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In Los Angeles today, researchers announced new discoveries in the treatment of breast cancer. The drugs Raloxifene and Herceptin were found to be effective in the treatment or prevention of the cancer. Elizabeth Farnsworth discusses the findings with Dr. V. Craig Jordan, director of Breast Cancer Research at Northwestern University, and Dr. Larry Norton, head of Medical Oncology at Memorial Sloan-Kettering Cancer Center.
ELIZABETH FARNSWORTH: The good news was announced today in Los Angeles at the Annual Meeting of the American Society of Clinical Oncology. Researchers said the drug Raloxifene had reduced the risk of breast cancer by 58 percent in one study and by 66 percent in another, which involved nearly 8,000 women. Researchers also announced that the drug Herceptin, when used in combination with chemotherapy, slowed progression of a virulent form of breast cancer, causing large tumors to stop growing, shrink, or in some cases disappear. Here with more are Dr. V. Craig Jordan, director of Breast Cancer Research at Northwestern University Medical Center and a lead researcher for one of the Raloxifene studies, and Dr. Larry Norton, head of Medical Oncology at Memorial Sloan-Kettering Cancer Center. He was the lead investigator in the Herceptin study and a researcher in one of the Raloxifene studies. And thank you both for being with us. Dr. Jordan, what is Raloxifene?
DR. V. CRAIG JORDAN, Northwestern University Medical Center: Well, Raloxifene is a selective estrogen receptor modulator. It's a drug that is FDA-approved for the prevention of osteoporosis. It's been FDA-approved since the beginning of this year. But it has some unusual properties, and we've learned a lot about these unusual properties over probably the last ten years for this group of drugs. It switches things on and switches things off around a woman's body. So it may be building bone, but from the pharmacology, from how we know this drug works. We believed that it could be switching off the development of breast cancer. And that's what we've been testing.
ELIZABETH FARNSWORTH: Describe your study for us please.
DR. V. CRAIG JORDAN: Well, there are about 10,500 women that have been in a randomized clinical trial with Raloxifene and a placebo, a sugar-coated pill, and these women were being evaluated over the past two and a half, three years for bone density and ultimately fractures. But what we wanted to do at the same time is have a look at breast safety. And we had an expert committee that I chaired, and this particular committee evaluated all of those women who got breast cancer. We looked at mammograms, looked at the pathology, and really counted up the numbers of cancers that were seen. And the remarkable finding was that there is a 50 percent decrease in the cancers in those women that have been taking Raloxifene for osteoporosis. So this is good news because it gives us valuable information to go on to the next step with this drug development.
ELIZABETH FARNSWORTH: So, Dr. Jordan, you were looking at the drug for osteoporosis, but did you also run tests for all kinds of cancer on these women?
DR. V. CRAIG JORDAN: Could you repeat that question?
ELIZABETH FARNSWORTH: Yes. You were looking at the drug for osteoporosis, but at the same time, did you also test it for all kinds of cancer on these women?
DR. V. CRAIG JORDAN: Yes. I think that's an important point. There was an evaluation for endometrial cancer. There was a decrease in endometrial cancer, but this was not statistically significant. So there were fewer but not enough numbers to make sense. Ovarian cancer was tested in all of these women, and there was no change in the incidence of ovarian cancer. All of the side effects of the drugs were monitored very, very carefully, as one has to do for a drug that is for the general population of post-menopausal women.
ELIZABETH FARNSWORTH: And, Dr. Norton, you also were involved in this study. What did yours show about Raloxifene?
DR. LARRY NORTON, Memorial Sloan-Kettering Cancer Center: Well, there are really several very important studies at this meeting-that Raloxifene is a drug that clearly can reduce the incidence of breast cancer. It does so in a manner that's probably very much like Tamoxifen, that we've already heard about. But it has some advantages, it seems, and one of them is that there's clearly no increase in the risk of endometrial cancer.
ELIZABETH FARNSWORTH: We should just say, by the way, that that's a cancer of the lining of the uterus, right?
DR. LARRY NORTON: That's a cancer of the lining of the uterus, right. It's particularly in post-menopausal women, and it's obviously a very important finding. We're going to have to follow up on this very carefully.
ELIZABETH FARNSWORTH: And, Dr. Norton, explain how it works.
DR. LARRY NORTON: Well, the drug works by attaching to the estrogen receptor like estrogen does, but making the-
ELIZABETH FARNSWORTH: And explain-I'm sorry-what's an estrogen receptor?
DR. LARRY NORTON: An estrogen receptor is a protein that's found in many cells of the body. It's the way that many cells in the body respond to the female hormone estrogen. The reason that breast cells grow is because they have a receptor for estrogen. And when estrogen gets near the cell, the cell absorbs it, it goes to the center of the cell, and tells the cell to divide. Well, when Raloxifene attaches the estrogen receptor, it also goes to the center of the cell, but it tells the cell not to divide in the breast. And that is obviously something that is very important in terms of decreasing the instance of breast cancer. But when the same complex of Raloxifene and estrogen receptor goes to the bone, it makes the bone cells grow. And that's why the drug works to prevent osteoporosis. Tamoxifen seems to have an effect like estrogen on the lining of the uterus and makes it grow. Raloxifene seems to have the opposite effect. It doesn't make the lining of the uterus grow. And that's probably why it does not increase the risk of endometrial cancer.
ELIZABETH FARNSWORTH: Dr. Jordan, you know there's been some criticism of all the hype surrounding this drug. For example, Fran Bisco, who's president of the National Breast Cancer Coalition, has said that there's been to much hype, given the time of testing that you all have had. It's only been a couple of years. How do you respond to that?
DR. V. CRAIG JORDAN: Well, I know Ms. Bisco very well. And I think that there is a reason for caution, but I think there's more of a reason for optimism. And I think that the reason I say that is that for the past 25 years we've evaluated the first of this class of drugs, Tamoxifen. We have 10 million women years of experience with Tamoxifen. We have a beautiful series of predictive animal experiments that have come into fruition in the clinics. This is the next in the line of a series of these drugs. So we now know what to look for with Raloxifene. We have a clear and competent path forward because the National Cancer Institute just announced yesterday that they are going to compare in post-menopausal women in a trial that they're calling STAR the effects of Raloxifene and Tamoxifen head to head in 22,000 women. So this is exciting preliminary data. But at this point it's exciting data that is going to take us on to get more reassurance with this drug in the area of breast cancer.
ELIZABETH FARNSWORTH: And, Dr. Jordan, who should take it?
DR. V. CRAIG JORDAN: Well, essentially, the drug is available for the woman who is concerned about her bone densities. It's FDA-approved for an indication in the prevention of osteoporosis. It's for the woman, I think, who has difficulty taking hormone replacement therapy, estrogen; the woman who may have completed courses of hormone replacement therapy, getting her past the menopause; women who are in their now late 50's.
ELIZABETH FARNSWORTH: But I mean eventually for cancer who would take it.
DR. V. CRAIG JORDAN: This is not a cancer indication. And I think that that should be made absolutely clear. This is not a drug for breast cancer. This is a drug that's approved for osteoporosis that has an exciting beneficial side effect that will be looked at in clinical trials for its prevention activity and compared with Tamoxifen that is really the gold standard at this point.
ELIZABETH FARNSWORTH: Okay. Now, Dr. Norton, moving on to Herceptin, tell us about your study of Herceptin.
DR. LARRY NORTON: Well, Herceptin is also, you know, an extremely exciting drug that's been presented at this meeting. Herceptin is an entirely different type of drug. Herceptin is a monoclonal antibody. Now, as you know, antibodies are the substances produced by all of our bodies to fight infections. Well, Herceptin is an antibody that's produced outside the human body and can be given by injection once a week. And what Herceptin does, it attacks a certain molecule called Her 2. Her 2 is found in abundance not in normal tissues. It's found in abundance in certain kinds of cancer. And breast cancer is one of the cancers where it's found. And when the Herceptin attacks the Her 2, it can kill the cell. And what's been reported at this meeting is that Herceptin all by itself can knock out cancer cells in a lot of patients but what's even more profound is that it greatly augments the effect of a certain chemotherapy drug called Taxol. That's from the Pacific Yew Tree, and we've known for a long time that it's a very effective drug for treating breast cancer. If we can augment that effect, of course, we're going to have a much better result and much better ability to treat patients.
ELIZABETH FARNSWORTH: And you were testing this drug on patients with advanced breast cancer, right?
DR. LARRY NORTON: That is absolutely right. These trials-a trial of Herceptin alone and a trial of Herceptin in combination with chemotherapy was done in patients with advanced disease. But we are right now in the final stages of planning of a trial where we're going to be applying Taxol and Herceptin with other chemotherapy in the setting of high-risk primary disease. That's right at the time of surgery for high-risk breast cancer. Our hope is that this is going to increase the ability of all these treatments to kill cancer cells. And we know that this can, indeed, improve the cure rate. So we're very excited about the possibilities. There's not a cure yet, but it's an important step in the right direction.
ELIZABETH FARNSWORTH: And, Dr. Norton, this drug is only available for people on a lottery basis who are in trials, is that right?
DR. LARRY NORTON: Well, while the trials have been in progress, the purpose of trials is to find out does the drug work and is the drug safe. It's absolutely imperative that we do both things before we have an approved drug. And the Food & Drug Administration will not approve a drug until it's shown to be both effective and safe for a certain indication. While the trial's been in progress, there was some evidence that this was an effective drug. And so, to be fair to the public, the company did have a system of distributing drug to patients who could benefit from it. That system, since there was clearly not enough drug to go around to everybody, was a lottery, which tried to make it as fair as possible. I know the company is trying to increase the amount of drug in the lottery now until the drug is approved. But once the drug is approved, which we hope will be this summer, I am confident from talking to the company that the drug will be available to anybody who needs it.
ELIZABETH FARNSWORTH: Okay. Well, Dr. Jordan and Dr. Norton, thank you very much.
DR. LARRY NORTON: Thank you.
DR. V. CRAIG JORDAN: Thank you very much.
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