The Tomosynthesis Mammographic Imaging Screening Trial (TMIST) is more than halfway to its recruiting goal of 128,905 participants, with more than 20% of participants in the United States being Black. Recruitment of women from diverse backgrounds is vital to ensuring that the TMIST trial results will be applicable across races, ethnicities, and under-served communities.

Led by the ECOG-ACRIN Cancer Research Group, TMIST is the first randomized trial that seeks to identify women for whom digital breast tomosynthesis, also called three-dimensional (3-D) mammography, may outperform digital (2-D) mammography in reducing advanced cancers—those more likely to kill women. Although tomosynthesis is the newer technology, and more sensitive, investigators want to confirm if this sensitivity actually benefits women and improves their probability of living longer.

During the COVID-19 pandemic, enrollment dropped initially like all other cancer screening. However, enrollment rebounded to record levels, and minority participation continued to grow due to:

• Coverage for exams for many uninsured or under-insured women;
• Effective, personalized recruiting of women to take part in TMIST by staff at local facilities;
• Funding to sites for special initiatives to enhance the representation of under-represented populations;
• Additional financial support for sites demonstrating high accrual to sustain that volume over time;
• National association and local provider efforts to reconnect with women for breast cancer screening;
• A wide variety of educational and recruitment materials (clinic poster, phone script, etc.);
• Availability of recruitment materials in English, Spanish, Chinese Simplified, Korean, and Vietnamese;
• Promotion by the National Medical Association (the collective voice for physicians of African descent); and
• Advanced payment to qualifying sites to fund dedicated research staff as they begin TMIST participation.

The trial is open at 120 study sites in US and abroad, with a current enrollment of more than 65,000 women. TMIST is one of the most successful NCI-funded trials at attracting Black participation. The participation rate of more than 20% is far higher than the average Black cohort in NCI-funded trials (about 9%).

“TMIST sites are effectively reaching women in their communities, especially women of color, to gain a study population able to provide needed data to move breast cancer screening and health equity forward,” said TMIST Study Chair Etta Pisano, MD, FACR (pictured).

An important TMIST goal is the development of individualized screening guidelines to reduce breast cancer’s impact on women not as well served by current screening strategies — including minority women and those in under-served (eg, rural) communities. Many US TMIST sites are outside of major cities.

“We are encouraged by the high number of under-represented minority patients in TMIST,” said Edith Mitchell, MD (pictured), Co-Chair of the Health Equity Committee of the ECOG-ACRIN Cancer Research Group, which is leading TMIST, and a medical oncologist at the Sidney Kimmel Cancer Center in Philadelphia.

“Considering the high mortality rates among individuals in these populations, TMIST is on the right track towards helping us understand the predictive factors of breast cancer. This information will be important to improve early detection for as many women as possible,” said Dr. Mitchell.

For women who are uninsured or under-insured, TMIST pays for mammography screening at a participating site, enabling screening of more women from under-served groups and areas.

“By covering exams for women with inadequate insurance, TMIST enables researchers to gauge screening effectiveness across patient groups and care settings,” said Dr. Mitchell.

Only 45% of accredited mammography scanners are 3-D units. Nearly 20% of US imaging facilities do not have 3-D scanners. Many of these sites may be in under-served areas. A Journal of the American College of Radiology (JACR®) study shows Black women are far less likely to be screened with digital breast tomosynthesis than white or Asian women.

“Support for special initiatives to enhance the representation of under-represented populations is available. I encourage eligible sites to take part in this uniquely accessible, yet landmark, clinical trial,” said Mitchell Schnall, MD, PhD (pictured), Co-Chair of the ECOG-ACRIN Cancer Research Group.

To help researchers discover ways to tailor future screening to a woman’s individual risk, the study is creating a large curated dataset of breast cancer screening clinical data, images, and biospecimens. The data collected through TMIST will lead to better, individualized screening strategies based on each woman’s risk factors. Some women may benefit from less screening, while others may require more intensive screening.

"Wouldn’t it be better if we could adapt based on all of our new knowledge and provide individualized recommendations?” asks Dr. Pisano. “We could develop a tool that allows us to tell individual women, ‘Given your risk factors, your particular circumstances, and your genetics, here is what we recommend'.” The National Cancer Institute, part of the National Institutes of Health, funds and supports TMIST and the ECOG-ACRIN Cancer Research Group’s outreach efforts to recruit a diverse mix of sites and participants. The American College of Radiology Center for Research and Innovation™ manages trial implementation at TMIST sites, including site readiness and support for trial accrual, data collection and management, as well as image collection and management.

In addition to TMIST sites in the US, women can participate at sites in Canada, South America, Italy, and Korea. However, trial leaders continue to seek new sites to participate.

“While TMIST trial participation continues to grow, we need more sites to take part, particularly those in under-served areas,” said Dr. Pisano. “For more information, I urge practices with tomosynthesis and digital mammography to visit acr.org/TMIST, read this card, watch this video and contact TMIST staff at tmist@acr.org.”

Learn more about TMIST at ecog-acrin.org.