Stage IV gastric cancer is classified into four subcategories: positive peritoneal cytology without clear macroscopic peritoneal involvement (surgery is usually performed in these cases); gross appearance peritoneal carcinomatosis [surgery, eventually with hyperthermic intraoperative peritoneal chemotherapy (HIPEC) may be considered in very selected cases with limited PCI]; nodal metastases outside the loco-regional nodes (surgery may not bedenied for metastatic nodes in stations 13 and 16); and hematogenous metastases (surgery should be performed in selected cases with liver metastases suitable to R0 resection).
At the time of the first PIPAC, the median PCI was 17 (1-39), 57 patients presented with symptomatic PC (pain: 33; ascites: 35; transit disorder like diarrhea and constipation: 11).
Independent predictors of OS were PC on the small bowel combined with PC on 4 or more non-small bowel regions (p = 0.0004), number of regions involved (p = 0.0029), and overall PCI score (p = 0.0104).