A randomized Phase II trial of systemic chemotherapy with and without trastuzumab followed by surgery in HER2-positive advanced gastric or esophagogastric junction adenocarcinoma with extensive lymph node metastasis: Japan Clinical Oncology Group study JCOG1301 (Trigger Study)

Pre-operative chemotherapy with S-1 plus cisplatin is considered to be acceptable as one of the standard treatment options for gastric cancer patients with extensive lymph node metastases in Japan. Addition of trastuzumab to chemotherapy is shown to be effective for HER2-positive advanced gastric cancer patients, and we have commenced a randomized Phase II trial in March 2015 to evaluate S-1 plus cisplatin plus trastuzumab compared with S-1 plus cisplatin alone in the neoadjuvant setting for HER2-positive gastric cancer patients with ELM, which are followed by adjuvant chemotherapy with S-1 for 1 year. A total of 130 patients will be accrued from 41 Japanese institutions over 3 years. The primary endpoint is overall survival. The secondary endpoints are progression-free survival, response rate of pre-operative chemotherapy, proportion of patients with R0 resection, proportion of patients who complete the pre-operative chemotherapy and surgery, proportion of patients who complete the protocol treatment including post-operative chemotherapy, pathological response rate and adverse events. This trial has been registered in the UMIN Clinical Trials Registry as UMIN 000016920.