Tamoxifen is used to treat which of the following conditions?

Tamoxifen is primarily used in the treatment of breast cancer, particularly hormone receptor-positive breast cancer. It functions as a selective estrogen receptor modulator (SERM), which means it binds to estrogen receptors and has an antagonistic effect in breast tissue, thereby inhibiting the growth of estrogen-dependent tumors. This property makes it an established treatment option for both early-stage and metastatic breast cancer, especially in premenopausal women.

While tamoxifen may have other off-label uses, such as in certain infertility treatments due to its effects on estrogen pathways, its main and most significant clinical application is in the management of breast cancer. The medication's impact on reducing the risk of breast cancer recurrence and improving survival rates underscores its importance in oncology.