A Contemporary Large Single-Institution Evaluation of Resected Retroperitoneal Sarcoma

Retroperitoneal sarcomas (RPS) are rare malignancies, comprising just 10-15 % of all soft-tissue sarcomas. These are challenging tumors to treat, with surgical resection being the only modality capable of providing a cure. This study analyzed the management and survival of patients resected at a large academic institution. A retrospective study of all patients with primary localized RPS referred to the University of Washington between January 2000 and January 2013 was performed. Univariate and multivariate Cox regression models were used to analyze progression-free survival (PFS) and overall survival (OS) by patient, tumor, and treatment variables. The study identified 132 patients. Median follow-up was 31.8 months. Median PFS was 33 months, and median OS was 111 months. Sixty patients (45.5 %) underwent a margin-negative resection (R0), 59 (44.7 %) had a microscopic margin-positive resection (R1), and 7 (5.3 %) had a macroscopic margin-positive resection (R2). Forty (30.3 %) patients received preoperative radiation, 28 (21.2 %) received neoadjuvant chemotherapy, and 7 (5.3 %) received both. Tumor grade and microscopic margin status emerged as statistically significant predictors for both PFS and OS. Tumor size was also found to correlate with PFS. No significant difference in OS or PFS was observed for histologic subtype, neoadjuvant chemotherapy, or neoadjuvant radiation. Complete surgical resection should remain the mainstay of management for RPS, with emphasis on achieving negative microscopic margins. Neither neoadjuvant chemotherapy nor radiation was shown to significantly improve survival, and their unclear role in the management of RPS requires evaluation in a prospective setting.