title: HER2-positive gastric cancer with paraaortic nodal metastasis successfully resected after chemotherapy with trastuzumab: a case report.
abstract: We report on a case of human epidermal growth factor receptor-2 (HER2)-positive gastric cancer with paraaortic lymph node metastasis. The patient (a 49-year-old female) received chemotherapy (capecitabine and cisplatin) plus molecular-targeted therapy (trastuzumab), followed by curative resection. Interestingly, the resected residual cancer was HER2-negative. Intra-tumor heterogeneity hinders molecular-targeted therapy for gastric cancer. In our case, continued trastuzumab administration presented few benefits since the residual cancer cells were HER2-negative. No consensus exists regarding the appropriate therapy for unresectable gastric cancers whose non-curative factors disappear following trastuzumab chemotherapy. The principal options are treatment with surgery or continued chemotherapy with trastuzumab. In our case, resection treated the HER2-negative residual cancer effectively, resulting in curative therapy. This is the first case of positive-to-negative change in the HER2 expression of residual tumor cells following trastuzumab therapy. It suggests that, due to intra-tumor heterogeneity, the risks presented by remnant HER2-negative cancer cells persist despite trastuzumab therapy.
authors: Department of Chemotherapy and Palliative Care, Tokyo Women's Medical University, 8-1, Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan nakajima@ige.twmu.ac.jp.
authors: Naoki
authors: N
authors: Ikari
authors: Go
authors: G
authors: Nakajima
authors: Kiyoaki
authors: K
authors: Taniguchi
authors: Tsuyoshi
authors: T
authors: Sasagawa
authors: Kosuke
authors: K
authors: Narumiya
authors: Takuji
authors: T
authors: Yamada
authors: Kenji
authors: K
authors: Kudo
authors: Yoichi
authors: Y
authors: Kitamura
authors: Kazuhiko
authors: K
authors: Hayashi
authors: Toshio
authors: T
authors: Nishikawa
authors: Masakazu
authors: M
authors: Yamamoto
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000601:surgery / Q000628:therapy*; D000068878:Trastuzumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D018719:Erb-b2 Receptor Tyrosine Kinases; D000068878:Trastuzumab
keywords: Gastric cancer; HER2; heterogeneity; neoadjuvant chemotherapy; trastuzumab