Breast Cancer Drug Is Endorsed By Susan Okie Washington Post Staff Writer Thursday, September 3, 1998; Page A03 A federal advisory panel yesterday gave a qualified endorsement to the first breast cancer prevention drug, recommending that the Food and Drug Administration approve tamoxifen for some women at high risk for developing the disease. But the expert panel refused to say that the drug "prevents" breast cancer in high-risk women, because no study has yet shown that those who take tamoxifen are ultimately less likely to die from the disease. "I think doctors and patients should be allowed to decide this issue on an individual basis," said George Sledge, a panel member and professor of medicine at the Indiana Cancer Pavilion. "Having said that, I am tremendously concerned about how it is going to be used." The FDA is not required to follow the recommendations of its advisory panels but the agency usually does. Earlier this year, a five-year government-funded study of more than 13,000 women was halted with great fanfare when it found that women at high risk for breast cancer who took tamoxifen had 45 percent fewer cases of breast cancer than similar women given a placebo. The study raised hopes that a drug could reduce the risk of being stricken for the first time with the leading type of cancer among U.S. women. The study, however, was not large enough or long-lasting enough to detect a difference in mortality. Panel members and speakers at yesterday's meeting said longer follow-up of women in this and other studies is urgently needed to learn whether tamoxifen prevents tumors or merely slows their growth and delays their appearance. They also expressed concern about tamoxifen's side effects, which are sometimes fatal. Three women who took tamoxifen in the U.S. study died of blood clots in the lungs. Consumer activists and some medical experts worried about ex posing many women to a powerful drug to prevent cancers that would otherwise strike a small percentage of them. "We are talking about large numbers of healthy women, and there are risks," said Trevor Powles, who headed a smaller British study that failed to find a reduction in breast cancers with tamoxifen use. Tamoxifen users in the U.S. study had more than twice as many cases of cancer of the endometrium (the lining of the uterus) as women given a placebo, and an increased risk of serious blood clots in the legs and lungs. They also developed more cataracts. However, they suffered fewer fractures than placebo users. There was no significant difference in heart attacks or strokes, nor in overall mortality. Although women on tamoxifen showed a striking reduction in breast cancers, the study used a complex formula to decide which women had a high enough risk of breast cancer to justify trying the drug. All women age 60 or older were considered high-risk on the basis of age. Women between 35 and 60 were considered high-risk if they had various combinations of risk factors, such as first-degree relatives with breast cancer, no children or late child-bearing, early onset of first menstruation, or a history of various breast abnormalities. Leslie Ford of the National Cancer Institute said health educators have been working on a "user-friendly way of assessing a woman's risk of breast cancer" that patients and doctors could use to decide whether a woman should take tamoxifen. An estimated 29 million U.S. women -- 21 percent of the adult female population -- might be considered candidates for preventive treatment with tamoxifen. Most of them are at high risk because they are over 59 years old. Internet users can order a computer disk to help with the decision by consulting the NCI's Web site: cancertrials.nci.nih.gov, Ford said. Jerry Lewis, senior medical director of Zeneca Pharmaceuticals of Wilmington, Del., which markets tamoxifen under the brand name Nolvadex, hailed yesterday's panel as a milestone. "It is the first time this advisory committee has gathered to deliberate and vote on a drug for breast cancer prevention," Lewis said. Zeneca representatives said the company plans to develop materials to help doctors and women decide who should take the drug. But consumer advocates predicted that once the drug is approved, it is likely to be aggressively marketed to consumers. "Women will be asking for it, doctors will be granting it," said Ann E. Fonfa, a breast cancer survivor and member of SHARE, a consumer group. "I envision a situation where women go to their doctors and they say, 'Do you want hormone replacement or do you want tamoxifen?' " Tamoxifen is already used to reduce the risk of a recurrence among women who have already had breast cancer. The advisory panel also recommended approval of Herceptin, a new cancer treatment that has produced tumor shrinkage and some improvement in survival in certain women with advanced breast cancer when combined with other chemotherapy drugs. Herceptin is potentially useful only in about 25 percent to 30 percent of women with breast cancer, because tumors must have a particular genetic abnormality to respond to the treatment. However, it represents an exciting new approach that may turn out to be useful in other cancers as well, said Marc Lippman, director of Georgetown University's Lombardi Cancer Center. Certain tumors appear to flourish because they have extra copies of a gene, Her 2, that makes a protein on the surface of their cells, Lippman said. This protein binds to a growth factor, another protein that induces uncontrolled growth of the cell. Herceptin, also called trastuzamab, is a designer "antibody" (the type of molecular weapon used by the body's immune system) that is specially shaped to bind to the Her 2 gene and turn off the uncontrolled growth of cancer cells. Many tumors have extra copies of the gene, including about 40 percent of stomach cancers, 40 percent of lung adenocarcinomas, and 25 percent of ovarian cancers, he said. Herceptin is also being tested in these diseases, he said. © Copyright 1998 The Washington Post Company Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.