A Simplified Peritoneal Sarcomatosis Score for patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

BACKGROUND: With the introduction of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), long-term survival can be achieved in selected patients with peritoneal surface malignancy. In patients with peritoneal sarcomatosis (PS), CRS/HIPEC remains a topic of debate. It is important that patient selection and outcome be improved with a tool that better predicts survival in such patients. To this end, we devised a Simplified Peritoneal Sarcomatosis Score (SPSS) adopted from the previously-described peritoneal surface disease severity score (PSDSS). METHODS: Patients were included if they were diagnosed with PS and underwent CRS/HIPEC with intended complete cytoreduction between 2007 and 2017. To calculate SPSS, we recorded symptoms (none =0, present =1), peritoneal carcinomatosis index (PCI) (≤10=0, >10=1), and grade of tumor (low =0, high =1). Thus, SPSS ranged from 0 to 3. SPSS-L (low) included patients with score of 0-1; SPSS-H (high) included patients with scores 2-3. Survival curves were generated using Kaplan-Meier method according to the two tiers of SPSS. RESULTS: 16±6 months, respectively; P<0.001). On multivariate analysis, advanced disease (SPSS-H) was an independent predictor of OS (P=0.020) and DFS (P=0.018). CONCLUSIONS: SPSS can be used as a tool for patient selection for surgery, prognosis prediction, and stratification into clinical trials of PS patients.