Glycogen-rich pleomorphic xanthoastrocytoma with clear-cell features: confirmatory report of a rare variant with implications for differential diagnosis

Demography, Pattern of Care, and Survival in Patients with Xanthoastrocytoma: A Systematic Review and Individual Patient Data Analysis of 325 Cases

Objectives Xanthoastrocytoma (XA) is a low-grade glial tumor seen in young adults and there is lack of robust data on treatment of this rare tumor. In this systematic review and individual patient's data analysis, we aimed to look into the demography, pattern of care, survival outcomes, and prognostic factors in patients with both Grade II and III XA. Methods A comprehensive search was conducted with the Medical Subject Heading terms: "Xanthoastrocytoma; Pleomorphic Xanthoastrocytoma; Anaplastic Xanthoastrocytoma; Xanthoastrocytoma AND treatment; and Anaplastic Xanthoastrocytoma AND survival" to find all possible publications. Results A total of 325 individual patients from a total of 138 publications pertaining to XA were retrieved. Median age of the entire cohort was 19 years. About 56.1% of the patients underwent a gross total resection (GTR) and 31.4% underwent a subtotal resection. Nearly, 76.6% of the patients had a Grade II tumor and adjuvant radiation was delivered in 27.4% of the patients. Estimated 2- and 5-year progression-free survival (PFS) were 68.5 and 51.2%, respectively. Age, grade, and extent of surgery were significant factors affecting PFS. Estimated 2- and 5-year overall survival (OS) was 88.8 and 78%, respectively. The median OS for Grade II and Grade III tumors were 209 and 49 months, respectively. Age and extent of surgery were significant factors affecting OS. Conclusion XA is a disease of young adults with favorable prognosis. Younger patients (<20 years), patients who undergo a GTR, and patients with a lower grade tumor have a better treatment outcome.

Grade II Pleomorphic Xanthoastrocytoma; a meta-analysis of data from previously reported 167 cases

Pleomorphic Xanthoastrocytoma [PXA] is a rare low grade glial tumor commonly affecting young adults. We did this systematic review and meta-analysis to identify prognostic factors and optimal treatment in these patients. A thorough search of the PubMed, Google scholar was made to find all possible publications related to grade II PXA. A total of 167 patients from 89 articles were included in the analysis. Median age of the entire cohort was 20 years. Headache was the most common presentation in 49.1% of the patients followed by seizure in 27.9%. Temporal lobe was the most common location of the tumor. 63% patents underwent a gross total resection [GTR] and 26.7% underwent a sub total excision [STR]. Adjuvant radiation was given to 17.6% of patients. Median follow-up for the entire cohort was 33 months. Estimated median overall survival [OS] for the entire cohort was 209.0 months [96% CI: 149.7-268.3]. Estimated median progression free survival [PFS] was 48 months [95% CI: 31.9-64.0]. In univariate and multivariate analysis younger patients and patients who underwent a GTR had a significantly better survival outcome. Use of adjuvant therapy was not found to be a significant factor affecting PFS or OS. Radiotherapy was used in salvage treatment in 76.1% of the patients. Younger patients and patients who undergo a GTR, have better survival outcomes. There is inadequate evidence to recommend routine adjuvant radiation or chemotherapy in all patients with grade II PXA.

Pleomorphic Xanthoastrocytoma: Natural History and Long-Term Follow-Up

Prognostic significance of histological anaplasia and BRAF V600E mutation were retrospectively evaluated in 74 patients with pleomorphic xanthoastrocytoma (PXA). Median age at diagnosis was 21.5 years (31 pediatric, 43 adult) and median follow-up 7.6 years. Anaplasia (PXA-AF), defined as mitotic index ≥ 5/10 HPF and/or presence of necrosis, was present in 33 cases. BRAF V600E mutation was detected in 39 (of 60) cases by immunohistochemical and/or molecular analysis, all negative for IDH1 (R132H). Mitotic index ≥ 5/10 HPF and necrosis were associated with decreased overall survival (OS; P = 0.0005 and P = 0.0002, respectively). In all cases except two, necrosis was associated with mitotic index ≥ 5/10 HPF. Patients with BRAF V600E mutant tumors had significantly longer OS compared with those without BRAF V600E mutation (P = 0.02). PXA-AF patients, regardless of age, had significantly shorter OS compared with those without (P = 0.0003). Recurrence-free survival was significantly shorter for adult PXA-AF patients (P = 0.047) only. Patients who either recurred or died ≤ 3 years from diagnosis were more likely to have had either PXA-AF at first diagnosis (P = 0.008) or undergone a non-gross total resection procedure (P = 0.004) as compared with patients who did not. This study provides further evidence that PXA-AF behaves more aggressively than PXA and may qualify for WHO grade III "anaplastic" designation.