Drug Shows Promise In Reducing Breast Cancer Risk

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MELISSA BLOCK, host:

From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.

MICHELE NORRIS, host:

And I'm Michele Norris.

Over the weekend, we learned about a new tool that might be used to prevent breast cancer. A new study has found that a hormone-blocking drug used to help prevent a recurrence of breast cancer may also help prevent some women from getting the disease in the first place.

The women in the study were all postmenopausal and at higher-risk for breast cancer. The drug in question is exemestane. And the study found that a preventive use of that drug cut the risk of invasive breast cancer by 65 percent.

For more on those findings, we're joined now by Dr. Otis Brawley. He's chief medical officer and executive vice president of the American Cancer Society. Welcome to the program.

Dr. OTIS BRAWLEY (Chief Medical Officer and Executive Vice President, American Cancer Society): Thank you for having me.

NORRIS: How significant is this study in the war against breast cancer?

Dr. BRAWLEY: Well, it's an important study. We've actually already had two studies to tell us that tamoxifen and raloxifene also prevent breast cancer. Now we have a third drug, so women who are concerned about breast cancer, and concerned that they are at high risk, can actually look and have a choice of three drugs to try to change their risk.

NORRIS: This study looked at women who were all postmenopausal. Do the findings apply to women who have not yet reached menopause?

Dr. BRAWLEY: Unfortunately, they only work in women who are postmenopausal. It will not work in women who are premenopausal. However, the other two drugs, tamoxifen and raloxifene, actually do have a track record in decreasing risk of breast cancer in premenopausal women.

NORRIS: Doctor, were you at all concerned that the study was relatively short, only three years? And I ask because other studies have been promising, but then later proved to be less than promising over time.

Dr. BRAWLEY: I am concerned that this study is only three years in length. And the truth be told that most of these drugs actually decreased the risk of breast cancer while a woman is taking the drug. This is a drug that does have side effects. I do worry what are the side effects of taking it for five years, or for 10 years over time.

Tamoxifen in a postmenopausal woman can even cause uterine cancer. Interestingly, it can prevent breast cancer, but it increases risk of uterine cancer. It increases risk of blood clots and pulmonary emboli. And it's something that a woman needs to consider if she's going to want to take one of these drugs to try to decrease their risk of getting breast cancer.

NORRIS: Tamoxifen is in wide use for many reasons, but in part because it's affordable. Would that apply to this drug?

Dr. BRAWLEY: This drug right now costs somewhere around $300 a month. And most women, by the way, who take this drug also will need to take a drug to prevent osteoporosis. Fortunately, exemestane is about to become a generic drug. And so the drug itself is going to become much cheaper within the next year.

NORRIS: So how, or who, or what entity will ultimately determine how this drug might potentially be used? Will doctors began prescribing them to be used for prevention? Will women ask for them if they happen to know that they are in this high-risk category?

Dr. BRAWLEY: Well, I would encourage women who think that they might be at high risk to ask their doctor, please calculate my risk for me. And if they are really concerned about breast cancer, consider taking these drugs. Look at all three drugs - look at the various side effects, the various costs.

Now, that being said, I'm very concerned that a lot of women will think, gee, I can just take a pill and decrease my risk to zero. That is not true. Women will still need to get good mammography.

And also, people need to focus on other factors in breast cancer prevention. We know high caloric intake and lack of exercise all cause breast cancer. So people need to focus on all of those things. I'm a little worried, the fact that we have a pill to lower risk will make people ignore the other things.

NORRIS: Are you worried anytime you hear the word prevention in the same sentence with cancer?

Dr. BRAWLEY: No. I worry that people think that prevention is 100 percent. Whereas prevention in my academic world means lowering risks - where if I don't smoke, I lower my risk of getting lung cancer but still, 15 percent of people who get lung cancer are non-smokers.

If a woman does everything that she should do, she still may get breast cancer. So frequently, I have patients who come to me and say, well, I did everything that I was supposed to do, and I still got breast cancer. And unfortunately, telling that woman but you did lower your risk, is not very satisfying.

But I'd like people to know that it does improve overall health, and improves the chances that you won't get these diseases.

NORRIS: Dr. Brawley, thank you for your time.

Dr. BRAWLEY: My pleasure.

NORRIS: That's Dr. Otis Brawley. He's the chief medical officer and executive vice president of the American Cancer Society. Dr. Brawley is also a professor at Emory University.

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