University of Helsinki, Faculty of Medicine Department of Public Health THE HEALTH OF THE FINNISH SAMI IN LIGHT OF MORTALITY AND CANCER PATTERN Leena Soininen ACADEMIC DISSERTATION To be presented, with the permission of the Faculty of Medicine, University of Helsinki, for public examination in the Auditorium K 171 of the Department of Psychologicum, Siltavuorenpenger 1 B, Helsinki, on 27th May 2015, at 12 o’clock noon. Helsinki 2015 Supervisors: Eero Pukkala Professor in Epidemiology Director of Statistics Finnish Cancer Registry Institute for Statistical and Epidemiological Cancer Research Finland Helena Mussalo-Rauhamaa Ph D, MD, Adjunct professor Department of Public Health University of Helsinki Finland Reviewers: Simo Näyhä Professor emeritus Adjunct Professor in Public Health University of Oulu Center for Environmental and Respiratory Health Research University of Oulu Timo Sahi Ph D, MD, Adjunct Professor Department of Public Health University of Helsinki Finland Opponent: Arja Rautio Research professor Centre for Arctic Medicine Thule Institute University of Oulu DISSERTATIONES SCHOLAE DOCTORALIS AD SANITATEM INVESTIGANDAM UNIVERSITATIS HELSINKIENSIS ISBN 978-951-51-1111-1 (pbk.) ISBN 978-951-51-1118-2 (PDF) ISSN 2342-3161 (print) ISSN 2342-317X (online) Helsinki University Print Helsinki 2015 LIST OF ORIGINAL PUBLICATIONS: I Soininen L, Pukkala E. Mortality of the Sami in Northern Finland 1979–2005. International Journal of Circumpolar Health 2008;67:43-55. II Soininen L, Järvinen S, Pukkala E. Cancer incidence among Sami in Northern Finland, 1979–1998. International Journal of Cancer 2002;100:342-6. III Hassler S, Soininen L, Sjölander P, Pukkala E. Cancer among the Sami – a review on the Norwegian, Swedish and Finnish Sami Populations. International Journal of Circumpolar Health 2008;67:421-32. IV Soininen L, Pokhrel A, Dyba T, Pukkala E, Hakulinen T. Survival of Sami cancer patients. International Journal of Circumpolar Health 2012;71:18959: 1-5. 3 CONTENTS ABBREVIATIONS .............................................................................................7 ABSTRACT ........................................................................................................9 1 INTRODUCTION ......................................................................................13 2 LITERATURE REVIEW .............................................................................14 2.1 THE SAMI ..........................................................................................14 2.2 THE ENVIRONMENT OF THE SAMI ..............................................27 2.3 THE WAY OF SAMI LIFE AND HEALTH RISKS .............................41 2.4 THE HEALTH CARE ORGANIZATION ............................................56 2.5 DISEASES OF THE SAMI ................................................................. 60 3 THE AIM OF THE STUDY ........................................................................ 80 4 MATERIAL AND METHODS ....................................................................81 4.1 THE DESCRIPTION OF THE COHORT ..........................................81 4.2 OUTCOME EVENTS ........................................................................ 84 4.3 FOLLOW UP AND STATISTICAL METHODS ................................ 86 4.4 PERMISSIONS .................................................................................. 90 5 THE RESULTS ...........................................................................................91 5.1 MORTALITY (I) .................................................................................91 5.2 CANCER INCIDENCE (II) ............................................................... 101 5.3 COMPARISON OF THE INCIDENCE AND MORTALITY OF CANCER AMONG THE NORWEGIAN, SWEDISH AND FINNISH SAMI POPULATIONS (III) .............................................104 5 5.4 CANCER SURVIVAL (IV) ................................................................107 6 DISCUSSION ............................................................................................108 6.1 MATERIAL AND METHODS ..........................................................108 6.2 THE MORTALITY OF THE SAMI (I, III) .................................... 112 6.3 CANCER AMONG THE SAMI (Study I, II, III) ..............................128 6.4 SURVIVAL OF SAMI CANCER PATIENTS (Study IV) ...................143 7 CONCLUSIONS ........................................................................................146 8 ACKNOWLEDGEMENTS ........................................................................149 9 REFERENCES ...........................................................................................151 10 ORIGINAL ARTICLES .............................................................................187 11 APPENDICES ...........................................................................................188 6 ABBREVIATIONS AH Arctic haze AMAP/HH Arctic Monitoring and Assessment Program/Human Health subprogram Bq Becquerel (unit of radioactivity) Ca Calcium Cd Cadmium Ci Curie (unit of radioactivity) 95% CI 95% confidence interval Cs Caesium Cu Copper CVD Cardiovascular disease E% Energy% (per cent of energy of a food stuff of the total energy) EVIRA Elintarviketurvallisuusvirasto EVIRA, Finnish Food Safety EVIRA FCR Finnish Cancer Registry FD Food diary method FQ Food frequency questionnaire method Gy Gray. Unit of the absorbed amount of radioactivity. µGy Mikrogray = 10-6 Gy Hg Mercury IARC International Agency for Research on Cancer (WHO) IASC International Arctic Science Committee IBP/HA International Biological Program/Human Adaptability- section ICD International Classification of Diseases ICD-O-3 International Classification of Diseases for Oncology IHD Ischaemic heart disease Kcal 1000 calories Kela Kansaneläkelaitos (The Social Insurance Institution of Finland) OHD Other heart disease OR Odds ratio pCi Picocurie = Ci x 10-12 Pb Lead PHN Public health nurse 7 PCB Polychlorinated biphenyl Po Polonium P/S ratio Fat ratio of polyunsaturated and saturated fats Pu Plutonium RL Region of the Hospital District of Lapland RKTL Riista- ja kalatalouden tutkimuslaitos (Finnish Game and Fisheries Research Institute) RO Region Oulu, Region of University Hospital of Oulu Se Selenium SIR Standardized incidence ratio SMR Standardized mortality ratio Sr Strontium Standard population The population, which is used as reference when the SIRs and SMRs are calculated (also called reference population) UCD Underlying cause of death Zn Zinc WHO World Health Organization (United Nations) Explanations: Municipality The local administrative unit in Finland, which is responsible for the health services of its inhabitants. Sometimes the word “commune” is used in the same meaning. 8 ABSTRACT Objectives. The Sami are regarded as indigenous people of Scandinavia and northwest Russia. Their traditional dwelling zone consists of the most northern parts of those countries. The Sami consist of rather small groups that have been living in isolation for a long time in harsh circumstances. Because there was not much data about the health and diseases of these Finnish ethnic minorities, the health of the Sami is the object of this dissertation, approached in terms of cause specific mortality, cancer incidence and the cancer patient survival. Material and methods. All persons living in the two northern municipalities of Finland (Inari and Utsjoki) on 31st December 1978 were identified from the National Population Register. The Sami cohort was extracted from that by using the grouping of Sami of the International Biological Program, Human Health Adaptability-study. Dates of death and emigration of the cohort members were obtained from the Population Register. Follow-up for cancer through the files of the population-based countrywide Finnish Cancer Registry was done using the personal identification code as the key. The first period of the follow-up for mortality and cancer started on 1st January 1979 and ended at death or on 31st December 2005 (Study I, mortality), on 31st December 1998 (Study II, cancer), and on 31th December 2009 (Study IV, survival of cancer patients). The second period started on 1st January 2006 and ended 31st December 2010 (Study I) and Study II started on 1st January 1999, and ended on 31st December 2010. In Study III, a comparison of several cancer studies from Finland, Sweden and Norway from different time periods between the years 1961–2006 was made. A person representing at least 75 per cent of any ethnic group of Sami was classified as Sami. A non-Sami is a person without any Sami ethnicity, and the remaining persons were classified into the mixed group. The Sami group was divided into subcategories of North Sami, Inari Sami and Skolt Sami with the same principle: to be classified in a specific Sami subgroup, a person had to represent at least 75 per cent of this type of the three specific Sami ethnicity. In Study III, in Sweden and Norway the defining of Sami people for epidemiological studies has been different. In Sweden, all possible registers have been combined to find the Sami, and in Norway, the defining is concentrated to the Sami counties and the interview. In all countries, the Sami have mixed more or less with the main population, and therefore the Finnish cohort was recalculated for Study III. The Finnish cohort in that study has included all Sami with 1–100% of Saminess. 9 Abstract Results. The overall mortality among the Finnish Sami in the first time period studied, 1979–1987, was statistically