Occupational variation in the risk of female breast cancer in the Nordic countries
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This study aimed to determine occupational variations in the incidence of breast cancer in the population-based cohort of Nordic Occupational Cancer Study (NOCCA).
The study included long-term follow-up data from almost 7.5 million Nordic women. Participants were assigned to one of the 54 occupational categories based on census records at the ages of 30–64 years. Sixty-two thousand cases of breast cancer were identified through record linkages between nationwide cancer registries in Finland, Sweden, Norway, Denmark, and Iceland, followed up between 1961 and 2005. Country-specific standardized incidence ratios (SIRs) with 95% confidence intervals were estimated.
Overall, the highest risk elevations were seen among military personnel (SIR 1.58, 95% CI 1.03–2.32), dentists (SIR 1.43, 95% CI 1.31–1.56), and physicians (SIR 1.35, 95% CI 1.26–1.46). The lowest risks were observed among gardeners (SIR 0.76, 95% CI 0.74–0.78), farmers (SIR 0.80, 95% CI 0.78–0.82), and woodworkers (SIR 0.75, 95% CI 0.70–0.81). Welders, tobacco workers, and painters had higher SIRs for breast cancer diagnosed at age < 50. A reduced risk was observed among forestry workers, welders, and fishery workers for breast cancers diagnosed both before and after age 50. The SIRs for breast cancer did not vary substantially by histology. A significantly increased risk of breast cancer was observed among laboratory workers in the latest calendar period (1991–2005) compared with earlier periods (1976–1990 and 1961–1975). Occupations such as farming, forestry, driving, and gardening had low SIRs during all periods.
The study suggests that the risk of breast cancer varies by occupation. Heterogeneity is also observed in some occupational categories according to age (before or after 50), histology, and calendar period.
KeywordsBreast cancer Nordic Occupational exposure Risk factors
- 1.Ferlay J, Soerjomataram I, Ervik M, Dikshit R, Eser S, Mathers C, Rebelo M, Parkin DM, Forman D, Bray F (2013) Cancer incidence and mortality worldwide: IARC cancer base no. 11. http://globocan.iarc.fr. Accessed 6 March 2017
- 2.Engholm G, Ferlay J, Christensen N, Hansen HL, Hertzum-Larsen R, Johannesen TB, Kejs AMT, Khan S, Ólafsdóttir E, Petersen T, Schmidt LKH, Virtanen A, Storm HH (2017) Cancer incidence, mortality, prevalence and survival in the Nordic countries, version 8.0. http://www.ancr.nu. Accessed 27 Dec 2017
- 24.Altman DG, Machin D, Bryant TN, Gardner MJ (2000) Statistics with confidence: confidence intervals and statistical guidelines, 2nd edn. BMJ Books, LondonGoogle Scholar
- 25.Kullberg C, Selander J, Albin M, Borgquist S, Manjer J, Gustavsson P (2017) Female white-collar workers remain at higher risk of breast cancer after adjustments for individual risk factors related to reproduction and lifestyle. Occup Environ Med 74(9):652–658CrossRefPubMedPubMedCentralGoogle Scholar
- 44.Akinyemiju T, Ogunsina K, Sakhuja S, Ogbhodo V, Braithwaite D (2016) Life-course socioeconomic status and breast and cervical cancer screening: analysis of the WHO’s study on global ageing and adult health (SAGE). BMJ Open. https://doi.org/10.1136/bmjopen-2016-012753 PubMedPubMedCentralGoogle Scholar
- 59.IARC Working Group on the Evaluation of Carcinogenic Risks to Humans (2000) Ionizing radiation, part 1: X- and gamma radiation, and neutrons. IARC Monogr Eval Carcinog Risks Hum 75:1–459Google Scholar
- 65.Band PR, Le ND, Fang R, Deschamps M, Gallagher RP, Yang P (2000) Identification of occupational cancer risks in British Columbia: a population-based case-control study of 995 incident breast cancer cases by menopausal status, controlling for confounding factors. J Occup Environ Med 42(3):284–310CrossRefPubMedGoogle Scholar
- 69.Brophy JT, Keith MM, Watterson A, Park R, Gilbertson M, Maticka-Tyndale E et al (2012) Breast cancer risk in relation to occupations with exposure to carcinogens and endocrine disruptors: a Canadian case-control study. Environ Health. https://doi.org/10.1186/1476-069X-11-87 PubMedPubMedCentralGoogle Scholar
- 74.Lemarchand C, Tual S, Boulanger M, Levêque-Morlais N, Perrier S, Clin B et al (2016) O14-4: breast cancer risk among postmenopausal women in the agriculture and cancer cohort. Occup Environ Med 73(Suppl 1):A27Google Scholar
- 75.Pukkala E (1995) Cancer risk by social class and occupation: a survey of 109,000 cancer cases among Finns of working age. In: Wahrendorf J (ed) Contributions to epidemiology and biostatistics, vol 7. Karger, BaselGoogle Scholar
- 80.Pukkala E, Engholm G, Højsgaard Schmidt LK, Storm H, Khan S, Lambe M, Pettersson D, Ólafsdóttir E, Tryggvadóttir L, Hakanen T, Malila N, Virtanen A, Johannesen TB, Larønningen S, Ursin G (2018) Similarities and differences of the Nordic cancer registries: an overview of their procedures and data comparability. Acta Oncol 57:440–455CrossRefPubMedGoogle Scholar