A team of researchers at the University of Nebraska Medical Center has
determined that certain estrogen metabolites could serve as biomarkers
to predict the risk of someone getting breast cancer. The results of the
study are published in the April issue of Carcinogenesis.
In the study, breast biopsy tissues were examined for 49 women without
breast cancer and 28 women with breast cancer. The tissue samples were
analyzed to detect the levels of 31 estrogen metabolites.
In the women with breast cancer, it was found that estrogen levels were
higher, and that the levels of two estrogen metabolites 4-hydroxyestradiol
and estrogen-3,4-quinone were nearly four times higher than seen in women
without breast cancer. These results suggest that in women with breast
cancer their metabolism of estrogens is out of balance and damage to DNA
is more likely.
The team of researchers was headed by Eleanor Rogan, Ph.D., and Ercole
Cavalieri, D.Sc., both professors in the Eppley Research Institute at UNMC.
Other members of the research team included James Edney, M.D., UNMC department
of surgery, and William West, M.D., UNMC department of pathology and microbiology.
The ramifications of this study are significant, Dr. Rogan said. We
are discovering the biomarkers that we can use to determine a womans risk
of getting breast cancer.
Dr. Cavalieri said the research group thinks that estrogen-3,4-quinone
reacts with DNA to produce specific mutations that trigger cancer.
Estrogens can become carcinogenic only when natural mechanisms of protection
do not work properly in our body, Dr. Cavalieri said. In fact, if these
protections go away due to genetic, lifestyle or environmental influences,
then metabolism of estrogen can get out of balance and cancer can be triggered.
In addition to this research, Dr. Cavalieri was awarded a four-year
grant totaling $5.6 million from the U.S. Department of Defense earlier
this month. This grant involves five other research centers and will investigate
the role estrogens play in causing breast cancer and look for new approaches
to detecting and preventing the disease.