The advent of targeted therapies using the HER2 receptor as a delivery mechanism in breast cancer, introduced a need for re-evaluation HER2 scoring in previously classified negative cases (2+ ISH -ve; and 1+), as patients with these tumours may benefit from these innovative treatments. At The Christie Hospital. Manchester, U.K., our specialised unit (BTRU) has been exclusively reporting ER, PR, and HER2 status in breast cancers for the past 25 years with a dedicated staff, adhering to consistent technical guidelines and stringent UKAS accreditation standards, with an annual assessment of approximately 1,600 cases. This study aimed to evaluate the performance of an AI solution in the identification of HER2 ultra-low compared to a cohort of reported HER1+ and 0 cases that were manually scored by the BTRU.

Xu Xuan Lim, MBChB¹, Angela Cramer, CLS¹, Jeppe Thagaard, PhD², Thomas Wichmand Ramsing², Pedro Oliveira, MD¹

1. The Christie NHS Foundation Trust
2. Visiopharm