In particular, for the roughly 8% of women who have extremely dense breasts, it’s worth having a conversation with a doctor about additional screening, said Dr. Mass.
Similarly, for women with dense breasts who have additional risk factors for breast cancer, such as a family history of the disease or a personal history of breast biopsies to check suspected cancers, supplemental screening may make sense, she said.
Dense breasts are relatively common. In the United States, an estimated 43% of women 40 and older have breasts that are considered dense or extremely dense. In addition to making it harder to interpret mammograms, women with dense breasts are up to twice as likely to develop breast cancer as women with average-density breasts, research shows.
Studies have shown that mammograms reduce breast cancer mortality. But even though it seems intuitive that more testing would improve someone’s odds of beating cancer, research hasn’t found that women are any less likely to die from breast cancer if they get a supplemental ultrasound or MRI after a negative mammogram result.
A few studies have found that women with dense or very dense breasts who got an ultrasound or an MRI in addition to a mammogram had fewer so-called interval cancers between regular screening mammograms. But it’s unclear whether those results have any effect on their risk of dying from breast cancer.
“Not every small abnormality is going to lead to something that needs treatment,” said Dr. Mangione.
Thirty-eight states and the District of Columbia have laws requiring that patients be notified about breast density after a mammogram, though some require only a general notice rather than mandate that individual women be informed about their own status. Some states require insurers to cover supplemental testing, but others do not.
In 2019, the FDA proposed that information about breast density be incorporated into the letters patients receive after a mammogram. That rule hasn’t yet been finalized, but the agency told lawmakers that it expects to issue the rule no later than early next year.
In a statement to KHN, FDA spokesperson Carly Kempler said, “The FDA is committed to improving mammography services for patients and working diligently to finalize the rule to amend the existing mammography regulations.”
The cost of additional testing is another factor to consider. Because the Preventive Services Task Force recommends women get regular screening mammograms, health plans are generally required to cover them without charging people anything out-of-pocket. That’s not the case with supplemental screening for women with dense breasts, which the task force does not recommend. Some states require insurance coverage of those tests, but those laws don’t apply to the many plans in which employers “self-fund” workers’ benefits rather than buy state-regulated insurance coverage.
Supplemental imaging can be pricey if your health plan doesn’t cover it. A screening ultrasound might cost $250 out-of-pocket while a breast MRI could cost $1,084, according to the Brem Foundation to Defeat Breast Cancer.
Rep. Rosa DeLauro (D-Conn.) recently tweeted that she is working on a bill with Ms. Couric that would cover MRIs and ultrasounds for women with dense breasts without any out-of-pocket costs.
Some doctors recommend other steps that may be more effective than extra screening for women with dense breasts who want to reduce their breast cancer risk.
“If you really want to help yourself, lose weight,” said Dr. Karla Kerlikowske, a professor of medicine and epidemiology/biostatistics at the University of California, San Francisco, who has worked with other researchers to develop calculators that help providers assess patients’ breast cancer risk. “Moderate your alcohol intake and avoid long-term hormone replacement. Those are things you can control.”
KHN (Kaiser Health News) is a national newsroom that produces in-depth journalism about health issues. Together with Policy Analysis and Polling, KHN is one of the three major operating programs at KFF (Kaiser Family Foundation). KFF is an endowed nonprofit organization providing information on health issues to the nation.