Selective estrogen receptor modulators (SERMs) and aromatase inhibitors are two classes of hormonal agents used to treat estrogen receptor-positive breast cancer by disrupting estrogen signaling: SERMs are synthetic compounds that bind estrogen receptors (alpha or beta) with tissue-dependent agonist or antagonist activity, competing with estrogen to block transcriptional activation in receptor-positive cancer cells, while aromatase inhibitors block the enzyme aromatase (CYP19A1) that converts androgens to estrogens, thereby reducing estrogen synthesis. Hormone and SERM action follows a common mechanism—diffusion into the cell and nucleus, receptor binding, altered DNA transcription, and downstream mRNA-directed protein synthesis—with SERMs generally favored in premenopausal patients and aromatase inhibitors in postmenopausal patients, reflecting differing dominant sources of circulating estrogen by menopausal status.
Selective estrogen receptor modulators (SERMs) and aromatase inhibitors are two classes of hormonal agents used to treat estrogen receptor-positive breast cancer by disrupting estrogen signaling: SER…