The association between the incidence of postmenopausal breast cancer and occupational exposure to selected organic solvents, Montreal, Canada, 2008-2011

Sydney Westra; Mark S Goldberg; France Labrèche; Jill Baumgartner; Vikki Ho

doi:10.1002/ajim.23525

The association between the incidence of postmenopausal breast cancer and occupational exposure to selected organic solvents, Montreal, Canada, 2008-2011

Am J Ind Med. 2023 Nov;66(11):911-927. doi: 10.1002/ajim.23525. Epub 2023 Aug 11.

Authors

Sydney Westra¹, Mark S Goldberg^{1

2}, France Labrèche^{3

4}, Jill Baumgartner^{1

5}, Vikki Ho^{6

7}

Affiliations

¹ Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Québec, Canada.
² Department of Medicine, McGill University, Montréal, Québec, Canada.
³ Department of Environmental and Occupational Health, School of Public Health and Centre de recherche en santé publique (CReSP), University of Montréal and CIUSSS Centre-Sud, Montréal, Québec, Canada.
⁴ Institut de recherche Robert-Sauvé en santé et en sécurité du travail, Montréal, Québec, Canada.
⁵ Department of Ethics, Equity and Policy, McGill University, Montréal, Québec, Canada.
⁶ Health Innovation and Evaluation Hub Université de Montréal Hospital Research Centre (CRCHUM), Montréal, Québec, Canada.
⁷ Department of Social and Preventive Medicine, Université de Montréal School of Public Health (ESPUM), Montréal, Québec, Canada.

PMID: 37565624
DOI: 10.1002/ajim.23525

Abstract

Background: Breast cancer is the most diagnosed cancer among women and recognized risk factors explain 25%-47% of cases. Organic solvents are used widely in the workplace and exposure may increase the risk of developing breast cancer, yet there are insufficient data to confirm this hypothesis. We sought to determine whether past occupational exposures to selected organic solvents were associated with the incidence of invasive breast cancer in postmenopausal women in Montréal, Canada.

Methods: From a population-based case-control study (2008-2011), using in-depth interviews we elicited information on risk factors and lifetime occupational histories. Industrial hygienists and chemists translated job descriptions into specific chemical and physical exposures. We assessed 11 individual solvents and four solvent groups. Unconditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for metrics of past exposures to selected solvents. Exposure metrics included any previous exposure, average frequency in hours per week, duration in years, and average cumulative concentration weighted by hours per workweek exposed.

Results: We enrolled 695 cases and 608 controls. We found increased ORs for average cumulative concentration of exposure to mononuclear aromatic hydrocarbons (OR: 1.52, 95% CI: 1.04, 2.28), chlorinated alkanes (OR: 2.42, 95% CI: 1.23, 5.68), toluene (OR: 1.59, 95% CI: 1.02, 2.59), and a group of organic solvents with reactive metabolites (OR: 1.53, 95% CI: 1.08, 2.24). Positive associations were found across all exposure metrics and were higher among women with estrogen-positive/progesterone-negative tumors.

Conclusion: Our findings suggest occupational exposure to certain organic solvents may increase the risk of incident postmenopausal breast cancer.

Keywords: breast cancer; case-control study; occupational exposures; organic solvents; population-based; postmenopausal.

Abstract

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