Daughter hugging her mother
Daughter hugging her mother

Endocrine Therapy

Also known as: Hormone Therapy for Breast Cancers

Whether your breast cancer is at an early stage or has already spread, hormone therapy can help reduce tumor size, decrease the chance of cancer recurrence and aid in your cancer management.

Hormone therapy, also called endocrine therapy or anti-hormone therapy, is used to treat receptor-positive cancers. These are cancers that are sensitive to hormones like estrogen or progesterone.

Hormonal therapy takes advantage of the fact that some breast cancers depend on hormones to grow. The therapy uses drugs to inhibit the production or reception of those different hormones, helping shrink and control cancerous tumors.

There are newer endocrine therapies that use trastuzumab and tyrosine kinase inhibitors to target specific proteins or molecular pathways in the body, rather than specific hormones. These therapies, called molecular based therapies, also help halt the growth of breast cancer and can sometimes shrink tumors.

Your menopausal status affects your estrogen and progesterone levels, and therefore will determine your specific hormonal therapy.

Premenopausal patients can be treated with tamoxifen, an estrogen receptor blocker, which helps keep tumors from receiving the estrogen needed to grow.

For premenopausal patients, doctors may choose to add medications that suppress ovarian function to make the patient “post-menopausal” so that they may be candidates for aromatase inhibitor therapy instead.

Aromatase inhibitor therapy helps restrict production of estrogen and is given to postmenopausal patients. By blocking the hormone, these aromatase inhibitors, such as anastrozole, have been effective at starving cancer cells of the substance they need for growth.

Hormonal therapy can cause menstrual irregularities, infertility, hot flashes, decreased libido, vaginal dryness and bone aches in some women. Side effects include uterine cancer, blood clots in the legs and brittle bones.