It is widely accepted that the efficacy of chemotherapy for patients with inoperable, advanced, and metastatic gastric cancer is better than that compared to best supportive care. In general, combination chemotherapies are more efficient than monotherapy and so it is reasonable to give combination chemotherapy to patients with good performance status.~Especially dual combination chemotherapy with fluoropyrimidine and platinum has shown the objective response rate of 25-48% in patients with newly diagnosed advanced metastatic gastric cancer and several studies about triple combination with oxaliplatin, irinotecan, and fluoropyrimidine have shown the response rate of 53~75% but also higher rate of hematologic adverse events. So the investigators had conducted the phase I study of these three drugs with modification of dosage and schedule and will conduct a phase II study with recommended dose of triple chemotherapy from this phase I study.
This study will conduct a phase II study of triple combination with oxaliplatin, irinotecan, and S-1 as the first-line chemotherapy in patients with advanced gastric cancer.