Long-term follow-up outcomes in intracranial solitary fibrous tumor compared with meningioma: a propensity score matching study

OBJECTIVE Intracranial solitary fibrous tumor (ISFT) is a rare type of neoplasm that resembles meningioma. The authors aimed to compare the long-term postoperative outcomes between patients with ISFT and those with meningioma, and to create a model to identify patients with ISFT who are at high risk of recurrence. METHODS A total of 187 patients with de novo ISFT and 473 patients with de novo meningioma who underwent tumor resection at a single neurosurgical center from 2013 to 2021 were included in this study. Cohorts were matched using propensity score matching (PSM). Univariate and multivariate Cox regression analyses were performed to evaluate prognostic values of clinicopathological characteristics. RESULTS The ISFT cohort was comprised of 187 patients (106 male, mean age 46.6 years) and, after PSM, the meningioma cohort was comprised of 187 patients (95 male, mean age 49.2 years) for comparison. The survival analysis showed that the ISFT cohort had significantly worse progression-free survival (PFS) after 5 years of follow-up (p < 0.0001) compared with the meningioma cohort. No significant difference in disease-specific survival (DSS) was observed between the cohorts during the first 5 years. However, beyond 5 years, the ISFT cohort had significantly worse DSS than the meningioma cohort (p = 0.025). Further analysis of prognostic factors revealed that an age at diagnosis ≤ 57 years, Ki-67 index ≤ 6%, mitotic count ≤ 15, low WHO grade, and receiving postoperative radiation therapy (RT) were significantly associated with prolonged PFS. Moreover, age at diagnosis, mitotic count, and postoperative RT were identified as independent factors for predicting PFS. Finally, a prognostic model was constructed to identify patients with ISFT at high risk of recurrence. The model demonstrated excellent predictive performance, particularly for predicting PFS beyond 5 years after surgery. CONCLUSIONS The long-term prognosis of patients with ISFT was significantly worse compared with that of patients with meningioma after surgery, and this was impacted by age at diagnosis, mitotic count, and undergoing postoperative RT. The prognostic model showed excellent predictive performance for identifying patients with ISFT at high risk of recurrence.