{"entity":{"id":"tmist","kind":"trial","name":"TMIST (Tomosynthesis Mammographic Imaging Screening Trial)","aka":[],"tldr":"The trial that will settle whether 3D mammograms prevent more dangerous cancers than standard 2D ones, or just find more small ones.","summary":"TMIST (ECOG-ACRIN EA1151) is the only randomised trial comparing tomosynthesis with digital mammography on a clinically meaningful endpoint, the rate of advanced cancers (larger, node-positive, metastatic or aggressive subtypes) over 4.5 years, rather than detection rate. Enrolment of about 108,000 women across North America, Argentina and other countries closed in 2024 after a slow start and a downsized target; the trial also builds a biorepository for risk-based screening research. Observational studies show tomosynthesis finds more cancers with fewer recalls, especially in dense breasts, but whether that translates into fewer advanced cancers is exactly what is unknown.","status":"active","asOf":"2026-09-10","links":[{"label":"ClinicalTrials.gov NCT03233191","url":"https://clinicaltrials.gov/study/NCT03233191"},{"label":"ECOG-ACRIN: TMIST","url":"https://ecog-acrin.org/clinical-trials/tmist-breast-cancer-screening-trial/"}],"tags":[],"related":[],"cancers":["breast-hr-positive","tnbc","breast-her2-positive"],"sections":[],"technologies":["mammography"],"targets":[],"drugs":[],"companies":["ecog-acrin"],"institutions":[],"pathways":[],"terms":["screening","overdiagnosis"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"nct":"NCT03233191","phase":"3","setting":"Women aged 45 to 74 randomised to screening with digital breast tomosynthesis (3D) or standard digital mammography, primary endpoint advanced breast cancer","sponsor":"ECOG-ACRIN / NCI","started":"2017-09-28","startedType":"actual","enrolledBasis":"registry","outcomes":[]},"route":"/trials/tmist/","neighbours":{"cancer":[{"id":"breast-her2-positive","kind":"cancer","name":"HER2-positive breast cancer","route":"/cancers/breast-her2-positive/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"technology":[{"id":"mammography","kind":"technology","name":"Mammography & tomosynthesis","route":"/technologies/mammography/"}],"company":[{"id":"ecog-acrin","kind":"company","name":"ECOG-ACRIN Cancer Research Group","route":"/companies/ecog-acrin/"}],"term":[{"id":"overdiagnosis","kind":"term","name":"Overdiagnosis","route":"/terms/overdiagnosis/"},{"id":"screening","kind":"term","name":"Screening","route":"/terms/screening/"}]}}