The Digital Breast Tomosynthesis Trial in Bergen

Study Overview
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Brief Summary
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Compare synthetic mammography+digital breast tomosynthesis (SM+DBT) with digital mammography (DM) as a screening tool for women aged 50-69 years, invited to participate in the Norwegian Breast Cancer Screening Program at the screening unit in Bergen, Norway, with regard to early performance measures, including prognostic and predictive tumor characteristics, radiation doses and cost-effectiveness.

Detailed Description
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DBT is a new screening tool, argued to be better than standard DM. This statement is based on a lower recall rate, and a higher rate of early-stage screen-detected cancer. No studies have so far reported results from women screened with DBT from GE Healthcare, as far as the investigators know. DBT from GE offer synthetic two-dimensional DM generated from the DBT data (SM), and studies have shown similar detection rates for this technique as of adjacent DM. By comparing results of early performance measures and economic aspects in two comparable populations of women in the same age group, residing in the same county, the investigators can measure the effect of SM+DBT versus standard DM with equipment from GE Healthcare. The populations will be examined by the same radiographers, screen-read by the same radiologists, histologically breast cancer proven by the same pathologists, and treated by the same surgeons and oncologists. A prospective cohort study targeting 45,000 women invited to breast cancer screening in Bergen, Hordaland in the study period, 2016-2018, will be performed. A screening participation of approximately 75% is expected. All attending women will be asked if they are willing to participate in the study after receiving written and oral information about the study. Women willing to participate in the study will sign an informed consent. Of the attending women it is expected that about 90-95% will consent to participate in the study. The women will be randomized into two groups, a study group and a control group. The randomization will take place at the screening unit in Bergen. The outcome of the randomization is based on the 11-digit personal identification number assigned to every citizen in Norway. In the study group, the women will be screened with SM+DBT. In the control group, the women will be screened with DM. Women not willing to participate in the study will be screened with DM, and not included in our study. The investigators aim to address the following topics and research questions: Study 1: Early performance measures in a population based screening program using SM+DBT versus DM - interim analyses. Study 2: Use of SM+DBT versus DM in a population based screening program - a randomized controlled trial. Study 3: Prognostic and predictive histopathologic characteristics of breast tumors detected in a population based program using SM+DBT versus DM. Study 4: SM+DBT and DM in a populations based screening program - which technology has the highest sensitivity for women with mammographic dense breast? Study 5 and 6: Costs of SM+DBT and DM in a populations based screening program - is SM+DBT cost-effective?

Official Title
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Digital Breast Tomosynthesis - The Future Screening Tool for Breast Cancer?

Conditions
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Breast Neoplasms

Intervention / Treatment
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* Radiation: Synthetic Mammography + Digital Breast Tomosynthesis
* Radiation: Digital mammography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent Exclusion Criteria: Breast implants

Ages Eligible for Study
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Minimum Age: 48 Years
Maximum Age: 71 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Digital Breast Tomosynthesis<br>Synthetic Mammography (SM) + Digital Breast Tomosynthesis (DBT) The SM+DBT will be independently read by two radiologists. A consensus meeting will decide whether to recall the woman or not. Women selected for further assessment (positive screening exam) will be recalled. | Radiation: Synthetic Mammography + Digital Breast Tomosynthesis<br>* Two-view tomosynthesis performed with GE Senoclaire 3D Breast Tomosynthesis.<br>* Other names: SM+DBT;|
| Active Comparator: Digital mammography<br>The digital mammograms will be independently read by two radiologists. A consensus meeting will decide whether to recall the woman or not. | Radiation: Digital mammography<br>* Two-view digital mammography performed with GE Senoclaire 3D Breast Tomosynthesis.<br>* Other names: DM;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Participants With Screen-Detected Breast Cancer | Comparison of rates of screen-detected breast cancer in tomosynthesis versus digital mammography as performed in a population based screening program. | 36 months from start up of the trial | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number and Percentage of Participants Screen-Detected Breast Cancer Among Participants Recalled for Further Assesment | Positive predictive value of recalls (number of screen-detected breast cancer among participants recalled for further assesment) for tomosynthesis versus digital mammography in a population based screening program. | 36 months from start up of the trial | 
| Number of Participants Recalled for Further Assesment Due to Mammographic Findings | Comparison of rate of recall for further assesment due to mammographic findings in tomosynthesis versus digital mammography as performed in a population based screening program. | 36 months from start up of the trial | 
| Incremental Costs of Screening With Tomosynthesis Versus Digital Mammography | The incremental cost per woman screened with digital breast tomosynthesis versus digital mammography in a population-based breast cancer screening program. | 36 months from start up of the trial | 
| Prognostic and Predictive Tumor Characteristics for Screen-Detected Breast Cancer | Distribution of characteristics among the women diagnosed with breast cancer screened with tomosynthesis versus digital mammography in a population based screening program. | 36 months from start up of the trial | 
| Number of Participants With Interval Breast Cancer | Rate of interval breast cancer among those screened with tomosynthesis versus digital mammography as performed in a population based screening program. | 60 months from start up of the trial | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Mammography, Cost, Diagnostic Imaging, Randomized Controlled Trial, Tomosynthesis, Early performance measures, Recall, Radiation dose, Cancer detection, Sensitivity, Specificity, Economy