Abstract
Objectives
Growing literature demonstrates widening socio-economic gradients in cancer incidence in different countries. However, few studies have measured the magnitude of socio-economic inequalities in the incidence of different types of cancers. This study aimed to evaluate socio-economic inequalities in bladder cancer incidence in Canada over time.
Methods
Using data obtained from the Canadian Cancer Registry (CCR), the Canadian Census of Population (CCP), and the National Household Survey (NHS), we examined socio-economic inequalities of bladder cancer incidence among men and women in Canada from 1992 to 2010. Income- and education-related inequalities were measured using the concentration index (C) approach. We also analyzed the trends of income- and education-related inequalities over the study period.
Results
There is an increasing trend in bladder cancer incidence in Canada. The estimated C suggested a higher incidence of bladder cancer among low socio-economic-status individuals. The results revealed that income-related inequality in bladder cancer incidence increased among the female population. Education-related inequality in the incidence of bladder cancer widened for both males and females in Canada.
Conclusion
The concentration of bladder cancer in Canada is growing among the socio-economically disadvantaged population. Further studies are required to help elucidate causal relationships between socio-economic status and bladder cancer incidence in Canada.
Résumé
Objectifs
L’élargissement des gradients socioéconomiques de l’incidence du cancer dans différents pays est de plus en plus attesté dans la littérature scientifique. Peu d’études ont toutefois mesuré l’ampleur des inégalités socioéconomiques dans l’incidence de différents types de cancers. Nous avons cherché à évaluer les inégalités socioéconomiques dans l’incidence du cancer de la vessie au Canada au fil du temps.
Méthode
À l’aide des données du Registre canadien du cancer (RCC), du Recensement de la population canadienne (RPC) et de l’Enquête nationale auprès des ménages (ENM), nous avons examiné les inégalités socioéconomiques de l’incidence du cancer de la vessie chez les hommes et les femmes au Canada de 1992 à 2010. Nous avons mesuré les inégalités liées au revenu et au niveau d’instruction par la méthode de l’indice de concentration (C). Nous avons également analysé les tendances des inégalités liées au revenu et au niveau d’instruction sur la période de l’étude.
Résultats
L’incidence du cancer de la vessie est en hausse au Canada. L’indice C estimatif indique une incidence supérieure du cancer de la vessie chez les personnes de faible statut socioéconomique. Selon les résultats que nous avons obtenus, les inégalités liées au revenu dans l’incidence du cancer de la vessie ont augmenté dans la population féminine. Les inégalités liées au niveau d’instruction dans l’incidence du cancer de la vessie se sont creusées chez les hommes et les femmes au Canada.
Conclusion
La concentration des cancers de la vessie au Canada s’accentue dans les populations défavorisées sur le plan socioéconomique. Il faudrait pousser la recherche pour élucider les relations causales entre le statut socioéconomique et l’incidence du cancer de la vessie au pays.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abajobir, A. A., Abate, K. H., Abbafati, C., Abbas, K. M., Abd-Allah, F., Abdulkader, R. S., et al. (2017). Global, regional, and national incidence, prevalence, and years lived with disability for 328 diseases and injuries for 195 countries, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet, 390(10100), 1211–1259. https://doi.org/10.1016/S0140-6736(17)32154-2.
Antoni, S., Ferlay, J., Soerjomataram, I., Znaor, A., Jemal, A., & Bray, F. (2017). Bladder cancer incidence and mortality: a global overview and recent trends. European Urology, 71(1), 96–108. https://doi.org/10.1016/j.eururo.2016.06.010.
Booth, C. M., Li, G., Zhang-Salomons, J., & Mackillop, W. J. (2010). The impact of socioeconomic status on stage of cancer at diagnosis and survival. Cancer, 116(17), 4160–4167. https://doi.org/10.1002/cncr.25427.
Canadian Cancer Society’s Advisory Committee on Cancer Statistics (2017). Canadian Cancer Statistics 2017. Toronto, ON: Canadian Cancer Society. http://www.cancer.ca/~/media/cancer.ca/CW/cancer%20information/cancer%20101/Canadian%20cancer%20statistics/Canadian-Cancer-Statistics-2017-EN.pdf.
Cancer Research UK. (2017). Retrieved July 6, 2018, from https://www.cancerresearchuk.org/health-professional/cancer-statistics/statistics-by-cancer-type/bladder-cancer/incidence#ref-.
Chavan, S., Bray, F., Lortet-Tieulent, J., Goodman, M., & Jemal, A. (2014). International variations in bladder cancer incidence and mortality. European Urology, 66(1), 59–73. https://doi.org/10.1016/j.eururo.2013.10.001.
Chen, E., & Miller, G. E. (2013). Socioeconomic status and health: mediating and moderating factors. Annual Review of Clinical Psychology, 9(1), 723–749. https://doi.org/10.1146/annurev-clinpsy-050212-185634.
Clegg, L. X., Reichman, M. E., Miller, B. A., Hankey, B. F., Singh, G. K., Lin, Y. D., et al. (2009). Impact of socioeconomic status on cancer incidence and stage at diagnosis: selected findings from the surveillance, epidemiology, and end results: National Longitudinal Mortality Study. Cancer Causes & Control, 20(4), 417–435. https://doi.org/10.1007/s10552-008-9256-0.
Evans, G. W., & Kantrowitz, E. (2002). Socioeconomic status and health: the potential role of environmental risk exposure. Annual Review of Public Health, 23(1), 303–331. https://doi.org/10.1146/annurev.publhealth.23.112001.112349.
Goy, J., Rosenberg, M. W., & King, W. D. (2008). Health risk behaviors: examining social inequalities in bladder and colorectal cancers. Annals of Epidemiology, 18(2), 156–162. https://doi.org/10.1016/j.annepidem.2007.09.004.
Hajizadeh, M., Mitnitski, A., & Rockwood, K. (2016). Socioeconomic gradient in health in Canada: is the gap widening or narrowing? Health Policy, 120(9), 1040–1050. https://doi.org/10.1016/j.healthpol.2016.07.019.
Hawkins, N. M., Jhund, P. S., McMurray, J. J. V., & Capewell, S. (2012). Heart failure and socioeconomic status: Accumulating evidence of inequality. European Journal of Heart Failure, 14(2), 138–46. https://doi.org/10.1093/eurjhf/hfr168.
Huang, J., Chaloupka, F. J., & Fong, G. T. (2014). Cigarette graphic warning labels and smoking prevalence in Canada: a critical examination and reformulation of the FDA regulatory impact analysis. Tobacco Control, 23(suppl 1), i7–i12. https://doi.org/10.1136/tobaccocontrol-2013-051170.
Mackillop, W. J., Zhang-Salomons, J., Boyd, C. J., & Groome, P. A. (2000). Associations between community income and cancer incidence in Canada and the United States. Cancer, 89(4), 901–912. https://doi.org/10.1002/1097-0142(20000815)89:4<901::AID-CNCR25>3.0.CO;2-I.
Mahdavifar, N., Ghoncheh, M., Pakzad, R., Momenimovahed, Z., & Salehiniya, H. (2016). Epidemiology, incidence and mortality of bladder cancer and their relationship with the development index in the world. Asian Pacific Journal of Cancer Prevention, 17(1), 381–386. https://doi.org/10.7314/APJCP.2016.17.1.381.
Marmot, M. (2005). Social determinants of health inequalities. Lancet, 365(9464), 1099–1104. https://doi.org/10.1016/S0140-6736(05)71146-6.
National Cancer Institute SEER - Bladder Cancer. (2015). Retrieved July 6, 2018, from https://seer.cancer.gov/statfacts/html/urinb.html.
OECD. (2019). What are equivalence scales? Retrieved March 27, 2019, from http://www.oecd.org/els/soc/OECD-Note-EquivalenceScales.pdf.
Quaglia, A., Lillini, R., Mamo, C., Ivaldi, E., Vercelli, M., & SEIH (Socio-Economic Indicators, Health) Working Group. (2013). Socio-economic inequalities: a review of methodological issues and the relationships with cancer survival. Critical Reviews in Oncology/Hematology, 85(3), 266–277. https://doi.org/10.1016/j.critrevonc.2012.08.007.
Sahni, S., Talwar, A., Khanijo, S., & Talwar, A. (2017). Socioeconomic status and its relationship to chronic respiratory disease. Advances in Respiratory Medicine, 85(2), 97–108https://doi.org/10.5603/ARM.2017.0016.
Sanli, O., Dobruch, J., Knowles, M. A., Burger, M., Alemozaffar, M., Nielsen, M. E., & Lotan, Y. (2017), 13 (3), 17022. Bladder cancer. Nature Reviews. Disease Primers. https://doi.org/10.1038/nrdp.2017.22.
Surveys and Statistical Programs - Canadian Cancer Registry (CCR). (2018). Retrieved June 11, 2018, from http://www23.statcan.gc.ca/imdb/p2SV.pl?Function=getSurvey&SDDS=3207.
Wang, J. L., Schmitz, N., & Dewa, C. S. (2010). Socioeconomic status and the risk of major depression: the Canadian National Population Health Survey. Journal of Epidemiology and Community Health, 64(5), 447–452. https://doi.org/10.1136/jech.2009.090910.
Weiner, A. B., Keeter, M.-K., Manjunath, A., & Meeks, J. J. (2018). Discrepancies in staging, treatment, and delays to treatment may explain disparities in bladder cancer outcomes: an update from the National Cancer Data Base (2004–2013). Urologic Oncology: Seminars and Original Investigations. https://doi.org/10.1016/J.UROLONC.2017.12.015.
Wong, M. C. S., Fung, F. D. H., Leung, C., Cheung, W. W. L., Goggins, W. B., & Ng, C. F. (2018). The global epidemiology of bladder cancer: a joinpoint regression analysis of its incidence and mortality trends and projection. Scientific Reports, 8(1), 1129. https://doi.org/10.1038/s41598-018-19199-z.
Woods, L. M., Rachet, B., & Coleman, M. P. (2006). Origins of socio-economic inequalities in cancer survival: a review. Annals of Oncology, 17(1), 5–19. https://doi.org/10.1093/annonc/mdj007.
World Bank. (2019). Quantitative techniques for health equity analysis: Concentration curve. Retrieved May 28, 2019, from http://siteresources.worldbank.org/INTPAH/Resources/Publications/Quantitative-Techniques/health_eq_tn06.pdf.
Acknowledgements
Ryan Densmore was a recipient of a Research in Medicine (RIM) studentship funding from the Faculty of Medicine Patrick Madore Memorial Student Fund. Mohammad Hajizadeh acknowledges a Research Development Grant from the Faculty of Health at Dalhousie University to conduct this study. The analyses for this paper were conducted at Statistics Canada’s Atlantic Research Data Centre (ARDC) at Dalhousie University, which is part of the Canadian Research Data Centre Network (CRDCN). We would like to thank CRDCN for facilitating the access to data, and ARDC analyst Heather Hobson for her support and assistance.
Funding
This research was conducted with the support of the Dalhousie Medical Research Foundation Cresco Studentship and a Research Development Grant from the Faculty of Health at Dalhousie University.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Ethics
The data for this study were accessed through Statistics Canada’s Research Data Centre (RDC). Statistics Canada has put in place strict disclosure practices which the RDC closely obeys, allowing their approved project to be exempt from research ethics board review based on Tri-council policy statement: Ethical conduct for research involving humans (TCPS2) article 2.2 (a).
Conflict of interest
The authors declare that they have no conflict of interest.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Appendix
Appendix
Rights and permissions
About this article
Cite this article
Densmore, R., Hajizadeh, M. & Hu, M. Trends in socio-economic inequalities in bladder cancer incidence in Canada: 1992–2010. Can J Public Health 110, 722–731 (2019). https://doi.org/10.17269/s41997-019-00227-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.17269/s41997-019-00227-y