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
croache@hsph.harvard.edu
617-432-6052
Harvard School of Public Health
