Starting Sept. 10, the FDA will require hospitals to notify women if their mammogram reveals they have dense breast tissue, but there's still some disagreement on what to do once the women are given this information, The Wall Street Journal reported Sept. 6.
Nearly half of women with dense breast tissue will not have the cancer spotted early through a mammogram. Dense tissue appears white on a mammogram, as do tumors, allowing the tumors to grow undetected.
Currently, nearly 40 states require women to be notified about dense breast tissue, but there's no consensus on what to do with the results. Physicians often encourage women with dense tissue to consider additional tests that are more sensitive, such as ultrasound and MRI, but these tests could be unnecessary procedures and are not always covered by insurance.
The U.S. Preventive Services Task Force has found insufficient evidence to recommend more testing. Ultrasounds catch about two more cancers per 1,000 women with dense tissue, and MRIs catch 16 more cancers per 1,000 women — and there have been no large clinical trials conducted to show if these additional tests reduce breast cancer deaths. The extra tests could also result in more false alarms; for instance, of women with extremely dense breast tissue who got a biopsy after a positive MRI, only 25% had breast cancer.
"Density alone is just one factor," Karla Kerlikowske, MD, a professor in the departments of medicine and epidemiology/biostatistics at the University of California, San Francisco, told the Journal. "If people have dense breasts, they need to calculate their risk."