Mary Beth Terry, PhD

Developing better risk prediction models in high-risk individuals by incorporating biomarkers of environmental exposures, genetic susceptibility, and non-genetic alterations to DNA.

Impact

Environmental chemicals such as polyaromatic hydrocarbons (PAH) and dichlorodiphenyltrichloro-ethane (DDT) cause DNA damage that can lead to cancer. The severity of the damage and the ability to repair it influences the risk for development of breast cancer. Women with an already high risk of breast cancer, due to inherited factors or strong family history, may be more vulnerable to environmental pollutant exposure. Using the data from two established registries of high-risk families, Drs.Terry and Santella have been examining the impact of environmental exposures in young girls. Their studies include investigating how environmental exposures and genetic susceptibility—specifically as it relates to the ability to repair DNA damage—are related to breast cancer risk. This work will be used to develop better risk prediction models and allow for more precise preventive strategies.

Progress Thus Far

In previous studies, Drs. Terry and Santella have shown that exposure to PAH, a common environmental pollutant, increased the risk of breast cancer in high-risk women. Using a method developed in their laboratories, they discovered that this risk is almost 3-fold greater in women whose cells were deficient in DNA repair functions. Recently, they have extended their studies beyond PAHs and are examining the impact of other compounds that interfere with estrogen metabolism (endocrine disruptors) on breast cancer risk and prognosis—analyses are ongoing. In addition, Drs. Santella and Terry are conducting similar studies in breast cancer patients in Ghana.

What’s next

In the coming year, Drs. Terry and Santella will continue their studies to confirm the role of DNA repair deficiency in breast cancer risk due to environmental exposures and other endocrine disrupting chemicals. They will also employ new technologies to measure exposures of a broad range of environmental contaminants to better understand their impact on breast cancer risk. The team will expand these studies and explore a novel method for detecting DNA damage. They will induce DNA damage in blood cells from women with or without cancer and assessed the resulting damage immediately after treatment and several hours later after cells have had a chance to repair it—this comparison will indicate the level of DNA repair. Since studies suggest that the ability to repair DNA damage is a major risk factor for the development of many cancers including breast, they hope that a relatively simple DNA repair assay can eventually be applied in the clinic for better risk assessment.