Karoline Freeman

The NHS breast screening programme aims to identify malignancies early but also detects an increasing number of epithelial atypia. The presence of atypia is believed to confer a four to ten times increased long-term risk of subsequent breast cancer.  The short-term risk is unknown. Nonetheless, current guidelines recommend vacuum assisted excision (VAE) followed by annual mammographic surveillance to ensure no cancers are missed. Therefore, the current management pathway for atypia may not to be in line with these women’s short-term risk of having subsequent breast cancer detected.

The Sloane atypia project was initiated to collect data from the English breast screening programme on number and type of cancers detected following atypia diagnosis to provide the evidence for management guidelines of screen detected breast atypia. The first analysis of 3238 women diagnosed with epithelial atypia between 01/04/2003 and 30/06/2018 showed that:

·         Atypia cases increased 4-fold in the study period.

·         Number of cancers post atypia short-term were low and the cancers were similar to those in the general screening population regarding histological type and number.

·         The ipsilateral and contralateral risk was similar.

·         The number of cancers did not significantly differ by atypia type, breast density or age.

·         Few cancers appeared to be missed at atypia diagnosis; VAE did not result in more cancers missed than management with diagnostic surgery.

·         Recent short-term cancer risk was lower than historical risk.

Following a consensus meeting with NHSE national policy stakeholders, new recommendations recommend routine screening rather than annual mammography for 5 years after atypia diagnosis.