Tamoxifen is a drug that's widely used to treat early and metastatic breast cancer, and has been shown to reduce the risk of breast cancer recurrence. Tamoxifen has also been approved for use to reduce breast cancer risk in high-risk women who have not developed breast cancer. Most notably, several clinical trials have shown that the benefits of tamoxifen persist long after the treatment is stopped, reports a 2009 review published in the journal "Breast Cancer Research." However, tamoxifen does has several side effects that patients need to be aware of.
Menopausal Symptoms
Tamoxifen has been shown to worsen menopausal symptoms, such as hot flashes and vaginal discharge, in 20 percent of users, according to a 2008 review published in the journal "Breast Cancer."
Blood Clots
One of the major complications of tamoxifen is increased risk of blood clots. The risk of pulmonary embolism (blood clots in the lung) is increased four-fold in tamoxifen users compared to non-users. Similarly, the risk of deep vein thrombosis (blood clots in a leg vein, for example) is increased by almost two-fold in tamoxifen users.
Endometrial Cancer
Tamoxifen therapy also increases the risk of endometrial cancer (cancer of the lining of the uterus). Several studies suggest that endometrial cancer survival among long-term tamoxifen users is shorter than that of non-users.
Contraindications
Tamoxifen is contraindicated in patients requiring concomitant coumarin-type anticoagulant therapy. It is also contraindicated in women who are at high risk for--or those with a history of--blood clots.
References
- "Current Breast Cancer Reports"; Is chemoprevention practical?; Fabian and Kilmer; March 2009
- "Cancer of the Breast"; Donega and Spratt; 2007
- "Breast Cancer"; Chemoprevention of breast cancer; Cuzick; January 2008
