Retroperitoneal sarcomas: Outcomes of repeated resections

PURPOSE: Retroperitoneal sarcomas (RPS) are rare malignant tumors arising from mesenchymal cells. The objective of this study was to review the treatment experiences and to identify prognostic factors for overall survival (OS) after primary resection and subsequent reoperations for recurrences. METHODS: The medical records of patients who underwent resection for RPS at our institution between June 2002 and December 2016 were retrospectively reviewed. Univariate and multivariable Cox proportional hazards modeling was used to assess the prognostic factors for OS. RESULTS: A total of 48 patients were enrolled. On multivariable analysis in primary resection group, the FNCLCC (Fédération Nationale des Centres de Lutte Contre le Cancer) grade was a significant prognostic factor for OS (P=0.006). The patients who received chemotherapy after primary resection were significantly associated with poor prognosis (P=0.009). The 5-year OS rate after primary resection (n=48) were 58.1% and the 5-year cumulative reoperation rate after primary resection was 62.5%. After second resection for recurrence after primary resection (n=23), the 5-year OS rate was 64.3%. There was a tendency towards decreased surgery-free survival rate as the number of repeated resections for recurrent RPS increased. In the subset of patients (n=16) who underwent more than 3 repeated resections at our institute, the 5-year OS rate was 75.0%, indicating that repeated resections are not associated with worse outcome. CONCLUSION: Only low tumor grade was an independent favorable prognostic factor for OS. Although the prognosis for RPS remains poor, repeated resections for recurrence are not associated with poor prognosis. Aggressive surgical strategies for recurred RPS patients are warranted.