Digital image analysis of HER2 immunohistochemistry in gastric- and oesophageal adenocarcinoma: a validation study on biopsies and surgical specimens.

Aims: To test the validity of diagnostics incorporating digital image analysis (DIA) for human epidermal growth factor 2 (HER2) immunohistochemistry (IHC) in gastro-oesophageal adenocarcinomas, as an alternative to current standard diagnostics using manual scoring.

Methods And Results: We included 319 consecutive gastro-oesophageal adenocarcinomas (232 biopsies and 87 surgical specimens). DIA was applied to determine HER2 IHC classification, using both standard breast cancer (BC) and modified gastro-oesophageal cancer (GEC) cut-offs.

Pathologic diagnostics of HER2 positivity in gastroesophageal adenocarcinoma.

Objectives: The human epidermal growth factor receptor 2 (HER2) oncogene shows overexpression in 15% to 30% of gastroesophageal adenocarcinomas. Targeted anti-HER2 therapy with trastuzumab has been recently validated in advanced gastric and gastroesophageal junction cancer treatment. A standardized modified scoring system was recently introduced for gastroesophageal HER2 scoring.