Impact of Severe Postoperative Complications and P-POSSUM Score on Oncological Outcomes in Primary Retroperitoneal Sarcoma: Insights from a Tertiary Cancer Center.

Background: RPS are rare tumors requiring complex surgery. The impact of postoperative complications on long-term outcomes is still debated. This study aimed to identify predictors of severe complications and assess their influence on overall survival (OS) and disease-free survival (DFS).

Methods: We retrospectively analyzed 61 patients who underwent curative surgery for primary RPS between 2013 and 2023 at a tertiary cancer center. Patients with pelvic or recurrent sarcomas were excluded. Severe complications were defined as Clavien-Dindo (CD) grade ≥ 3A. Cox regression and Fine-Gray competing risk models were used for OS and DFS, respectively. Sarculator and P-POSSUM scores were included in multivariable models.

Results: Severe complications occurred in 14.8% of patients; 30-day mortality was 1.6%. Predictive factors for complications included longer operative time, gastric resection, intraoperative complications, and transfusions. In multivariable analysis, Sarculator was significantly associated with both DFS (HR 0.97; = 0.004) and OS (HR 0.97; = 0.008). The P-POSSUM mortality score predicted OS (HR 1.12; = 0.002). Severe complications were not independently associated with DFS or OS.

Conclusions: In this cohort, severe complications did not impact long-term oncological outcomes. Prognostic tools such as Sarculator and P-POSSUM may enhance risk stratification in RPS surgery. Prospective validation is warranted.