Advertisement

Canadian Journal of Public Health

, Volume 108, Issue 5–6, pp e558–e564 | Cite as

Geographic variation and factors associated with colorectal cancer incidence in Manitoba

  • Harminder SinghEmail author
  • Zoann Nugent
  • Kathleen Decker
  • Alain Deniers
  • Jewel Samaddar
  • Mahmoud Torabi
Quantitative Research
  • 1 Downloads

Abstract

OBJECTIVES: Although individuals living in areas with lower household income have been shown to have higher rates of mortality from colorectal cancer (CRC), findings on the effect of income on CRC incidence in countries with universal health care have been inconsistent. There are limited data from Canada. We investigated the geographic variation and factors associated with CRC incidence in Manitoba, a central Canadian province.

METHODS: The Manitoba Cancer Registry and Manitoba Health population registry were used to determine age-sex-standardized CRC incidence rates between 1985 and 2012, which were geocoded to 498 small geographic areas (SGAs). The 2001 Canadian Census was used to determine the socio-demographic characteristics of the SGAs. Bayesian spatial Poisson modelling was used to assess geographic variation and factors associated with CRC incidence.

RESULTS: CRC incidence in SGAs ranged from 11 to 1026 per 100 000 population per year. Importantly, in the fully adjusted model there was no significant association between either average household income or proportion of recent immigrants in the SGAs and CRC incidence. Individuals living in urban areas had an overall lower CRC incidence (incidence rate ratio: 0.76; 95% credible interval: 0.58–0.98).

CONCLUSIONS: In a province with a universal health care system, our study suggests there are no disparities in CRC incidence by socio-economic level of the areas of residence. Rural areas should be a focus of CRC reduction initiatives in Manitoba. Similar analysis in other jurisdictions should be performed to evaluate the effect of the characteristics of SGAs on CRC incidence in different settings and target some of the efforts to reduce CRC burden.

Key words

Epidemiology spatial analysis variation in risk disparities 

Résumé

OBJECTIFS: Il a été démontré à maintes reprises que les résidents des zones où le revenu des ménages est faible présentent des taux de mortalité due au cancer colorectal (CCR) plus élevés, mais l’effet du revenu sur l’incidence du CCR dans les pays dotés d’un système de soins de santé universel ne fait pas l’unanimité. Les données du Canada en la matière sont limitées. Nous avons étudié la variation spatiale de l’incidence du CCR et les facteurs associés au Manitoba, une province du centre du Canada.

MÉTHODE: Le Registre du cancer du Manitoba et le registre de la population de Santé Manitoba ont servi à déterminer les taux d’incidence du CCR standardisés pour l’âge et le sexe entre 1985 et 2012; ces taux ont ensuite été géocodés selon 498 petites régions géographiques (PRG). Le Recensement du Canada du 2001 a servi à déterminer le profil sociodémographique de ces PRG. Un modèle bayésien d’analyse de données spatiales et de régression de Poisson a servi à évaluer la variation spatiale de l’incidence du CCR et des facteurs associés.

RÉSULTATS L’incidence du CCR dans les PRG variait de 11 à 1 026 pour 100 000 habitants par année. Il est important de noter que dans le modèle entièrement rajusté, aucune association significative n’a été observée entre le revenu moyen des ménages ou la proportion d’immigrants récents dans les PRG, et l’incidence du CCR. Les résidents des agglomérations urbaines présentaient dans l’ensemble une plus faible incidence de CCR (rapport de taux d’incidence: 0,76; intervalle de crédibilité de 95 %: 0,58–0,98).

CONCLUSIONS: Dans une province dotée d’un système de soins de santé universel, notre étude indique qu’il n’y a aucune disparité dans l’incidence du CCR selon le niveau socioéconomique des régions de résidence. Les milieux ruraux devraient faire l’objet d’initiatives de réduction du CCR au Manitoba. Des analyses semblables devraient être effectuées dans d’autres collectivités publiques pour évaluer l’effet des caractéristiques des PRG sur l’incidence du CCR dans différents milieux et pour cibler une partie des efforts de réduction de la charge de morbidité de ce cancer.

Mots clés

épidémiologie analyse spatiale variation du risque disparités 

References

  1. 1.
    Canadian Cancer Society’s Advisory Committee on Cancer Statistics. Canadian Cancer Statistics 2015. Toronto, ON: Canadian Cancer Society, 2015.Google Scholar
  2. 2.
    Murphy CC, Sandler RS, Sanoff HK, Yang YC, Lund JL, Baron JA. Decrease in incidence of colorectal cancer among individuals 50 years or older after recommendations for population-based screening. Clin Gastroenterol Hepatol 2016;15(6):903–9.e6. PMID: 27609707. doi: 10.1016/j.cgh.2016.08.037.CrossRefGoogle Scholar
  3. 3.
    Saldana-Ruiz N, Clouston SA, Rubin MS, Colen CG, Link BG. Fundamental causes of colorectal cancer mortality in the United States: Understanding the importance of socioeconomic status in creating inequality in mortality. Am J Public Health 2013;103:99–104. PMID: 23153135. doi: 10.2105/AJPH.2012.300743.CrossRefGoogle Scholar
  4. 4.
    Doubeni CA, Laiyemo AO, Major JM, Schootman M, Lian M, Park Y, et al. Socioeconomic status and the risk of colorectal cancer: An analysis of more than a half million adults in the National Institutes of Health-AARP Diet and Health Study. Cancer 2012;118:3636–44. PMID: 22898918. doi: 10.1002/cncr.26677.CrossRefGoogle Scholar
  5. 5.
    Link BG, Phelan J. Social conditions as fundamental causes of disease. J Health Soc Behav 1995;35(Extra Issue):80–94. PMID: 7560851. doi: 10.2307/2626958.CrossRefGoogle Scholar
  6. 6.
    Gorey KM, Holowaty EJ, Laukkanen E, Fehringer G, Richter NL. Association between socioeconomic status and cancer incidence in Toronto, Ontario: Possible confounding of cancer mortality by incidence and survival. Cancer Prev Control 1998;2:236–41. PMID: 10093638.PubMedGoogle Scholar
  7. 7.
    Mackillop WJ, Zhang-Salomons J, Boyd CJ, Groome PA. Associations between community income and cancer incidence in Canada and the United States. Cancer 2000;89:901–12. PMID: 10951356. doi: 10.1002/1097-0142(2000 0815)89:4<901::AID-CNCR25>3.0.CO;2-I.CrossRefGoogle Scholar
  8. 8.
    Torabi M, Green C, Nugent Z, Groome PA. Geographical variation and factors associated with colorectal cancer mortality in a universal health care system. Can J Gastroenterol Hepatol 2014;28:191–97. PMID: 24729992. doi: 10.1155/2014/707420.CrossRefGoogle Scholar
  9. 9.
    Manitoba Health. Manitoba Health, Healthy Living and Seniors Population Report June 1, 2015. Winnipeg, MB: Government of Manitoba, 2015.Google Scholar
  10. 10.
    Hotes Ellison J, Wu XC, McLaughlin C, Lake A, Firth R, Cormier M, et al. Cancer in North America: 1999–2003. Volume One: Incidence. Springfield, IL: North American Association of Central Cancer Registries Inc., 2006; 11–325.Google Scholar
  11. 11.
    Torabi M, Rosychuk RJ. Hierarchical Bayesian spatiotemporal analysis of childhood cancer trends. Geogr Anal 2012;44:109–20. doi: 10.1111/j.1538-4632.2012.00839.x.CrossRefGoogle Scholar
  12. 12.
    Torabi M. Hierarchical Bayes estimation of spatial statistics for rates. J Stat Plan Inference 2012;142:358–65. doi: 10.1016/j.jspi.2011.07.026.CrossRefGoogle Scholar
  13. 13.
    Jenks GF. The data model concept in statistical mapping. In: Frenzel K, Philip G (Eds.), International Yearbook of Cartography, Vol. 7. Bonn-Bad Godesberg, Germany: Kirschbaum Verlag, 1967; 186–90.Google Scholar
  14. 14.
    Iacopetta B. Are there two sides to colorectal cancer? Int J Cancer 2002;101:403–8. PMID: 12216066. doi: 10.1002/ijc.10635.CrossRefGoogle Scholar
  15. 15.
    Nawa T, Kato J, Kawamoto H, Okada H, Yamamoto H, Kohno H. Differences between right- and left-sided colon cancer in patient characteristics, cancer morphology and histology. J Gastroenterol Hepatol 2008;23:418–23. PMID: 17532785. doi: 10.1111/j.1440-1746.2007.04923.X.CrossRefGoogle Scholar
  16. 16.
    Singh H, Nugent Z, Demers AA, Kliewer EV, Mahmud SM, Bernstein CN. The reduction in colorectal cancer mortality after colonoscopy varies by site of the cancer. Gastroenterology 2010;139:1128–37. PMID: 20600026. doi: 10.1053/j.gastro.2010.06.052.CrossRefGoogle Scholar
  17. 17.
    Baxter NN, Goldwasser MA, Paszat LF, Saskin R, Urbach DR, Rabeneck L. Association of colonoscopy and death from colorectal cancer. Ann Intern Med 2009;150:1–8. PMID: 19075198. doi: 10.7326/0003-4819-150-1-200901060-00306.CrossRefGoogle Scholar
  18. 18.
    Atkin WS, Edwards R, Kral]-Hans I, Wooldrage K, Hart AR, Northover JM, et al. Once-only flexible sigmoidoscopy screening in prevention of colorectal cancer: A multicentre randomised controlled trial. Lancet 2010;375:1624–33. PMID: 20430429. doi: 10.1016/S0140-6736(10)60551-X.CrossRefGoogle Scholar
  19. 19.
    Haug U, Knudsen AB, Brenner H, Kuntz KM. Is fecal occult blood testing more sensitive for left- versus right-sided colorectal neoplasia? A systematic literature review. Expert Rev Mol Diagn 2011;11:605–16. PMID: 21745014. doi: 10.1586/erm.11.41.CrossRefGoogle Scholar
  20. 20.
    Decker KM, Demers AA, Nugent Z, Biswanger N, Singh H. Longitudinal rates of colon cancer screening use in Winnipeg, Canada: The experience of a universal health-care system with an organized colon screening program. Am J Gastroenterol 2015;110:1640–46. PMID: 26169513. doi: 10.1038/a]g.2015.206.CrossRefGoogle Scholar
  21. 21.
    Singh H, Bernstein CN, Samadder JN, Ahmed R. Screening rates for colorectal cancer in Canada: A cross-sectional study. CMAJ Open 2015;3:E149–57. PMID: 26389092. doi: 10.9778/cma]o.20140073.CrossRefGoogle Scholar
  22. 22.
    Aarts MJ, Lemmens VEPP, Louwman MWJ, Kunst AE, Coebergh JW. Socioeconomic status and changing inequalities in colorectal cancer? A review of the associations with risk, treatment and outcome. Eur J Cancer 2010;46:2681–95. PMID: 20570136. doi: 10.1016/j.ejca.2010.04.026.CrossRefGoogle Scholar
  23. 23.
    Brooke HL, Talbâck M, Martling A, Feychting M, Ljung R. Socioeconomic position and incidence of colorectal cancer in the Swedish population. Cancer Epidemiol 2016;40:188–95. PMID: 26773279. doi: 10.1016/j.canep.2016.01.004.CrossRefGoogle Scholar
  24. 24.
    Decker KM, Kliewer EV, Demers AA, Fradette K, Biswanger N, Musto G, et al. Cancer incidence, mortality, and stage at diagnosis in First Nations living in Manitoba. Curr Oncol 2016;23:225–32. PMID: 27536172. doi: 10.3747/CO.23.2906.CrossRefGoogle Scholar
  25. 25.
    Elias B, Kliewer EV, Hall M, Demers AA, Turner D, Martens P, et al. The burden of cancer risk in Canada’s indigenous population: A comparative study of known risks in a Canadian region. Int J Gen Med 2011;4:699–709. PMID: 22069372. doi: 10.2147/IJGM.S24292.CrossRefGoogle Scholar
  26. 26.
    Decker KM, Demers AA, Kliewer EV, Musto G, Shu E, Biswanger N, et al. Colorectal cancer screening in first nations people living in Manitoba. Cancer Epidemiol Biomarkers Prev 2015;24:241–48. PMID: 25336562. doi: 10.1158/1055-9965.EPI-14-1008.CrossRefGoogle Scholar
  27. 27.
    Wu X, Chen VW, Martin J, Roffers S, Groves FD, Correa CN, et al. Subsite-specific colorectal cancer incidence rates and stage distributions among Asians and Pacific Islanders in the United States, 1995 to 1999. Cancer Epidemiol Biomarkers Prev 2004;13:260–69. PMID: 15247133. doi: 10.1158/1055-9965.EPI-03-0012.CrossRefGoogle Scholar
  28. 28.
    Cheng X, Chen VW, Steele B, Ruiz B, Fulton J, Liu L, et al. Subsite-specific incidence rate and stage of disease in colorectal cancer by race, gender, and age group in the United States, 1992–1997. Cancer 2001;92:2547–54. PMID: 11745188. doi: 10.1002/1097-0142(20011115)92:10<2547::AID-CNCR1606>3.0.CO;2-K.CrossRefGoogle Scholar
  29. 29.
    Mustard CA, Derksen S, Berthelot JM, Wolfson M. Assessing ecologie proxies for household income: A comparison of household and neighbourhood level income measures in the study of population health status. Health Place 1999;5:157–71. PMID: 10670997. doi: 10.1016/S1353-8292(99)00008-8.CrossRefGoogle Scholar

Copyright information

© The Canadian Public Health Association 2017

Authors and Affiliations

  • Harminder Singh
    • 1
    • 2
    • 3
    Email author
  • Zoann Nugent
    • 4
  • Kathleen Decker
    • 3
    • 4
  • Alain Deniers
    • 3
  • Jewel Samaddar
    • 5
  • Mahmoud Torabi
    • 3
  1. 1.Internal MedicineUniversity of ManitobaWinnipegCanada
  2. 2.Department of Hematology and OncologyCancerCare ManitobaWinnipegCanada
  3. 3.Community Health SciencesUniversity of ManitobaWinnipegCanada
  4. 4.Department of Epidemiology and Cancer RegistryCancerCare ManitobaWinnipegCanada
  5. 5.Internal MedicineUniversity of UtahSalt Lake CityUSA

Personalised recommendations