A US study of 13,000 patients showed Tamoxifen reduced the rate of expected cancers from one in 130 to one in 236 – a cut of about 45%. The American researchers ended their trial early when they said the drug’s benefits became overwhelmingly obvious.
Other studies found that tamoxifen AND chemotherapy improved survival improved survival rates by about 40–50% compared to taking one treatment or the other.
Should women taking tamoxifen avoid pregnancy?
Yes. Tamoxifen may make premenopausal women more fertile, but doctors advise women on tamoxifen to avoid pregnancy because animal studies have suggested that the use of tamoxifen in pregnancy can cause fetal harm. Women who have questions about fertility, birth control, or pregnancy should discuss their concerns with their doctor.
Does tamoxifen cause a woman to begin menopause?
Tamoxifen does not cause a woman to begin menopause, although it can cause some symptoms that are similar to those that may occur during menopause. In most premenopausal women taking tamoxifen, the ovaries continue to act normally and produce estrogen in the same or slightly increased amounts.
Do the benefits of tamoxifen in treating breast cancer outweigh its risks?
The benefits of tamoxifen as a treatment for breast cancer are firmly established and far outweigh the potential risks. Patients who are concerned about the risks and benefits of tamoxifen or any other medications are encouraged to discuss these concerns with their doctor.
Tamoxifen ( ta-MOX-i-fen) is a medicine that blocks the effects of the estrogen hormone in the body. It is used to treat breast cancer in women or men. It may also be used to treat other kinds of cancer, as determined by your doctor.
Tamoxifen also may be used to reduce the risk of developing breast cancer in women who have a high risk of developing breast cancer. Women at high risk for developing breast cancer are at least 35 years of age and have a combination of risk factors that make their chance of developing breast cancer 1.67% or more over the next 5 years. Your doctor will help to determine your risk of developing breast cancer.