1583P - Intraperitoneal chemotherapy for peritoneal metastases of gastric origin: A systematic review and meta-analysis

Background

Gastric cancer with peritoneal metastases is associated with a dismal prognosis. Catheter-based intraperitoneal (IP) chemotherapy and pressurized intraperitoneal aerosol chemotherapy (PIPAC) are methods to deliver chemotherapy intraperitoneally leading to higher intraperitoneal concentrations of cytotoxic drugs, compared to intravenous administration. We reviewed the effectiveness of palliative intraperitoneal chemotherapy for patients with peritoneal metastases of gastric origin.

Methods

Embase, MEDLINE, Web of Science, and Cochrane were searched for articles on chemotherapy with palliative intent in patients with peritoneal metastases of gastric origin published up to April 2023. The primary outcome was overall survival. Secondary outcomes included toxicity and clinicopathological outcomes in patients that underwent conversion surgery. A Bayesian random effect model was used to calculate the pooled median overall survival (mOS).

Results

21 studies including 904 patients were retrieved, categorized in 3 treatment groups (IP docetaxel, IP paclitaxel and PIPAC). The pooled mOS for all intraperitoneal chemotherapy treatments was 14.2 months (95% CI: 10.8 – 17.7 months). The pooled hazard ratio of IP paclitaxel and docetaxel favored the combination of IP and systemic chemotherapy compared to systemic chemotherapy only (0.64, 95% CI: 0.47 – 0.86). mOS of IP paclitaxel, IP docetaxel and PIPAC with cisplatin and doxorubicin were respectively 18.3 months (95% CI: 14.0 – 22.7 months), 13.2 months (95% CI: 3.6 – 25.1 months) and 9.0 months (95% CI: 2.3 – 16.5 months). All treatment methods had a relatively safe toxicity profile. Conversion surgery was performed in 14% of the patients and a radical resection was achieved in 69%, with a mOS ranging from 24 to 33 months.

Conclusions

Patients with peritoneal metastases of gastric origin treated with intraperitoneal chemotherapy had a pooled median overall survival of 14.2 months and a pooled hazard ratio of 0.64 compared to systemic chemotherapy. Intraperitoneal chemotherapy, regardless of method of administration, is a safe treatment and conversion surgery is possible in a selected subset of patients.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

B. Mostert: Financial Interests, Institutional, Research Grant: Sanofi, Pfizer, BMS; Financial Interests, Institutional, Speaker, Consultant, Advisor: Lilly, Servier; Financial Interests, Personal and Institutional, Speaker, Consultant, Advisor: BMS. B.P.L. Wijnhoven: Financial Interests, Institutional, Research Grant: BMS; Financial Interests, Institutional, Speaker, Consultant, Advisor: BMS. R.H. Mathijssen: Financial Interests, Institutional, Research Grant, Investigator-initiated research: Astellas, Bayer, Cristal Therapeutics, Pfizer, Roche, Sanofi, Servier, Boehringer Ingelheim, Novartis; Financial Interests, Institutional, Coordinating PI: Pamgene. All other authors have declared no conflicts of interest.