by John R. Fischer
, Senior Reporter | September 28, 2020
While Adamson does not deny the impact of COVID-19 on TMIST, he asserts that other clinical trials have encountered the same issue, and questions if the pandemic was used as an “excuse” for creating a public forum about TMIST. He also objected to TMIST investigators not being invited to present an “action plan” for increasing recruitment.
Dr. Etta D. Pisano, the principal investigator of the trial and chief research officer at the American College of Radiology, says she and her colleagues have heard nothing about ending TMIST. She says the primary goal of TMIST has often been "misportrayed" and is prepared to work with NCI to meet the objectives laid out for TMIST.
"It is not to determine whether digital breast tomosynthesis finds more cancers than standard 2-D digital mammography, but whether the newer technology may help reduce breast cancer deaths by finding more of the types of advanced cancers likely to kill women," she told HCB News, adding that there are several factors that set TMIST apart from earlier, technology-focused studies. "TMIST will develop the world's largest biorepository for women undergoing cancer screening and study the genetic basis of the development of breast cancer. Another important output of the trial may be more scientifically-based recommendations for personalized screening strategies, which is likely why the study has appealed to women who are not ideally served by current age-based screening strategies."
Enrollment for the trial quadrupled and sites where it was conducted doubled in the 14 months prior to the pandemic, according to Pisano. In addition, an unheard-of 19% of the 30,000 women enrolled at 99 sites were African-American, a population of people that carries higher risks of mortality when it comes to certain cancers.
One or more 3D mammography units are used by certified mammography facilities in the U.S., with 40% of all units being 3D. This is probably an understated figure, as all 3D units have a built-in 2D function. The FDA, however, equally counts both components in a single machine, even when 3D is used exclusively, according to Medscape Medical News.
The initial design of the trial was made in 2012, before 3D mammography rose in popularity, which may be a reason for its enrollment and site participation issues. The trial period for TMIST, which uses “advanced” breast cancers as novel surrogate outcomes, is 4.5 years. Women are screened annually to determine which imaging scanner results in fewer advanced cancers. They include larger HER2-positive and triple-negative malignancies; those associated with positive nodes; and metastatic disease, all of which correlate with breast cancer mortality, according to Pisano.