Pressurized intraperitoneal aerosol chemotherapy in advanced gastric cancer with peritoneal metastases: a comprehensive meta-analysis of feasibility, efficacy, and safety.

Pressurized intraperitoneal aerosol chemotherapy (PIPAC) has emerged as a promising therapeutic approach for treating advanced gastric cancer with peritoneal metastases. Herein, we conducted this meta-analysis to evaluate the feasibility, efficacy, and safety of PIPAC in this patient population. The literature between January 2011 and February 2024 was comprehensively searched on the following databases: PubMed, Embase, Web of Science, and the Cochrane Library. The search, guided by the Population-Intervention-Comparison-Outcome (PICO) framework, focused on studies reporting on the feasibility, efficacy, and safety of PIPAC. Data were pooled by using log transformation (PLN) or Freeman-Tukey double arcsine transformation. Of the 451 initially identified studies, 18 were included in the meta-analysis, comprising 671 patients who underwent 1,357 PIPAC procedures. Our data analysis indicated that 32.6% of the patients (95% confidence interval [CI], 23.5%-42.3%) completed three or more PIPAC procedures. Conversely, 2.3% of patients (95% CI, 0.6%-5%) either did not have access to or could not undergo PIPAC. The average rate of histological response across the included studies was 66.3% (95% CI, 59.1%-73.1%). Pooled results showed that 13.1% of patients (95% CI, 7.0%-20.7%) had reduced ascites after PIPAC, and 7.8% (95% CI, 4.8%-11.4%) became resectable. Adverse events were reported in 17.1% of patients (95% CI, 5.3%-33.4%), with 3.6% (95% CI, 1.4%-6.6%) experiencing severe adverse events (grade 3-5, Common Terminology Criteria for Adverse Events [CTCAE]). The pooled mortality related to PIPAC was 0.1% (95% CI, 0%-0.5%). The pooled proportions for 6-month, 1-year, and 2-year overall survival rates were 82.4% (95% CI, 69.2%-92.8%), 54.0% (95% CI, 45.7%-62.3%), and 20.0% (95% CI, 11.3%-30.3%), respectively. The average median overall survival was 11.7 months (95% CI, 9.3-14.0 months). Our study suggests that most patients can benefit from PIPAC treatment, such as improved quality of life and significantly longer median overall survival. Patients who received first-line chemotherapy prior to PIPAC and concomitant systemic chemotherapy during PIPAC treatment, and who underwent the PIPAC procedure on more than three occasions, exhibited a more favorable survival prognosis.