Dense Breasts, Clear Answers: MRI’s Dominance in Cancer Detection and FDA’s Tightened Grip on Mammography Standards

On March 9, 2023, the U.S. Food and Drug Administration (FDA) rolled out revised mammography regulations mandating mammography providers to inform patients of their breast density. These updates were made to the Mammography Quality Standards Act (MQSA) of 1992, legislation originally created to uphold mammography quality which is crucial in the early detection of breast cancer. A pivotal aspect of these MQSA’s amended regulations requires healthcare facilities to inform patients about their breast density as part of regular screenings.

Breast density describes the proportion of glandular to fatty tissue in the breast. Every breast has a combination of these tissues, but those with more glandular tissue are deemed “denser.” It is common for about 40% of women undergoing mammography to have dense breasts, but higher breast density can increase breast cancer risk. And a “normal” mammogram doesn’t always rule out cancer effectively.

Why MRI Reigns Supreme: Screenings Need to Start Earlier in Women’s Lives

Recent research supports the importance of MRI scans as the most effective supplemental imaging technique and annual mammograms serve as a crucial tool in the early detection of breast cancer, especially for women aged 40-49 with dense breasts. The frequency of these screenings is under continuous evaluation and assessment, but for some experts, the belief is that younger women could benefit from even more regular screenings.

In women with dense breasts, but who otherwise show no signs of cancer on mammograms and are at average or intermediate risk for breast cancer, MRI has consistently outperformed handheld breast ultrasound, automated whole-breast ultrasound, and digital breast tomosynthesis.

A study conducted by the University of Washington explored the cases of 576 women diagnosed with breast cancer in the intervals between their mammograms. And the findings highlighted the disparity based on the age of the women and the interval duration. Specifically, for women screened annually, about 30% of the younger demographic were diagnosed with “interval cancer,” in contrast to only 14% of their older counterparts. Extending the interval to 24 months saw a rise in these numbers: and over half of the younger women and a quarter of the older women were diagnosed with interval cancers.

These statistics underscore the possible benefits of annual mammographic screenings, particularly for women aged 40-49 with dense breasts. And it also emphasizes the need for these women to consult with their healthcare providers. An individually tailored approach, and considering each woman’s unique risk profile, could be the key to enhancing the early detection of breast cancer.

Informed Decision-Making: Breast Density Implications

While common, dense breasts can sometimes pose challenges in mammographic interpretations. Dense breast tissue can mask or even camouflage cancer on mammograms, which might explain why MRI has emerged as a superior imaging tool for these patients. And since dense breast tissue may also increase the risk of developing breast cancer, the newly-implemented regulations by the FDA stress the importance of ensuring that patients are well-informed about their breast density and the associated implications.

It empowers patients to make informed choices about further screenings, whether those screenings involve supplemental MRIs or other imaging modalities.

Future Directions in Breast Cancer Screening

As technology and research advance, especially with the advent of A.I., the tools and techniques used for breast cancer detection continue to evolve. While the current focus is on MRI as a supplemental tool, the medical community at large remains open to newer innovations that might offer even better detection rates, especially for those with dense breasts.

The ongoing dialogue between patients and their healthcare providers about breast density, especially the risks associated and optimal screening strategies available, is of critical importance here. Communication is always the best tool a patient has for understanding what direction they need to go in their healthcare journey.

And now, with the FDA’s heightened oversight and the continual advancements in medical technology, the goal remains clear: Early detection that helps bring about improved outcomes and much longer, healthier lives for breast cancer patients.

About Dr. C.H. Weaver, M.D.

Dr. Charles Weaver is a Medical Oncologist, and the founder and editor of CancerConnect. After training at University of Pennsylvania, Fred Hutchinson Cancer Center and The National Institute of Health Dr Weaver founded CancerConnect with the goal of providing information and support to cancer patients and their caregivers. He has published in the New England Journal of Medicine, Blood, Journal of Clinical Oncology and has authored over 9000 articles for patients on the management of cancer.

References and Supplemental Reading:

• Barlow WE, White E, Ballard-Barbash R et al. Prospective Breast Cancer Risk Prediction Model for Women Undergoing Screening Mammography. Journal of the National Cancer Institute. 2006;98:1204-14.
• Chen J, Pee D, Ayyagari R et al. Projecting Absolute Invasive Breast Cancer Risk in White Women with a Model that Includes Mammographic Density. Journal of the National Cancer Institute. 2006;98:1215-26.
• Gierach GL, Ichikawa L, Kerlikowske K, et al. Relationship between mammographic density and breast cancer death in the breast cancer surveillance consortium. Journal of the National Cancer Institute. 2012; 104 (16): 1218-1227.
• Buist DSM, Porter PL, Lehman C, et al. Factors contributing to mammography failure in women aged 40-49 years. Journal of the National Cancer Institute. 2004;96:1432-1440.
• Hussein H, Abbas E, Keshavarzi S, et al. Supplemental breast cancer screening in women with dense breasts and negative mammography: A systematic review and meta-analysis. Radiology. Published online January 31, 2023. doi:10.1148/radiol.221785

Article originally published on Cancer Connect. Modified on 10/2023 with author permission.