Mammogram rates fell among U.S. women in 2005, which puzzled public health officials because rates had been consistent for many years. A new study offers a possible explanation: The backlash against hormone therapy for menopausal symptoms led to the drop in mammograms.
Hormone therapy was a popular strategy for post-menopausal women throughout the 1980s and '90s. The pills were used to ease menopausal symptoms and with the expectation that they might also help prevent some of the diseases of aging, such as heart disease and some types of cancer.
However, studies in 2002 and later found that hormones can increase the risk of breast cancer in some women and may not help protect against heart disease. Hormone use plummeted between 2000 and 2005.
In the new study, researchers from the National Cancer Institute examined data from more than 7,000 women who were interviewed in 2005. They found the drop in hormone therapy explained the decline in mammograms in women ages 50 to 64 but not in women ages 65 and older. Of the 4.7% drop in women ages 50 to 64, an estimated 3.9% appears due to changes in hormone therapy usage.