Breast cancer research priorities using occupational populations

Background and Objectives: Endocrine disrupting chemicals and carcinogens in occupational environments may cause breast cancer. A large case-control study identified automotive plastics workers as having substantially elevated breast cancer risk, and proposed testable hypotheses on causation.

Methods: In order to verify and examine evidence in support of a role for chemicals in plastics being causes and co-factors in breast cancer initiation, two study designs are proposed. The first makes use of the National Health and Nutrition Examination Survey (NHANES) conducted periodically by CDC which collects detailed demographic, reproductive and health outcomes as well as blood levels for specific classes of chemicals, including some present in plastics formulations such as flame retardants and plasticizers. The second design identifies a cohort of automotive plastics workers from historical records and performs a mortality follow-up to identify breast cancer deaths. If an excess is confirmed, a detailed retrospective exposure assessment and survey questionnaire on demographic and reproductive risk factors will be performed permitting examination of exposure associations.

Results: The results from the NHANES analysis will be presented. The automotive plastics worker cohort will be described, including available work history and historical plant process characterization.

Conclusions: The observations will be discussed in relation to the specific prior  hypotheses linking breast cancer risk and exposures to carcinogens and endocrine disruptors. Implications for research in the current breast cancer epidemic and appropriate responses for the cancer research establishment will be discussed.