Nationwide treatment patterns and outcomes of localised soft tissue sarcoma in Austria: real-world data from the Austrian Sarcoma Registry.

BACKGROUND: Population-based cancer registries provide incidence and survival data but lack granular treatment-specific information. However, this information can be critical for rare malignancies as soft tissue sarcoma (STS). The Austrian Sarcoma Registry (ASR) has been established to close this gap by capturing detailed clinical and therapeutic data across Austria. METHODS: Data of 748 patients (median age 65 years) with localised extremity or trunk STS diagnosed between 1999 and 2024 at six Austrian institutions were retrospectively analysed. Prognostic factors for local recurrence (LR), distant metastasis (DM), and overall survival (OS) were assessed using competing risk regression and Cox regression models. RESULTS: Perioperative RTX and RTX, respectively, had been applied in 57% and 7.6% of patients. Unplanned resections occurred in 30%. At a median follow-up of 46 months, LR and DM rates were 13.9% and 25.3%. Five-year OS was 77.6%. R1/2 resection margins independently associated with higher LR-risk (SHR 5.92; 95% CI 2.61-13.43; p < 0.001). High-grade STS independently associated with increased DM-risk (SHR 4.89, 95% CI 1.20-20.00, p = 0.027). Perioperative RTX was independently associated with improved OS (HR 0.59, 95% CI 0.40-0.88, p = 0.009), while perioperative CTX showed no association with OS (HR 0.86, 95% CI 0.18-4.07, p = 0.846). In addition, advanced patient age, large tumour size, and high-grade STS were associated with worse OS. CONCLUSION: ASR data demonstrate a survival advantage with surgery plus perioperative RTX, the absence of OS benefit from perioperative CTX in unselected patients, and a strong impact of patient age, tumour size, and grade on prognosis.