"Tamoxifen is probably the most important cancer drug yet to be discovered,” according to Victor G. Vogel, MD, director of Pennsylvania's Geisinger Cancer Institute1. He adds that “published estimates indicate that it has saved about 6 million lives worldwide."
Tamoxifen is an oral drug used in hormone therapy as an anti-cancer agent, most significantly against breast cancer. Work on this compound began in the 1960s in the wake of the birth control pill, largely under the aegis of Northwestern University researcher V. Craig Jordan.
Drug profile
- Class: Non-steroidal antiestrogen, endocrine antihormone, or selective estrogen receptor modulator (SERM)
- Mechanism of action: Among a handful of perceived mechanisms, tamoxifen is believed to work as an estrogen antagonist (it blocks the action of estrogen) with cytostatic effects, inhibiting the cell cycle in the G0 and G1 phases.
- Treatment type: Hormone therapy, chemoprevention
- US approval: 1977
- Synonyms: Tam, Apo-Tamox, Tamofen
- FDA Use-in-Pregnancy Rating: Category D
What Tamoxifen is effective for and why
Although tamoxifen has uses, on and off-label, in endometrial cancers, pancreatic cancer, brain tumors and melanomas, its chief application is against breast cancer. In fact, tamoxifen has applications for a broad class of breast cancer patients. It is used in patients with metastatic breast cancer as a first-line therapy with anti-tumor effects, it is used in patients following breast cancer surgery as an adjuvant therapy, and it is used in patients who are at high risk of developing breast cancer as a prophylactic, or chemopreventive.
Side effects
Tamoxifen was and remains a true blockbuster cancer drug, and it hit the ground running when it first appeared in clinical trials in part because its toxicity profile is, comparatively speaking, extremely low. Patients report very few side effects, and certainly almost none of the side effects traditionally associated with chemotherapeutic drugs. The most common side effects reported include sweating, hot flashes, and thromboembolic events.
Unfortunately, and a little curiously, tamoxifen is considered carcinogenic, with secondary malignancies often manifesting as endometrial cancer or a uterine sarcoma.
References
- "SERMs: Underused and under the radar", HemOncToday.
Sources
- Cancer Drug Manual, BC Cancer Agency
- Ko, Andrew H MD et al. 2008. Everyone's Guide to Cancer Therapy, Fifth Ed. Kansas City. Andres McMeel Publishing LLC.
- Boyiadzis, Michael M. et al. Hematology-Oncology Therapy. 2007. New York: McGraw Hill, Medical Publishing Division.
Significant studies relating to tamoxifen
