title: Durable response of human epidermal growth factor receptor-2-positive gastric adenosquamous carcinoma to trastuzumab-based chemotherapy.
abstract: Here, we report a patient with gastric adenosquamous carcinoma (ASC) with human epidermal growth factor receptor-2 (HER2) overexpression who was successfully treated with trastuzumab-based chemotherapy. The patient was a 66-year-old man preoperatively diagnosed with gastric adenocarcinoma with no evidence of distant metastases. On histopathological examination, the curatively resected tumor was identified as ASC with mixed adenocarcinoma and squamous cell carcinoma components. Multiple liver metastases developed 2.5 months after surgery. Because immunohistochemical staining for HER2 was strong in both components, combination chemotherapy with capecitabine, cisplatin, and trastuzumab was initiated. A partial response was confirmed after 6 treatment cycles and PET and CT scans performed after 13 cycles revealed disease resolution with no uptake in the metastatic lesions. No evidence of disease progression has been observed 16 months after initial chemotherapy. This report suggests the potential utility of trastuzumab-based chemotherapy for HER2-positive gastric ASC.
authors.affiliation: Department of Clinical Oncology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Shigenori
authors.initials: S
authors.lastname: Kadowaki
authors.affiliation: Department of Pathology and Molecular Diagnostics, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yatabe
authors.affiliation: Department of Clinical Oncology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Sohei
authors.initials: S
authors.lastname: Nitta
authors.affiliation: Department of Gastroenterological Surgery, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Clinical Oncology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Muro
keywords: Adenosquamous carcinoma; Human epidermal growth factor receptor-2; Stomach; Trastuzumab