Pressurized intraperitoneal aerosol chemotherapy (PIPAC) for peritoneal malignancy: initial experience of the first program in the Baltic countries

Background Peritoneal malignancies include primary and metastatic cancer of the peritoneal cavity. The most common origin for peritoneal metastasis is ovarian, gastric, and colorectal cancers. Irrespective of the origin, peritoneal metastases represent the advanced disease and are associated with poor long-term outcomes. The minimally invasive approach of pressurized intraperitoneal aerosol chemotherapy (PIPAC) allows repeated applications and objective assessment of tumor response by comparing histological samples. This study aimed to investigate the initial experience with PIPAC in the Baltic region. Methods All patients who underwent PIPAC at Vilnius University Hospital Santaros Klinikos between 2015 and 2020 were included in this retrospective study. The primary outcome of the study was overall survival (OS) in patients with peritoneal carcinomatosis treated by PIPAC. The secondary outcomes included postoperative morbidity; peritoneal carcinomatosis index (PCI) and ascites reduction after treatment by PIPAC. Results In total, 15 patients underwent 34 PIPAC procedures. PIPAC-related intraoperative and postoperative morbidity occurred in 3 (8.8%) of 34 procedures. Following PIPAC, the median PCI decreased from 8 (4; 15) to 5 (1; 16) in GC patients, although, the difference failed for significance, p = 0.581. In OC patients, PCI after PIPAC remained stable. Median overall survival after PIPAC procedure was 25 (95% CI 5-44) months. Ovarian cancer patients (22; 95% CI 12-44 months) had significantly higher OS, compared to gastric cancer patients (8; 95% CI 4-16 months), p = 0.018. Conclusions PIPAC is safe and feasible for patients with gastric and ovarian cancers peritoneal metastases.