Cancer among circumpolar populations: an emerging public health concern

1School of Public Health, University of Alberta, Edmonton, Alberta, Canada; 2Alaska Native Epidemiology Center, Alaska Native Tribal Health Consortium, Anchorage, AK, USA; 3Department of Clinical Oncology, Rigshospitalet, Copenhagen, Denmark; 4Department of Public Health, University of Helsinki, Helsinki, Finland

Abstract

Objectives. To determine and compare the incidence of cancer among the 8 Arctic States and their northern regions, with special focus on 3 cross-national indigenous groups – Inuit, Athabaskan Indians and Sami.

Methods. Data were extracted from national and regional statistical agencies and cancer registries, with direct age-standardization of rates to the world standard population. For comparison, the “world average” rates as reported in the GLOBOCAN database were used.

Findings. Age-standardized incidence rates by cancer sites were computed for the 8 Arctic States and 20 of their northern regions, averaged over the decade 2000–2009. Cancer of the lung and colon/rectum in both sexes are the commonest in most populations. We combined the Inuit from Alaska, Northwest Territories, Nunavut and Greenland into a “Circumpolar Inuit” group and tracked cancer trends over four 5-year periods from 1989 to 2008. There has been marked increase in lung, colorectal and female breast cancers, while cervical cancer has declined. Compared to the GLOBOCAN world average, Inuit are at extreme high risk for lung and colorectal cancer, and also certain rare cancers such as nasopharyngeal cancer. Athabaskans (from Alaska and Northwest Territories) share some similarities with the Inuit but they are at higher risk for prostate and breast cancer relative to the world average. Among the Sami, published data from 3 cohorts in Norway, Sweden and Finland show generally lower risk of cancer than non-Sami.

Conclusions. Cancer among certain indigenous people in the Arctic is an increasing public health concern, especially lung and colorectal cancer.

Keywords: cancer; Arctic; epidemiology; prevention; Indigenous people; Inuit; North American Indians; Sami

Citation: Int J Circumpolar Health 2016, 75: 29787 – http://dx.doi.org/10.3402/ijch.v75.29787

Copyright: © 2016 T. Kue Young et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 International License, allowing third parties to copy and redistribute the material in any medium or format and to remix, transform, and build upon the material for any purpose, even commercially, provided the original work is properly cited and states its license.

Received: 16 September 2015; Revised: 9 December 2015; Accepted: 9 December 2015; Published: 12 January 2016

Competing interests and funding: The authors have not received any funding or benefits from industry or elsewhere to conduct this study.

*Correspondence to: T. Kue Young, School of Public Health, University of Alberta, Edmonton, Alberta, T6G 1C9, Canada, Email: kue.young@ualberta.ca

The 8 member states of the Arctic Council (Canada, Denmark, Finland, Iceland, Norway, Sweden, Russian Federation and the United States, hereafter referred to as the Arctic States) comprise some of the world’s economically most developed countries. Yet, within these countries, substantial health disparities persist, between northern and southern regions, and within the North, between indigenous and non-indigenous peoples, although the extent of the disparities varies across countries (1–3).

We report on an epidemiological review of cancer in the Arctic States and their northern regions. Cancers such as lung and breast can be viewed as an indicator of the rapid social, economic and environmental changes that Arctic populations, especially indigenous peoples, are experiencing. A circumpolar comparative framework is particularly useful as countries and regions that share many commonalities can learn best practices from one another in cancer prevention and control.

Previous reviews have focused on specific regions such as Greenland (4), Alaska (5), northern Canada (6), and specific populations such as the Inuit (7,8). The current review compares all northern regions within the Arctic (for which data are available), with special focus on 3 indigenous populations whose traditional homelands span across present day national boundaries – Inuit, Athabaskans and Sami. We also offer a global perspective by putting the circumpolar populations in the context of major geopolitical regions of the world.

Methods and data sources

We obtained data on cancer incidence among the Arctic States and their northern regions from national statistical agencies, cancer registries and regional health authorities. Such data refer to the total populations with all ethnicities combined. These agencies are listed in the notes of Table I. There are also international cancer databases such as NORDCAN for the Nordic countries (9) and GLOBOCAN for the member states of the World Health Organization (10). With the exception of Russia, the Arctic States have national cancer registries that are considered to be of sufficient quality to be included in the International Agency for Research on Cancer’s statistical compendium Cancer Incidence in Five Continents, CI5 (11). The St. Petersburg registry is the only Russian entry in CI5. National and regional cancer incidence data from Russia are available from the annual reports of the P.A. Hertzen Research Institute of Oncology in Moscow (12). In recent years, Norwegian international assistance efforts have been directed at improving the quality of the cancer registry of an Arctic region in north-western Russia (13). In this study we did not access data from this registry.

ILR5