Objective: To examine the association between population mixing and the incidence of childhood leukemia, specifically the acute lymphocytic leukemia (ALL) subtype among young children.
Methods: This ecologic study was based on incidence rates of leukemia in children aged 0–14 years. The Ontario Cancer Registry was used to identify the residence of 1394 leukemia cases between 1978 and 1992. Ecologic units were composed of census subdivisions in a 5-year period. Percent population change, determined from the Census of Canada, was employed as a measure of population mixing. The relationship between population mixing and childhood leukemia was examined separately after stratifying by the level of geographic isolation, defined according to urban–rural status. Analyses were also conducted separately in specific age groups and for the ALL subtype.
Results: Population growth in rural areas was associated with an increased incidence of leukemia, particularly for the ALL subtype in children aged 0–4 years (rate ratio = 1.8, 95% confidence interval 1.1–2.8, for a greater than 20% population change relative to no increase in population). In contrast, an elevated risk due to population mixing was not observed in urban areas.
Conclusions: Results from this study are consistent with results from similar studies conducted in the United Kingdom, which are suggestive of a role for an infectious agent in the etiology of childhood leukemia, as proposed in the Kinlen hypothesis.
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Alexander FE (1993) Viruses, clusters and clustering of childhood leukaemia: a new perspective? Eur J Cancer 29A: 1424–1443.
Schulz TF, Neil JC (1996) Viruses and leukemia. In: Henderson ES, Lister TA, Greaves MF, eds. Leukemia, 6th edn. Philadelphia: Saunders, pp. 160–178.
Kinlen LJ (1988) Evidence for an infective cause of childhood leukaemia: comparison of a Scottish New Town with nuclear reprocessing sites in Britain. Lancet 2: 1323–1327.
Kinlen LJ (1995) Epidemiological evidence for an infective basis in childhood leukaemia. Br J Cancer 71: 1–5.
Kinlen LJ, Dickson M, Stiller CA (1995) Childhood leukaemia and non-Hodgkin's lymphoma near large rural construction sites, with a comparison with Sellafield nuclear site. BMJ 310: 763–768.
Kinlen LJ, Petridou E (1995) Childhood leukemia and rural population movements: Greece, Italy, and other countries. Cancer Causes Control 6: 445–450.
Gilman EA, Knox EG (1998) Geographical distribution of birth places of children with cancer in the UK. Br J Cancer 77: 842–849.
Langford I (1991) Childhood leukaemia mortality and population change in England and Wales 1969–73. Soc Sci Med 33: 435–440.
Rodrigues L, Hills M, McGale P, Elliott P (1991) Socio-economic factors in relation to childhood leukaemia and non-Hodgkin lymphomas: an analysis based on small area statistics for census tracts. In: Draper GJ, ed. The Geographical Epidemiology of Childhood Leukaemia and Non-Hodgkin's Lymphomas in Great Britain, 1966–83, London: HMSO, pp. 47–56.
Stiller CA, Boyle PJ (1996) Effect of population mixing and socioeconomic status in England and Wales, 1979–85, on lymphoblastic leukaemia in children. BMJ 313: 1297–1300.
Alexander FE, Chan LC, Lam TH, et al. (1997) Clustering of childhood leukaemia in Hong Kong: association with the childhood peak and common acute lymphoblastic leukaemia and with population mixing. Br J Cancer 75: 457–463.
Dickinson HO, Parker L (1999) Quantifying the effect of population mixing on childhood leukaemia risk: the Seascale cluster. Br J Cancer 81: 144–151.
MacMahon B (1992) Is acute lymphoblastic leukemia in children virus-related? Am J Epidemiol 136: 916–924.
Alexander FE, Ricketts TJ, McKinney PA, Cartwright RA (1990) Community lifestyle characteristics and risk of acute lymphoblastic leukaemia in children. Lancet 336: 1461–1465.
Petridou E, Hsieh CC, Kotsifakis G, Skalkidis Y, Trichopoulos D (1991) Absence of leukaemia clustering on Greek islands. Lancet 338: 1204–1205.
Dockerty JD, Cox B, Borman B, Sharples K (1996) Population mixing and the incidence of childhood leukaemias: retrospective comparison in rural areas of New Zealand. BMJ 312: 1203–1204.
National Cancer Institute of Canada (2000) Canadian Cancer Statistics 2000. Toronto, Ontario: NCIC.
Statistics Canada (1993) Geography Guide Book. Ottawa: Industry, Science and Technology Canada. 1991 Census of Canada. Catalogue number 92–310E.
Clarke EA, Marrett LD, Kreiger N (1991) Cancer registration in Ontario: a computer approach. In: Jensen OM, Parkin DM, MacLennan R, Muir CS, Skeet RG, eds. Cancer Registration: Principles and Methods. IARC Scientific Publications No. 95. Lyon: International Agency for Research on Cancer, pp. 246–257.
Robles SC, Marrett LD, Clarke EA, Risch HA (1988) An application of capture-recapture methods to the estimation of completeness of cancer registration. J Clin Epidemiol 41: 495–501.
World Health Organization (1977) Ninth Revision Conference, 1975. Manual of the International Statistical Classification of Diseases, Injuries and Causes of Death, vol. 1. Geneva: World Health Organization.
World Health Organization (1976) ICD-O. International Classification of Diseases for Oncology, 1st edn. Geneva: World Health Organization.
Statistics Canada (1982) Census Divisions and Subdivisions — Population, Occupied Private Dwelling, Private Households, Census Families in Private Households Selected Characteristics. Ottawa: Supply and Services Canada, 1982. 1981 Census of Canada. Catalogue number 93-X-918 (E-564).
Statistics Canada (1987) Population and Dwelling Characteristics-Census Divisions and Subdivisions Ontario: Part 1. Profiles. Ottawa: Supply and Services Canada. 1986 Census of Canada. Catalogue number 94–111.
Statistics Canada (1992) Profile of Census Divisions and Subdivisions in Ontario, Part A. Ottawa: Industry, Science and Technology Canada. 1991 Census of Canada. Catalogue number 95–337.
Statistics Canada (1992) 1991 Census Dictionary. Ottawa: Supply and Services Canada. 1991 Census of Canada. Catalogue number 92–301E.
Hertz-Picciotto I (1998) Environmental epidemiology. In: Rothman KJ, Greenland S, eds. Modern Epidemiology, 2nd edn. Philadelphia: Lippincott-Raven, pp. 555–583.
Sandler DP, Ross JA (1997) Epidemiology of acute leukemia in children and adults. Semin Oncol 24: 3–16.
Westergaard T, Andersen PK, Pedersen JB, et al. (1997) Birth characteristics, sibling patterns, and acute leukemia risk in childhood: a population-based cohort study. J Natl Cancer Inst 89: 939–947.
Greaves MF, Alexander FE (1993) An infectious etiology for common acute lymphoblastic leukemia in childhood? Leukemia 7: 349–360.
Greaves MF (1997) Aetiology of acute leukaemia. Lancet 349: 344–349.
Alexander FE, Cartwright RA, McKinney PA, Ricketts TJ (1990) Leukaemia incidence, social class and estuaries: an ecological analysis. J Public Health Med 12: 109–117.
Petridou E, Kassimos D, Kalmanti M, et al. (1993) Age of exposure to infections and risk of childhood leukaemia. BMJ 307: 774.
Petridou E, Trichopoulos D, Kalapothaki V, et al. (1997) The risk profile of childhood leukaemia in Greece: a nationwide case-control study. Br J Cancer 76: 1241–1247.
Kaye SA, Robison LL, Smithson WA, Gunderson P, King FL, Neglia JP (1991) Maternal reproductive history and birth characteristics in childhood acute lymphoblastic leukemia. Cancer 68: 1351–1355.
Kinlen LJ, Clarke K, Hudson C (1990) Evidence from population mixing in British New Towns 1946–85 of an infective basis for childhood leukaemia. Lancet 336: 577–582.
Walter SD (1991) The ecologic method in the study of environmental health. II. Methodologic issues and feasibility. Environ Health Perspect 94: 67–73.
Morgenstern H (1995) Ecologic studies in epidemiology: concepts, principles, and methods. Annu Rev Public Health 16: 61–81.
Muirhead CR (1995) Childhood leukemia in metropolitan regions in the United States: a possible relation to population density? Cancer Causes Control 6: 383–388.
Alexander FE, Boyle P, Carli P-M, et al. (1999) Population density and childhood leukaemia: Results of the EUROCLUS study. Eur J Cancer 35: 439–444.
Li C-Y, Lin RS, Lin C-H. (1998) Urbanization and childhood leukaemia in Taiwan. Int J Epidemiol 27: 587–591.
Hjalmars U, Gustafsson G. (1999) Higher risk for acute childhood lymphoblastic leukaemia in Swedish population centres 1973–94. Br J Cancer 79: 30–33.
Draper GJ, ed. (1991) The Geographical Epidemiology of Childhood Leukaemia and Non-Hodgkin's Lymphomas in Great Britain, 1966–83. London: HMSO.
Langford IH, Bentham G. (1993) Epidemiology of childhood leukaemia. BMJ 307: 445–446.
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Koushik, A., King, W.D. & McLaughlin, J.R. An ecologic study of childhood leukemia and population mixing in Ontario, Canada. Cancer Causes Control 12, 483–490 (2001). https://doi.org/10.1023/A:1011266413087
- age distribution
- childhood leukemia
- population mixing
- urban–rural status