The burden of cancer risk in Canada's indigenous population: a comparative study of known risks in a Canadian region

Brenda Elias¹, Erich V Kliewer^1–3, Madelyn Hall¹, Alain A Demers^1,2, Donna Turner^1,2, Patricia Martens¹, Say P Hong¹, Lyna Hart⁴, Caroline Chartrand⁵, Garry Munro^4
1Faculty of Medicine, Department of Community Health Sciences, University of Manitoba, Winnipeg, MB, Canada; ²CancerCare Manitoba, Winnipeg, MB, Canada; ³British Columbia Cancer Agency, Vancouver, BC, Canada; ⁴Assembly of Manitoba Chiefs Health Information Research Governance Committee, Winnipeg, MB, Canada; ⁵Manitoba First Nations Diabetes Integration Project, Winnipeg, MB, Canada

Background: Canadian First Nations, the largest of the Aboriginal groups in Canada, have had lower cancer incidence and mortality rates than non-Aboriginal populations in the past. This pattern is changing with increased life expectancy, a growing population, and a poor social environment that influences risk behaviors, metabolic conditions, and disparities in screening uptake. These factors alone do not fully explain differences in cancer risk between populations, as genetic susceptibility and environmental factors also have significant influence. However, genetics and environment are difficult to modify. This study compared modifiable behavioral risk factors and metabolic-associated conditions for men and women, and cancer screening practices of women, between First Nations living on-reserve and a non-First Nations Manitoba rural population (Canada).
Methods: The study used data from the Canadian Community Health Survey and the Manitoba First Nations Regional Longitudinal Health Survey to examine smoking, binge drinking, metabolic conditions, physical activity, fruit/vegetable consumption, and cancer-screening practices.
Results: First Nations on-reserve had significantly higher rates of smoking (P < 0.001), binge drinking (P < 0.001), obesity (P < 0.001) and diabetes (P < 0.001), and less leisure-time physical activity (P = 0.029), and consumption of fruits and vegetables (P < 0.001). Sex differences were also apparent. In addition, First Nations women reported significantly less uptake of mammography screening
(P < 0.001) but similar rates for cervical cancer screening.
Conclusions: Based on the findings of this retrospective study, the future cancer burden is expected to be high in the First Nations on-reserve population. Interventions, utilizing existing and new health and social authorities, and long-term institutional partnerships, are required to combat cancer risk disparities, while governments address economic disparities.

Keywords: indigenous population, cancer risk, health behaviors, metabolic diseases, cancer screening