Tamoxifen Not Being Offered to All Those at High Risk for Breast Cancer
June 6, 2000 -- Despite the availability of tamoxifen, a drug that may significantly reduce the risk of breast cancer, many women at high risk for the disease are not being counseled by their doctors and offered the drug.
Tamoxifen has been used for over 20 years to treat breast cancer. In 1998, the FDA approved it for use as a preventive agent after a large study found that women at high risk of breast cancer who took it for five years had a 49% reduction in risk of a new or subsequent cancer.
Edith Fitts, a 65-year old breast cancer survivor from Wheaton, Ill., who started taking tamoxifen three years ago to prevent future cancer, says the only problem she has encountered is worsening of hot flashes. "They got worse for a little while, but they leveled off. I have maybe a couple a day." But she says overall, they are tolerable, especially if the five-year regimen prevents her from getting cancer again in the same or the opposite breast.
But obstetrician/gynecologists are not being quick to prescribe tamoxifen for their otherwise healthy patients at especially high risk of breast cancer, says Steven R. Goldstein, MD, in an editorial in the May issue of the American Journal of Obstetrics and Gynecology.
Goldstein, who is a professor of ob/gyn at New York University School of Medicine, says women with non-cancerous breast diseases that are known to increase the risk of breast cancer should be offered tamoxifen. Also included in this group are premenopausal women at sufficient risk and women over 50 years at sufficient risk who have undergone a hysterectomy.
"Sufficient risk" is determined by the Gail model, a 30 second calculation that includes figures such as age; race; age at first menstrual period; age at first live birth; number of mothers, sisters, or daughters with breast cancer; number of previous biopsies; and an abnormal increase in the number of cells or tissue enlargement found in the biopsies.
Goldstein says the risks and benefits for each woman must be weighed on an individual basis and women should be told that while tamoxifen can reduce the incidence of breast cancer, it may not completely eliminate their risk.
When breast cancer prevention is discussed, women should also be told about other factors that may help cut their risk, such as quitting smoking, exercising, and eating a healthy diet. If women do decide to take tamoxifen, they should also be aware that for women over 50, there is an increased risk of endometrial or uterine cancer, or polyps. Because of this, women on tamoxifen should receive at least a pelvic exam and a Pap smear annually, Goldstein says
Tamoxifen and another drug, raloxifene, belong to a class of agents known as selective estrogen receptor modulators (SERMs). Raloxifene, a drug commonly used to prevent osteoporosis, is currently being studied in a head-to-head trial with tamoxifen to see if it is as effective and possibly safer than tamoxifen in reducing breast cancer risk in otherwise healthy women who have a high risk of the disease. Both drugs work by binding to estrogen receptors on breast cells and blocking the signals that trigger cells to divide out of control.