LAUSR

AIM To assess the impact of vacuum-assisted excision (VAE) on the management of B3 lesions in the England NHS Breast Screening Programme following an update of national guidance. A secondary aim was to investigate the histological features of malignancies resulting from upgrade of B3 lesions by either VAE or surgery. MATERIALS AND METHODS The study population was all women recalled for assessment after breast screening who had a wide-bore needle biopsy with a B3 result over the period 01/04/2018 to 31/03/2019. Data were extracted from the National Breast Screening Service (NBSS) computer system at unit level. Women with a B3 result were split into those with and without atypia. The upgrade rates and histological features of malignancies in the different groups were analysed. RESULTS In total, 2,234,514 women attended for screening between 1/4/218 and 31/3/2019, 84,559 women were referred to assessment, and of those 40,037 women had a core biopsy resulting in 3,355 were B3 lesions (8.38%). Within these, 556 cancers were diagnosed, giving an upgrade rate of 16.57% (556/3,355). The upgrade for B3 lesions with atypia was significantly higher than for B3 lesions without atypia (29.1% versus 13.3%, p<0.001). CONCLUSION The introduction of the new B3 guidelines has resulted in 73.8% of B3 lesions with atypia and 65.1% of B3 lesions with no atypia having VAE rather than surgery. The data highlights the importance of managing these indeterminate lesions appropriately with an overall upgrade rate of 16.57%.