Spatial clustering of childhood cancer in Great Britain during the period 1969–1993

Authors

  • Richard J.Q. McNally,

    Corresponding author
    1. School of Clinical Medical Sciences (Child Health) and Institute of Health and Society, Sir James Spence Institute, Newcastle University, Royal Victoria Infirmary, Newcastle-upon-Tyne, United Kingdom
    • Sir James Spence Institute, Newcastle University, Royal Victoria Infirmary, Queen Victoria Road, Newcastle-upon-Tyne NE1 4LP, United Kingdom
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    • Fax: +44 191 202 3060

  • Freda E. Alexander,

    1. Department of Public Health Sciences, The University of Edinburgh Medical School, Teviot Place, Edinburgh, United Kingdom
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  • Tim J. Vincent,

    1. Childhood Cancer Research Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
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  • Michael F.G. Murphy

    1. Childhood Cancer Research Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom
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Abstract

The aetiology of childhood cancer is poorly understood. Both genetic and environmental factors are likely to be involved. The presence of spatial clustering is indicative of a very localized environmental component to aetiology. Spatial clustering is present when there are a small number of areas with greatly increased incidence or a large number of areas with moderately increased incidence. To determine whether localized environmental factors may play a part in childhood cancer aetiology, we analyzed for spatial clustering using a large set of national population-based data from Great Britain diagnosed 1969–1993. The Potthoff-Whittinghill method was used to test for extra-Poisson variation (EPV). Thirty-two thousand three hundred and twenty-three cases were allocated to 10,444 wards using diagnosis addresses. Analyses showed statistically significant evidence of clustering for acute lymphoblastic leukaemia (ALL) over the whole age range (estimate of EPV = 0.05, p = 0.002) and for ages 1–4 years (estimate of EPV = 0.03, p = 0.015). Soft-tissue sarcoma (estimate of EPV = 0.03, p = 0.04) and Wilms tumours (estimate of EPV = 0.04, p = 0.007) also showed significant clustering. Clustering tended to persist across different time periods for cases of ALL (estimate of between-time period EPV = 0.04, p =0.003). In conclusion, we observed low level spatial clustering that is attributable to a limited number of cases. This suggests that environmental factors, which in some locations display localized clustering, may be important aetiological agents in these diseases. For ALL and soft tissue sarcoma, but not Wilms tumour, common infectious agents may be likely candidates. © 2008 Wiley-Liss, Inc.

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