Macroscopically complete excision is a beneficial strategy for selected patients with peritoneal sarcomatosis.

The occurrence of peritoneal sarcomatosis (PS) in patients with retroperitoneal sarcoma (RPS) indicates a poor prognosis. However, the appropriate treatment modality remains unclear. This study aimed to identify its prognostic factors and further explore the role of macroscopically complete excision (CE) in the management of PS. A retrospective database was established to evaluate patients with RPS who underwent resection between January 2011 and January 2019. Univariate and multivariate survival analyses were performed to analyze the prognostic factors and identify the population that will optimally benefit from CE. This study included a total of 49 patients with PS from 211 patients with RPS, and 34 (69.4%) patients of whom with PS underwent CE successfully. The median follow-up time was 36.0 months. There were 8 patients excluded because of loss to follow-up (n = 4) or death from complications within 90 days postoperatively (n = 4). The CE group had a marginally better prognosis compared to the macroscopically incomplete excision (IE) group (median disease-specific survival: 20 months vs. 8 months). Multivariate survival analysis demonstrated that completeness of operation (CE vs. IE) was the only independent prognostic factor in PS patients (P = 0.042). There was no significant difference in the overall complications between the CE and IE groups (P = 0.205). In conclusion, completeness of macroscopical excision is an independent prognostic predictor of PS. If technically possible, CE is a feasible strategy to improve the prognosis of selected patients with PS.