Breast Cancer May Be Determined In Womb
A renowned cancer epidemiologist, HSPH Professor Dimitrios Trichopoulos has received a U.S. Department of Defense (DoD) "Innovator Award" to explore fetal and early-life factors associated with adult breast cancer, including whether exposure to hormones such as estrogens and insulin-like growth factors while in the womb may cause the disease years later.
The grant, for $5.8 million over five years, is given by the DoD's Breast Cancer Research Program of the Office of the Congressionally Directed Medical Research Programs. The Innovator Award recognizes individuals who have a "history of visionary scholarship, leadership, and creativity."
"There has admittedly been little progress in the prevention of breast cancer, despite efforts in molecular, clinical, and epidemiological research, which have focused on adult life exposures and experiences," said Trichopoulos, Vincent L. Gregory Professor of Cancer Prevention in the Department of Epidemiology at HSPH. "A possible explanation for the slow progress is that a window of opportunity for the prevention of breast cancer lies much earlier in life, as early as in utero or in the first years of life."
Since 1990, Trichopoulos has advanced a theory that exposure to certain levels of naturally occurring hormones amplifies the number of undifferentiated cells in the mammary glands of female fetuses.
During cell division in later life, mutations in this broader pool of cells are associated with increased risk for breast cancer. Larger mammary glands have more cells at risk. The size of mammary glands is not reflected in breast size, which is largely determined by body fat.
The theory is supported by evidence presented in epidemiologic studies that indicate certain early-life conditions, such as large birth size, are associated with breast cancer risk. In addition, correlates of mammary gland mass, such as the density of breast tissue, are considered to be predictors of breast cancer risk.
With the Innovator Award, Trichopoulos and colleagues in the U.S., Sweden, and Greece will undertake a series of five complementary studies designed to investigate links between early life exposures, mammary gland stem cells, mammary gland mass, and adult breast cancer.
The studies will focus on:
- whether the number of mammary gland-specific stem cells depends on the presence of certain growth hormones in umbilical cord blood
- whether certain hormone levels in maternal blood and umbilical cord blood are associated with perinatal characteristics related to breast cancer risk
- whether infant growth shortly after birth, when the number of undifferentiated mammary cells susceptible to cancer is likely to change, is associated with future breast cancer risk
- whether mammographic patterns, reflecting mammary gland mass, are associated with perinatal characteristics and post-birth growth
- whether genes involved in hormone exposure and response may affect the association of perinatal characteristics with adult breast cancer risk
Contact: Christina Roache
Harvard School of Public Health