Fig. 4

The overall survival (OS) and recurrence-free survival (RFS) curve. The observation period was 5 years after surgery. The average survival duration was 19 months. The survival rates of 1, 3, and 5 years after surgery were 64.7, 52.9, and 47.1 %, respectively. Six patients suffered from local recurrence, one suffered from local recurrence combined with liver metastasis, and two suffered from retroperitoneal recurrence. The average time to recurrence was 14 months. The recurrence-free survival rates of 1, 3, and 5 years after surgery were 58.8, 47.1, and 35.3 %, respectively