Clinical characteristics and prognostic factors of adult patients with pilocytic astrocytoma

Abstract

Introduction Pilocytic astrocytoma (PA) is the most common primary brain neoplasm in children and treated in curative intent with gross total resection (GTR). However, PA is rare in adults, resulting in limited knowledge on the natural clinical course. This study aimed to describe the clinical course and identify prognostic factors of adult patients with PA. Methods 46 patients ≥ 18 years at diagnosis of PA and neurosurgical resection or biopsy between 2000 and 2018 were identified from the Neuro-Biobank of the Medical University of Vienna. In two cases with differing histopathological diagnosis at recurrence, DNA methylation analysis was performed using Illumina Infinium HumanMethylation850 BeadChip (850 k) arrays and the Molecular Neuropathology classifier. Clinico-pathological features were correlated with patient outcomes. Results Median age at diagnosis was 32.5 years (range: 19-75) and median Ki67 proliferation index was 2.8% (0.5-13.4%). Tumor location significantly correlated with resectability (p < 0.001). Tumor progression or recurrence was observed in 9/46 (19.6%) patients after a median follow up time of 53.0 months (range 0.5-300). 5-year overall and progression-free survival rates were 85.3% and 70.0%, respectively. 2/9 (22.2%) patients presented with histological changes in the recurrent tumor specimen. In detail, methylation classification redefined the histological diagnosis to anaplastic astrocytoma with piloid features and glioma in one patient, each. Age > 40 and higher body mass index (BMI) were associated with impaired progression-free and overall survival (p < 0.05). Conclusions Tumor recurrence or progression in adult PA patients was higher than the one reported in pediatric patients. Higher age and BMI were associated with impaired prognosis.

Soluble PD-L1 is associated with local and systemic inflammation markers in primary and secondary brain tumours

“…However, in contrast to our observation, Liu et al detected higher sPD-L1 levels in biologically more aggressive tumours as represented by elevated mitotic activity (Ki67 proliferation index) and higher WHO grade. 25 Of note, the cohort in Liu et al —in contrast to our cohort—also included pilocytic astrocytoma (WHO grade I) which is known to exhibit a distinctly lower immune cell infiltration 27 as well as more favourable clinical course than GBM 28 and therefore could cause the correlation with WHO grade and sPD-L1 concentration. Of note, the majority of the patients in our control group suffered from MS, although only few patients were admitted for disease activity.…”

Adult pilocytic astrocytoma in the molecular era: a comprehensive review

“…In a smaller, single institution cohort of 20 adults, the six that experienced symptomatic progression did so at a median of 16.5 months [ 7 ]. Resectability is highly correlated with tumor location and recurrence rate; significantly higher recurrence rate was noted in incompletely resected (38.9%) versus totally resected (4%) tumors [ 8 ]. This contributes to worse prognosis in unresectable locations, such as the brainstem and diencephalon.…”

“…Gross total resection, the mainstay of therapy, is associated with greater than 95% 10-year survival in pediatric PA [ 2 ]. A majority of adults have favorable outcomes after gross total resection, with evidence of both improved PFS and overall survival [ 8 ], though long-term outcome is generally not as favorable as in pediatric PA. A retrospective aggregation of 254 adult patients with an average follow-up of 77 months showed a 28% rate of subsequent recurrence after gross total resection [ 4 ] compared with a recurrence rate of 10% reported in pediatric patients [ 94 ]. A watch-and-wait approach after maximal resection remains the standard of care for most adult PA patients.…”

“…higher recurrence rate was noted in incompletely resected (38.9%) versus totally resected (4%) tumors [8]. This contributes to worse prognosis in unresectable locations, such as the brainstem and diencephalon.…”

High-grade astrocytoma with piloid features (HGAP): the Charité experience with a new central nervous system tumor entity

“…One case was reevaluated at recurrence and DNA methylation-based classification revealed an HGAP. The patients’ clinical course was not described [ 9 ].…”