HER2-positive adenocarcinoma of gastroesophageal junction

HER2-positive adenocarcinoma of the gastroesophageal junction is a distinct histological and molecular subtype of upper gastrointestinal cancer arising from glandular epithelial tissue at the anatomical transition between the distal esophagus and proximal stomach This receptor tyrosine kinase overexpression drives unregulated cellular proliferation, invasion, and aggressive tumor biology in affected patients, defining an oncogenic subset that is specifically susceptible to HER2-directed targeted...

HER2-positive adenocarcinoma of the gastroesophageal junction is a distinct histological and molecular subtype of upper gastrointestinal cancer arising from glandular epithelial tissue at the anatomical transition between the distal esophagus and proximal stomach This receptor tyrosine kinase overexpression drives unregulated cellular proliferation, invasion, and aggressive tumor biology in affected patients, defining an oncogenic subset that is specifically susceptible to HER2-directed targeted...

Pathophysiologically, the tumor is characterized by amplification of the *ERBB2* gene or overexpression of the human epidermal growth factor receptor 2 (HER2) protein, typically confirmed by standard immunohistochemistry (IHC 3+) or in situ hybridization (IHC 2+/ISH+) testing

Pathophysiologically, the tumor is characterized by amplification of the *ERBB2* gene or overexpression of the human epidermal growth factor receptor 2 (HER2) protein, typically confirmed by standard immunohistochemistry (IHC 3+) or in situ hybridization (IHC 2+/ISH+) testing

This receptor tyrosine kinase overexpression drives unregulated cellular proliferation, invasion, and aggressive tumor biology in affected patients, defining an oncogenic subset that is specifically susceptible to HER2-directed targeted therapies