A report on Tamoxifen, Breast cancer, Estrogen receptor and Aromatase inhibitor

Tamoxifen, sold under the brand name Nolvadex among others, is a selective estrogen receptor modulator used to prevent breast cancer in women and treat breast cancer in women and men.

Aromatase inhibitors (AIs) are a class of drugs used in the treatment of breast cancer in postmenopausal women and in men, and gynecomastia in men.

Tamoxifen (a SERM) traditionally was the drug treatment of choice, but the ATAC trial (Arimidex, Tamoxifen, Alone or in Combination) showed that in women with localized estrogen receptor-positive breast cancer, women receiving the AI anastrozole had better results than the tamoxifen group.

Tamoxifen is used for the treatment of both early and advanced estrogen receptor-positive (ER-positive or ER+) breast cancer in pre- and postmenopausal women.

The medications tamoxifen or raloxifene may be used in an effort to prevent breast cancer in those who are at high risk of developing it.

The ERα is found in endometrium, breast cancer cells, ovarian stromal cells, and the hypothalamus. In males, ERα protein is found in the epithelium of the efferent ducts.

Selective estrogen receptor modulators (e.g., tamoxifen, clomifene, raloxifene)

Endocrine therapy for breast cancer involves selective estrogen receptor modulators (SERMS), such as tamoxifen, which behave as ER antagonists in breast tissue, or aromatase inhibitors, such as anastrozole.

The aromatase inhibitor aminoglutethimide induces the metabolism of tamoxifen.

Additionally, G-protein coupled estrogen receptors have been associated with various cancers of the female reproductive system including breast cancer.

Aromatase inhibitors (such as exemestane and anasatrozole) may be more effective than selective estrogen receptor modulators (such as tamoxifen) at reducing breast cancer risk and they are not associated with an increased risk of endometrial cancer and thromboembolism.