Contrast Enhanced Mammography: A New Way to Find Cancer in Dense Breasts

Bolstered by growing research and media coverage, a new kind of mammogram is getting women's attention. Contrast enhanced mammography, or CEM, is positioned to help fill a gap in breast cancer screening, particularly for women with dense breasts who could benefit from more sensitive testing, but who may not need—or be able to have—a breast MRI.

"The potential for contrast-enhanced mammography and the acceptance throughout the nation and the world has really changed in the past decade," says Janice Sung, MD, associate chief of the Division of Breast Imaging and director of the CEM program at Columbia. "There's a lot more interest in it now."

Dr. Sung has watched that evolution firsthand. She helped launch a CEM screening program while at Memorial Sloan Kettering Cancer Center and has since brought the program to Columbia, where CEM is now offered for screening. As CEM has received more attention, breast imaging centers have been getting calls from women requesting it, Dr. Sung says. And she expects that interest to grow as more women learn what the test can do.

"I think they'll realize the power of it and understand the increased cancer detection," Dr. Sung says. "And they'll see that the actual imaging time is the same as a regular mammogram that they are very familiar with."

Dr. Sung explains CEM, the benefits it offers, and what could be next for this new screening approach.

What is contrast enhanced mammography?

CEM is much like a regular mammogram with this addition: An iodine-based contrast agent is first injected into a vein. The contrast travels through the bloodstream and can highlight areas of increased blood flow.

That matters because cancers need a blood supply to grow. As a tumor develops, new blood vessels form around it. CEM can make that activity visible on a mammogram.

This can be particularly useful for women with dense breasts. Dense tissue appears white on a mammogram, and tumors can appear white, too, potentially making cancer more difficult to see.

"Without question CEM can find cancers that mammography alone misses," Sung says.

Can CEM find more cancers than a standard mammogram?

Yes, a regular screening mammogram detects about five to six cancers per 1,000 women screened. Studies of CEM have found an additional seven to 24 cancers per 1,000 women, depending on the study and population.

Researchers are still studying an important question, however: whether finding those additional cancers earlier ultimately reduces breast cancer deaths.

Is CEM an option for women who already get breast ultrasound or MRI?

This is where Dr. Sung believes CEM could make a real difference.

Women with dense breasts who need supplemental screening have often received ultrasound, which can find about three to four additional cancers compared to traditional mammogram alone per 1,000 women screened. But Dr. Sung says, ultrasound can also lead to false positives, additional imaging, and benign biopsies.

MRI is much more sensitive and recommended for women at high risk for breast cancer. But it is expensive, requires specialized equipment, and isn't practical for every woman who could benefit from more sensitive screening. Some women also cannot tolerate an MRI.

"This is where contrast mammogram fills a void," Dr. Sung says.

CEM helps existing mammography equipment better detect cancers. And the imaging portion of the test takes about the same amount of time as the mammogram women already know.

Who should consider CEM?

There aren't yet universal guidelines defining exactly who should have CEM. Until clearer guidelines are established, doctors may consider factors such as a person's breast density, overall breast cancer risk, medical history, and ability to undergo other types of breast imaging when deciding whether CEM is appropriate.

At Columbia, Dr. Sung says CEM is being recommended primarily for women at intermediate risk of developing breast cancer—generally a 15% to 20% lifetime risk—particularly those with dense breasts.

Women whose lifetime breast cancer risk is 20% or greater should generally continue to have MRI screening because MRI remains the most sensitive breast imaging test.

Could CEM change breast cancer screening?

Yes, over time, Dr. Sung expects screening to become increasingly tailored to an individual woman's risk rather than relying on breast density alone.

"I think a lot more women are going to be undergoing a screening contrast mammogram," she says.