Pilocytic Astrocytoma: An institutional perspective over the last decade

Pilocytic astrocytoma primarily affects children, commonly originates in the cerebellum, and generally has a favorable prognosis. The prognostic significance of patient age, tumor location, and extent of resection remains debated. This retrospective study aimed to evaluate clinicopathological and radiological features, identify prognostic factors, and assess progression-free survival at 1 and 5 years and overall survival at one, five and 10 years.

This retrospective study was conducted at The Aga Khan University Hospital (2013-2022) on patients with histologically confirmed pilocytic astrocytoma. Patients with less than one year of follow-up were excluded. Data on demographics, clinical presentation, tumor characteristics, extent of resection, adjuvant therapy, and outcomes were collected. Survival outcomes were analyzed using Kaplan-Meier and Cox regression methods, with statistical significance set at p < 0.05.

In the study of 101 patients, 53 (52.5%) were male and 48 (47.5%) were female. Of these, 59 were pediatric patients (<14 years), 35 were aged 15-39 years, and 7 were over 39, with a mean age of 16.9 years. The median pre-operative Lansky/KPS score was 80. The cerebellum was the most common site for tumors, and most tumors were solid-cystic (69.6%), while 14.5% were purely cystic. The mean preoperative tumor volume was 52.9 ml (SD 62.5). Hydrocephalus was present in 49.5% of patients, and leptomeningeal dissemination was seen in five patients. Gross total resection (GTR) was achieved in 37 (43.0%), near-total resection (NTR) in 7 (8.1%), subtotal resection (STR) in 38 (44.1%), and four patients (4.6%) had biopsy only. As an adjuvant treatment, 8 patients received both chemoradiation, four patients had received only chemotherapy, and 4 had received radiation only. Two patients died within 30 days after surgery, and 22 had recurrence/progression. The 1-year survival rate was 92%, 5-year survival was 87%, and 10-year survival was 83%. The 1-year progression-free survival (PFS) was 50%, and 5-year PFS was 10%. Kaplan-Meier analysis showed trends for better overall survival (OS) with GTR or NTR, cystic tumors with nodules, pediatric patients, absence of leptomeningeal dissemination, and microvascular proliferation, but these differences were not statistically significant.

This study of pilocytic astrocytoma over the past decade in a low-and-middle-income country highlights survival rates (1-year, 5-year, 10-year) reported for the first time in this population. Survival trends varied by age, leptomeningeal disease, extent of resection, and radiological tumor patterns. Cox regression identified radiological patterns, CNS infections, and endocrinological dysfunction as key predictors of overall survival.