The incidence of all cancers combined was similar for Métis men and significantly higher for Métis women compared to non-Aboriginal men and women, found a study published in CMAJ (Canadian Medical Association Journal)
Canada's Métis people are 1 of 3 groups officially named in the Canadian Constitution as the "aboriginal peoples of Canada", along with Inuit and First Nations peoples. Métis people, who are descendants of early unions between First Nations women and European fur traders, have unique culture, traditions and nationhood. Aboriginal peoples in Canada have higher rates of poverty and unemployment as well as obesity, tobacco smoking and unhealthy diet compared with non-Aboriginal Canadians.
There are more than 450 000 Métis in Canada (1.4% of the total population). However, there is a lack of national data on the incidence of cancer as well as cancer survival rates in this unique population.
In this large study, researchers linked data on self-reported Métis ancestry from the 1991 Canadian census to national cancer and mortality databases between 1992 and 2009. In the 11 050 Métis adults (aged 25 to 99 years), 1090 cancers were diagnosed over 185 000 person-years. Compared with non-Aboriginal adults in the study, Métis adults were significantly younger, were more likely to live in rural areas as well as Canada's Prairie provinces, and had lower educational and income levels.
The rates of cancer were similar for Métis and non-Aboriginal people for many types of cancer, although Métis adults had significantly higher rates for lung cancer in both sexes separately; for liver, larynx and gallbladder cancers in both sexes combined; and for female breast and cervical cancers. Survival rates for prostate cancer were poorer for Métis men compared with non-Aboriginal men with prostate cancer. Incidence rates were significantly lower for melanoma and leukemia in Métis adults and for colorectal cancer in Métis women, compared with non-Aboriginal people.
"The cancer burden of Métis people has been understudied in Canada, so this study substantially increases our knowledge of cancer risk and prognosis in this community," says Dr. Loraine Marrett, Scientist Emeritus, Cancer Care Ontario. "The evidence found in this study shows us that more action is needed to reduce the incidence of cancer, improve survival and provide better health outcomes for Métis people."
The study was conducted by researchers from Cancer Care Ontario, University of Toronto, Statistics Canada and Métis National Council. It was funded by a grant from the Canadian Institutes of Health Research.
"Cancer incidence and survival among Métis adults in Canada: results from the Canadian census follow-up cohort (1992-2009)" is published March 19, 2018.
Canadian Medical Association Journal