Abstract
Objectives
To address the issue of comparative risk of cancer in Canada’s immigrant population, an area-based methodology was applied to examine whether or not estimated cancer incidence rates among individuals living in given areas vary systematically according to the concentration of foreignborn individuals living in the same area. This method provides an alternative, accessible surveillance method in the absence of linked individual-level information to extend the work of others by providing both national and subnational standardized, hence comparable, results to address this issue.
Methods
Canadian Cancer Registry data (2001 to 2006) and 2006 Census data provided dissemination area information regarding the concentration of the foreign-born population and population estimates for rate denominators. Cancer (all cause and cause-specific) incidence rate ratios (agestandardized and by age/sex) were calculated by foreign-born concentration areas at both national and regional levels.
Results
An inverse gradient was identified between cancer incidence rates and area concentration of foreign-born, with the all-sites cancer rate ranging from a low of 388 per 100,000 among individuals living in areas with a high concentration of foreign-born to a high of 493 per 100,000 among individuals living in areas with a low concentration of foreign-born. This pattern occurred nationally for lung, colorectal, prostate and female breast cancers. However, for liver, nasopharynx, and thyroid cancers, higher cancer rates were observed in areas with a higher versus lower concentration of foreign-born populations.
Conclusion
The study findings provide suggestive evidence of decreased cancer risk among foreign-born populations for most cancers except nasopharynx, liver and thyroid for which risks were higher. The results of this study demonstrate the value of ecological-based methods for disease surveillance in the absence of individual-level information on immigrant status in the national cancer registry.
Key words: Immigrants, cancer incidence, vital statistics
Résumé
Objectifs
Pour aborder la question du risque comparatif de cancer dans la population immigrante du Canada, nous avons appliqué une méthode régionale pour déterminer si les taux d’incidence estimatifs du cancer chez les résidents de certaines régions varient systématiquement selon la concentration de personnes nées à l’étranger vivant dans la même région. En l’absence de données individuelles maillées, une telle méthode offre une solution de surveillance accessible pour compléter le travail d’autres chercheurs; elle offre des résultats à la fois nationaux et sousnationaux standardisés, et donc comparables, pour aborder la question.
Méthode
Les données du Registre canadien du cancer (2001 à 2006) et celles du Recensement de 2006 ont fourni de l’information par aire de diffusion sur la concentration de personnes nées à l’étranger et des estimations démographiques pour les dénominateurs des taux. Les ratios des taux d’incidence (standardisés pour l’âge et pour l’âge/le sexe) du cancer (toutes causes confondues et par cause) ont été calculés pour chaque zone de concentration de personnes nées à l’étranger à l’échelle nationale et régionale.
Résultats
Nous avons observé un gradient inversé entre les taux d’incidence du cancer et la concentration régionale de personnes nées à l’étranger: les taux de cancer tous sites confondus variaient de 388 p. 100 000 (chez les résidents des régions à forte concentration de personnes nées à l’étranger) à 493 p. 100 000 (chez les résidents des régions à faible concentration de personnes nées à l’étranger). Cette tendance se manifestait à l’échelle nationale pour les cancers du poumon, colorectal et de la prostate et pour le cancer du sein féminin. Toutefois, pour les cancers du foie, du nasopharynx et de la thyroïde, nous avons observé des taux de cancer supérieurs dans les régions à forte plutôt qu’à faible concentration de personnes nées à l’étranger.
Conclusion
Les constatations de l’étude donnent à penser que le risque de cancer est réduit au sein des populations nées à l’étranger pour la plupart des cancers sauf ceux du nasopharynx, du foie et de la thyroïde, pour lesquels les risques sont supérieurs. Ces résultats démontrent la valeur des méthodes écologiques pour la surveillance des maladies en l’absence de données individuelles sur le statut d’immigrant dans le registre national du cancer.
Mots clés: immigrants, incidence du cancer, statistiques de l’état civil
Footnotes
Acknowledgements: The authors acknowledge the importance of Canada’s provincial and territorial cancer registrars who submit cancer records to Statistics Canada to compile the Canadian Cancer Registry. Canadian Partnership Against Cancer provided additional funding for this work.
Conflict of Interest: None to declare.
References
- 1.Chui T, Tran K, Maheux H. Immigration in Canada: A Portrait of the Foreign-Born Population, 2006 Census, Census year 2006. Ottawa, ON: Statistics Canada; 2007. [Google Scholar]
- 2.Malenfant EC, Lebel A, Martel L. Projections of the Diversity of the Canadian Population 2006 to 2031. Ottawa: Statistics Canada; 2007. [Google Scholar]
- 3.Khadilkar A, Chen Y. Rates of cervical cancer screening associated with immigration status and number of years since immigration in Ontario, Canada. J Immigr Minor Health. 2013;15(2):244–48. doi: 10.1007/s10903-012-9711-6. [DOI] [PubMed] [Google Scholar]
- 4.Shields M, Wilkins K. An update on mammography use in Canada. Health Rep. 2009;20(3):1–14. [PubMed] [Google Scholar]
- 5.Wilkins K, Shields M. Colorectal cancer testing in Canada-2008. Health Rep. 2009;20(3):1–10. [PubMed] [Google Scholar]
- 6.BMC Public Health. 2013.
- 7.Lofters AK, Moineddin R, Hwang SW, Glazier RH. Predictors of low cervical cancer screening among immigrant women in Ontario, Canada. BMC Women’s Health. 2011;11:20. doi: 10.1186/1472-6874-11-20. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Ellison LF, Wilkins K. Canadian trends in cancer prevalence. Health Rep. 2012;23(1):1–10. [PubMed] [Google Scholar]
- 9.Li D. Hospitalizations 2006–2008 in a British Columbia population-based cohort of three-year breast cancer survivors; 2013. [Google Scholar]
- 10.McDermott S, DesMeules M, Lewis R, Gold J, Payne J, Lafrance B, et al. Cancer incidence among Canadian immigrants, 1980–1998: Results from a national cohort study. J Immigr Minor Health. 2011;13:15–26. doi: 10.1007/s10903-010-9347-3. [DOI] [PubMed] [Google Scholar]
- 11.DesMeules M, Gold J, Kazanjian A, Manuel D, Payne J, Vissanjée B, et al. New approaches to immigrant health assessment. Can J Public Health. 2004;95(3):122–26. doi: 10.1007/BF03403661. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Ng E. Longitudinal Health and Administrative Data Research Team. Insights Into the Healthy Immigrant Effect: Mortality by Period of Immigration and Place of Birth. Ottawa: Statistics Canada; 2011. [Google Scholar]
- 13.Sheth T, Nair C, Nargundkhar M, Anand S, Yusuf S. Cardiovascular and cancer mortality among Canadians of European, south Asian and Chinese origin from 1979 to 1993: An analysis of 1.2 million deaths. CMAJ. 1999;161(2):132–38. [PMC free article] [PubMed] [Google Scholar]
- 14.McCracken M, Olsen M, Chen MS, Jemal A, Thun M, Cokkinides V, et al. Cancer incidence, mortality and associated risk factors among Asian Americans of Chinese, Filipino, Vietnamese, Korean, and Japanese ethnicities. CA Cancer J Clin. 2007;57(4):190–205. doi: 10.3322/canjclin.57.4.190. [DOI] [PubMed] [Google Scholar]
- 15.Ferlay J, Shin HR, Bray F, Forman D, Mathers C, Parkin DM. GLOBOCAN 2008 v2.0, Cancer Incidence and Mortality Worldwide: IARC Cancer Base No. 10 [Internet] Lyon, France: International Agency for Research on Cancer; 2010. [Google Scholar]
- 16.Rotermann M. The impact of considering birthplace in analyses of immigrant health. Health Rep. 2011;22(4):37–43. [PubMed] [Google Scholar]
- 17.Auluck A, Hislop G, Bajdik C, Poh C, Zhang L, Rosin M. Trends in oropharyngeal and oral cavity cancer incidence of human papillomavirus (HPV)-related and HPV-unrelated sites in a multicultural population: The British Columbia experience. Cancer. 2010;116(11):2635–44. doi: 10.1002/cncr.25087. [DOI] [PubMed] [Google Scholar]
- 18.Wang ZJ, Ramcharan S, Love EJ. Cancer mortality of Chinese in Canada. Intl J Epidemiol. 1989;18(1):17–21. doi: 10.1093/ije/18.1.17. [DOI] [PubMed] [Google Scholar]
- 19.Luo W, Birkett NJ, Ugnat A-M, Mao Y. Cancer incidence patterns among Chinese immigrant populations in Alberta. J Immigr Health. 2004;6(1):41–48. doi: 10.1023/B:JOIH.0000014641.68476.2d. [DOI] [PubMed] [Google Scholar]
- 20.Yavari P, Hislop TG, Bajdik C, Sadjadi A, Nouraie M, Babai M, Malekzadeh R. Comparison of cancer incidence in Iran and Iranian immigrants to British Columbia, Canada. Asian Pac J Cancer Prev. 2006;7(1):86–90. [PubMed] [Google Scholar]
- 21.Hislop TG, Bajdik CD, Saroa SR, Yeole BB, Barroetavena MC. Cancer incidence in Indians from three areas: Delhi and Mumbai, India, and British Columbia, Canada. J Immigr Minor Health. 2007;9(3):221–27. doi: 10.1007/s10903-006-9035-5. [DOI] [PubMed] [Google Scholar]
- 22.Kliewer EV, Smith KR. Breast cancer mortality among immigrants in Australia and Canada. J Natl Cancer Inst. 1995;87(15):1154–61. doi: 10.1093/jnci/87.15.1154. [DOI] [PubMed] [Google Scholar]
- 23.Kliewer EV, Smith KR. Ovarian cancer mortality among immigrants in Australia and Canada. Cancer Epidemiol Biomarkers Prev. 1995;4:453–58. [PubMed] [Google Scholar]
- 24.Parkin DM, Chen VW, Ferlay J, Galceran J, Storm HH, Whelan SL. Comparability and Quality Control in Cancer Registration (IARC Technical Report No.19) Lyon, France: IARC, World Health Organization and International Association of Cancer Registries; 1994. [Google Scholar]
- 25.Fritz A, Percy C, Jack A, Shanmugaratnam K, Sobin L, Parkin DM, Whelan S, editors. International Classification of Diseases for Oncology. Third Edition. Geneva, Switzerland: WHO; 2000. [Google Scholar]
- 26.Horner MJ, Ries LAG, Krapcho M, Neyman N, Aminou R, Howlader N, et al. SEER Cancer Statistics Review, 1975–2006. Bethesda, MD: National Cancer Institute; 2009. [Google Scholar]
- 27.Canadian Cancer Registry System Guide–2007 Edition. Catalogue No. 82–225 X. Ottawa: Health Statistics Division, Statistics Canada; 2008. [Google Scholar]
- 28.Statistics Canada. Profiles for Canada, Provinces, Territories, Census Divisions, Census Subdivisions and Dissemination Areas, 2006 Census. Ottawa: Statistics Canada; 2008. [Google Scholar]
- 29.Carrière G, Peters PA, Sanmartin C. Area-based methods to calculate hospitalization rates for the foreign-born population in Canada, 2005/2006. Health Rep. 2012;23(3):43–51. [PubMed] [Google Scholar]
- 30.Wilkins R, Khan S. PCCF Version 5F User’s Guide. Ottawa: Statistics Canada; 2011. [Google Scholar]
- 31.Esteve J, Benhamou E, Raymond L, editors. Statistical Methods in Cancer Research, Volume IV, Descriptive Epidemiology. Lyon: International Agency for Research on Cancer, IARC Scientific Publications No. 128; 1994. [PubMed] [Google Scholar]
- 32.Fay MP, Feuer EJ. Confidence intervals for directly standardized rates: A method based on the gamma distribution. Stat Med. 1997;16(7):791–801. doi: 10.1002/(sici)1097-0258(19970415)16:7<791::aid-sim500>3.0.co;2-#. [DOI] [PubMed] [Google Scholar]
- 33.Int J Health Geogr. 2008.
- 34.Merican I, Guan R, Amarapuka D, Alexander M, Chutaputti A, Chien R, et al. Chronic hepatitis B virus in Asian countries. J Gastroenterol Hepatol. 2000;15(12):1356–61. doi: 10.1046/j.1440-1746.2000.0150121356.x. [DOI] [PubMed] [Google Scholar]
- 35.El-Serag HB, Davila JA, Petersen NJ, McGlynn KA. The continuing increase in the incidence of hepatocellular carcinoma in the United States: An update. Ann Intern Med. 2003;139:817–23. doi: 10.7326/0003-4819-139-10-200311180-00009. [DOI] [PubMed] [Google Scholar]
- 36.Immigrants in Rural Canada: 2006. Rural and Small Town Canada Analysis Bulletin. 2009.
- 37.The Health of Rural Canadians: A Rural-Urban Comparison of Health Indicators. Rural and Small Town Canada Analysis Bulletin. 2003.
- 38.Canadian Partnership Against Cancer. Population Health in Canada’s Largest Cities: A Cancer System Performance Spotlight Report. Toronto, ON: Canadian Partnership Against Cancer; 2013. [Google Scholar]
- 39.Li FX, Robson PJ, Chen Y, Qiu Z, Lo Siou G, Bryant HE. Prevalence, trend and sociodemographic association of five modifiable lifestyle risk factors for cancer in Alberta and Canada. Cancer Causes Control. 2009;20(3):395–407. doi: 10.1007/s10552-008-9254-2. [DOI] [PubMed] [Google Scholar]
- 40.Perez CE. Health status and health behaviours among immigrants. Health Rep. 2002;13(Suppl.):1–13. [Google Scholar]
- 41.Stirbu I, Kunst AE, Vlems FA, Visser O, Bos V, Deville W, et al. Cancer mortality rates among first and second generation migrants in the Netherlands: Convergence toward the rates of native Dutch population. Int J Cancer. 2006;119(11):2665–72. doi: 10.1002/ijc.22200. [DOI] [PubMed] [Google Scholar]
- 42.Canadian Cancer Society’s Steering Committee on Cancer Statistics. Canadian Cancer Statistics 2012. Toronto: Canadian Cancer Society; 2012. [Google Scholar]