Changes in HER2 Expression and Amplification Status Following Preoperative Chemotherapy for Gastric Cancer

Autor: Hiroshi Saeki, Tomoko Jogo, Yoshihiko Maehara, Eiji Oki, Ryota Nakanishi, Makoto Iimori, Sei Shu
Rok vydání: 2018
Předmět:
Zdroj: In vivo (Athens, Greece). 32(6)
ISSN: 1791-7549
Popis: Background It is essential to establish a strategy for second-line treatment for human epidermal growth factor receptor 2 (HER2)-positive gastric cancer; however, HER2 expression status after chemotherapy treatment is not routinely determined. Materials and methods We analyzed 25 cases of gastric cancer that received preoperative chemotherapy and selected the six pre-treatment samples that were HER2-positive. Pre- and post-treatment tumor samples were examined for HER2 expression, and for HER2, epidermal growth factor receptor (EGFR), and hepatocyte growth factor receptor (MET) gene amplification. Results Three patients had been treated with trastuzumab plus chemotherapy, and three patients with cytotoxic chemotherapy alone. Only one case that had an initial HER2 score of 3+ and had received trastuzumab plus chemotherapy remained HER2-positive after treatment. Decrease or loss of HER2 expression and amplification was observed in the other five patients. Amplification of EGFR or MET was not observed in any pre- or post-treatment specimens. Conclusion Our data suggest that trastuzumab plus chemotherapy or chemotherapy alone may induce loss of HER2 positivity.
Databáze: OpenAIRE