Environment and Breast Cancer: Science Review

Evidence From Humans
Print this page
Perfluorinated compounds are related to breast cancer risk in Greenlandic Inuit: a case control study
Bonefeld-Jorgensen, E. C., Long, M., Bossi, R., Ayotte, P., Asmund, G., Kruger, T., Ghisari, M., Mulvad, G., Kern, P., Nzulumiki, P., Dewailly, E. Environ Health. 2011. 10, 88.
Topic area
Environmental pollutant - PCBs PFCs Organochlorine pesticides OCPs
Study design
Population based case-control
Funding agency
International Polar Year Committee Commission for
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Analyses by menopausal status were restricted to comparison of serum POP, metal, and POP-related xenobiotic induced receptor transactivity levels.
Number of Controls
Controls: 115
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Cases were women of Greenland Inuit descent (more than two grandparents born in Greenland), who were in the breast cancer registry at a hospital in Greenland, where all breast cancer cases are registered in the country. Controls were also women of Greenland Inuit descent, who participated in another study of POP measurements, or they were in the Artic Monitoring Assessment Program. The controls were matched to the cases based on age (4 year intervals), and frequency matched with cases based on districts. The sampling period was from 2000-2003.
Comment about participation selection
Forty-two percent of cases were missing data for BMI. Several cases and controls were also missing data on number of full-term pregnancies and menopausal status, leading to small numbers in adjusted analyses.
Exposure Investigated
Exposures investigated
12 PCB congeners 8 OCPs: DDT, DDE, HCH, aldrin, HCB, oxychlordane, cis-nonachlor, trans-nonachlor 10 PFCs: PFHpA, PFOA, PFNA, PFDA, PFUnA, PFDoA, PFTrA, PFHxS, PFOS, PFOSA 5 metals: selenium, zinc, lead, mercury, cadmium The transactivity of estrogen, an
Exposure assessment comment
Blood POP measurements were lipid adjusted.
Breast cancer outcome investigated
Primary incident breast cancer
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
Inuit descent
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
Age, BMI, pregnancy, cotinine, breastfeeding, menopausal status. (Confounders not considered for comparison of median levels between cases and controls).
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Strength of associations reported
PFOS, per ng/ml: aOR 1.03 (95% CI 1.00-1.07)
Sum PFSA, per ng/ml: aOR 1.03 (95% CI 1.00-1.05)
Sum PCB, OCP, PFSA, and PFCA, per ng/ml: aOR 1.02 (95% CI 1.01-1.04)

Median levels (ng/ml), cases vs. controls:
PFOS: 45.6 vs. 21.9 (p<0.0001)
PFOA: 2.5 vs. 1.6 (p=0.04)
Sum PFSA: 48.2 vs. 24.6 (p<0.0001)
Sum PFCA: 8.0 vs. 5.2 (p=0.001)

Xenobiotic receptor transactivities, cases vs. controls:
% agonistic XAR: 18.5% vs. 5.17% (p=0.02)
Median AhR-TEQ, pg/g lipid: 56.8 vs. 65.4 (p=0.009)
Results Comments
Differences in median PFOS, sumPFSA, sum PFCA between cases and controls were not significant among premenopausal women.
Author address
Centre for Arctic Environmental Medicine, Department of Public Health, Aarhus University, Denmark. ebj@mil.au.dk
Reviewers Comments
The Arctic Inuit population has one of the highest burden of POPs globally. Greenland Inuit women have only started to see breast cancer increase since the 1970s. Cases had significantly higher median PFOS, sumPFSA and sumPFCA compared to controls.