Overall Benefit Many clinical studies show that former breast cancer patients live longer and better if they take tamoxifen. For women with the most common types of breast cancer, it can reduce the risk of microscopic cancer seeds growing. Ovarian Ablation Ovarian ablation causes the ovaries to stop making the female hormones estrogen and progesterone. It works because the ovaries are the major source of estrogen in premenopausal women, and it deprives breast cancers of the female hormones many of them need to grow. Because postmenopausal women's ovaries do not make much estrogen, ovarian ablation is not effective and is not recommended.
Oophorectomy is a small surgical procedure.
In some situations, it can be done and the woman can go home the same day. Oophorectomy is, of course, permanent and need only be done once. Ovarian ablation can be done by treating the ovaries with radiation, which stops them from making estrogen. This technique can work well, but is not often done in the United States because it takes longer than surgery and sometimes does not work. In premenopausal women, the ovaries are the major source of estrogen.