And why the Find It Early Act is so crucial for women with dense breasts.
If you’re a woman over 40, you’ve no doubt had your doctor remind you to get a mammogram. Though these screenings might not be comfortable for some, they’re invaluable for detecting breast cancers at an early stage. By identifying breast cancers before they cause symptoms, such as a lump, this type of screening lowers the risk of dying from breast cancer by up to 40 percent. While that’s praiseworthy, I often wonder how we could enhance this process: What kind of screening improvements would we need to reduce deaths from metastatic breast cancer by 100 percent?
Early detection is essential when it comes to breast cancer: Metastatic breast cancer (stage 4) is treatable yet incurable, despite all the medical breakthroughs that have happened to date. To cure breast cancer, doctors need to intervene before breast cancer becomes stage 4, if not much earlier. Ultimately, all breast cancers need to be detected before they spread, aka metastasize.
So why does screening mammography fall short, and fail to detect all breast cancers early enough? One major reason is that 43 percent of people being screened have dense breast tissue, which can mask, or hide, breast cancers from detection on a mammogram. This masking effect is sometimes compared to spotting a white bunny in a snowy field, or the challenge of finding Waldo — from the Where’s Waldo books — in a crowd. Moreover, in dense breasts, there’s no guarantee that breast cancer will be visible at all. Cancer in a dense breast may be completely hidden from view.
It’s a sobering question: How many cancers might we be failing to detect in dense breasts? I recently estimated that screening mammography failed to detect 267,000 cancers in 2021 in the United States. That’s a large number that likely accounts for many, if not most cancers, that will metastasize before being detected.
To be clear, mammograms do easily detect many cancers in non-dense breasts and — often with more difficulty — do identify many cancers in dense breasts, too. That’s why doctors continue to recommend mammography, regardless of breast density. No one should miss their chance for early detection. But it’s important to communicate that a negative mammogram in dense breasts doesn’t mean there’s no breast cancer present; additional screening might still be needed.
The good news is that there are already plenty of additional screening options. Imaging exams like contrast-enhanced breast MRI, molecular breast imaging, and contrast-enhanced mammography can identify cancers that would’ve otherwise been masked by dense breast tissue on a typical mammogram. (Whole breast ultrasound also improves cancer detection in dense breasts, but to a lesser degree, and 3D mammograms are a good option for initial screening but they don’t replace other options for supplemental screening in dense breasts, because 3D mammography detects very few additional cancers in dense breasts.)
Liquid biopsies, such as blood draws which test for cancer DNA in the blood, have potential for breast cancer screening but they’re still being refined for clinical use. Stay tuned, though, because these liquid biopsies could revolutionize breast cancer screening, including for those with dense breasts.
There are approximately 17 million people with dense breasts who undergo screening mammography in the United States each year, and they may benefit from supplemental screening. Yes, that potentially means significant costs, including to the patient, especially if those supplemental screenings aren’t covered by insurance. But improving early cancer detection could have a huge payoff. If more cancers are detected at a curable stage, patients can avoid chemotherapy and other expensive interventions including expensive end-of-life care.
In one sense, society pays either way: Current costs of late-stage treatment for breast cancer are large. By failing to detect many cancers at early stages in dense breasts, we also increase rates of death from this horrible disease. There are presently around 40,000 breast cancer deaths per year in the United States and far more worldwide. This societal toll is huge and tragic. I believe that robust supplemental screening in dense breasts would lower metastatic breast cancer to the lowest levels we’ve ever seen. Making that screening widely available could avoid tens of thousands of breast cancer deaths per year.
Critics of supplemental breast cancer screenings like breast MRI say that they do more harm than good: that they raise false alarms and make those being screened too anxious. But the risk of not going through with additional screening — especially in dense breasts — far outweighs these concerns. Overdiagnosis of some cancers — aka detection of cancers that wouldn’t harm a person during their lifetime — is also a concern. (For example, a breast cancer diagnosed in a 75-year-old who dies that same year from an unrelated heart attack could be considered an overdiagnosed cancer). However, 40,000 breast cancer deaths occur each year in the U.S. because of underdiagnosis. Early detection of cancers is the larger and more urgent problem to solve.
Without supplemental screening, many with dense breasts have worse outcomes. These individuals are more likely to be younger and non-white, including Black, Asian, and Hispanic women. It’s unethical and troubling to allow disparities in screening outcomes to continue, especially since we already have multiple technologies that can solve this problem, but they’re not widely implemented. We simply need to make these technologies more available to those who need them. The time to act was yesterday. So what will we do today?
The Find It Early Act is national legislation that mandates coverage for dense breast supplemental screening using ultrasound, breast MRI, and other recommended screening options. It would ensure that supplemental screening for dense breasts is covered by private insurance and Medicare/Medicaid. If enacted, the Find It Early Act would lower deaths from metastatic breast cancer and reduce disparities and inequality in breast cancer screening. (To support this act, click here.) To learn more about the past, present, and potential future of supplemental breast cancer screening, read more here.
Matt Covington, MD is an assistant professor of radiology at the University of Utah and Huntsman Cancer Institute. Dr. Covington provides comprehensive breast imaging and leads clinical trials on new imaging techniques for cancer detection. Dr. Covington has received compensation from GE Healthcare for consulting services and currently has research funding from Fujifilm for contrast-enhanced mammography. Follow Dr. Covington on Twitter (X) and LinkedIn.
