Mammograms have been considered the gold standard for breast cancer screening for decades, but today’s mammogram screening recommendations don’t always offer a personalized approach. Today, most women may begin screenings at age 40, regardless of unique personal factors like ethnicity, family history or breast density. Researchers are exploring new ways to personalize breast cancer screening through clinical trials.
In recent studies, one type of mammography called digital breast tomosynthesis, or 3D breast imaging, has already shown many potential benefits that traditional 2D mammography cannot offer. So, what are 3D mammograms, and how could someone potentially benefit from them?
The Differences Between 2D and 3D Mammography
Traditional 2D mammograms take two digital X-rays of the breast, one taken from the top and one taken from the side. With computer-generated images from a 2D mammogram, radiologists can closely examine areas of concern and compare past records to future scans.
In comparison, 3D mammograms capture multiple X-rays at different angles around the breast. A computer then reconstructs these images into thin slices, which allows radiologists to examine the breast layer by layer. These slices are then combined to make a 3D image of the breast. This comprehensive view can help radiologists detect cancers that might be obscured in a 2D mammogram.
A recent study involving more than 1 million women found 3D mammograms detected more breast cancers and resulted in fewer false positives compared to 2D mammograms. While these results are promising, more data is needed to understand the full capabilities of 3D mammography.
The Tomosynthesis Mammographic Imaging Screening Trial (TMIST) is the first randomized study to compare the benefits of 2D and 3D mammography for breast cancer screening. Funded in part by Susan G. Komen, this phase 3 study aims to identify the most effective methods for detecting breast cancer in women who have no warning signs or symptoms.
The Tomosynthesis Mammographic Imaging Screening Trial (TMIST)
Through TMIST, Etta Pisano, M.D., F.A.C.R., and her team will determine whether 3D mammography is more effective than 2D mammography in detecting aggressive breast cancers early, like triple negative breast cancer. They will also investigate whether 3D mammograms can help certain groups of women have fewer diagnoses of advanced breast cancers. Dr. Pisano is principal investigator of TMIST and is also chief radiation officer at the American College of Radiology.
“TMIST is helping researchers learn about the best way to find life-threatening breast cancer early, when it may be easier to treat, reducing the chance that someone may die from it,” Dr. Pisano said.
For the study, participants have been randomly assigned either 2D or 3D mammography for a screening period of five years. TMIST will determine whether 3D mammograms cause fewer false positives, and whether there is a link between certain findings on mammograms and aggressive breast cancers.
Through a long-term follow up with participants, TMIST will determine how each type of mammogram affects the death rate from breast cancer. If 3D mammography is superior to 2D mammography, there should be a decrease in the number of aggressive breast cancers found in those who received 3D mammograms.
With data collected from TMIST, researchers are also comparing the cost of screenings and the health care resources used. These are critical factors because 3D mammograms often cost more than 2D mammograms and may not be covered by insurance.
Collecting Data that is Inclusive and Diverse
TMIST is unique in that it includes a large, culturally diverse group of women including Black or African American, Hispanic/Latina, Caucasian, Asian, and Pacific Islander and Native American. Worldwide, 48% of the study participants are Hispanic or Latina, and approximately 21% of participants are Black or African American. With higher mortality rates in many of these under resourced populations, the diversity of TMIST can help researchers better understand how to improve early detection for more women, potentially helping to address breast cancer disparities.
In addition to collecting mammography data, Dr. Pisano and her team are creating a collection of biological samples for a growing biorepository, or tissue bank, that is being built for future research. TMIST participants are being asked to provide blood samples and swabs of cells collected from the inside of the mouth. The data provided from these samples could help researchers develop more personalized screening methods that take a person’s genetics and personal risk factors into account.
A Goal for More Personalized Screening
Because early detection is key to reducing breast cancer mortality, researchers are focused on better screening strategies that take each person’s unique risk factors into account. A more personalized approach to screening could help doctors better identify women who are at high risk for developing breast cancer in the future.
As Dr. Pisano explains, TMIST is playing a key role in research aimed at enhancing breast cancer screening and improving long-term outcomes for women around the world.
“Participants in TMIST are contributing to cancer research that may one day help improve breast cancer screening for others, potentially saving lives,” she said.
The ECOG-ACRIN Cancer Research Group designed this trial and is conducting it with funding from the National Cancer Institute through its Division of Cancer Prevention.
Susan G. Komen® believes all people should have access to regular screening when they and their health care providers decide it’s best based on their personal risk of breast cancer.
Komen’s Center for Public Policy is working with state and federal lawmakers to ensure needed screening and diagnostic imaging are covered by health plans, with no out-of-pocket costs for patients.