Implications of peritoneal cancer index distribution on patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

Objectives:Peritoneal cancer index (PCI) score is a common prognostication tool in peritoneal metastases (PM). We hypothesize that the distribution of PCI score and involvement of specific regions affects survival and morbidity outcomes. Methods:Data was collected from a prospective database of patients who underwent CRS and HIPEC for PM at the National Cancer Centre Singapore. We evaluate the relationship between PCI, PCI distribution, and survival and morbidity outcomes. Results:One hundred and fifty-two patients underwent CRS and HIPEC with a median PCI score of nine (range 0-31). Median overall survival (OS) and progression free survival (PFS) were 43 and 17 months, respectively. Region six (pelvis) was most commonly involved and had the highest frequency of heavy disease burden. Presence of PM in the lower abdomen, flanks, and small bowel were associated with poorer OS (p=0.01, 0.03, <0.001) and PFS (p=0.04, 0.02, <0.001). Involvement of porta hepatitis predicted poorer OS but not PFS (p=0.03). Involvement of the gastric antrum resulted in higher rates of postoperative complications. Conclusions:The pattern of PCI distribution may be associated with varying survival and morbidity outcomes.