High-grade, metastatic disease, and adjuvant radiotherapy are independent prognostic factors for progression-free survival in patients with solitary fibrous tumors.

Background: Solitary fibrous tumors (SFTs)/hemangiopericytoma are rare central nervous system tumors exhibiting high recurrence rates and the ability to metastasize. This study evaluated SFT prognosis and survival outcomes, focusing on the 2021 WHO classification. Methods: A retrospective study was conducted on 49 patients who underwent SFT resection in our Neurosurgery Department between 2001 and 2023. Data were analyzed regarding sex, age, WHO grade at time of diagnosis and reclassified according to the 2021 WHO classification, tumor localization, resection grade, tumor size, adjuvant therapy, progression-free (PFS), and overall survival (OS). Kaplan-Meier survival analyses were conducted to evaluate OS and PFS, and Cox regression analyses were performed to assess prognostic factors. Results: Cohort median age was 54 (22-86) years with a female predominance of 1.22. The median follow-up was 46 (0-307) months. Primary SFTs were mainly located in the supratentorial region, followed by the infratentorial region and spine. Initially, 10% of primary tumors were graded as WHO grade 1, 49% as grade 2, and 18% as grade 3. Reclassification to WHO 2021 downgraded 65% of tumors. The five-year PFS and OS were 41.5% and 100%, respectively. In total, 41% of patients had local recurrent disease and 20% were metastatic. In univariate analyses, WHO grades, younger age (< 54 years), sex, and adjuvant radiotherapy were associated with survival. In multivariate analyses, WHO grade 3, metastatic disease, and adjuvant radiotherapy were independent PFS prognostic factors. Conclusion: Our data shows that WHO grade 3, metastatic disease, and adjuvant radiotherapy are independent PFS factors in SFTs.