Clinical outcomes for pleomorphic xanthoastrocytoma patients

Abstract

Background: Report our institutional experience with pleomorphic xanthoastrocytoma (PXA) to contribute to limited data on optimal management.

Methods: Patients with pathologically confirmed PXA treated at our institution between 1990 and 2019 were identified. Demographic information, tumor grade, treatment variables, and clinical outcomes were collected from patient charts. Kaplan-Meier estimates were used to summarize 2 primary outcome measurements: progression-free survival (PFS) and overall survival (OS). Outcomes were stratified by tumor grade and extent of resection. Cox regression and log-rank testing were performed.

Results: We identified 17 patients with pathologically confirmed PXA. Two patients were excluded due to incomplete treatment information or <6 m of follow-up; 15 patients were analyzed (median follow-up 4.4 years). Six patients had grade 2 PXA and 9 had grade 3 anaplastic PXA. The 2- and 5-year PFS for the cohort was 57% and 33%, respectively; 2- and 5-year OS was 93% and 75%, respectively. Patients with grade 2 tumors exhibited superior PFS compared to those with grade 3 tumors (2-year PFS: 100% vs. 28%, 5-year PFS: 60% vs. 14%), hazard ratio, 5.09 (95% CI: 1.06-24.50), P = .02. Undergoing a gross total resection was associated with numerical longer survival but this was not of statistical significance (hazard ratio: 0.38, P = .15). All but one (89%) of the grade 3 patients underwent RT.

Conclusions: The poor survival of the cohort, especially with grade 3 tumors, suggests the need for more aggressive treatment, including maximal resection followed by intensive adjuvant therapy. Better prognostics of tumor recurrence are needed to guide the use of adjuvant therapy.

Keywords: BRAF V600E mutation; anaplastic; pleomorphic xanthoastrocytoma; radiotherapy; surgery.

Figure 1.

Swimmer plot depicting the clinical course for the fifteen included patients. Abbreviations: Gr 2, grade 2; Gr 3, grade 3; GTR, gross total resection; RT, radiation therapy; RT + Chemo, radiation therapy and chemotherapy; STR, subtotal resection.

Figure 2.

Kaplan–Meier survival curves showing (A) overall survival, (B) progression-free survival, (C) progression-free survival stratified by tumor grade, and (D) progression-free survival stratified by extent of resection. Abbreviations: GTR, gross total resection; STR, subtotal resection.