Background: We hypothesized that survival varied significantly between retroperitoneal soft tissue sarcoma (STS) and extremity/trunk STS. This study explored the reasons for the different outcomes and identified patient characteristics for survival.
Methods: This retrospective study identified 213 consecutive patients with localized primary STS from January 2002 to July 2013, including 47 retroperitoneal STS (22.1%) and 166 extremity/trunk STS (77.9%). Local failure-free survival (LFFS), distant metastasis-free survival (DMFS) and overall survival (OS) were constructed by the Kaplan-Meier method. Univariate Cox proportional hazards regression models were fit to assess the ability of patient characteristics to predict survival.
Results: At presentation, patients with retroperitoneal STS had larger tumor size (median size 18 cm vs. 6 cm; P < 0.001) and positive margin (21.3% vs. 8.4%; P = 0.014), and less often received radiotherapy (2.1% vs. 45.8%; P < 0.001). The median follow-up time for the entire population was 68 months (range, 5-127 months). Local recurrence was more frequent in patients with retroperitoneal STS compared with patients with extremity/trunk STS (53.2% vs. 28.3%; P = 0.001). LFFS and OS were lower in patients with retroperitoneal STS than extremity/trunk STS, with 5-year LFFS (50% vs. 74.3%; P < 0.001) and 5-year OS (65.4% vs. 77.5%; P = 0.017), respectively.
Conclusion: Retroperitoneal STS was associated with significantly worse survival compared with extremity/trunk STS. Larger tumor size, more patients with positive margin and fewer patients received radiotherapy in retroperitoneal group may result in worse survival compared with extremity/trunk disease.