Clinical Practice Observation of Trastuzumab in Patients with Human Epidermal Growth Receptor 2-Positive Metastatic Adenocarcinoma of the Stomach or Gastroesophageal Junction

Abstract

Real-world data of trastuzumab treatment of patients with gastroesophageal or gastric metastatic adenocarcinoma confirmed the positive results of the pivotal clinical trial. The observed median overall survival was 14.1 months and the median progression-free survival was 7.9 months. Although recommendations concerning administration of trastuzumab were well implemented, a high diversity of chemotherapy regimens were combined with trastuzumab. Regimens other than the in-label regimens, especially oxaliplatin-based doublets or 5-fluorouracil, leucovorin, oxaliplatin, taxane triplets, were used in 29% of patients. Observation of a second, marginal HER2-positivity population confirmed the benefit of trastuzumab predominantly for well-confirmed human epidermal growth receptor 2 (HER2)-positive tumors and the requirement of reliable HER2 testing.