Analysis of outcomes and predictors of long-term survival following resection for retroperitoneal sarcoma.

BACKGROUND: Retroperitoneal sarcomas (RPS) include a heterogeneous group of rare malignant tumours, and various treatment algorithms are still controversially discussed until today. The present study aimed to examine postoperative and long-term outcomes after resection of primary RPS. PATIENTS AND METHODS: Clinicopathological data of patients who underwent resection of primary RPS between 2005 and 2015 were assessed, and predictors for overall survival (OS) and disease-free survival (DFS) were identified. RESULTS: Sixty-one patients underwent resection for primary RPS. Postoperative morbidity and mortality rates were 31 and 3%, respectively. After a median follow-up time of 74 months, 5-year OS and DFS rates were 58 and 34%, respectively. Histologic high grade (5-year OS: G1: 92% vs. G2: 54% vs. G3: 43%, P = 0.030) was significantly associated with diminished OS in univariate and multivariate analyses. When assessing DFS, histologic high grade (5-year DFS: G1: 63% vs. G2: 24% vs. G3: 22%, P = 0.013), positive surgical resection margins (5-year DFS: R0: 53% vs. R1: 10% vs. R2: 0%, P = 0.014), and vascular involvement (5-year DFS: yes: 33% vs no: 39%, P = 0.001), were significantly associated with inferior DFS in univariate and multivariate analyses. CONCLUSIONS: High-grade tumours indicated poor OS, while vascular involvement, positive surgical resection margins, and histologic grade are the most important predictors of DFS. Although multimodal treatment strategies are progressively established, surgical resection remains the mainstay in the majority of patients with RPS, even in cases with vascular involvement.