The Tomosynthesis Mammographic Imaging Screening Trial, known as TMIST or study EA1151, is a randomized breast cancer screening trial that will help researchers learn about the best ways to find breast cancer in women who have no symptoms. It compares two Food and Drug Administration (FDA)-approved types of digital mammography: standard digital mammography (2-D) with a newer technology called tomosynthesis mammography (3-D). 2-D mammography takes pictures from two sides of the breast to create a flat image. 3-D mammography images are taken from different angles around the breast and then built into a 3-D-like image.
The goal of breast cancer screening is to find breast cancer early when it may be easier to treat. Although 3-D mammography, being the newer technology, is likely to detect more findings that require follow-up, it is also likely to lead to more procedures and treatments. It is not known if the newer technology is more effective than conventional 2-D mammography at reducing life-threatening (advanced) breast cancers. The TMIST trial aims to find out.
The ECOG-ACRIN Cancer Research Group opened the trial on July 6, 2017, and plans to enroll about 165,000 women by the end of 2020.
Women ages 45 to 74 who are planning to get a routine screening mammogram are eligible for this trial.
Women who decide to participate in this trial will be involved through the end of the study in 2025. Once enrolled in the trial, women will be randomized (assigned by a computer) to get either 3-D or 2-D screening mammograms for five years. Each woman will need to agree to let her doctor tell her how often to get screened—either every year or every other year—based on her individual risks for developing breast cancer.
During the study, the results of every mammogram from every woman will be collected. Information about any medical follow-up, such as more imaging or a biopsy, will also be recorded. All women will be followed until the end of the study for breast cancer status, treatment, and results from treatment.
TMIST is publicly funded by the National Cancer Institute (NCI), part of the National Institutes of Health, through the NCI Community Oncology Research Program.