HER2-Directed Therapy in Advanced Gastric and Gastroesophageal Adenocarcinoma: Triumphs and Troubles

Gastric and gastroesophageal junction (GEJ) cancers represent the third leading cause of malignancy-associated death worldwide. Approximately 15–20% of these adenocarcinomas overexpress the human epidermal growth factor receptor 2 (HER2), a pro-proliferative receptor tyrosine kinase that has been therapeutically exploited in other disease contexts. The landmark ToGA trial demonstrated that trastuzumab, an anti-HER2 antibody, could improve...