Many of today's female cancers breast in particular are estrogen dependent. If your body has too much estrogen, the normally supportive hormone can become toxic, leading to cancer.
Most medical professionals refer to excess estrogen as estrogen dominance. To thoroughly understand why estrogen dominance is a major risk factor for female cancers, let's take a quick look at the way estrogen is metabolized in your body.
Though we speak of estrogen in general, your body actually produces three types of estrogen: estradiol (the most potent), estrone, and estriol.
During estrogen metabolism, estradial is converted into estrone. Estrone then becomes either 2-hydroxyestrone a "good" estrone metabolite or 16-alpha-hydroxyestrone a "bad" estrogen metabolite. The good metabolite (2-hydroxyestrone) is then converted into 2-methoxyestrone and 2-methoxyestrodial.