Abstract
Background & Aims: Retroperitoneal sarcomas (RSs) are usually found at an advanced stage, and complete resection of the tumor with wide margins including excision of other organs is difficult. Thus, the incidence of tumor recurrence is high, but the optimal chemotherapy for this tumor has not been defined. We retrospectively analyzed seven cases of huge RSs, especially focused in chemotherapy.
Materials and Methods: Between 2006 and 2017, 7 huge primary RSs were operated in our hospital. Histopathologically, liposarcoma was detected in four patients, leiomyosarcoma in two, and Ewing sarcoma in one. At the initial operation, mean tumor weight of 7 patients was 2,385 grams (range: 1,000 grams - 4,500 grams), and complete tumor resection was achieved in five patients, but incomplete tumor resection occurred in two patients.
Results: The overall survival was longer (not significant) for patients with complete than incomplete tumor resection. Chemotherapy was started for 5 patients after detection of recurrent tumors and having given up operative treatment through multiple operations. But the median survival time of 5 patients after the start of chemotherapy was very short (10 months; range, 4–19 months).
Conclusions: Complete tumor resection at the first surgical procedure is the only way to prevent death from local recurrence. However, chemotherapy after detection of recurrent tumors is not effective now.

Key words: Chemotherapy, Chemo-radiotherapy, Complete tumor resection, Overall survival, Retroperitoneal sarcoma, Tumor recurrence