PHILADELPHIA (April 16, 2002) -- Postmenopausal women with relatively high serum concentrations of estrogen and testosterone have about twice the risk of developing breast cancer as women with relatively low serum concentrations of these sex hormones. That is the result of an international study published in the April 17, 2002 issue of the Journal of the National Cancer Institute (volume 93, number 8).
The finding was reported by the Endogenous Hormones and Breast Cancer Collaborative Group. Joanne F. Dorgan, M.P.H, Ph.D., a member of the Population Science Division at Fox Chase Cancer Center is a lead investigator of one of nine cohorts included in the analysis.
"The overall results show that postmenopausal women with higher serum sex hormone levels including estradiol and testosterone were twice as likely to develop breast cancer," explained Dorgan.
"Associations between serum sex hormone levels and risk of developing breast cancer were not different in women who donated blood closer in time to diagnosis, indicating higher hormone levels in these women were not a preclinical finding."
In each of the nine cohorts included in the analysis, women who donated blood were followed for an average of 2 to 12 years. During that time 663 women developed breast cancer. Hormones in their blood were compared with the hormones of 1,765 women who were the same age when blood was donated as the women who developed breast cancer.
The results are highly statistically significant and were not altered when we adjusted for established risk factors for breast cancer, added Dorgan. Some of the known risk factors for breast cancer are never having been pregnant, early menarche, and in postmenopausal women, late menopause, use of hormone replacement therapy, and being overweight."
More analyses are planned to increase our understanding of what factors influence a woman's risk of breast cancer," Dorgan stated. "The ultimate goal is to identify ways to
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Contact: Karen Carter Mallet
K_Carter@fccc.edu
215-728-2700
Fox Chase Cancer Center
16-Apr-2002