[LONG-TERM OUTCOME IN PATIENTS WITH RETROPERITONEAL LIPOSARCOMA, A SINGLE INSTITUTION STUDY].

(Objectives) To evaluate the outcomes of patients who were surgically treated for retroperitoneal liposarcoma in our hospital from February 2002 to August 2015. (Methods) Fifteen patients were surgically treated for retroperitoneal liposarcoma in our hospital during the study period. All patients were diagnosed with liposarcoma on pathological examination. The mean follow-up period was 46.7 months (range, 1-126 months). (Results) There was no difference in the sex distribution of the patients (7 men and 8 women). The median age was 67 years (range, 33-78 years). The median tumor diameter was 24 cm (range, 7.5-45 cm) and the median tumor weight was 1,959 g (range, 545-15,400 g). One patient's operation was unsuccessful, with incomplete tumor resection. The surgical margin was positive in two patients. The 5- and 10-year survival rates were 67% and 50%, respectively. There was a significant difference in the survival rate between complete resection and incomplete resection, including surgical margin-positive patients (p=0.0019). Moreover, there was a significant difference in the recurrence-free rate between complete resection and surgical margin-positive patients (p=0.013). There was no significant difference according to whether removal of the tumor with adjacent viscera or removal of the tumor only had been performed (p=0.09 and 0.90, respectively). (Conclusions) Surgery is the mainstay of treatment for retroperitoneal liposarcoma, and complete resection is necessary.