Identifying Environmental Risk Factors for Cancer
- Alexandra J. White, Ph.D., M.S.P.H.
- Tel 984-287-3713
- P.O. Box 12233Mail Drop A3-05Durham, N.C. 27709
As head of the Environment and Cancer Epidemiology Group, Alexandra White, Ph.D., and staff identify novel and modifiable environmental exposures that are related to cancer risk and explore underlying biologic mechanisms. Given the high incidence of breast cancer and the widespread prevalence of environmental exposures, the group’s research has the potential to have a substantial impact on public health. With the long-term goal of reducing the incidence of cancer, the group aims to identify environmental carcinogens for which exposure can be mitigated either with policy changes or individual-level interventions.
White’s work has leveraged two studies focused on identifying environmental risk factors for cancer, the Long Island Breast Cancer Study Project and the Sister Study prospective cohort. The work has uncovered the role of indoor and outdoor air pollution, which includes chemicals such as polycyclic aromatic hydrocarbons (PAHs) and metals, in breast carcinogenesis. White has also had successful collaborations with other study populations including the nationwide Breast Cancer Surveillance Consortium, funded by the National Cancer Institute.
The group’s research is grounded in the following principles:
- As risks associated with environmental factors tend to be modest, studies require large sample sizes or novel designs to quantify and detect associations with environmental exposures.
- Environmental exposures do not exhibit their effects on cancer in a vacuum. Studies need to consider potentially important interactions and susceptible subgroups. For example, chemicals often have co-exposure patterns with other chemicals and a one-chemical-at-a-time analytic approach will not identify relevant synergistic relationships or co-pollutant confounding that may mask associations.
- Improved exposure assessment methods are needed by integrating biomarkers, epigenetics, and comprehensive questionnaire data to best capture exposure patterns.
Ongoing work is focused on the role of air pollution components and other environmental chemicals, individually and in combination, in relation to breast cancer risk. The group also focuses on the role of epigenetics as a biomarker of exposure and as a potential biologic mechanism linking the environment with breast carcinogenesis.
White obtained her M.S.P.H. and Ph.D. in epidemiology at the University of North Carolina at Chapel Hill Gilling’s School of Global Public Health. She completed a postdoctoral fellowship in the NIEHS Epidemiology Branch and joined the Branch as an Earl Stadtman Tenure-Track Investigator in 2019.
StudiesThe Sister Study
The Sister Study is a prospective cohort that aims to identify environmental and familial risk factors for breast cancer in more than 50,000 sisters of women who have had breast cancer. Breast cancer-free participants aged 35-74 from across the U.S. and Puerto Rico who had a sister diagnosed with breast cancer enrolled in 2003-2009 by providing questionnaire data about life-time exposures and completing home exams, including collection of biological samples. Participants are being followed with brief annual updates and periodic comprehensive questionnaires. As of September 2016, more than 3,000 breast cancers were diagnosed in the cohort.