Estrogen Metabolites as Biomarkers for Breast Cancer Risk
H. Leon Bradlow, Ph.D., principal investigator
Strang Cancer Prevention Laboratory, New York, NY
Long Island investigators investigated whether differences in the way women's bodies process the natural hormone estrogen may be related to breast cancer risk. Estrogen is metabolized by two main, competing pathways, either to 2-hydroxyestrone or to 16-hydroxyestrone. Earlier studies suggested that the balance between the estrogen metabolite 16-hydroxyestrone, which has been associated with breast cancer, and 2-hydroxyestrone, which has not, may affect risk for the disease. Dr. H. Leon Bradlow, of Strang Cancer Research Laboratory, and colleagues examined the ratio between the two metabolites in urine. They found that postmenopausal women with very low levels of the "good" metabolite relative to the "bad" metabolite had a greatly increased risk of breast cancer, compared to women with high levels of the "good" metabolite. Because of the small number of study participants, further study is needed to confirm the findings.