Aggressive resection of retroperitoneal sarcoma is superior to simple excision: an animal study using a novel model for retroperitoneal sarcoma.

Background and Objectives Retroperitoneal sarcomas constitute a difficult management problem. The need for, and extent of, aggressive surgery continues to be debated. The aim of our study was to compare the impact of radical en bloc resection of retroperitoneal sarcoma with complete resection of the tumor alone in a rat model. Methods Under laparoscopic guidance, a fibrosarcoma cell line suspension was injected into the left paranephric space of a rat, resulting in the development of a macroscopic retroperitoneal tumor. Ten days after inoculation, 50 rats were randomized into three groups: (1) local resection, (2) radical resection, and (3) follow-up only. Groups 1 and 2 were further randomized for sacrifice 1 month after surgery or were followed up for 2 months. Results Local recurrence: 46% of group 1, while none in group 2 developed local recurrence during the same follow-up period (P = 0.02). Survival: 33% of group 1 were alive after 2 months, as compared with 54.5% of group 2. (P = 0.04). All rats in the control group died within <25 days. Conclusions Our results suggest that aggressive en bloc resection of retroperitoneal sarcomas with adjacent viscera, even when macroscopically uninvolved with disease, has an advantage over complete local resection alone. J. Surg. Oncol. 2002;81:144–147. © 2002 Wiley-Liss, Inc.