, infection and in particular that situations involving the unusual mixing of urban and rural groups (approximating to, respectively, groups infected with, and susceptible to, the relevant microorganism) can produce localised epidemics with consequent increases of the infrequent leukaemic complication. During the Second World War, explosives production factories were built and operated at Drigg and Sellafield, and a shell filling factory at Bootle, in west Cumbria, England, requiring substantial numbers of construction workers to be brought into this remote and isolated area. Following the design of an earlier study of CL near large (post-war) rural construction sites, mortality from this disease was investigated with the help of the Office of National Statistics, in the area around these Cumbrian factories where local workers largely lived, during the construction period and with particular reference to the overlapping construction and operational phase when the mixing of local and migrant workers would have been greatest. An excess of leukaemia deaths at ages 1-14 was found during the construction period (observed 3; observed/expected (O/E) 2.2, 95% confidence interval (CI): 0.6, 6.0), which was more marked and statistically significant during the overlap with operations (O 3; O/E 4.5, 95% CI: 1.1, 12.2), especially at ages 1-4 (O 2; O/E 7.1, CI: 1.2, 23.6). A previous investigation did not detect this excess because it considered only a small part of west Cumbria that omitted the communities where most of the workforce lived, having incorrectly attributed the post-war expansion of the village of Seascale (situated between Drigg and Sellafield) to the wartime ordnance factories. The present findings are consistent with the results of the earlier study of rural construction projects and with the general evidence that marked rural-urban population mixing increases the risk of CL.
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Affiliation(s)
- L Kinlen
- Cancer Research UK Epidemiology Unit, University of Oxford, Richard Doll Building, Roosevelt Drive, Headington, Oxford OX3 7LF, UK.
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Kroll ME, Draper GJ, Stiller CA, Murphy MFG. Childhood leukemia incidence in Britain, 1974-2000: time trends and possible relation to influenza epidemics. J Natl Cancer Inst 2006; 98:417-20. [PMID: 16537835 DOI: 10.1093/jnci/djj095] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Time trends in incidence of disease may cast light on etiology. We investigated time trends in childhood leukemia by using Poisson regression methods to analyze data from the National Registry of Childhood Tumours, a long-standing high-quality registry that covers the whole childhood population of Britain. During 1974-2000, the average annual percentage change in rate (AAC) of childhood acute lymphoblastic leukemia (ALL) in Britain was 0.7% (95% confidence interval [CI] = 0.4 to 1.0). This increase was apparently driven by the "common" subtype (expressing the CD10 antigen) of precursor B-cell ALL, for which the estimated AAC during 1980-1996 was 1.4% (95% CI = 0.8 to 2.0). There was no statistically significant time trend in other subtypes of ALL combined (1980-1996) or in acute myeloid leukemia (1974-2000). Small peaks in incidence of ALL in 1976 and 1990 coincided with years immediately following influenza epidemics. These results are consistent with hypotheses that some childhood leukemia may be triggered by infection occurring close to the time of diagnosis of leukemia, particularly in conditions of low herd immunity, and raise the possibility that contact with influenza shortly before the diagnosis of leukemia may sometimes be involved.
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Affiliation(s)
- Mary E Kroll
- Childhood Cancer Research Group, University of Oxford, Oxford, United Kingdom.
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Abstract
Childhood leukaemia is the principal subtype of paediatric cancer and, despite success in treatment, its causes remain enigmatic. A plethora of candidate environmental exposures have been proposed, but most lack a biological rationale or consistent epidemiological evidence. Although there might not be a single or exclusive cause, an abnormal immune response to common infection(s) has emerged as a plausible aetiological mechanism.
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Affiliation(s)
- Mel Greaves
- The Institute of Cancer Research, Chester Beatty Laboratories, 237 Fulham Road, London SW3 6JB, United Kingdom.
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Ostroumova E, Gagnière B, Laurier D, Gudkova N, Krestinina L, Verger P, Hubert P, Bard D, Akleyev A, Tirmarche M, Kossenko M. Risk analysis of leukaemia incidence among people living along the Techa River: a nested case-control study. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2006; 26:17-32. [PMID: 16522942 DOI: 10.1088/0952-4746/26/1/001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Large quantities of radioactive materials released over time from the Mayak nuclear weapons facility caused significant internal and external exposure for people living along the banks of the Techa River (Southern Urals, Russia). We conducted a nested case-control study in the Extended Techa River Cohort to determine whether the risk of leukaemia incidence increased with protracted exposure to ionising radiation or with other non-radiation risk factors. The study included 83 cases identified over 47 years of follow-up and 415 controls matched for sex, age at diagnosis, age (within a 5 year age group), and date of initial residence in the riverside area. External and internal doses have been calculated using the Techa River Dosimetry System 1996 (TRDS96). Conditional logistic regression was used to calculate odds ratios per Gray (OR/Gy) and 95% confidence intervals (95% CI). After excluding cases of chronic lymphoid leukaemia, the OR/Gy of total, external, and internal doses were 4.6 (95% CI: 1.7-12.3), 7.2 (95%CI: 1.7-30.0) and 5.4 (95%CI: 1.1-27.2), respectively. A history of solid tumour, either malignant or benign, before the leukaemia diagnosis was associated with a 2.5-fold increase in the leukaemia risk (95% CI: 1.1-5.9). Even though the analysis of confounders was less useful than expected because of missing data, multivariate analyses that took the exposure dose into account confirmed the association between leukaemia incidence and tumour history.
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Affiliation(s)
- E Ostroumova
- Urals Research Center for Radiation Medicine, Chelyabinsk, Russia
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Heath CW. Community clusters of childhood leukemia and lymphoma: evidence of infection? Am J Epidemiol 2005; 162:817-22. [PMID: 16177146 DOI: 10.1093/aje/kwi289] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Information suggesting that infection may be an underlying cause of childhood leukemia and lymphoma includes the occasional appearance of cases in time-space clusters within communities and increased incidence after communities experience marked population influxes (population mixing). Among 50 clusters involving cases of childhood leukemia and lymphoma investigated in the United States in 1961-1977, eight showed suggestive evidence of underlying infectious causation. In seven of the eight communities, case occurrence was associated with the attendance of patients or their siblings at particular schools or with family participation in particular church groups. In five, rapid population growth had occurred. Other findings included the possible association of cases with unusual patterns of infectious disease (rheumatic illness in one community, chickenpox in another) and with other childhood diseases, including other forms of childhood cancer. In one community, two cases of Burkitt's lymphoma occurred at the same time, and a third case arose 3 years later in boys living in a newly developing neighborhood. Such community observations support the need for continued biologic research regarding the possible role of infectious agents in childhood leukemia and lymphoma.
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Draper G, Vincent T, Kroll ME, Swanson J. Childhood cancer in relation to distance from high voltage power lines in England and Wales: a case-control study. BMJ 2005; 330:1290. [PMID: 15933351 PMCID: PMC558197 DOI: 10.1136/bmj.330.7503.1290] [Citation(s) in RCA: 219] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To determine whether there is an association between distance of home address at birth from high voltage power lines and the incidence of leukaemia and other cancers in children in England and Wales. DESIGN Case-control study. SETTING Cancer registry and National Grid records. SUBJECTS Records of 29 081 children with cancer, including 9700 with leukaemia. Children were aged 0-14 years and born in England and Wales, 1962-95. Controls were individually matched for sex, approximate date of birth, and birth registration district. No active participation was required. MAIN OUTCOME MEASURES Distance from home address at birth to the nearest high voltage overhead power line in existence at the time. RESULTS Compared with those who lived > 600 m from a line at birth, children who lived within 200 m had a relative risk of leukaemia of 1.69 (95% confidence interval 1.13 to 2.53); those born between 200 and 600 m had a relative risk of 1.23 (1.02 to 1.49). There was a significant (P < 0.01) trend in risk in relation to the reciprocal of distance from the line. No excess risk in relation to proximity to lines was found for other childhood cancers. CONCLUSIONS There is an association between childhood leukaemia and proximity of home address at birth to high voltage power lines, and the apparent risk extends to a greater distance than would have been expected from previous studies. About 4% of children in England and Wales live within 600 m of high voltage lines at birth. If the association is causal, about 1% of childhood leukaemia in England and Wales would be attributable to these lines, though this estimate has considerable statistical uncertainty. There is no accepted biological mechanism to explain the epidemiological results; indeed, the relation may be due to chance or confounding.
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Affiliation(s)
- Gerald Draper
- Childhood Cancer Research Group, University of Oxford, Oxford OX2 6HJ.
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Mejía-Aranguré JM, Bonilla M, Lorenzana R, Juárez-Ocaña S, de Reyes G, Pérez-Saldivar ML, González-Miranda G, Bernáldez-Ríos R, Ortiz-Fernández A, Ortega-Alvarez M, Martínez-García MDC, Fajardo-Gutiérrez A. Incidence of leukemias in children from El Salvador and Mexico City between 1996 and 2000: population-based data. BMC Cancer 2005; 5:33. [PMID: 15807901 PMCID: PMC1090561 DOI: 10.1186/1471-2407-5-33] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2004] [Accepted: 04/04/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND There are very few studies that report the incidence of acute leukemias in children in Latin America. This work assesses the incidence of acute leukemias, between 1996 and 2000, in children from 0-14 years old who were attended at the Mexican Social Security Institute in Mexico City and in children from 0-11 years old in El Salvador. METHODS DESIGN Population-based data. Hospitals: In San Salvador, El Salvador, Hospital Nacional de Niños "Benjamin Bloom", the only center in El Salvador which attends all children, younger than 12 years, with oncologic disease. The Pediatric Hospital and the General Hospital of the Mexican Social Security Institute in Mexico City, the only centers in Mexico City which attend all those children with acute leukemia who have a right to this service. DIAGNOSIS All patients were diagnosed by bone marrow smear and were divided into acute lymphoid leukemia (ALL), acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and unspecified leukemias (UL). The annual incidence rate (AIR) and average annual incidence rate (AAIR) were calculated per million children. Cases were stratified by age and assigned to one of four age strata: 1) <1 year; 2) 1-4 years; 3) 5-9 years, or 4) 10-14 or 10-11 years, for Mexico City and El Salvador, respectively. RESULTS The number of cases was 375 and 238 in El Salvador and Mexico City, respectively. AAIRs in Mexico City were 44.9, 10.6, 2.5, 0.5, and 58.4 per million children for ALL, AML, CML, UL, and total leukemias, respectively. The AAIRs in El Salvador could not be calculated because the fourth age stratum in El Salvador included children only from 0-11 years old. The incidence rates for the Salvadorian group of 0-11 year olds were 34.2, 7.1, 0.6, 0.2, and 43.2 per million children for ALL, AML, CML, UL, and total leukemias, respectively. CONCLUSION Reported AIRs for each age group in El Salvador were similar to those from other American countries. The AAIR of ALL in Mexico City is one of the highest reported for North America.
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Affiliation(s)
| | - Miguel Bonilla
- Hematology-Oncology, Hospital Nacional de Niños "Benjamín Bloom", San Salvador, El Salvador
- Department of Pediatrics, School of Medicine, Universidad de El Salvador, San Salvador, El Salvador
| | | | - Servando Juárez-Ocaña
- Clinical Epidemiology, Pediatric Hospital, Centro Médico Nacional "Siglo XXI", Mexico City, Mexico
| | - Gladys de Reyes
- Hematology-Oncology, Hospital Nacional de Niños "Benjamín Bloom", San Salvador, El Salvador
| | | | | | | | | | - Manuel Ortega-Alvarez
- Clinical Epidemiology, Pediatric Hospital, Centro Médico Nacional "Siglo XXI", Mexico City, Mexico
| | | | - Arturo Fajardo-Gutiérrez
- Clinical Epidemiology, Pediatric Hospital, Centro Médico Nacional "Siglo XXI", Mexico City, Mexico
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Kinlen LJ. Childhood leukemia, military aviation facilities, and population mixing. ENVIRONMENTAL HEALTH PERSPECTIVES 2004; 112:A797-A798. [PMID: 15471717 PMCID: PMC1247579 DOI: 10.1289/ehp.112-a797] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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Abstract
An infective, mostly viral, basis has been found in an increasing number of different human cancers. In all cases, the neoplasm is a rare response to the relevant infection, which is usually present in persistent form, and requiring specific cofactors for malignancy to develop. In some cases, epidemiological evidence of infectivity preceded and promoted identification of the specific infection involved and even the discovery of the microbe itself, as in Burkitt's lymphoma and cervix cancer. In other cases, the discovery of the agent came first as in stomach and nasopharynx cancers, and epidemiology has been concerned mainly with confirming the relationship, measuring the size of the risk and identifying cofactors. Infection-linked cancers include some of the commonest malignancies in certain large world regions, amounting to over 20% of all cancer in the developing countries. In addition to these cancers are others such as childhood leukaemia that show features indicative of an infective basis though no underlying agent has been identified. Advances in this field invite speculation about possible future discoveries and how these might be promoted. However, in that majority of cancers that are unrelated to sexual behaviour, there will be nothing even at the population level to suggest an infective basis because what is transmitted from one individual to another is not the neoplasm itself, but the underlying, often silent, infection to which the malignancy is an uncommon response. The increasing prevalence of immune impairment in human populations, as a result of the use of immunosuppressive drugs with organ transplants and the spread of HIV infection, has produced marked effects on cancer incidence in the affected groups including increases, of skin cancers, non-Hodgkin's lymphoma and Kaposi's sarcoma and to a lesser extent of many other cancers, in some cases at least due to the release from immunological control of incipient infection-based malignancies.
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Affiliation(s)
- Leo Kinlen
- Cancer Epidemiology Unit, Gibson Building, Radcliffe Infirmary, Oxford OX2 6HE, UK.
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