Understanding of Low Breast Cancer Rate in Japanese Holds Implications for Prevention
It has long been known that presence of the estrogen hormone is related to risk of breast cancer. However, researchers have been puzzled by breast cancer rate disparities between women in the US and those in Japan and China. Breast cancer rates are five times higher in the US than in Asia, even among women with similar estrogen levels.
Now,
researchers from HSPH, Australia, and Japan have discovered that a protein
that "recognizes" estrogen and allows it to be absorbed by cells
is found in significantly lower levels in Japanese women. The protein
is called an estrogen receptor.
The identification of estrogen receptors as a risk factor for breast cancer opens new possibilities for the prevention of breast cancer. "If the findings hold true," said Dimitrios Trichopoulos, Vincent L. Gregory professor of cancer prevention at HSPH, "then we may be able to prevent breast cancer by controlling the expression of estrogen receptors." Possible means of controlling the receptors include diet and drugs.
The research is published in the November 20, 1999, issue of Lancet as "Low Estrogen Receptor alpha Expression in Normal Breast Tissue Underlies Low Breast Cancer Incidence in Japan."
