Digital Breast Tomosynthesis Compared to Diagnostic Mammographic Projections (including Magnification) Among Women Recalled at Screening Mammography: a Systematic Review for the European Commission Initiative on Breast Cancer (ECIBC)

Background: Diagnostic mammography projections (DxMM) have been traditionally used in the assessment of women recalled after a suspicious screening mammogram. Digital breast tomosynthesis (DBT) reduces the tissue overlap effect, thus improving image assessment. Some studies have suggested DBT might replace DxMM with at least equivalent performance.

Objective: To evaluate the replacement of DxMM with DBT in women recalled at screening.

Methods: We searched PubMed, EMBASE, and the Cochrane Library databases to identify diagnostic paired cohort studies or RCTs comparing DBT vs DxMM, published in English that: reported accuracy outcomes, recruited women recalled for assessment at mammography screening, and included a reference standard. Subgroup analysis was performed over lesion characteristics. We provided pooled accuracy estimates and differences between tests using a quadrivariate model. We assessed the certainty of the evidence using the GRADE approach.

Results: We included ten studies that reported specificity and sensitivity. One study included 7060 women while the remaining included between 52 and 738 women. DBT compared with DxMM showed a pooled difference for the sensitivity of 2% (95% CI 1%-3%) and a pooled difference for the specificity of 6% (95%CI 2%-11%). Restricting the analysis to the six studies that included women with microcalcification lesions gave similar results. In the context of a prevalence of 21% of breast cancer (BC) in recalled women, DBT probably detects 4 (95% CI 2-6) more BC cases and has 47 (95%CI 16-87) fewer false-positive results per 1000 assessments. The certainty of the evidence was moderate due to risk of bias.

Conclusion: The evidence in the assessment of screen-recalled findings with DBT is sparse and of moderate certainty. DBT probably has higher sensitivity and specificity than DxMM. Women, health care providers and policymakers might value as relevant the reduction of false-positive results and related fewer invasive diagnostic procedures with DBT, without missing BC cases.