Environment and Breast Cancer: Science Review

Evidence From Humans
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Occupational exposure to solvents and risk of breast cancer
Glass, D. C., Heyworth, J., Thomson, A. K., Peters, S., Saunders, C., Fritschi, L. Am J Ind Med. 2015. .
Topic area
Environmental pollutant - Occupation Organic solvents
Study design
Population based case-control
Funding agency
Not reported
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Analysis stratified by menopausal status
Number of Controls
Controls: 1,785
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Women aged 18-80 were enrolled as cases through the Western Australian Cancer Registry and included in the study if they received a first incident invasive primary breast cancer diagnosis between 2009 and 2011. 1,789 age-matched controls were chosen at random from the Western Australian electoral roll and excluded if they had a previous diagnosis of invasive breast cancer. Cases and controls without correct addresses, confirmed residency in Western Australia, and inadequate English language skills were excluded, as were those too unwell to participate.
Exposure Investigated
Exposures investigated
Lifetime occupational exposure to benzene, aromatic, aliphatic, chlorinated, and alcohol based solvents assessed by telephone interview using OccIDEAS
How exposure was measured
Questionnaire, self-administered Questionnaire, by telephone
Exposure assessment comment
Exposure to solvents assigned to participants as none, possible, and probable using the OccIDEAS methodology. The authors note that, since exposures were assigned based on responses to task-related questions, misclassification is possible.
Breast cancer outcome investigated
Primary incident breast cancer
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, solvent exposures in other time windows, BMI, age at menarche, smoking, alcohol consumption, hormonal replacement therapy, age at first birth, parity, and family history of breast cancer.
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
Any solvent exposure OR 1.15 (95% CI 0.98-1.35)
Benzene OR 1.08 (95% CI 0.80-1.47)
Aromatic solvents other than benzene OR 1.21 (95% CI 0.97-1.52)
Aliphatic compounds OR 1.21 (95% CI 0.99-1.48)
Chlorinated solvents OR 1.05 (95% CI 0.69-1.61)
Alcohol-based solvents OR 1.15 (95% CI 0.96-1.37)

Exposure before first childbirth:
Benzene OR 0.82 (95% CI 0.50–1.36)
Aromatic solvents other than benzene OR 1.17 (95% CI 0.83–1.66)
Aliphatic compounds OR 1.21 (95% CI 0.88–1.68)
Chlorinated solvents OR 1.34 (95% CI 0.76–2.37)
Alcohol-based solvents OR 1.03 (95% CI 0.83–1.27)

Any solvent exposure OR 1.14 (95% CI 0.84-1.56)
Benzene OR 1.53 (95% CI 0.84-2.80)
Aromatic solvents other than benzene OR 1.43 (95% CI 0.92-2.21)
Aliphatic compounds OR 1.33 (95% CI 0.89-2.00)
Chlorinated solvents OR 1.47 (95% CI 0.62-3.45)
Alcohol-based solvents OR 1.05 (95% CI 0.74-1.49)

Any solvent exposure OR 1.25 (95% CI 1.05-1.48)
Benzene OR 1.10 (95% CI 0.78-1.54)
Aromatic solvents other than benzene OR 1.25 (95% CI 0.98-1.60)
Aliphatic compounds OR 1.28 (95% CI 1.03-1.60)
Chlorinated solvents OR 1.12 (95% CI 0.70-1.78)
Alcohol-based solvents OR 1.24 (95% CI 1.02-1.50)
Results Comments
P-value for interaction with menopausal status not significant for any solvent. P-value for difference between ER+ and ER- cases was marginally statistically significant (p < 0.10) for alcohol-based solvents. OR for alcohol-based solvents and ER- cases: OR = 0.86; 95% CI: 0.57-1.29. Authors noted small number of ER negative cases and put results for ER+ and ER- in supplemental information.
Author address
Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia. School of Population Health, The University of Western Australia (M431), Crawley, Western Australia, Australia. School of Public Health, Curtin Universi
Reviewers Comments
Because controls were not selected based on work history, these results may be underestimated due to the healthy worker effect. Duration of exposure was not addressed.