Survival outcomes of surgery for retroperitoneal sarcomas: A systematic review and meta-analysis

BACKGROUND: Definitive evidence to guide clinical practice on the principles of surgery for retroperitoneal sarcomas (RPSs) is still lacking. This study aims to summarise the available evidence to assess the relative benefits and disadvantages of an aggressive surgical approach with contiguous organ resection in patients with RPS, the association between surgical resection margins and survival outcomes, and the role of surgery in recurrent RPS. METHODS: We searched PubMed, the Cochrane Library, and EMBASE for relevant randomised trials and observational studies published from inception up to May 1, 2021. Prospective or retrospective studies, published in the English language, providing outcome data with surgical treatment in patients with RPS were selected. The primary outcome was overall survival (OS). FINDINGS: In total, 47 articles were analysed. There were no significant differences in the rates of OS (HR: 0.93; 95% CI: 0.83-1.03; P = 0.574) and recurrence-free survival (HR: 1.00; 95% CI: 0.74-1.27; P = 0.945) between the extended resection group and the tumour resection alone group. Organ resection did not increase postoperative mortality (OR: 1.00; 95% CI: 0.55-1.81; P = 0.997) but had a relatively higher complication rate (OR: 2.24, 95% CI: 0.94-5.34; P = 0.068). OS was higher in R0 than in R1 resection (HR: 1.34; 95% CI: 1.23-1.44; P < 0.001) and in R1 resection than in R2 resection (HR: 1.86; 95% CI: 1.35-2.36; P < 0.001). OS was also higher in R2 resection than in no surgery (HR: 1.26; 95% CI: 1.07-1.45; P < 0.001), however, subgroup analysis showed that the pooled HR in the trials reporting primary RPS was similar between the two groups (HR, 1.14; 95% CI, 0.87-1.42; P = 0.42). Surgical treatment achieves a significantly higher OS rate than does conservative treatment (HR: 2.42; 95% CI: 1.21-3.64; P < 0.001) for recurrent RPS. CONCLUSIONS: For primary RPS, curative-intent en bloc resection should be aimed, and adjacent organs with evidence of direct invasion must be resected to avoid R2 resection. For recurrent RPS, surgical resection should be considered as a priority. Incomplete resection remains to have a survival benefit in select patients with unresectable recurrent RPS.