Second annual report from the ISSPP PIPAC database

Objectives: To monitor the results of PIPAC directed therapy based on data from the International Society for the Study of the Pleura and Peritoneum (ISSPP) PIPAC database.Methods Analysis of data from patients entered between June 15th, 2020, and February 28th, 2023.Results: Twelve centers reported 2,456 PIPAC procedures in 809 patients (median 2, range 1-18) with peritoneal metastasis (PM) from different primary tumors. Approximately 90 % had systemic chemotherapy prior to PIPAC. Twenty-eight percent were treated in prospective protocols. Overall non-access rate was 3.5 %. Concomitant surgical procedures were performed during PIPAC in 1.6 % of the patients. Median length of stay was 2 days. A total of 95 surgical complications were recorded, but only 22 % of these were graded >= 3b. Seventeen-hundred-and-three adverse events were noted, and 8 % were classified >= 3. The rate of complete or major histological response (peritoneal regression grade score, PRGS <= 2) increased between the first and the third PIPAC in the group of patients who were evaluated by PRGS, and a PRGS <= 2 or a reduction of the mean PRGS of at least 1 between first and third PIPAC were observed in 80 %. Disease progression (50 %) or technical issues (19 %) were the most important reasons for stopping PIPAC treatment. Median overall survival from first PIPAC directed treatment varied from 10.7 months (CI 8.7-12.5) in gastric cancer to 27.1 months (16.4-50.5) in mesothelioma.Conclusions: The ISSPP PIPAC database provides substantial real-world data supporting the use of PIPAC directed therapy in patients with PM from different primary tumors.