Visceral Fat Content Correlates with Retroperitoneal Soft Tissue Sarcoma (STS) Local Recurrence and Survival

BACKGROUND: Our aim was to evaluate the association between visceral fat content with soft tissue sarcoma (STS) local recurrence and survival. METHODS: One hundred and one computed tomography imaging studies of primary STS patients who had complete macroscopic resection at our institution between 2002 and 2012 were reviewed, and retroperitoneal and circumferential fat contents were measured. Correlations between imaging findings and clinical data were analyzed. RESULTS: Fifty-seven STS tumors (56.4%) were retroperitoneal; of them, 65% were high grade, median size was 15 cm (range 3-49), and the most common histological subtype was high grade liposarcoma (31.6%). Median follow-up length for the entire cohort was 64 months (range 6-95). High visceral fat (VF) content≥15 versus <15 mm was identified as a risk factor for retroperitoneal STS local recurrence; 65.1 versus 26.7%, respectively (p=0.04); VF content did not correlate with distant metastasis. Median overall survival (OS) length of patients with VF≥15 versus <15 mm was 57 months (range 2-144) versus not reached, respectively (p=0.007). Multivariable analysis identified VF≥15 mm as an independent risk factor for decreased OS (HR: 4.2, 95% CI 1.07-16.67). In contrast, circumferential fat content did not correlate with retroperitoneal STS patient outcomes. CONCLUSION: High VF content is an independent adverse prognosticator associated with significantly higher rates of retroperitoneal STS local recurrence and decreased patients survival. Local tumor biology may be affected by the presence of adipose cells. Further clinical and molecular research is needed to establish this premise.