July 2025 | George M. Pikler, M.D., Ph.D., FACP, Lead Oncology Advocate N1X10

Extra Tests Find Cancer in Dense Breasts

Underdiagnosis of breast cancer with screening mammography is a problem in women with dense breast tissue. Breast density, a measure of the amount of fibro-glandular tissue, is a known risk factor for breast cancer—in women with the densest breasts there is a 4-fold increased risk compared with women with fatty breasts.

Millions of women undergo breast screening, but regular mammograms can be less effective at spotting cancer in the 10% with very dense breasts, as the tissue can hide tumors on X-rays. This is because very dense breasts look whiter on scans, making it harder to detect early-stage disease, which also appears white. Reporting of breast density for women is mandated by the Food and Drug Administration since September 2024.

In a study (1) from the University of Cambridge, 9,361 seemingly cancer-free women with dense breasts who had received a negative mammogram result, extra screening with an abbreviated magnetic resonance imaging (Ab-MRI), which is faster than a regular MRI or a contrast-enhanced mammogram (CEM)— in which a dye reveals the blood vessels — led to an additional 85 cancers being found. The tumors were around half the size of those found using standard mammograms. A third scanning method used in the trial – automated breast ultrasound (ABUS) – also picked up cancers but was much less effective than CEM and Ab-MRI.

The research’s lead author, Prof Fiona Gilbert, said: “Getting a cancer diagnosis early makes a huge difference for patients in terms of their treatment and outlook. We need to change our national screening program so we can make sure more cancers are diagnosed early, giving many more women a much better chance of survival.”

This study shows that contrast-enhanced techniques such as abbreviated MRI and contrast-enhanced mammography have a superior performance compared with whole breast ultrasound.

Although the trial showed the scans could detect additional small cancers, which would probably save lives, further research is needed to confirm whether they could reduce the number of deaths, in order to establish the risk of overdiagnosis and to estimate the cost-benefit ratio of offering extra scans.

(1) The Lancet. 2025, May 21.
close menu icon
Erica

Erica Cross, PA

PA

Erica is a board certified Physician Assistant. She obtained her Master’s degree in Physician Assistant studies from Our Lady of the Lake College in Baton Rouge, LA. She began practicing in 2011 and has worked clinically in Orthopedics and Dermatology. The majority of her career has been spent in a Dermatology practice where she assisted in Mohs surgery, treating various types of skin cancer. She also teaches in the medical simulation department at the University of South Alabama and enjoys every aspect of medical education.