Novel Surgical and Radiologic Risk Factors for Progression or Recurrence of Pediatric Pilocytic Astrocytoma.

INTRODUCTION

Pilocytic astrocytomas (PA) are a common, benign childhood tumor known for their slow growth rates and excellent prognosis. The aim of our study was to characterize patient, tumor, and imaging-related risk factors for recurrence and progression of disease.

METHODS

We identified 116 patients with PA who underwent surgery at our institution between 2000 and 2015. Data were collected retrospectively from the clinical charts.

RESULTS

The mean age at resection was 7 ± 5 years (range 0.5-31) and mean follow-up was 6 ± 3 years. Initial resection was complete in 33 patients (29%), subtotal in 78 patients (67%), and biopsy in 5 patients (4%). A total of 45/116 (40%) patients experienced either recurrence or progression after initial resection with a mean time to recurrence or progression of 2.2 years. Bivariate analysis identified subtotal resection, tumor location, age at diagnosis, and imaging features (i.e., T2 invasion, exophytic component, hemorrhage, and solid tumors) as factors significantly associated with recurrence or progression (p < 0.05). Conversely, PAs that were completely resected, predominately cystic, and located in the cerebellum were significantly associated with no recurrence or progression (p < 0.05). Multivariate regression analysis narrowed down 4 robust risk factors: extent of resection, T2 invasion, predominantly solid lesions, and presence of an exophytic component (p < 0.05).

CONCLUSION

Total surgical removal of PA has been the most important prognostic factor for the clinical course of PA. Our study reveals additional risk factors for the recurrence or progression of disease: tumor invasion, solid composition, and tumors with an exophytic component.