[Treatment and prognosis of retroperitoneal liposarcoma with multiple primary tumor]

Objective: To investigate the multiple origin of retroperitoneal liposarcoma and its postoperative prognosis. Methods: A total of 49 retroperitoneal liposarcoma patients underwent total (ipsilateral) retroperitoneal lipectomy in our center from May 2017 to December 2019 were recruited. Clinical data and the follow-up information were reviewed and the origin and prognosis were analyzed. Results: A total of 15 patients were pathologically diagnosed as multiple primary cancer (MPC), the incidence rate of retroperitoneal liposarcoma with MPC was 30.6% (15/49), while other 34 cases was non-MPC. The postoperative recurrence rates of patients with high differentiation and de-differentiation retroperitoneal liposarcoma were 31.8% and 44.4%, without significant difference (P>0.05). The postoperative recurrence rates of MPC and non-MPC were 40.0% and 38.2%, without significant difference (P>0.05). Five cases died within the follow-up. Conclusion: Retroperitoneal liposarcoma might origin form MPC, and total (ipsilateral) retroperitoneal lipectomy is recommended to reduce the recurrence rate.