A study adds to the evidence showing that as hormone replacement therapy (HRT) use by postmenopausal women has decreased, there also has been a decrease in new cases of hormone-receptor-positive breast cancer. Rates of hormone-receptor-positive breast cancer dropped 13% between 2001 and 2003 after HRT use decreased, starting in 2000.
A number of reports in the early 2000s showed a higher risk of hormone-receptor-positive breast cancer in postmenopausal women who took combination HRT (HRT that contains both estrogen and progesterone) for an extended period of time. The most notable report came from the Women's Health Initiative study in 2002. Since 2000, use of HRT by postmenopausal women has decreased dramatically. A couple years later, scientists noticed that cases of new breast cancers were also declining. These observations:
- HRT use is linked to increased risk
- decreased HRT use is linked to decreased risk
make it very likely that HRT really does affect breast cancer risk.
A few points about the role of HRT in breast cancer risk:
- Some doctors aren't completely convinced that the recent decline in invasive breast cancer cases is related only to the decrease in HRT use. The drop in HRT use began in 2000 and the decline in breast cancer cases in postmenopausal women was seen a couple years after that. The study reviewed here found a lower rate of breast cancer between 2001 and 2003. Some experts think that the effects of HRT on risk happen over more than a couple of years and that the lower rates of breast cancer happened too quickly to be explained only by lower HRT use just a year or two earlier.
- Unfortunately, mammogram screenings have decreased during the same time period. It's possible that some of the drop in breast cancer rates is because breast cancer isn't being found in women who aren't getting regular screening mammograms. Still, the researchers who did this study don't believe this is happening based on their findings.
- The link between HRT and breast cancer risk has focused on combination HRT. Combination HRT contains both estrogen and progesterone. But there are different kinds of HRT. Some HRT has only estrogen. Research has shown that estrogen-only HRT increased breast cancer risk only slightly.
- The researchers who did this study suggest that women who need HRT to control severe menopausal symptoms (such as severe hot flashes) but are concerned about breast cancer risk may consider a short-term course of HRT treatment.
The concerns about HRT and breast cancer risk are very real. Still, the side effects of menopause drastically affect quality of life for some women. They have to weigh the benefits of HRT against the risks. If you have severe menopause side effects and are considering HRT, talk to your doctor about your options. Together, you can decide which type of HRT, if any, might be right for you.