Breast cancer is the most common cancer in women. Some women have a family history of breast cancer. They are at especially increased risk. Unfortunately, most women who develop breast cancer do not have a family history. Therefore, all women must be considered to be at risk for breast cancer.
Some breast cancers are stimulated by estrogen. Women with a family history of breast cancer should generally avoid taking estrogen. Exposure to estrogen beyond age 70 is associated with increased breast cancer risk.
Hormone Replacement Therapy does carry an increased risk of breast cancer, especially in women over 70. Most physicians advise stopping HRT before age 70 for this reason.
There are 2 estrogen-like medications which actually decrease breast cancer risk. They do this by competing with a woman’s natural estrogen for the estrogen receptors in breast tissue. Raloxifene (Evista) and Tamoxifen both can occupy the estrogen receptors in breast tissue and block their activation by the woman’s own estrogen. This protects the woman from developing estrogen dependent breast cancer by about 70%.
Tamoxifen is approved for both prevention and treatment of breast cancer. Tamoxifen does not harm bone. The more aggressive modern breast cancer treatments (Aromatase Inhibitors) do harm bone. Unfortunately, Tamoxifen has not been shown to preserve bone either.
Evista preserves bone and decreases Fracture Risk. More about preventing breast cancer and decreasing fracture risk next time.
Jay Ginther, MD