Insulin and Estrogen linked to Breast Cancer
An interaction between the hormones estrogen and insulin may encourage the growth and proliferation of breast cancer cells. When breast cancer cells are chronically bathed with estrogen, the breast cancer cells are more susceptible and more sensitive to insulin, which stimulates the proliferative response of the cells. This was presented at the Experimental Biology '98 conference in San Francisco, California, on April 21.
The researchers found that in the presence of insulin alone, the number of insulin receptors on the surface of breast cancer cells decreased, a normal response. But when bathed in a solution of both insulin and estrogen, the number of insulin receptors on the cell surface remained the same, and the number of estrogen receptors increased by 12 times. This is a formula for increased tumor growth and proliferation. The ramifications have really already been noted by epidemiologist who found that in women with breast cancer there was a higher incidence of diabetes and conversely in women with diabetes there was a higher incidence of breast cancer.