Pilocytic astrocytomas in children: prognostic factors--a retrospective study of 80 cases
Carla Fernandez1, Dominique Figarella-Branger, Nadine Girard
1Service d'Anatomie Pathologique et de Neuropathologie, Hôpital de la Timone, Marseille, France.
Insights
Pilocytic astrocytomas (PA) are typically benign brain tumors. However, factors like partial resection and the pilomyxoid variant indicate a worse prognosis in pediatric patients.
Area of Science:
- Pediatric neuro-oncology
- Brain tumor pathology
Background:
- Pilocytic astrocytomas (PA) are WHO Grade I brain tumors with generally excellent outcomes.
- However, a subset of patients experiences unfavorable prognoses, necessitating investigation into prognostic indicators.
Purpose of the Study:
- To identify clinicopathological factors associated with prognosis in pediatric patients with pilocytic astrocytomas.
Main Methods:
- Retrospective review of clinical, neuroradiological, and histopathological data from 80 pediatric patients with PAs.
- Analysis included tumor location, histological subtype (classic PA vs. pilomyxoid variant), extent of surgical resection, and invasion of surrounding structures.
Main Results:
- Histopathological analysis identified 58 classic PAs and 20 pilomyxoid astrocytomas.
- Five-year progression-free survival was 75%, and 5-year survival rates were 100% (total resection) and 92% (partial resection).
- Univariate analysis linked partial resection, optochiasmatic location, and pilomyxoid variant to worse prognosis; multivariate analysis confirmed partial resection and invasion of surrounding structures as independent factors.
Conclusions:
- While generally benign, PAs can have poor outcomes.
- Factors such as partial surgical resection, optochiasmatic location, invasion of adjacent tissues, and the pilomyxoid histological variant are associated with a worse prognosis.
Objective:
Pilocytic astrocytomas (PA) are Grade I brain tumors characterized by an excellent prognosis. In some cases, however, the patient has a bad outcome. The aim of our study was to search for the clinicopathological factors underlying the prognosis for patients with this disease.
Methods:
We reviewed the clinical, neuroradiological, and histopathological features of 80 PAs (33 cerebellar, 18 optochiasmatic, 16 brainstem, 7 spinal cord, 3 thalamic, 2 optic nerve, and 1 hemispheric) in pediatric patients.
Results:
Pathological examination revealed 58 classic PAs and 20 pilomyxoid astrocytomas, which are a histological variant of PAs. Two cases remained unclassified. The mean overall follow-up period was 58 months, the 5-year progression-free survival rate was 75%, and the 5-year survival rates were 100 and 92% after total and partial removal. Univariate statistical analysis revealed that partial resection, optochiasmatic PA localization, and pilomyxoid variant were associated with a worse prognosis, but the latter two parameters were too closely related to the extent of resection to be independent prognostic factors in multivariate analysis. Among the patients who underwent partial surgical removal, only invasion of the surrounding structures was related to prognosis.
Conclusion:
PAs are benign tumors, but some clinicopathological factors, such as partial resection, optochiasmatic location, invasion of surrounding structures, and the pilomyxoid variant, have a worse prognosis.
