Research Summary

Alexandra White, Ph.D., MSPH, leads the Environment and Cancer Epidemiology group. The overarching research goal for the group is to identify novel and modifiable environmental exposures that are related to women’s cancer risk and to explore underlying biologic mechanisms. Given the high incidence of breast cancer and the widespread prevalence of environmental exposures, our research has the potential to have a substantial public health impact. With the long-term goal of reducing the incidence of cancer in women, we aim to identify environmental carcinogens for which exposure can be mitigated either with policy changes or individual-level interventions.

Dr. White’s work leverages the resources of the Sister Study prospective cohort, which aims to identify environmental risk factors for cancer. Recent findings have supported a role for exposure to indoor and outdoor air pollutants, use of chemical hair products and other environmental exposures in relation to breast cancer risk. A key aspect of this research has been in characterizing how suspected environmental risk factors for breast cancer are related to both biological and clinical markers relevant for cancer etiology, including epigenetics and breast tissue characteristics. Using data from the NCI-funded Breast Cancer Surveillance Consortium and the Komen Tissue Bank, findings have suggested that exposure to air pollution may be related to changes in the breast tissue that increase a woman’s susceptibility to developing breast cancer.

In order to successfully lead the field of environmental and cancer epidemiology, the research of this group is grounded in the following principles:

1. 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.
2. 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.
3. Improved exposure assessment methods are needed by integrating biomarkers, epigenetics, and comprehensive questionnaire data to best capture exposure patterns.

Dr. White obtained her MSPH and PhD 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 Epidemiology Branch at the NIEHS. She joined the Epidemiology Branch as an Earl Stadtman Tenure-Track Investigator in 2019.

Studies

The Sister Study: The Sister Study is a prospective cohort that aims to identify environmental and familial risk factors for breast cancer in over 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 2019, more than 4,000 breast cancers have been diagnosed in the cohort.

Komen Tissue Bank: The Komen Tissue Bank is a biorepository of normal breast tissue and matched serum, plasma and DNA from volunteers across the United States. At the time of sample donation, women fill out a questionnaire asking about demographics, lifestyle and reproductive factors.