Upfront observation versus radiation for adult pilocytic astrocytoma

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 ¼ .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 ¼ .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. Cancer 2011;117:4070-

Genetic alterations related to BRAF‐FGFR genes and dysregulated MAPK/ERK/mTOR signaling in adult pilocytic astrocytoma

“…Hence, in order to explore the genetic characteristics and associated signaling pathways as well as identify possible pharmacologic targets in APAs, this study was undertaken. All the 59 patients in the present study showed median age, age range, tumor site and MIB-LI nearly similar to the previous studies on adult PAs (14,18,33,40,44).…”

Adult patients with supratentorial pilocytic astrocytoma: long-term follow-up of prospective multicenter clinical trial NCCTG-867251 (Alliance)

“…9 Investigators from Princess Margaret Hospital identified 30 adult patients diagnosed from 1971 -2007 and noted 10-year progression-free survival and overall survival rates of 35% and 85%, respectively. 10 The improved outcome in this prospective trial compared with the two retrospective trials is likely due to the younger patient population enrolled in the prospective trial (with no patients over 47 years old) and the high rate of gross total resection. A review of adult pilocytic astrocytoma patients identified in the Surveillance, Epidemiology, and End Results (SEER) Program confirmed younger age and greater extent of resection to be positive prognostic factors.…”

“…2 Other studies have shown that while adjuvant RT significantly improves tumor control it has no impact on survival (due to efficacy of salvage therapies). 10 In the current prospective trial, a treatment paradigm of resection followed by close observation, reserving RT for salvage or for biopsy-only patients, resulted in good patient function over time. Neurologic function, prospectively measured and quantified with the NFS, was stable or improved for the majority of patients.…”

Surgical Management and Outcome of a Bilateral Thalamic Pilocytic Astrocytoma: Case Report and Review of the Literature

“…The present literature also supports up-front radiotherapy for pilocytic astrocytoma although mainly in adults. Ishkanian et al [5] published a study of adult pilocytic patients managed with up-front radiotherapy. They found that progression-free survival was superior in the radiation group than the observation group.…”