Doctors Support Offering Breast-Cancer Prevention Drug
Women who are at increased risk of breast cancer because of their medical history or abnormal exams should be offered the opportunity to receive the breast cancer drug tamoxifen as a preventive measure, according to a special panel convened by the American Society of Clinical Oncology. The panel issued its report last week in Atlanta at its annual meeting.
“We are not recommending that women take [tamoxifen],” said Dr. Rowan T. Chlebowski of Harbor-UCLA Medical Center, who was chairman of the panel. “We are recommending that women be offered it.” The decision to take the drug, sold under the trade name Nolvadex, would then depend on “a woman’s actual risk and the importance of that risk to her.”
The panel said the drug should be offered to women who have at least a 1.7% chance of developing breast cancer over the next five years--considered a modest risk. About 29 million women, or 20% of the U.S. female population, are in this category, including all women older than 60. The National Cancer Institute has already sent computer software for calculating this risk to thousands of physicians.
Tamoxifen, which is widely used in treating breast cancer, reduces the risk of developing the disease by about half. Unfortunately, it also produces side effects that include hot flashes and an increased risk of developing uterine cancer and blood clots.
That risk has caused some researchers to focus on another drug, called raloxifene or Evista, that has been approved to prevent osteoporosis. Some studies suggest that it also reduces the risk of breast cancer by about half, but it does not increase the risk of uterine cancer. The panel concluded, however, that the drug has not been studied long enough to justify recommending it for prevention of breast cancer.
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In other news at the meeting:
Early-stages drug: Premenopausal women with breast cancer in the early stages have a significantly better chance of living longer when they are treated with epirubicin, an anticancer drug used in more than 80 countries, but which has not been approved in the United States.
Researchers from the Danish Breast Cancer Cooperative Group, headquartered at Copenhagen University Hospital, studied 1,000 women in whom breast cancer had not spread to lymph nodes when it was detected. (About 200,000 U.S. women are diagnosed with this form of breast cancer each year.) Treatment included surgical removal of the tumor, followed by chemotherapy with cyclophosphamide, epirubicin and fluorouracil, or the standard chemotherapy regimen of cyclophosphamide, methotrexate and fluorouracil.
After six years, 93% of the women given the combination containing epirubicin were still alive, compared with 83% in the group given standard chemotherapy, Dr. Henning Mouridsen told the ASCO meeting. The Food and Drug Administration is reviewing these and other data while considering the drug’s approval.
Shortage of trial patients: New treatments for cancer are significantly delayed because the vast majority of cancer patients do not take part in clinical trials of such therapies, researchers argued. Less than 5% of all cancer patients are enrolled in such trials--perhaps as few as 2% to 3%--but researchers estimate that 20% of patients should be enrolled for adequate testing.
“We need clinical trials to know what works and what doesn’t,” said Dr. Allen Lichter, the organization’s president. By not taking part in such trials, patients are often deprived of the best care available, he said.
Researchers also argued strongly that insurers and health care providers should pay for patients to participate in such trials. Companies often argue that such participation is too expensive for unproven therapies, but a new study has found that the average cost of participating in such a trial is only about $2,300 more than conventional treatment.
Researchers from the Mayo Clinic in Rochester, Minn., found that the average cost of standard clinical care for cancer was about $44,133, compared with $46,424 for those enrolled in clinical trials.
Sarcoma-fighting nosedrops: An angiogenesis inhibitor administered in nosedrops may prove to be a valuable weapon against Kaposi’s sarcoma, a cancer common among people with AIDS, according to USC researchers. Kaposi’s is treatable--but not curable--with conventional chemotherapy, but many patients abandon treatment because of its side effects.
Dr. Parkash Gill and his colleagues at USC treated 35 Kaposi’s patients with an angiogenesis inhibitor called IM862, developed by Cytran Inc. of Kirkland, Wash. Angiogenesis inhibitors do not kill tumors directly, but prevent the growth of blood vessels that supply tumors with oxygen and nutrients.
They found complete tumor remission in four patients and a significant reduction in tumor size in nine within the first six weeks. An additional 17 patients showed no disease progression for at least six months.
“All this occurred with very few side effects, which were limited mostly to mild headaches,” Gill said.
Trial for potential “cure”: The first human trials of the highly touted angiogenesis inhibitor endostatin will begin this fall in Boston, Houston and Madison, Wis., the drug’s manufacturer announced. Endostatin, discovered by Dr. Judah Folkman of Boston Children’s Hospital, is one of a pair of drugs that received widespread publicity last year as a potential cure for cancer. Human trials of the drug have been delayed because of difficulties in producing enough for use in humans.
Promising herbs: An herbal compound called PC-SPES can reduce levels of prostate-specific antigen (PSA) in men with advanced prostate cancer, a sign that tumor cells are being killed, researchers from UC San Francisco said.
PC-SPES (PC stands for prostate cancer and “spes” is Latin for hope) is a combination of eight Chinese herbs, the most common of which is saw palmetto. It is available at health food stores.
Dr. Eric Small and his colleagues treated 27 men who had never received hormone therapy for their cancer and 34 whose tumors had grown resistant to hormone therapy with nine capsules of the herbal drug per day. They found that all 27 of the patients who had not received hormone treatments had at least a 50% reduction in PSA levels, as did 19 of the 34 with hormonal-resistant tumors. All the patients are still receiving the supplement.
The researchers do not know which of the ingredients are responsible for the effect.
