Upfront observation versus radiation for adult pilocytic astrocytoma

Adrian Ishkanian, Normand J. Laperriere, Wei Xu, Barbara Ann Millar, David Payne, Warren Mason, Arjun Sahgal

Research output: Contribution to journalReview article

25 Scopus citations

Abstract

Background: Although pilocytic astrocytoma accounts for up to 40% of all childhood brain tumors, it is a rare disease in adults. Consequently, there are few mature data on the impact of up-front treatment options after surgery that include observation or adjuvant radiotherapy. Methods: Ten women and 20 men were identified who were diagnosed with pilocytic astrocytoma from 1971 to 2007 and were retrospectively reviewed. The median patient age was 30 years (range, 18-64 years), and the median follow-up was 87 months (range, 16-420 months). Initial surgery included biopsy (10% of patients), subtotal resection (57% of patients), or gross-total resection (33% of patients). Nineteen patients were observed postoperatively, whereas 11 patients received up-front postoperative adjuvant radiotherapy (50 grays in 25 fractions). No patient received adjuvant or concurrent chemotherapy. Progression-free survival (PFS) and overall survival (OS) were calculated using the Kaplan-Meier method. Differences between survival curves were analyzed with the log-rank test. Results: For the entire cohort, the 5-year and 10-year OS rates were 95% and 85%, respectively, and the 5-year and 10-year PFS rates were 63% and 35%, respectively. The median PFS was 8.4 years. Initial radiation, compared with observation, did not have an impact on OS but significantly improved PFS. The 5-year PFS rate for patients who were observed versus those who received radiation was 42% versus 91%, respectively; and, at 10 years, the PFS rate was 17% versus 60%, respectively (P =.005). Patients who progressed after observation (11 of 19 patients) received various salvage therapies, resulting in a 2-year PFS rate of 68% compared with 33% for patients who progressed after initial radiation (3 of 11 patients) and were salvaged with either chemotherapy or surgery (P =.1). Conclusions: Adjuvant radiotherapy for pilocytic astrocytoma significantly prolonged PFS at both 5 years and 10 years compared with observation. However, equivalent OS was observed, which reflected the efficacy of salvage therapies.

Original languageEnglish (US)
Pages (from-to)4070-4079
Number of pages10
JournalCancer
Volume117
Issue number17
DOIs
StatePublished - Sep 1 2011

Keywords

  • adult
  • observation
  • pilocytic astrocytoma
  • radiation

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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    Ishkanian, A., Laperriere, N. J., Xu, W., Millar, B. A., Payne, D., Mason, W., & Sahgal, A. (2011). Upfront observation versus radiation for adult pilocytic astrocytoma. Cancer, 117(17), 4070-4079. https://doi.org/10.1002/cncr.25988