Ambient polycyclic aromatic hydrocarbon exposure and breast cancer risk in a population-based Canadian case-control study

Patrick Hinton; Paul J Villeneuve; Elisabeth Galarneau; Kristian Larsen; Deyong Wen; Jun Meng; Verica Savic-Jovcic; Junhua Zhang; Will D King

doi:10.1007/s10552-024-01866-4

Ambient polycyclic aromatic hydrocarbon exposure and breast cancer risk in a population-based Canadian case-control study

Cancer Causes Control. 2024 Apr 17. doi: 10.1007/s10552-024-01866-4. Online ahead of print.

Authors

Patrick Hinton¹, Paul J Villeneuve², Elisabeth Galarneau³, Kristian Larsen⁴, Deyong Wen³, Jun Meng³, Verica Savic-Jovcic³, Junhua Zhang³, Will D King⁵

Affiliations

¹ Department of Public Health Sciences, Queen's University, Kingston, ON, Canada.
² Department of Neuroscience, Carleton University, Ottawa, ON, Canada.
³ Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON, Canada.
⁴ Office of Environmental Health, Health Canada, Ottawa, ON, Canada.
⁵ Department of Public Health Sciences, Queen's University, Kingston, ON, Canada. kingw@queensu.ca.

PMID: 38630334
DOI: 10.1007/s10552-024-01866-4

Abstract

Purpose: Polycyclic aromatic hydrocarbons (PAHs) represent a class of ubiquitous pollutants recognized as established human carcinogens and endocrine-disrupting chemicals. PAHs have seldom been modeled at the population-level in epidemiological studies. Fluoranthene is a prevalent PAH in urban settings and correlates with the occurrence of other PAHs. The purpose of this study was to evaluate associations between long-term residential exposure to ambient PAHs and breast cancer risk, both pre- and post-menopausal, in Canada.

Methods: Using the National Enhanced Cancer Surveillance System (NECSS), a national-scale Canadian population-based case-control study, annual fluoranthene exposures were estimated using the GEM-MACH-PAH chemical transport model on the basis of geocoded residential histories throughout a 20-year exposure window. Odds ratios (ORs) and 95% confidence intervals (CIs) controlling for potential confounders were estimated using logistic regression. Separate analyses were conducted for Ontario and national samples given a finer-resolution exposure surface and additional risk factor information available for Ontario.

Results: Positive associations were observed between fluoranthene exposure and premenopausal breast cancer, with inconsistent findings for postmenopausal breast cancer. For premenopausal breast cancer, adjusted ORs of 2.48 (95% CI: 1.29, 4.77) and 1.59 (95% CI: 1.11, 2.29) were observed when comparing the second highest category of exposure to the lowest, among the Ontario and national samples, respectively. For postmenopausal breast cancer, adjusted ORs were 1.10 (95% CI: 0.67, 1.80) and 1.33 (95% CI: 1.02, 1.73). Associations for the highest level of exposure, across both samples and menopausal strata, were non-significant.

Conclusion: This study provides support for the hypothesis that ambient PAH exposures increase the risk of premenopausal breast cancer.

Keywords: Air pollution; Breast cancer; Case–control study; Polycyclic aromatic hydrocarbons.