Hormonal Therapy for Breast Cancer

Intro: This is Weekly Dose of Wellness brought to you by MemorialCare Health System. Here's Deborah Howell.

Bill Klaproth: I'm Bill Klaproth, in for Deborah Howell. Hormone sensitive breast cancer is the most common type of breast cancer. Oncologist Dr. Merry Tetef of Saddleback Memorial Medical Center is with us to talk about the causes, symptoms and treatments for hormone sensitive breast cancers including hormone blocking medication. Dr. Tetef, thanks for being on with us. Let's jump right in. What are hormone sensitive breast cancers and how do they develop?

Merry Tetef, MD: About two-thirds of breast cancers are what we call hormone sensitive, which means on the surface of the cancer cells they have what we call hormone receptors, estrogen or progesterone receptors. Occasionally that is related to women having taken hormones in the past, but most often they just develop unrelated to any prior hormonal history. The most common type of breast cancer and it tends to be unaggressive and very treatable.

Bill Klaproth: Well, that's very good news. So - so could you explain a little bit more how this type of breast cancer differs from other types of breast cancers?

Merry Tetef, MD: On the surface of the cells, they have what are called these receptors, which means in the presence of a woman's own estrogen, that can stimulate the breast cancer cells to grow. The other sort of breast cancers are what we call hormone receptor negative, which means that they are not stimulated by a woman's own hormones. The difference is how we treat them. When you have hormone sensitive breast cancer, we can use medicines that block or lower hormones to try to shrink them, whereas with the hormone negative breast cancers, changing hormone levels will not affect their treatment or outcome.

Bill Klaproth: Is this something that's new? Uh, as a man, I've never heard of this, but is this something that women have known about breast cancer for years? Because this sounds new to me.

Merry Tetef, MD: It's something that physicians have known about for years, but I think there are some misconceptions as to how a woman's own hormones affect the development of breast cancer. We just know that the majority of them are - have these hormone receptors, but in terms of thinking about it, most women are not aware of this information either, although scientifically it's something we have known for a long time.

Bill Klaproth: So this really is a - this is a weapon or really an aid to help you fight breast cancer then, correct?

Merry Tetef, MD: Correct. It's what we call targeted treatment when you're able to target what may be a stimulation of breast cancer cells, which is the hormones. When you can target that stimulation pathway by blocking or lowering hormones, you're giving a very specific type of treatment for this type of breast cancer.

Bill Klaproth: Well, that, you know, targeted treatment is always better than the - the wide shotgun approach, so this sounds - this sounds, you know, very positive a - a development for women with breast cancer. So what symptoms may women experience if they have hormone sensitive breast cancer?

Merry Tetef, MD: The symptoms of hormone receptor positive breast cancer are really no different than any other breast cancer. When women develop breast cancer, they may have no symptoms at all and it may be picked up on a mammogram or they may, or their doctor may feel a lump or a mass in the breast. Those are the two common ways that breast cancer is detected, either with a screening mammogram or it may be felt by the patient or her physician. In terms of how these are detected, it's really no different than the hormone receptor negative breast cancer. We don't tell the difference between the two types of breast cancer until a biopsy is done and those cancer cells are looked at under the microscope. That's how the diagnosis of a hormone receptor positive breast cancer is made. It's based on a biopsy and looking at the cells under the microscope.

Bill Klaproth: Is that done with every biopsy now, looking for those the hormone receptors?

Merry Tetef, MD: Yes, it is standard now. Uh, every time a diagnosis of breast cancer is made, the pathologist will do what we call special stains to look at the surface of the cancer cells to see if they have those hormone receptors for the reason that we give these specific targeted medicines to lower or block hormones to try to directly attack that type of breast cancer. So it is standard for all newly diagnosed breast cancers to have that evaluation made to see if they're hormone positive or not hormone positive. For the hormone negative breast cancers, the type of medicine we use is chemotherapy, which is a more general type of way to attack the cancer cells. For the hormone receptor positive breast cancer, some of those women still benefit from chemotherapy and hormone blocking medication.

Bill Klaproth: You mentioned that hormone sensitive breast cancer sometimes can be - um - can develop because women have taken hormones. So is there a way to prevent hormone sensitive breast cancer?

Merry Tetef, MD: We do know that women who take estrogen and progesterone after menopause - and those are women who still have their uterus who need to take both of those hormones - that can mildly increase the risk of breast cancer. So one way to decrease the risk of this type of breast cancer is by not taking hormones after menopause. There are also some medications that actually block hormones that can be used preventatively. A medicine called tamoxifen or some of the medicines in a group of drugs we call aromatase inhibitors. We usually only give those preventatively in women who are at a very high risk of breast cancer, such as a very strong family history or if they have a known inherited risk. We can give those medicines to cut the risk down in half. But for most women, they aren't in that high risk group and so stopping hormones after menopause can decrease the risk. We also know in general women who have less body fat, who exercise, keep their weight down, they have a lower risk of breast cancer. So staying in a healthy weight range and exercise may decrease the risk of this type of breast cancer.

Bill Klaproth: And what types of hormone therapy are used to treat hormone sensitive breast cancers?

Merry Tetef, MD: For women who have the breast - the cancer just in the breast and it hasn't spread, we either use the hormone blocking pill tamoxifen or if women have already gone through menopause, we use one of the medicines we call aromatase inhibitors. Those are all pills that are taken once a day that basically prevent estrogen from getting to a breast cancer cell and therefore the cancer cells can die. But we also for women who've had a recurrence of breast cancer have a whole group of medicines that can be helpful, some are oral, some are injectable and there are many new advances in this area, a lot of new medications that are being shown to help treat breast cancer that has recurred. And this is a very exciting area of research with a whole number of new drugs that are either approved or being approved in the near future, that take what used to be a more aggressive type of recurrence and now are able to treat this much more effectively. So women who've had recurrences of hormone sensitive breast cancer can live for many years on these medications that help block the hormones.

Bill Klaproth: When you talk about hormone therapy, I think this is a long term therapy. Are - do women have to take like tamoxifen for years then?

Merry Tetef, MD: So, women who take tamoxifen for breast cancer that has not spread, the latest recommendation is indeed to take it for 10 years. For the group of drugs aromatase inhibitors, we think for women who have maybe bigger tumors or more aggressive cancers, that somewhere between five to 10 years is appropriate. For women who've had recurrences where the cancer has spread, we often keep them on hormone blocking medicine basically chronically their whole lives to try to suppress any cancer cells that may have already spread. So the duration of treatment really depends on the type of medicine used and the features of the cancer, how big, how aggressive, if it has spread somewhere or if it's still early treatment. So that's also an area that is changing. There's a lot of research to evaluate whether women should be staying on these medications longer and there are many large studies that are being done to try to answer the question as to the optimal amount of time women should take these medications.

Bill Klaproth: So then what are the side effects of these medications?

Merry Tetef, MD: Uh, very good question. Uh, by lowering or blocking hormones, a lot of women do get hot flashes, which can be bothersome. And because hormones, which are one of the ways we treat hot flashes such as taking estrogen - because women who have hormone receptor positive breast cancer should not take estrogen, because that could stimulate breast cancer growth, we often have to look for other types of medicines or treatments such as acupuncture to treat hot flashes. In addition the hormone blocking medicine sometimes can cause some joint pain, sometimes can lower bone density or bone strength. Some women do get some vaginal dryness or feel that their sex drive, their libido, has decreased by lowering hormones. So there certainly are quality of life issues related to these treatments, although there are ways to try to work to make those side effects better. The important thing is that hormone sensitive breast cancer is curable, but it does require lowering or blocking hormones with these medications and so it's important every woman on these medications work with her oncologist to try to treat any side effects or symptoms that may arise. It's very important that women try to complete their whole recommended course of the hormone blocking medication in order to have the best chance of cure.

Bill Klaproth: Dr. Tetef, last question. What is the success rate of this hormone blocking therapy?

Merry Tetef, MD: The success rate in terms of cure really depends on how big and aggressive the cancer is when it is found. So the larger the tumor in the breast or the larger the number of lymph nodes, does raise the risk of recurrence. So in terms of putting a statistical number on it, it really depends on so many different features of the woman's specific cancer. But in general, the hormone blocking medication is very effective and many women with hormone sensitive breast cancer are cured with appropriate treatment. And with the newer medicines coming and all the research being done, this is becoming an increasingly exciting area where more and more women are being helped and hopefully cured.

Bill Klaproth: Sounds like great news on the front for breast cancer. Dr. Tetef, thanks for being on with us today. We really appreciate it. For more information on hormone sensitive breast cancers visit memorialcare.org. That's memorialcare.org. I'm Bill Klaproth in for Deborah Howell. This is your Weekly Dose of Wellness. Thanks for listening.