The Trial
TMIST is a randomized breast screening trial that will help researchers learn about the best ways to find breast cancer in women who have no symptoms. It compares two types of Food and Drug Administration (FDA)-approved digital mammography: standard digital mammography (2-D) and 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. Researchers are doing this trial because they do not know if 3-D is better than 2-D mammography for breast cancer screening.
Another important aspect of the trial is to build a tissue bank for future research. All women who join the trial will be asked to submit tissue samples, such as blood and swabs of cells from inside their mouths. Researchers hope that the information from these tissue samples will help personalize the way we screen for breast cancer in the future by taking a person’s genetics and other personal risk factors into account.
Who Can Enroll in TMIST
Women ages 45 to 74 who are planning to get a routine screening mammogram are eligible for this trial. Women can also contact a participating site to ask about joining the study. Open sites are listed in the Locations & Contacts section of the trial record.How to Enroll in TMIST
The trial is taking place in mammography clinics around the United States, with a few sites in Canada and Argentina. Eventually, there will be over 100 clinics taking part in the trial. When women call one these participating clinics to schedule a routine mammogram, they may be asked to take part in TMIST. Researchers plan to enroll nearly 165,000 women.What Happens Once Women Enroll in TMIST
Once enrolled in the trial, women will be randomly assigned by a computer to receive either 3-D or 2-D screening mammograms for 5 years. How often they receive mammograms will be based on their:- Age
- Breast density
- Family history of breast cancer
- Presence of genetic changes known to cause breast cancer
- Use of hormone replacement therapy
- Menopausal status
- Have regular periods, had their most recent period within the last 12 months, or are younger than 52 and have had a hysterectomy but still have ovaries
- Have dense breasts
- Take hormone replacement therapy prescribed by a doctor
- Have a family history of breast cancer or genetic changes known to cause breast cancer
- Have dense breasts
- Take hormone replacement therapy prescribed by a doctor
Follow-Up after Completing TMIST
The study team will continue to follow women who have completed the trial for 3 years. During the follow-up period, women and their primary care doctors will decide on the type of mammogram they will have.Goals of TMIST
Even though some 3-D mammography machines are FDA-approved, no one knows if 3-D mammography is better than 2-D at finding breast cancers before they become more difficult to treat. Therefore, the main goal of TMIST is to measure and compare the rates of newly diagnosed breast cancer that meet certain criteria. These criteria include:- Tumors that are at least as big as a nickel (20 millimeters or larger)
- Tumors larger than 10 millimeters and HER2-positive
- Tumors larger than 10 millimeters and triple-negative
- Cancer has spread from the breast to at least one nearby lymph node
- Cancer has spread from the breast to distant organs in the body
- Among the women who receive 3-D mammography, will there be fewer harder-to-treat cancers in certain groups, such as those with dense breasts, African Americans, premenopausal women, and women on hormone replacement therapy?
- Will there be fewer false-positive test results in the entire study group or among certain groups?
- Is there a link between certain findings from the mammograms and the most aggressive breast cancers?
