Natural history and role of radiation in patients with supratentorial and infratentorial WHO grade II ependymomas: results from a population-based study

Abstract

Patients with World Health Organization (WHO) grade II supratentorial ependymomas are commonly observed after gross total resection (GTR), although supporting data are limited. We sought to characterize the natural history of such tumors. We used the Surveillance, Epidemiology, and End Results program to identify 112 patients ages 0-77 diagnosed with WHO grade II ependymomas between 1988 and 2007, of whom 63 (56 %) and 49 (44 %) had supratentorial and infratentorial primaries, respectively. Inclusion criteria were strict to ensure patient homogeneity. Of 33 patients with supratentorial tumors after GTR, 18 (55 %) received adjuvant radiation therapy and 15 (45 %) did not. Ependymoma-specific mortality (ESM) was the primary endpoint. With a median follow up of 4.5 years, only 1 of 33 patients with supratentorial ependymoma died of their disease after GTR; the 5-year estimate of ESM in this population was 3.3 % (95 % CI 0.2-14.8 %). Among patients with infratentorial ependymomas after GTR, the 5-year estimate of ESM was 8.7 % (95 % CI 1.4-24.6 %). In patients with subtotally resected tumors, 5-year estimates of ESM in patients with supratentorial and infratentorial primaries were 20.1 % (95 % CI 8.0-36.2 %) and 12.3 % (95 % CI 2.9-28.8 %), respectively. Among the whole cohort, on both univariable and multivariable regression, extent of resection was predictive of ESM, while tumor location and use of radiation were not. After GTR, patients with WHO grade II supratentorial ependymomas have a very favorable natural history with low associated cancer-specific mortality. Observation, with radiation reserved as a salvage option, may be a reasonable postoperative strategy in this population.

The Role of Radiation Therapy in Gross Totally Resected Meningiomas

“…The effectiveness of salvage treatment in atypical meningiomas is an important consideration. Recurrences typically occur only locally, frequently without malignant progression (2), and are often well controlled with re-resection or radiotherapy (3). Recurrence rates range between 9% and 50% in the literature and the present metaanalysis reports a 33% recurrence rate.…”

The role of postoperative radiotherapy in pediatric patients with grade II intracranial ependymomas: a population-based, propensity score-matched study

“… 9 , 16 – 20 In addition, response rates to photon beam RT in patients with grade II intracranial EPNs are reported to be greater than 80%, emphasizing the efficacy of RT. 21 In contrast, Aizer et al 11 demonstrated that RT was not an independent prognostic factor for patients with grade II EPNs (RT vs non-RT; HR, 2.77; 95% CI, 0.57–13.52); however, this SEER-based study included only 112 patients, the majority of whom were adults. Adult patients are inclined to be resistant to RT, relative to children, which may have masked the effects of RT in the children in their analysis.…”

“… 5 , 6 The standard treatment for EPN varies by geographic location and treatment center; however, there is a consensus that surgery and radiotherapy (RT) are the cornerstone for the treatment of children. 7 , 8 Postoperative radiotherapy (PORT) is reported to predict superior survival in anaplastic or infratentorial EPNs; 9 – 11 however, there have been few detailed investigations of the contribution of PORT to survival in patients with intracranial grade II EPNs as a separate group. Moreover, those reports that are available are inconclusive, particularly regarding patients undergoing complete tumor resection.…”

Treatment Decisions of World Health Organization Grade II and III Ependymomas in Molecular Era

“…In pediatric supratentorial EPNs, it could be acceptable to withhold radiotherapy if gross total resection with adequate margins has been achieved and the pathology is not anaplastic [ 32 ]. In adult patients, observation after gross total resection of World Health Organization (WHO) II EPN and adjuvant radiation after subtotal resection are the standard practice [ 1 , 5 , 17 ]. Radiation is recommended especially for cases of extensive residual disease and anaplastic EPN.…”