NCOG-10. LONG-TERM SURVIVAL ANALYSIS OF PLEOMORPHIC XANTHOASTROCYTOMA: INSIGHTS INTO PROGNOSTIC FACTORS AND TREATMENT STRATEGIES

Abstract

Abstract PURPOSE Pleomorphic xanthoastrocytoma (PXA) is rare, accounting for less than 1% of astrocytomas. Despite its pleomorphic histologic features, PXA generally carries a favorable prognosis. Limited research exists regarding the clinical course and treatment outcomes of PXA. This study aimed to identify prognostic factors and evaluate treatment strategies in PXA. METHODS We retrospectively analyzed PXA patients who underwent surgical resection at our institution from 2000 to 2021. Demographic data, radiologic characteristics, and treatment outcomes were collected. Tumors were classified as grade 2 or grade 3 based on the 2021 World Health Organization criteria. RESULTS Among the included patients, 40 were diagnosed with grade 2 PXA, while 9 had grade 3 PXA. Five-year progression-free survival (PFS) rates were 75.8% for grade 2 and 37.0% for grade 3 (p = 0.003). Multivariate Cox regression analysis revealed that both grade (p = 0.044) and tumor infiltration (p = 0.008) significantly influenced PFS. Factors such as hydrocephalus (p = 0.005) and tumor infiltration (p = 0.017) were found to affect overall survival (OS). Subgroup analysis in grade 2 PXA showed significantly better OS and PFS when gross total resection (GTR) was performed during the initial surgery, as opposed to subtotal resection (STR). Adjuvant radiation therapy did not significantly alter the prognosis of grade 2 PXA. CONCLUSIONS Tumor infiltration was associated with improved PFS and OS in grade 2 and 3 PXA cases. GTR had a significant positive impact on PFS in the overall group, and both PFS and OS in grade 2 PXA. Adjuvant radiation therapy did not significantly alter the prognosis of grade 2 PXA.