Trastuzumab has anti-metastatic and anti-angiogenic activity in a spontaneous metastasis xenograft model of esophageal adenocarcinoma

HER-2/neu over-expression occurs in 10–40% of patients with esophageal adenocarcinoma. Therefore, inhibitory effects of trastuzumab on proliferation, neoangiogenesis and metastatic spread of the esophageal adenocarcinoma cell line PT1590 were investigated (subcutaneous xenograft model). PT1590 revealed an amplified copy number of c-erbB2 and HER-2/neu over-expression occured in xenograft tumors and spontaneous lung metastases. PT1590 proliferation was significantly inhibited by trastuzumab in vitro. In vivo, tumor weight, volume, microvessel density and number of lung metastases decreased significantly after three weeks of treatment. These data suggest the importance of HER-2/neu for metastatic spread in esophageal adenocarcinoma and encourages clinical trials.