Objective  To investigate the effect of intraperitoneal perfusion on the survival of patients with gastric cancer peritoneal metastasis.

  Methods  The clinical data of 353 patients with advanced gastric cancer and peritoneal metastasis admitted to the Cancer Hospital Affiliated to Harbin Medical University from January 2014 to December 2020 were analyzed retrospectively. The patients were assigned into intraperitoneal perfusion group and non-intraperitoneal perfusion group, based on the application of the intraperitoneal perfusion. The patients underwent regular follow-up. The survival curve was constructed via the Kaplan-Meier method. The Cox risk ratio model analysis was used to determine the effect on patient prognosis, and the sub-group analysis was performed based on the lesion's location and degree of differentiation.

  Results  The median overall survival time of intraperitoneal perfusion group and non-intraperitoneal perfusion group was 9.50 months (95% confidence interval CI:7.39-11.61) and 7.83 months (95%CI:5.74-9.92), P= 0.022. Patients with a BMI>25 and abdominal metastasis with ascites benefitted significantly from intraperitoneal perfusion. Based on the multi-factor analysis, abdominal effusion (hazard ratio HR=1.52, 95%CI: 1.18-1.94), systemic treatment (HR=0.43, 95%CI: 0.33-0.56), surgical treatment (HR=0.52, 95%CI: 0.39-0.70), and intraperitoneal perfusion treatment (HR=0.65, 95%CI:0.52-0.82) significantly affected the survival of patients.

  Conclusions  Patients with gastric cancer and peritoneal metastasis were effectively treated with intraperitoneal perfusion. Compared with non-intraperitoneal perfusion group, patients treated via intraperitoneal perfusion had a significantly prolonged survival period. Cox multi-factor analysis showed that patients with ascites, surgical treatment, systemic treatment, and intraperitoneal perfusion had more favorable outcomes. The layout analysis showed that patients with gastric cancer and peritoneal metastasis benefitted from intraperitoneal perfusion.