Surgery confers survival benefit in De Novo metastatic soft tissue sarcoma patients with low Ki67 or low total lesion glycolysis: a combined PET/CT and clinicopathological analysis.

Abstract

The role of primary tumor surgery in patients with de novo metastatic soft tissue sarcoma (STS) is controversial, with a lack of objective selection criteria. This study aimed to identify patients who may benefit from surgery and to evaluate the prognostic value of integrated ¹⁸F-FDG PET/CT metabolic parameters and clinicopathological factors. Forty patients with de novo metastatic STS undergoing pretreatment ¹⁸F-FDG PET/CT were analyzed. Clinical data and metabolic parameters (maximum standardized uptake value [SUVmax], total metabolic tumor volume, and total lesion glycolysis [TLG]) were collected. Prognostic factors for overall survival (OS) were assessed using Cox regression. Heterogeneity was examined through pre-specified subgroup analyses and formal interaction tests. Multivariate analysis identified age > 50 years, lactate dehydrogenase (LDH) > 200 U/L, and SUVmax > 10.0 as independently associated with worse OS (all p < 0.05). Significant interactions were observed between surgical treatment and both the Ki67 index and TLG (P for interaction = 0.006 and 0.042, respectively). Surgery was associated with significantly improved OS in patients with low Ki67 (HR = 0.24, 95% CI: 0.06-0.89; p = 0.032) or low TLG (HR = 0.21, 95% CI: 0.04-0.97; p = 0.046), with no significant benefit observed in corresponding high-expression subgroups (all p > 0.05). The survival benefit of primary tumor surgery in de novo metastatic STS is restricted to patients with less aggressive tumor dbiology, characterized by low proliferative activity (Ki67 ≤ 35%) or low TLG. Integrated assessment of Ki67 and PET/CT parameters, particularly TLG, provides a practical framework for personalized surgical decision-making. Question Does primary tumor surgery provide a survival benefit for patients with de novo metastatic STS based on PET/CT and clinicopathological markers? Findings Surgery was associated with improved survival only in patients with low Ki67 or low TLG, with significant interaction effects (p = 0.006 and 0.042, respectively). Clinical relevance Surgical selection in metastatic STS should be guided by tumor biology. Integrating Ki67 and TLG provides a practical framework to identify patients most likely to derive a survival benefit from primary tumor resection.