Online Program

Breast cancer, carcinogens and endocrine disruptors: A Canadian occupational study and strategy for future investigation

Wednesday, November 6, 2013 : 9:30 a.m. - 9:45 a.m.

Robert Park, MS, Risk Evaluation Branch, National Institute for Occupational Safety and Health, Cincinnati, OH
James Brophy, PhD, University of Windsor (Canada), 2 University of Windsor, Ontario, Ontario, ON, Canada
Margaret Keith, PhD, University of Windsor, Ontario
Andrew Watterson, PhD, University of Stirling, U.K.
Michael Gilbertson, PhD, University of Stirling, U.K.
Background and Objectives: Endocrine disrupting chemicals and carcinogens in occupational environments may cause observable, excess breast cancer. This study examined breast cancer risk and occupation particularly in farming and manufacturing in SW Ontario. Methods: Detailed occupational, reproductive and demographic histories were obtained from 1006 cases and 1146 controls. Jobs were industry- and occupation-coded, exposure metrics constructed for likely exposure to carcinogens and endocrine disruptors, and data analyzed in a frequency-matched case-control design. Results: All women in jobs with potentially high exposures had elevated breast cancer risk (OR = 1.42 (95% CI, 1.18-1.73), for 10 years exposure duration). Specific sectors with elevated risk included: agriculture (OR = 1.36; 95% CI, 1.01-1.82); bars-gambling (OR = 2.28; 95% CI, 0.94-5.53); automotive plastics (OR = 2.68; 95% CI, 1.47-4.88), and metalworking (OR = 1.73; 95% CI, 1.02-2.92). Risk varied with tumor estrogen receptor status and was highest for premenopausal women in automotive plastics (OR = 4.76; 95% CI, 1.58-14.4) and food canning (OR = 5.70; 95% CI, 1.03-31.5). Conclusions: These observations support hypotheses linking breast cancer risk and exposures to carcinogens and endocrine disruptors. The value of occupational studies in breast cancer is affirmed. Based on these results priority objectives for investigation include: rigorous retrospective exposure assessments in automotive plastics and canning operations, confirmatory studies in similar populations, and identification of other populations potentially at high risk. Implications in the current breast cancer epidemic and the appropriate responses for the cancer research establishment will be discussed.

Learning Areas:

Occupational health and safety
Public health or related research

Learning Objectives:
Demonstrate the importance of occupationl investigations of the causes of breast cancer. Describe an exposure assesment procedure for a population-based occupational case-control study.

Keyword(s): Breast Cancer, Occupational Exposure

Presenting author's disclosure statement:

Qualified on the content I am responsible for because: I have been employed by NIOSH for 14 yr doing exposure-response analyses and risk assessments. I advised the co-authors of this study on the implementation of this study and performed the bulk of the analysis and interpretation. I have participated in subsequent discussions on next steps needed to be taken in this vital area of public health. I have no conflcits of interest regarding the findings or implications of this study.
Any relevant financial relationships? No

I agree to comply with the American Public Health Association Conflict of Interest and Commercial Support Guidelines, and to disclose to the participants any off-label or experimental uses of a commercial product or service discussed in my presentation.