Clinical trial NCT03669926: The Tomosynthesis Trial in Bergen - Part 2
Official title: Digital Breast Tomosynthesis - The Future Screening Tool for Breast Cancer?
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Breast Neoplasms
Keywords: Diagnostic Imaging
Mammography
Tomosynthesis
Breast cancer screening
Subsequent screening
Cancer detection
Cost effectiveness
Early performance measures
Interval cancer
Lead sponsor: Norwegian Institute of Public Health
Sponsor class: OTHER_GOV
Collaborators: name: Haukeland University Hospital
name: University of Oslo
name: Norwegian Cancer Society
First posted: 2018-09-13
Enrollment: 31082
Sex: FEMALE
Minimum age (years): 48
Maximum age (years): 71
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: DIAGNOSTIC

Brief 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.

Eligibility criteria: Inclusion Criteria:

* Written, informed consent to participation

Exclusion Criteria:

* No written, informed consent to participation
* Breast implants

Primary outcomes:
measure: Compare rates of screen detected breast cancer after subsequent screening with DBT+SM after DBT+SM versus screening with DBT+SM after prior DM, as performed in a population based screening program.
timeFrame: 48 months from start up of the trial
Secondary outcomes:
measure: Compare recall rates after subsequent screening with DBT+SM after DBT+SM versus screening with DBT+SM after prior DM, as performed in a population based screening program.
timeFrame: 48 months from start up of the trial
measure: Positive predictive value of recalls after subsequent screening with DBT+SM after DBT+SM versus screening with DBT+SM after prior DM, as performed in a population based screening program.
timeFrame: 48 months from start up of the trial
measure: Prognostic and predictive tumor characteristics for screening detected breast cancer after subsequent screening with DBT+SM after DBT+SM versus screening with DBT+SM after prior DM, as performed in a population based screening program.
timeFrame: 48 months from start up of the trial
measure: Rate of interval breast cancer following screening with DBT+SM after DBT+SM versus screening with DBT+SM after prior DM, as performed in a population based screening program.
timeFrame: 48 months from start up of the trial
measure: Rate of missed and true screen-detected and interval breast cancer in mammographic screening with DBT+SM versus DM.
timeFrame: 24-48 month after start up of the trial
measure: Economical aspects of continuous use of DBT+SM
timeFrame: 48 months from start up of the trial
measure: Comparing interpretation times to investigate possible learning effects when reading DBT+SM in two consecutive screening rounds
timeFrame: 48 months from start up of the trial
measure: Assessing degree of experienced and expected pain in DBT+SM screening by compression pressure using questionnaire
timeFrame: 6 to 48 months after start up of the trial
Other outcomes:
Locations:
city: Oslo
country: Norway
facility: Cancer Registry of Norway
Study officials:
affiliation: Norwegian Institute of Public Health
name: Solveig Hofvind, Professor
role: PRINCIPAL_INVESTIGATOR
References: