Evidence Points to Higher Breast Cancer Risk If Two Drugs Are Combined

Tuesday, January 25th 2000, 12:00 am

By: News On 6

There is mounting evidence that women taking estrogen following menopause are at greater risk for breast cancer. A study released the week of January 24th showed the risk of breast cancer is higher when progesterone is combined with estrogen.

Doctors say women going through menopause must balance the benefits with the risk when deciding whether to take hormone replacement therapy. Benefits may include relief from menopause symptoms, reduction in fractures from osteoporosis, and lowering the risk of heart disease. However, estrogen has been proven to also increase the risk of uterine and breast cancer.

To lower the risk of uterine cancer, doctors often put their patients on the hormone progestin. But a recent study published in the January 24th issue of the Journal of the American Medical Association found adding the additional hormone adds risk. "Hormone replacement therapy consisting of estrogens and progestins was associated with greater increases in risk of breast cancer than hormone replacement therapy consisting of estrogen alone,â€ explained the National Cancer Instituteâ€™s spokesperson Catherine Schairer, Ph. D. â€œThese increases were evident in lean women, but not heavier women, and were also limited to women who had used hormones in the previous four years or were currently using hormones."

A team of researchers from the National Cancer Institute followed the health of 46,000 postmenopausal women for up to 15 years. For each year a lean woman received combined estrogen-progestin therapy, her risk of breast cancer increased by 12 per cent compared with a 4 per cent increase among lean women only taking estrogen replacement therapy. "I'd like to emphasize that no one study is definitive, and that these results need to be confirmed by other studies,â€ Schairer noted. â€œBut I do feel very comfortable in saying that a woman who does not have a uterus, who has had a hysterectomy, should not take estrogen/progestin replacement therapy."

An editorial in the J-A-M-A issue responding to the study says the research highlights the need of putting more emphasis on a healthy diet and maintaining a healthy lifestyle after menopause. Researchers say it also underscores the need for women taking hormone replacement therapy to check their breasts monthly and get their annual mammograms.
Researchers also note that every postmenopausal woman should have regular
mammograms and breast exams, not just those women on hormone replacement therapy.