Outcomes for Colorectal Cancer Cases With Peritoneal Metastases Treated With Cytoreductive Surgery With or Without Hyperthermic Intraperitoneal Chemotherapy: A Comparative Analysis of Survival Between Peritoneal Carcinomatosis Scores - PCI in a Single Centre.

BACKGROUND/AIM: Peritoneal cancer index (PCI) has been a strong indicator of prognosis for patients receiving cytoreductive surgery. The aim of this single institution study was to compare the survival of peritoneal carcinoma cases treated with cytoreduction surgery arising from colorectal cancer grouped by PCI scores.

PATIENTS AND METHODS: A retrospective study of a prospective dataset maintained from 2000 till September 2022, for peritoneal metastases from colorectal cancers was carried out. Of the total of 1,625 peritoneal metastases cases, 415 were identified with colorectal cancer and considered for analysis. Survival was followed for 60 months since the index-peritonectomy for cases in this study.

RESULTS: Hazard ratio for 5-year survival using the Cox regression analysis over time (t) with a Log-rank (Mantel-Cox) test for significance between the groups indicated, <15 vs. 15 (HR=2.121, p=0.0338), <15 vs. 16-20 (HR=2.748, p<0.0001), <15 vs. >20 (HR=3.158, p<0.0001), 15 vs. 16-20 (HR=1.262, p=0.5658), 15 vs. >20 (HR=1.566, p=0.2771) and for PCI category 16-20 vs. >20 (HR=1.204, p=0.5355) for survival. Median survival for the categories of PCI <15, PCI-15, PCI-16-20, and PCI >15 was 43.967 (95%CI=28.31-59.63), 20.67 (95%CI=5.01-36.33), 19.50 (95%CI=3.84-35.16), and 14.30 (95%CI=1.36-29.96), respectively.

CONCLUSION: A correlation of PCI with survival was confirmed in this study reinforcing the need for assessment of PCI at surgery to help prognostication. Detecting synchronous peritoneal metastases early and prompt treatment can help prevent recurrence and increase survival.