Cumulative Burden of Postoperative Complications in Patients Undergoing Surgery for Primary Retroperitoneal Sarcoma.

Background: Correlations between postoperative complications and oncological outcomes have been reported in several malignancies, but their impact in retroperitoneal sarcoma (RPS) is unclear. Our study aimed to evaluate the association between postoperative complications and prognosis in patients with RPS.

Methods: Patients undergoing surgery for primary RPS from 2008 to 2019 at a sarcoma center were evaluated. The cumulative burden of postoperative complications was quantified using the Comprehensive Complication Index (CCI), and associations with local recurrence (LR), distant metastases (DM) and overall survival (OS) were assessed.

Results: Data were available for 191 patients, of whom 160 (82.9%) developed at least one postoperative complication, with a median CCI of 20.9 (interquartile range 8.7-33.5). After postoperative deaths were excluded (n = 3, 1.6%), the remaining patients were divided into those with a CCI of 0-20.9 (n = 97) and > 20.9 (n = 91). Patients with a CCI >20.9 had significantly shorter OS than those with a CCI of 0-20.9 (43.3% vs. 69.5% at 5 years; p = 0.005), and this difference remained significant after multivariable adjustment for patient- and treatment-related factors [hazard ratio (HR) 2.31, 95% confidence interval (CI) 1.30-4.09; p = 0.004]. However, CCI > 20.9 was not found to be a significant independent predictor of either LR (HR 1.30, 95% CI 0.76-2.23; p = 0.333) or DM (HR 1.08, 95% CI 0.61-1.93; p = 0.786).

Conclusion: Increasing complication burden, as quantified by the CCI, is a significant independent predictor of OS; however, there is no evidence of a significant association with either LR or DM, which may be more related to tumor biological factors.