For women with dense breasts, getting a mammogram to screen for breast cancer can be something of a double whammy. Not only is cancer more difficult to detect in dense breasts, but dense breasts also are a risk factor for developing breast cancer in the first place.

“A lot of women think that if their mammogram is negative, they don’t have cancer,” says University of Colorado Cancer Center member Gretchen Ahrendt, MD. “But the test is only as good as your breast density. The higher your breast density, the harder it is to find a cancer.”

In an effort to help more women with dense breasts understand their screening options, the Food and Drug Administration (FDA) on March 9 updated its mammography guidelines to require mammography facilities to notify patients about the density of their breasts. The new rule amends regulations issued under the Mammography Quality Standards Act of 1992, a law passed to ensure quality mammography. The amendments are required to be implemented within 18 months.

Follow-Up Options for Women with Dense Breasts

Colorado already is one of 38 states that has legislation around breast density on the books, but the new FDA guidance requires that in every state, women whose mammograms detect dense breasts receive a follow-up communication that notifies them about their breast density and recommends they talk to their health care provider about follow-up screening options and their individual risk for breast cancer.

“Hopefully this will lead to earlier detection for women who have dense breasts,” says Ahrendt, professor in the CU Department of Surgery, adding that approximately half of women over the age of 40 in the U.S. have dense breast tissue.

Women with dense breasts have several options for follow-up breast cancer screening after mammography, including ultrasound, MRI, physical examination, and 3-D mammography, which gives radiologists a more complete view of the breast. They also can benefit from a conversation about breast cancer prevention strategies, whether it’s lifestyle modification or medications to lower their risk of breast cancer.

“When we know someone has dense breast tissue, it triggers a risk calculation to help the patient understand her personal risk of breast cancer,” Ahrendt says. “There are several web-based models where we can input a host of variables for each patient, and one of those variables includes breast density. The model will generate a short-term and a lifetime breast cancer risk, and then we can objectively discuss that with patients. A formal risk-assessment is also beneficial because if their lifetime risk crosses a certain threshold, then generally insurance will cover supplemental screening.”

Better Education for PCPs

Another potential positive outcome of the new FDA guidelines, Ahrendt says, is better education for primary-care providers around dense breasts and screening options for breast cancer.

“Primary care doctors have so many things on their plate. I think if they’re ordering the screening, that’s already a win,” Ahrendt says. “Expecting them to understand the nuances of mammography might be more than we should expect, but I think the FDA regulations will help improve awareness. We still have work to do to make sure women know that they can seek specialty advice about what the next best steps are for them.”

The new guidelines also provide women with a valuable reminder about the importance of mammograms, says CU Cancer Center member Dulcy Wolverton, MD, associate professor of radiology in the CU School of Medicine.

“Half of eligible women don’t even get mammograms, and they should really get one every one to two years,” Wolverton says. “We would like to see them every year, because we’re trying to find cancers when they’re small. If we screen annually, we are more likely to find a small cancer before it becomes palpable.”

Raising Awareness

Wolverton says the new FDA rules also should raise awareness about breast cancer symptoms, like lumps, that shouldn’t be ignored just because a mammogram didn’t detect the disease.

“There are a lot of stories of women who were getting regular mammograms, and then all of a sudden, they feel a lump, and it turns out to be cancer,” she says. “Somewhere along the line, they find out they had dense breast tissue and maybe it could have been found earlier. The take-home point is to pay attention to your breasts. Don’t ignore a lump because you had a normal mammogram.”

This article was originally published March 15, 2023, by the University of Colorado Cancer Center. It is republished with permission.