Final answer:
Tamoxifen and raloxifene work by blocking estrogen receptors, serving as targeted therapies in the treatment of estrogen receptor-positive breast cancer.
Step-by-step explanation:
Tamoxifen and raloxifene are drugs that act by blocking estrogen receptors. They are selective estrogen receptor modulators (SERMs) and are used in the treatment of certain types of breast cancer, namely those that have estrogen receptors expressed in their tumors.
By blocking these receptors, the drugs prevent estrogen from binding to them, thereby inhibiting the growth of estrogen-dependent cancer cells. Targeted therapies like these are beneficial to patients with lots of the estrogen receptor expressed in their tumor.