Estradiol is a paradoxical drug.  Women who use it to reduce menopausal symptoms run an increased risk of cancer, but women who have recurrent breast cancer may be surprised when their doctors prescribe it to control their cancer.

Let’s start with the basics.  Estradiol is a form of estrogen.  Spelling counts here!  Our bodies produce three forms of estrogen: estradiol, the main estrogen in women before menopause; estrone, the main estrogen found in women after menopause; and estriol,...