The Potential Impact of Digital Breast Tomosynthesis on the Benign Biopsy Rate in Women Recalled within the UK Breast Screening Programme.

Background Multiple studies showed digital breast tomosynthesis (DBT) has a higher cancer detection rate and a lower recall rate than full-field digital mammography (FFDM). However, there is a paucity of studies on whether the benign biopsy rate will be lower with DBT. Purpose To evaluate the benign biopsy rate of DBT versus that of FFDM in women recalled after breast screening within the National Health Service Breast Screening Programme. Materials and Methods This prospective single institution study included women who underwent screening FFDM or screening breast MRI between November 13, 2015, and July 29, 2016, and were recalled. Women who were recalled underwent a breast examination, additional imaging (mammography, US), and biopsy, if required. The number of interventions and the outcome of assessment were recorded. FFDM was performed at the screening appointment, and DBT images were acquired when participants attended a screening assessment within 3 weeks after screening FFDM. Two of four readers blinded to biopsy results analyzed DBT images in isolation and then in conjunction with FFDM images and any additional two-dimensional mammographic or US images. Two-tailed McNemar tests were used to test differences in sensitivity and specificity of the two conditions at 5% significance level. Results During the study period, 30 933 women underwent FFDM. A total of 1470 women were recalled (recall rate, 4.8%), and 827 were included after exclusion criteria were applied. Their mean age was 56.7 years ± 7.7 (standard deviation). A total of 145 breast cancers were detected (142 with FFDM, two with DBT only, one with surveillance MRI). Triple assessment without DBT resulted in 571 breast biopsies and enabled detection of 142 cancers. The addition of DBT would have resulted in 298 biopsies and detection of 142 cancers, reducing the number of biopsies from 571 of 827 (69.0%) to 298 of 827 (36.0%). Conclusion When compared with full-field digital mammography, digital breast tomosynthesis can reduce the benign biopsy rate while maintaining the cancer detection rate. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Skaane in this issue.

What is the significance of flat epithelial atypia and what are the management implications?

AIMS: To assess the significance of flat epithelial atypia (FEA) on core biopsy by evaluating the proportion of cases upgraded to in-situ and invasive carcinoma on further sampling with vacuum-assisted biopsy (VAB) or diagnostic surgical biopsy. METHODS: A retrospective analysis was performed of all core biopsies containing FEA and/or atypical intraductal proliferation (AIDP) in the pathology database from April 2008 to April 2010 (n=90). Before April 2009, the majority of core biopsies containing FEA and/or AIDP proceeded to surgical biopsy. From April 2009 onwards, a new patient management pathway was introduced incorporating VAB to sample core biopsies containing FEA and/or AIDP as an alternative to surgical biopsy. RESULTS: Of 90 core biopsies, the following were identified: FEA only in 42%; FEA with concomitant AIDP in 21% and AIDP only in 37%. There was a stepwise increase in the proportion of cases upgraded to in-situ or invasive carcinoma: 19% in the FEA group; 29% in the FEA and AIDP group and 53% in the AIDP group. In the FEA-only group, one invasive tumour (grade 1 tubular carcinoma) and six cases of ductal carcinoma in situ were found. CONCLUSION: The presence of FEA on core biopsy warrants further tissue sampling to ensure concomitant malignancy is not missed. Sampling with VAB provides sufficient tissue for histopathological evaluation, reducing the need for surgical biopsy. It is important that the utilisation of VAB is incorporated into a safe patient management pathway with careful multidisciplinary team discussion to ensure radiological-pathological concordance.