Metachronous liver and bone metastasis from small early gastric carcinoma without lymph node involvement: A case report.

A 65-year-old man was referred to our Hospital for examination of gastric cancer initially diagnosed by medical check-up. Esophagogastroduodenoscopy demonstrated a superficial depressed-type gastric cancer in the antrum, and abdominal computed tomography showed no evidence of distant metastases. A tumor measuring 11 mm in diameter was removed by endoscopic submucosal dissection (ESD). Since histological examinations of ESD specimens showed a well-differentiated adenocarcinoma invading the submucosal layer with lymphatic invasion, the patient subsequently underwent laparoscopy-assisted distal gastrectomy with regional lymph node dissection, resulting in no residual carcinoma and no lymph node metastasis. The patient developed solitary liver metastasis one year later and was treated with trastuzumab plus capecitabine/cisplatin since results of the immunohistochemical analysis of the resected specimens demonstrated overexpression of the human epidermal growth factor receptor 2 (HER2). The patient was alive 12 months after surgical resection of the liver metastasis and subsequently developed bone metastasis. Controversy remains over the role of HER2 status as a prognostic factor in gastric cancer. However, it has been generally reported that HER2 overexpression correlates with aggressive biological behavior and poor prognosis. HER2 overexpression is a potentially useful predictive factor for tumor recurrence and poor prognosis even in early gastric cancer cases.