ANNOUNCER: A woman diagnosed with breast cancer will have dozens of questions. It's hard to know which to ask first. One of the most important things to discover is whether the cancer is hormone receptor positive. But what does that mean?
LAWRENCE WICKERHAM, MD: In breast cancers that respond to hormones, those that are estrogen-receptor positive, this protein, the estrogen receptor, actually combines with normal circulating estrogen in the woman's body. It's this combination of estrogen and estrogen receptor that is necessary for the breast cancer to continue to grow. If we interrupt that combination, that binding, we can actually stop the progress of breast cancer growth.
ANNOUNCER: Normally, many parts of a woman's body have cells that contain estrogen receptors. It helps them routinely use estrogen to ensure strong bones and may help keep blood vessels unclogged. But in breast cancer, these receptors indicates the cancer will grow in response to estrogen.
STEVEN JONES, MD:These are cancers that overexpress estrogen receptor or progesterone receptor. Again it has nothing to do with whether the woman has taken estrogen or hasn't taken estrogen. It's just a feature of the cancer. And really up to 70% or so of breast cancer is either estrogen or progesterone receptor positive.
ANNOUNCER: Identifying a cancer as hormone receptor positive is important to determine hormonal treatment is an option. Hormonal treatment works to prevent estrogen from causing the cancer to grow, either by lowering the levels of estrogen in the body or preventing the estrogen from binding to the cancer cell.
LAWRENCE WICKERHAM, MD: For premenopausal women, the standard hormonal therapy, in this country at least, has been tamoxifen. It's a pill. It's given for five years and is a highly effective treatment for breast cancer. In postmenopausal women, the options are a little bit broader now. Tamoxifen is still an effective therapy, but we also have a newer class of treatments called aromatase inhibitors.
ANNOUNCER: There are three drugs in this class: Arimidex, Femara, and Aromasin. Arimidex has been approved for adjuvant use against all types of breast cancers including early-stage disease, when the cancer has not spread beyond the breast. Femara is approved for locally advanced cancer and metastatic cancer. And Aromasin has been approved for use against metastatic cancer if tamoxifen has proved ineffective.
Studies have been going on for several years to see whether the benefits of hormone therapy can be carried even further with the use of aromatase inhibitors in post-menopausal women. In all of these studies, the aromatase inhibitors showed an improvement in reducing the risk of recurrence. This was true at all of the time points studied: women who took the aromatase inhibitors immediately after surgery, ones who switched from tamoxifen to the aromatase inhibitors after some number of years -- so-called sequencing of hormonal therapy -- and women who added aromatase inhibitors after completing five years of tamoxifen. The aromatase inhibitors have been shown to improve upon the benefits that have already been seen with tamoxifen and should be incorporated into the care of all postmenopausal women with early stage breast cancer.
ANNOUNCER: Since the type of treatment is dependant on finding out whether breast cancer is hormone receptor positive, testing for this factor is something that's done very early on.
STEVEN JONES, MD: Once a biopsy is done, any type of biopsy, might be a needle biopsy, might be removal of a mass and there's breast cancer present, the test can be done on that tissue. So the pathologist is the one that will do those tests. And it's absolutely standard in this country to get that kind of information.
So that's certainly a question a woman could ask early on. If, for some reason, they haven't done it, they need to go back and do the test.
LAWRENCE WICKERHAM, MD: When we have cancers that have hormone receptors present, it almost universally results in consideration of adjuvant therapies that involve hormonal treatments. The specifics of which therapy and for how long can vary from individual to individual. But in somebody who has no hormone receptor present, then the concept of using hormonal therapies is off the table.
ANNOUNCER: While finding out there is breast cancer is never good news, identifying the hormone receptor status of the cancer might open up many more effective treatments for women.
STEVEN JONES, MD:Using hormonal therapy for five years and it's kind of a standard right now is one of the most important things we do for our patients. Sometimes it is the most important thing to improve the cure rate. So I do everything I can to get that patient to stay on there.