Total RNA was extracted from 50 ml of peritoneal wash from 11 SGC patients before and after cisplatin-based IPC. In 7 cases, more than 90% of the cancer cells were removed from the peritoneal cavity after cisplatin-based IPC. These 7 cases were named the IPC effective group, and the remaining 4 cases were named the IPC ineffective group. In the IPC effective group, elevated IL-2 and IL-6 genes were detected in 5 (71%) and in 6 (86%) after IPC. The correlation between IPC effectiveness and elevated gene expression after IPC (IL-2: p = 0.137, and IL-6: p = 0.044) was observed.