The Tomosynthesis Trial in Bergen - Part 2
Condition: Breast Neoplasms
MeSH terms: Breast Neoplasms
Study type: Interventional

Summary: 
      The aim of the study is to compare early performance measures and economic aspects of
      organized breast cancer screening for women screened using digital breast
      tomosynthesis+synthetic mammography (DBT+SM) to women with a prior DBT+SM or digital
      mammography (DM) from To-Be 1 (NCT02835625).
    

Detailed description: 
      Digital breast tomosynthesis (DBT) is a new "three-dimensional" screening tool for breast
      cancer, claimed to be superior to standard two-dimensional (2D) digital mammography (DM)
      based on results of lower or similar recall rate, and a 30-50% higher rate of screen-detected
      breast cancer for DBT compared to DM.

      The Bergen Tomosynthesis Trial (To-Be) is a randomized controlled trial investigating whether
      DBT, including synthetic mammography (SM), is superior for breast cancer screening to DM
      (ClinicalTrials.gov Identifier: NCT02835625) - hereafter referred to as To-Be 1. The study is
      run as part of BreastScreen Norway (inviting women aged 50-69 to screening every two years).
      It started in October 2015 and finished recruitment in December 2017, after two years - one
      screening round - of data collection.

      Results from To-Be 1 will fill some of the knowledge gaps regarding DBT+SM in screening.
      However, running To-Be 1 and recent publications on the topic have identified additional
      challenges and new evidence gaps that are important to address before DBT can be considered
      for use in organized screening. Thus, the To-Be trail will be extended with five more year
      (To-Be 2), consisting of one additional screening round (two years) where all women in the
      study population are screened with DBT+SM with a three year follow-up.

      To investigate the effect of subsequent screening with DBT+SM all women attending mammography
      screening in Bergen in 2018 and 2019 will be screened with DBT+SM. To-Be 2 is a prospective
      cohort study targeting 32 000 women, and all women attending screening will be asked if they
      are willing to take part in the study after receiving written and oral information about the
      study. Women willing to participate in the study will sign an informed consent form. We
      expect a participation rate of 90%. The participating women will be screened with DBT+SM.
      Women not willing to participate in the study will be screened with DM, and not included in
      our study.

      Continuing To-Be 1 with To-Be 2 is the only opportunity to get information on women
      subsequently screened with DBT+SM, that have a prior DBT+SM or DM based on random allocation.
      This will also allow the investigators to analyze data on interval breast cancer among women
      screened with DBT+SM after DBT+SM and with DBT+SM after DM in To-Be 1 in 2020.

      The investigators aim to address the following topics and research questions:

      Part I: Early performance measures for screening with DBT+SM after DBT+SM, and DBT+SM after
      DM.

      Part II: Interval breast cancer following screening with DBT+SM versus DM, focusing on
      interval breast cancers identified among women screened in To-Be 1.

      Part III: Missed and true screen-detected and interval breast cancer in mammographic
      screening with DBT+SM versus DM.

      Part IV: Expected and experienced discomfort and pain in DBT+SM by compression force and
      pressure.

      Part V: Economic evaluation of continuous use of DBT.
    

Intervention name(s): Digital Breast Tomosynthesis+synthetic mammography
Intervention type(s): Radiation
Intervention description(s): Two-view tomosynthesis performed with GE Senographe Pristina.
Other intervention name(s): DBT+SM
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Diagnostic
Keywords: Diagnostic Imaging; Mammography; Tomosynthesis; Breast cancer screening; Subsequent screening; Cancer detection; Cost effectiveness; Early performance measures; Interval cancer