Of the nearly 30 million American women who undergo screening mammograms every year, up to 11 percent receive “probably benign” test results — and therefore are asked to come back for a follow-up mammogram in three to six months. But according to a new study by UC Davis researchers, such frequent re-testing may be unnecessary. The study appears in tomorrow’s issue of the Journal of the National Cancer Institute. The UC Davis researchers examined the mammography records of nearly 60,000 women enrolled in the national Women’s Health Initiative project, one of the largest preventive health studies in the United States. Among the women who had probably benign mammograms, only 1 percent went on to develop breast cancer within two years, the investigation found.
Researchers confirmed that a daily, combined dose of estrogen and progestin increases breast cancer risk in post menopausal women, but added that this risk begins to return to normal about six months after women stop taking the hormones. “It is reassuring that breast cancer risk begins to return to normal six months after women stop combined dose estrogen-progestin therapy,” said Duane Alexander, M.D., Director of the NICHD. “Women, in consultation with their physicians, need to make the most informed decision possible. The study authors have provided them with one more piece of important information.”
Excessive bleeding, a troublesome side-effect that causes many women to stop taking hormone replacement therapies (HRT), is less likely with progesterone than with more commonly used synthetic versions. Results from a national clinical trial published in the November issue of the Journal of Obstetrics and Gynecology, show that a combination of estrogen and micronized progesterone (MP) causes fewer days and less intense bleeding than the most commonly used combination. Previous studies have shown that unacceptable bleeding is the reason that most women discontinue HRT during the first year of therapy.