Postoperative Complications Independently Predict Cancer-Related Survival in Peritoneal Malignancies.

Background: The authors hypothesized that postoperative complications after cytoreductive surgery-hyperthermic intraperitoneal chemoperfusion (CRS-HIPEC) have a negative impact on perioperative and oncologic outcomes and that the novel Comprehensive Comorbidity Index (CCI) would be a better predictor of such outcomes than the traditional Clavien-Dindo classification (CDC).

Methods: The study used a prospective database of 1296 patients with peritoneal metastases (PM) undergoing CRS-HIPEC between 2001 and 2016. The Kaplan-Meier method was used to estimate survival. Multivariate analyses identified associations with perioperative and oncologic outcomes. The Akaike information criterion and the Schwarz (Bayesian information) criterion were used to compare model fitting for CCI versus CDC.

Results: In this study, CRS-HIPEC was performed for malignant mesothelioma (12%) and PM from appendix (50%), colorectal (30%), and ovarian (8%) cancers. Major postoperative in-hospital complications (CDC grades 3-4) occurred for 24% of the patients. However, a range of CCI scores was calculated for each CDC grade because 36% of the patients experienced multiple complications. After a median follow-up period of 55 months, the median progression-free survival was 15 months, and the median overall survival was 39 months. In the multivariate Cox proportional hazards models, postoperative in-hospital complications (measured by CDC or CCI) were independent prognostic factors for 30-day post-discharge morbidity and readmission, as well as for survival. The CCI scores demonstrated higher prognostic sensitivity for these outcomes than CDC grades.

Conclusions: Reduction of postoperative complications after CRS-HIPEC is essential for optimal short- and long-term outcomes. For assessing total burden of postoperative complications per patient, CCI is superior to CDC and more sensitive for assessing surgery- and cancer-related outcomes after CRS-HIPEC.