Positive cases through HER2 reassessment in primary and metastatic sites in advanced gastric cancer with initially HER2-negative primary tumours: Results of GASTric cancer HER2 reassessment study 1 (GASTHER1)
Abstract Purpose: The intratumoural heterogeneity of human epidermal growth factor receptor
2 (HER2) expression in gastric cancer is a major challenge when identifying patients
who might benefit from HER2-targeting therapy. We investigated the significance of reevaluation
of HER2 status in primary sites and metastatic or recurrent sites in advanced
gastric cancer patients whose primary tumours were initially HER2-negative.