[A patient with advanced gastroesophageal junction cancer responding completely to S-1 monotherapy]

A 74-year-old woman was referred to our hospital for a close examination. A gastrointestinal endoscopic examination revealed an advanced gastroesophageal junction cancer type 3, which was diagnosed as well-differentiated adenocarcinoma. Computed tomography(CT)showed liver and para-aortic lymph node metastases.She was treated with oral S-1 at 100mg/ day for 28 days, followed by a 14-day rest. After 3 courses of treatment, the primary tumor was greatly reduced. After 18 months of treatment, CT showed a complete response of the liver and also the para-aortic lymph node metastases. She is alive without severe adverse effects and recurrence 2.5 years after the start of S-1 administration.