Evaluation of a peritoneal surface disease severity score in patients with colon cancer with peritoneal carcinomatosis

Introduction: Systemic therapy and cytoreduction (CRS) with hyperthermic intra-peritoneal chemotherapy (HIPEC) may benefit selected patients with carcinomatosis from colon cancer (PC). This study presents the results of a consecutive series of patients evaluated under a single strategy. Patients and Methods: Forty patients with PC referred for CRS were evaluated. Evaluation of their treatment was determined according to disease severity scored on a 3-point scale including: (1) symptoms, (2) extent of peritoneal dissemination (PCI), and (3) primary tumor histology. Overall survival (OS) was analyzed using Kaplan-Meier product-limit method and log rank testing according to four tiers of estimated disease severity based on the above parameters. Results: For patients with disease severity score I, II, III, and IV, 2-year OS following treatment was 100%, 80%, 80%, and 0%, respectively. Median OS with most advanced disease (IV: n=20) was 5 months versus 36 months for disease of lesser severity (I-III: n = 20; P < 0.001; RR = 0.2; 95%CI 0.1-0.5). Advanced disease (IV) was an independent predictor of adverse outcome on multivariate analysis with 2.6-fold increased likelihood of mortality. Conclusion: A treatment strategy based on disease severity determined at time of diagnosis, stratifies patients into prognostic groups and may improve selection of patients for appropriate therapy.