LANDMARK TMIST BREAST CANCER SCREENING TRIAL TO INFORM SCREENING POLICY
A CONVERSATION WITH STUDY CHAIR ETTA D. PISANO, MD
From the February 2019 E-Newsletter
The Tomosynthesis Mammographic Imaging Screening Trial (TMIST) is the first randomized controlled trial to compare two types of digital mammography for breast cancer screening, digital breast tomosynthesis (DBT), or 3D mammography, and conventional (2D) mammography. The 165,000 planned participants will help researchers identify women for whom DBT may outperform 2D mammography in reducing advanced breast cancer development. TMIST is currently enrolling healthy women ages 45 to 74 at 58 sites throughout North America and more sites are welcome. The study was developed by the ECOG-ACRIN Cancer Research Group and the National Cancer Institute (NCI), part of the National Institutes of Health. It is recruiting women through both the NCI National Clinical Trials Network (NCTN) and the National Community Oncology Research Program (NCORP).
TMIST is led by Etta D. Pisano, MD, of Beth Israel Deaconess Medical Center, Harvard Medical School, and the American College of Radiology. Learn more from our Q&A with her below, or visit the TMIST Home page.
Mammography clinics interested in participating in the trial may visit ACR.org/TMIST.
Can you provide some background on the TMIST trial?
TMIST is really a study about screening, not about the technologies per se. There hasn’t been a big screening trial since the 1980s and a lot has changed since then. The technologies have improved, and we are finding abnormalities much smaller, and earlier. Chemotherapy has improved, and so has our understanding of the different kinds of breast cancer. There is a lot more nuance to the diagnosis of breast cancer than there once was.
Now, people are asking questions like, “Does very early detection actually benefit women or are we just pushing back the diagnosis?” I believe there is a benefit to finding things as early as possible, because that often means less aggressive surgery or treatment. The real question is: Can we state with certainty that tomosynthesis improves patient care? We need to provide evidence that the more refined technologies actually do improve a woman’s probability of living longer.
What do you hope the study’s impact will be?
The other piece of this trial that’s really important, and will be integral in terms of changing screening, is that we are collecting blood and buccal smears for as many patients as we can. We will study the genomes of these patients, their demographic information, and pathology specimens – both benign and malignant. With all that information, we’ll be able to create models for how breast cancer screening should be accomplished with newer tools. In other words, we’re heading toward more individualized screening strategies for breast cancer. That’s something we haven’t studied well up until now. We have individualized therapies for breast cancer; we need to develop individualized screening strategies, too.
What are some challenges TMIST has faced and how have they been addressed?
We would like to have had more rapid site activation and recruitment, such that accrual is going more slowly than we’d hoped. We have learned that women are enthusiastic about participating, and we are working tirelessly to make the study available as broadly as possible.
That’s something we’re focusing on right now. If you’re reading this and want to participate we’d love to have you. Don’t wait to hear from us – get in touch by sending an email to us at gro.rcanull@TSIMT, or visit the website ACR.org/TMIST.
We’ve also learned some of the sites are only putting a part-time research associate on the study; that has to change. The volume that needs to be recruited at each site is so great, it really requires a full-time RA. We’re working with sites to address this issue. The study easily pays for itself if recruitment is up to the right level.
What would you say to a site that’s considering taking part in TMIST about why they should join the study?
Participating sites are all really interested in answering the basic questions we’re raising in this study. The sites, and the women, want to help develop the next screening strategy. Right now, we have one-size-fits-all screening, based primarily on age. Everybody goes through the same procedure regardless of how low risk they are. That’s extremely costly and inefficient.
There are other reasons to join as well. Sites that serve large numbers of uninsured women can benefit because we have a fund to reimburse those women for mammograms, potentially at a greater level than other sources of charity reimbursement. Additionally, this trial is well-funded by the NCI. Sites that want to participate can easily afford to do so, and will be compensated for their work.
What will the results of this trial mean for patient care?
When we devised our current screening strategies we didn’t have the genetic information we have now. We couldn’t sequence people’s genomes, and the way we looked at breast cancer was much less sophisticated. So much basic science has occurred since we last had a screening trial. The revolution in our understanding of the molecular biology of breast cancer and genetics needs to be applied to our screening strategies.
We could keep things the same for the next 50 years and women would benefit from screening, but wouldn’t it be better if we could adapt based on all this new knowledge and provide individualized recommendations? Women with lower risk could get screened less frequently and women with higher risk more intensively. 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.” Doctors will have better, more comprehensive information to advise patients as to what they, as individuals, will need. Improving breast cancer screening in this way is an important scientific and public health goal.