In the 7th AJCC/UICC TNM staging system, gastric cancer with positive peritoneal cytology (CY+) is defined as stage IV disease. In NCCN clinical practice guidelines, it is suggested that positive peritoneal cytology in the absence of visible peritoneal implants should be considered as M1 disease and surgery as initial treatment is not recommended for patients with positive peritoneal cytology. However, in the Japanese gastric cancer treatment guidelines 2014, it is suggested that standard gastrectomy can be proposed for patients with no other non-curative factors and if the CY+ status was revealed after surgery, postoperative treatment with S-1 can be recommended as the tentative standard. Previous studies have also proved that extensive intraperitoneal lavage(EIPL) and Hyperthermic Intraperitoneal Chemotherapy(HIPEC) are effective methods for the treatment of peritoneal metastasis.~In order to optimize the treatment strategy of this part of patients, this trial is designed to compare the effectiveness of 2 treatment strategies.
Gastric cancer with positive is defined as stage IV disease in 7th AJCC/UICC TNM staging system. Controversy exists on the treatment of this part of patients. This trial aimed to explore the optimal treatment strategy for stage IV gastric cancer with positive peritoneal cytology as the only non-curable factor.