Predictors of improved survival for patients with retroperitoneal sarcoma

Background. Retroperitoneal sarcomas are rare tumors that can be locally aggressive with high rates of recurrence. Given that data on survival in patients with retroperitoneal sarcomas are conflicting, we sought to use a nationwide cancer database to identify factors associated with survival in patients with retroperitoneal sarcomas. Methods. The Surveillance, Epidemiology, and End Results database was utilized to identify patients with retroperitoneal sarcomas from 2002 to 2012. Univariable and multivariable survival analysis was performed using a generalized gamma parametric survival function. Results. A total of 2,920 patients were included; overall 5- and 10-year survivals were 58.4% and 45.3%, respectively. On multivariable survival analysis, age, histologic type, grade, size, local extension, lymph node, and distant metastasis were associated with decreased survival (all P <.05). Patients undergoing operative resection survived 2.5 times longer (95% confidence interval: 2.0-3.0, P <.001) and those receiving radiation therapy 1.3 times longer (95% confidence interval: 1.1-1.6, P = .001), respectively. Conclusion. During the past decade, retroperitoneal sarcoma patients treated with radiation demonstrate longer survival compared with patients who did not receive radiation. Further study is needed to fully elucidate the mechanisms that underlie the radiation-related survival benefit observed in this study. (Surgery 2016; 160: 1628-35.)