Pressurized intraperitoneal aerosol chemotherapy (PIPAC) for unresectable peritoneal metastasis from gastric cancer.

Background: PIPAC is a recent approach with promising results for patients with peritoneal metastasis (PM). We aimed to evaluate survival and postoperative outcome of patients with unresectable PM from gastric origin treated with chemotherapy and PIPAC.

Methods: A retrospective analysis of a prospective maintained PIPAC database was queried for all patients diagnosed with unresectable PM from gastric cancer who underwent PIPAC before 2018. PIPAC with Cisplatin 7.5 mg/m2 and doxorubicin 1.5 mg/m2 were given for 30 min at 6-week intervals. Outcome criteria were overall survival and adverse events according to (CTCAE) version4.0.

Results: One hundred Sixty-three PIPAC were done in 42 consecutive patients. Twenty-two (52%) of the patients were female. Signet-ring cells were observed in 33/42 patients (78.6%). At the first PIPAC, median age was 51.5 years (32-74). Median PCI was 17 (1-39). Twenty (47.6%) patients underwent more than 2 lines of pre-PIPAC chemotherapy. All patients had systemic chemotherapy alternating with PIPAC. Median consecutive PIPAC procedures were 3 (1-12). Overall and major complications (CTCAE - III, IV) occurred in 10 (6.1%) and 5 procedures (3.1%), respectively. Two patients (4.7%) died within 30 days of a PIPAC procedure, one related to small bowel obstruction and a pulmonary embolism for the other. Overall Survival was 19.1 months. Six (14.3%) patients became resectable during treatment and underwent curative intent CRS and HIPEC.

Conclusions: PIPAC with low-dose cisplatin and doxorubicin is safe and feasible in association with systemic chemotherapy for gastric PM. Survival data are encouraging and justify further clinical studies in this indication.