Tamoxifen is a commonly prescribed drug for the prevention and treatment of breast cancer. Tamoxifen pills are taken orally. The brand name of tamoxifen citrate is Nolvadex.
The U.S. Food and Drug Administration (FDA) approved tamoxifen for treatment of breast cancer in the 1970s.
Tamoxifen is an example of an selective estrogen receptor modulator (SERM) type of drug that works by binding to estrogen receptors on estrogen-dependent breast cancer cells, thereby blocking their ability to absorb estrogen. Without a supply of estrogen to stimulate their growth, the breast cancer cells “starve” and die.
In 1998, Tamoxifen became the first drug to be approved by the FDA for the prevention of breast cancer. Research showed that tamoxifen reduced the chances of developing breast cancer by 50% in women at high risk for the disease.
In post-menopausal women treated for estrogen receptor- positive (ER-positive) breast cancer, tamoxifen reduces the risk of relapse (recurrence) and metastasis. Use of tamoxifen in these types of patients for 5 years resulted in 81.4% disease-free survival (i.e., survival with no evidence of recurrence).
As tamoxifen blocks the action of estrogen, some side effects are possible.
1. National Cancer Institute. NCI Cancer Bulletin. 2006; 3(2) :4.