Very large research studies have shown that using hormone replacement therapy (HRT) increases breast cancer risk. After the results were published, many postmenopausal women all over the world stopped using HRT.
A study found that overall use of HRT dropped dramatically among Australian women over 50 -- from about 20% in 2004 to about 12% in 2008. Still, women who are using HRT are increasingly using unapproved alternative forms of HRT. In 2004 use of unapproved alternative forms of HRT was rare, but by 2008 25% of the Australian women in this study who were taking HRT were using an unapproved, unregistered form of HRT.
This study, the South Australian Health Omnibus Study, asked postmenopausal Australian women about their use of HRT each year for 17 years. Other studies have shown that the link between HRT use and breast cancer risk has likely caused similar declines in HRT use among women in the United States. It's also likely that among women taking HRT, use of unapproved forms of HRT is on the rise worldwide.
Increasing numbers of postmenopausal women may be using unapproved forms of HRT, believing they may help relieve hot flashes without raising breast cancer risk. There is NO EVIDENCE that this is true. Manufacturers of unapproved forms of HRT may claim that the products are safe and effective. Again, there is NO EVIDENCE for these claims. The ingredients in these unapproved, alternative forms of HRT:
- haven't been proven effective
- have never been evaluated properly for safety
- haven't been approved for use
Some of these alternative HRT products contain the hormone estriol, a form of estrogen naturally produced during pregnancy. While estriol is a "natural" substance, it has never been carefully studied and it has never been shown to relieve menopausal symptoms. Also, it's never been shown that it's safe to take estriol as HRT. Since estriol is a form of estrogen, it might increase breast cancer risk and may have other, unknown health risks.
Menopausal side effects can dramatically reduce quality of life for some women. These women have to weigh the benefits of HRT against the risks. If you're having severe hot flashes or other menopausal side effects and are considering HRT, talk to your doctor about all of your options. Using an unapproved alternative form of HRT shouldn't be an option. Ask your doctor how you can minimize your breast cancer risk AND relieve your symptoms. Be sure to discuss the pros and cons of different types of approved HRT. Other research suggests that estrogen-only HRT appears to increase breast cancer risk less than combination HRT. If you do decide to take HRT, ask if you can take a lower-dose formula and try to take it for the shortest time possible.
Learn more about more about menopause and ways to manage side effects in the Breastcancer.org Managing Menopausal Symptoms section.