Tamoxifen is a selective estrogen receptor modulator used to treat estrogen receptor positive breast cancer, reduce the risk of invasive breast cancer following surgery, or reduce the risk of breast cancer in high risk women. Tamoxifen is used alone or as an adjuvant in these treatments.
- Mechanism
- Curator reviewed · 7 references
Tamoxifen competitively inhibits estrogen binding to its receptor, which is critical for it's activity in breast cancer cells. Tamoxifen leads to a decrease in tumor growth factor α and insulin-like growth factor 1, and an increase in sex hormone binding globulin. The increase in sex hormon binding globulin limits the amount of freely available estradiol. These changes reduce levels of factors that stimulate tumor growth.
Tamoxifen has also been shown to induce apoptosis in estrogen receptor positive cells. This action is thought to be the result of inhibition of protein kinase C, which prevents DNA synthesis. Alternate theories for the apoptotic effect of tamoxifen comes from the approximately 3 fold increase in intracellular and mitochondrial calcium ion levels after administration or the induction of tumor growth factor β.
- Primary indication
- Tamoxifen is indicated to treat estrogen receptor positive metastatic breast cancer in adults, as an adjuvant in the treatment of early stage estrogen receptor positive breast cancer in adults, to reduce the risk of invasive...Curator reviewed · 10 structured indications
- Formula / weight
- C26H29NO · 371.5146 g/mol (avg)
- First approval
- Canada, 1997 · United States, 1990
- Also known as
- trans-Tamoxifen
- Code names
- ICI-47699
- Brand names
Resolves to
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Which drugs share a target with Tamoxifen, and which of those have an active Phase 3 trial?
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