Soft tissue sarcomas (STS) of the extremities and trunk are biologically heterogeneous, and distant metastasis remains the leading cause of disease-related mortality. A subset of patients develops metastases very early (≤12 months after diagnosis), suggesting a distinct aggressive phenotype that is poorly characterized. We aimed to identify clinicopathologic determinants of early distant metastasis (DM ≤12) and to assess the performance of an OS-based nomogram in this high-risk window. METHODS: We conducted a retrospective cohort study of 344 adult patients with extremity and trunk STS treated at a high-volume sarcoma center between 2010 and 2020. Early metastasis was defined as distant recurrence within 12 months of diagnosis. Survival was estimated using the Kaplan-Meier method. Cox proportional hazards models identified independent predictors of DM ≤12. The ability of Sarculator-predicted 5-year overall survival to discriminate early metastatic risk was evaluated and compared with clinicopathologic variables. RESULTS: The median age was 47 years, and 50.6% were men. Tumors were predominantly deep (72.2%), large (median 11.3 cm), and high grade (G3, 62.3%), with liposarcoma (36.8%), synovial sarcoma (18%), and undifferentiated pleomorphic sarcoma (12.3%) as the most frequent histologies. Early distant metastasis occurred in 26% of patients and was associated with markedly inferior survival (median OS 21.5 vs. 89.1 months, p<0.001). On multivariable analysis, age <50 years, tumor size ≥10 cm, high grade, aggressive histologies (synovial sarcoma and undifferentiated pleomorphic sarcoma), deep location, and incomplete resection (R1/R2) independently predicted DM ≤12. The OS-based nomogram showed moderate discrimination for early metastasis (AUC 0.82, 95% CI 0.76-0.88) but did not outperform key clinicopathologic factors. CONCLUSION: Early distant metastasis defines a distinct ultra-high-risk phenotype in extremity and trunk STS, driven predominantly by tumor biology and surgical factors. Although Sarculator remains useful for global risk stratification, it does not fully capture patients destined for very early relapse.
Garcia-Ortega et al. (Tue,) studied this question.