title: Peritoneal metastatic lesions of gastric cancer exhibit low expression of human epidermal growth factor receptor 2.
abstract: The prognosis of gastric cancer patients with peritoneal metastasis is very poor. Recent findings suggest that use of trastuzumab, a monoclonal antibody-based agent that targets human epidermal growth factor receptor 2 (HER2), may improve the prognosis of gastric cancer patients with HER2 overexpression and/or gene amplification. However, whether these mechanisms of HER2 upregulation are present in gastric cancer patients with peritoneal metastasis is unclear. The status of HER2 expression in a cohort of samples obtained from 35 gastric cancer patients with peritoneal metastasis was investigated using immunohistochemistry and fluorescence in situ hybridization. In 18 cases, we also investigated the influence of induction chemotherapy on HER2 overexpression. The frequency of HER2 overexpression and gene amplification was 2.9 % (1/35) in peritoneal metastatic lesions. There was concurrence in HER2 status in the samples examined prior to and following induction of chemotherapy. Most samples from the gastric cancer patients with peritoneal metastasis did not show HER2 amplification and/or overexpression. Although our study size was small, these results suggest that trastuzumab, which is critically dependent on HER2 expression, might not be an effective agent for these patients. Consequently, other therapeutic approaches for these patients must be developed.
authors: Department of Surgery, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka 589-8511, Japan. imano@med.kindai.ac.jp
authors: Motohiro
authors: M
authors: Imano
authors: Takao
authors: T
authors: Satou
authors: Tatsuki
authors: T
authors: Itoh
authors: Atsushi
authors: A
authors: Yasuda
authors: Hiroaki
authors: H
authors: Kato
authors: Masayuki
authors: M
authors: Shinkai
authors: Ying-Feng
authors: YF
authors: Peng
authors: Masahiro
authors: M
authors: Tsubaki
authors: Takushi
authors: T
authors: Yasuda
authors: Haruhiko
authors: H
authors: Imamoto
authors: Shozo
authors: S
authors: Nishida
authors: Yoshifumi
authors: Y
authors: Takeyama
authors: Kiyokata
authors: K
authors: Okuno
authors: Hitoshi
authors: H
authors: Shiozaki
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D060828:Induction Chemotherapy; D008297:Male; D008875:Middle Aged; D010534:Peritoneal Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000556:secondary; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D055815:Young Adult
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human