Clinical Outcomes and Histologic Subtype-Specific Patterns in Oligometastatic Soft Tissue Sarcoma of the Extremities...

Oligometastatic soft tissue sarcoma (STS) may offer the possibility of cure compared with polymetastatic disease, with progression patterns and treatment responses varying across histologic subtypes. This study investigated the clinical characteristics, oncologic outcomes, and histologic subtype-specific features of oligometastatic STS.

We reviewed records of 1,243 patients with extremity/trunk STS who underwent curative surgery between 2000 and 2023. Oligometastatic recurrence occurred in 170 (13.6%), 149 of whom received local ablative therapy (LAT). Disease-specific survival (DSS) and progression-free survival (PFS) were analyzed, along with prognostic factors and subtype-specific characteristics.

The median follow-up was 52.5 months. Surgery alone was the most common LAT (71.2%), followed by surgery with radiotherapy, radiotherapy alone and radiofrequency ablation. The median DSS was 50.0 months (95% confidence interval [CI], 31.5-68.5), with a 5-year DSS rate of 45.2%. The median PFS was 12.0 months (95% CI, 7.6-16.4), with a 5-year PFS of 28.1%. On multivariate analysis, LAT was independently associated with longer DSS (hazard ratio [HR], 9.629; p<0.001). Smaller oligometastatic lesion size and adequate local control of the primary tumor were also independently associated with longer DSS. Metastasis-free interval > 6 months independently predicted longer PFS. Histologic subtypes demonstrated distinct clinical behaviors; for example, myxofibrosarcoma had a lower metastatic rate but poorer DSS, whereas synovial sarcoma showed relatively favorable long-term survival.

Oligometastatic STS represents an intermediate disease state in which LAT can provide meaningful survival benefit. Subtype-specific differences in metastatic behavior and survival outcomes would support individualized, multimodal, and potentially curative treatment strategies.