Background: Despite recent advances in the treatment of advanced gastric carcinomas, no satisfactory outcomes are available because of micrometastases and free-floating carcinoma cells already existing in the peritoneal cavity. From 1990, we started using intraperitoneal hyperthermo-chemo-perfusion (IHCP) to prevent and to treat peritoneal metastasis after surgical resection of stomach cancer.
Method: We analyzed 103 serosa-invasive gastric carcinoma patients who underwent surgical resection between 1990 and 1995. Fifty-two patients who received surgery plus IHCP were compared with 51 patients who underwent surgery only, as controls. IHCP was administered for 2 h with an automatic IHCP device (closed-circuit system) just after surgical resection, with the patient under hypothermic general anesthesia (32.4 degrees C-34.0 degrees C). As perfusate, we used 1.5% peritoneal dialysis solution mixed with 10 micrograms/ml of mitomycin-C (MMC), warmed at an inflow temperature of over 44 degrees C.
Results: The overall 5-year survival rate (5-YSR) of the 103 patients was 29.97%. The 5-YSR was higher in the IHCP group than in the control group, at 32.7% and 27.1%, respectively, but this difference was not significant. However, in the 65 serosa-invasive gastric carcinoma patients (excluding those in stage IV) the 5-YSR was significantly higher (P = 0.0379) in the IHCP group than in the control group, at 58.6% and 44.4%, respectively. On multivariate analysis of all 103 patients, depth of tumor invasion and lymph node metastasis were significant factors for survival, whereas significant factors on univariate analysis, such as combined operation, distant metastasis, and peritoneal metastasis, were not significant. The most common recurrence patterns were loco-regional in the IHCP group and peritoneal in the control group.
Conclusion: Complete cytoreductive surgery plus IHCP is effective to prevent and to treat peritoneal metastasis, and it should lead to long-term survival for serosa-invasive gastric carcinoma patients. However, there are some limitations for the treatment of peritoneal metastasis in stage IV patients with distant metastases.