Environment and Breast Cancer: Science Review

Evidence From Humans
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Breast cancer risk among relatively young women employed in solvent-using industries
Hansen, J. American Journal of Industrial Medicine. 1999. 36:1, 43-7.
Topic area
Environmental pollutant - Occupation, organic solvent
Study design
Case-control study
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post menopausal
Number of Controls
Controls: 7,226
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
7802 women born in 1934-1969 with primary breast cancer diagnosed in 1970-1989 and no previous cancer who had been employed. Controls from the population registry must be alive, cancer-free, and an employee before the date of diagnosis of the corresponding case.
Exposure Investigated
Exposures investigated
Employment in industries with extensive solvent use (metal product, wood and furniture, printing, chemical, textile and clothing industries), based on records of the national pension fund. Five industrial groups were considered exposed: fabricated metal
Exposure assessment comment
Misclassification of jobs is likely. Exposure to multiple chemicals outside the targeted ones is likely.
Statistical Analysis
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
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.
Socioeconomic status based on job category, gravidity, age at first birth
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Description of major analysis
Conditional logistic regression
Strength of associations reported
Odds ratios are elevated for all exposed job categories. Most confidence intervals exclude one. All ORs are higher with lag time.
Employed in an exposed job >1 year
No lag time OR 1.27 (1.13-1.43); 15 years lag time OR 1.43 (1.24-1.67)
Employed in an exposed job >10 year
No lag time OR 1.43 (1.01-1.75); 15 years lag time OR 1.97 (1.39-2.79)
Results Comments
Healthy worker effect is likely.
Author address
Danish Cancer Society, Institute of Cancer Epidemiology, Copenhagen, Denmark. johnni@cancer.dk