A comprehensive Cochrane review of nine randomized controlled trials involving 829 participants evaluated intraperitoneal chemotherapy (IPC) as either prophylactic therapy for high-risk gastric cancer or therapeutic treatment for confirmed peritoneal metastasis. The evidence—rated very low certainty—suggests that IPC may improve overall survival in both settings, though effects on disease-free survival, recurrence, and complication rates such as anastomotic leakage or intra-abdominal abscess were unclear or minimal. Trials varied in methodology, mostly used hyperthermic IPC, and rarely reported quality-of-life data or adverse event profiles, contributing to significant uncertainty.
For therapeutic IPC combined with cytoreductive surgery, IPC may extend median progression-free survival and slightly increase overall survival, but findings remain highly unstable due to small samples, indirectness, and imprecision. Evidence suggests little to no difference in serious adverse events or postoperative complications, and limited data showed no meaningful effect on quality of life. Overall, the authors conclude that current evidence is too uncertain to recommend routine use of IPC in gastric cancer, emphasizing the need for high-quality, long-term trials across diverse populations.