ERBB2 and gastric cancer: The ToGA results demonstrated that adding trastuzumab to chemotherapy significantly improved median OS (13.8 months vs. 11.1 months) and median PFS (6.7 months vs. 5.5 months) in patients with HER2-positive metastatic GC, alongside an enhanced ORR (47% vs. 35%; p = 0.0017) (Bang et al., 2010).