Re-evaluating surgery and re-irradiation for locally recurrent pediatric ependymoma – a multi-institutional study

Background The goal of this study was to evaluate extent of surgical resection, and timing and volume of re-irradiation, on survival for children with locally recurrent ependymoma. Methods Children with locally recurrent ependymoma treated with a second course of fractionated radiotherapy (RT2) from six North American cancer centres were reviewed. The index time was from the start of RT2 unless otherwise stated. Results 35 patients were included in the study. The median doses for first radiation (RT1) and RT2 were 55.8 and 54 Gy, respectively. Median follow-up time was 5.6 years. Median overall survival (OS) for all patients from RT2 was 65 months. Gross total resection (GTR) was performed in 46% and 66% of patients prior to RT1 and RT2, respectively. GTR prior to RT2 was independently associated with improved progression free survival (PFS) for all patients (HR 0.41, p = 0.04), with an OS benefit (HR 0.26, p = 0.03) for infratentorial tumours. Median PFS was superior with craniospinal irradiation (CSI) RT2 (not reached) compared to focal RT2 (56.9 months; log-rank p = 0.03). All distant failures (except one) occurred after focal RT2. Local failures after focal RT2 were predominantly in patients with less than GTR pre-RT2. Conclusions Patients with locally recurrent pediatric ependymoma should be considered for re-treatment with repeat maximal safe resection (ideally GTR) and CSI re-irradiation, with careful discussion of the potential side effects of these treatments.

RADT-27. EFFECTIVENESS ANALYSIS OF RADIOTHERAPY FOR INTRACRANIAL RECURRENT EPENDYMOMA

OBJECTIVE There is no standard treatment for recurrent ependymoma. This study aimed to investigated the role of radiotherapy in recurrent ependymoma. METHODS Retrospective analysis was performed on 49 cases of recurrent ependymoma diagnosed in Guangdong Sanjiu Brain Hospital from January 2008 to July 2020. Overall survival (OS) was calculated by Kaplan-Meier method and tested by Log-rank test. P < 0.05 was considered statistically significant. RESULTS The median age was 7 years (range:1-57 yrs). Nineteen patients were with ependymoma WHO grade II while 30 were with grade III, respectively. Recurrence treatment: 14 cases received re-surgery, 23 cases received radiotherapy, among them 16 cases received re-radiotherapy. To May, 2021, the median follow-up time was 35 months (range 3-153). Median PFS time was 17 months after initial diagnosis, median PFS time was 8 months after treatment to recurrence disease, Median OS time is 39 months, and median OS time is 20 months after recurrence. The median survival time for recurrence was 48 months vs. 11 months (P =0.001) in the radiotherapy group vs. non-radiotherapy group,res; Re-radiotherapy combined with chemotherapy vs reradiotherapy alone (0.194); RRT combined with anti-angiogenesis therapy vs. RRT alone (0.688). CONCLUSION Radiotherapy can prolong the survival time of recurrent ependymoma, and concurrent therapy as chemotherapy or anti-angiogenesis therapy with RT does not seem to improve the prognosis. Therefore, radiotherapy can be used as the main treatment for recurrent ependymoma.

Local and Systemic Therapy of Recurrent Ependymoma in Children and Adolescents: Short- and Long-term Results of the E-HIT-REZ 2005 Study

Background Survival in recurrent ependymomas in children and adolescents mainly depends on the extent of resection. Studies on repeated radiotherapy and chemotherapy at relapse have shown conflicting results. Methods Using data from the German multi-center E-HIT-REZ-2005 study, we examined the role of local therapy and the efficacy of chemotherapy with blockwise temozolomide (TMZ) in children and adolescents with recurrent ependymomas. Results 53 patients with a median age of 6.9 years (1.25–25.4) at 1 st recurrence and a median follow-up time of 36 months (2–115) were recruited. Gross and near total resection (GTR/NTR) were achieved in 34 (64.2%) patients and associated with a markedly improved 5-year overall survival (OS) of 48.7% vs. 5.3% in less than GTR/NTR. Radiotherapy showed no improvement in OS following complete resection (OS: 70 (CI: 19.9–120.1) vs. 95 (CI: 20.7–169.4) months), but an advantage was found in less than GTR/NTR (OS: 22 (CI: 12.7–31.3) vs. 7 (CI: 0–15.8) months). Following application of TMZ, disease progression was observed in most evaluable cases (18/21). Subsequent change to oral etoposide and trofosfamide showed no improved response. PF-A EPN were most abundant in relapses (n = 27). RELA-positive EPN (n=5) had a 5-year-OS of 0%. Conclusions The extent of resection is the most important predictor of survival at relapse. Focal re-irradiation is a useful approach if complete resection cannot be achieved, but no additional benefit was seen after GTR/NTR. Longer-term disease stabilization (>6 months) mediated by TMZ occurred in a small number of cases (14.3%).

EPEN-49. RESPONSE OF RECURRENT EPENDYMOMA TO MEMMAT BASED METRONOMIC ANTIANGIOGENIC COMBINATION THERAPY UTILIZING TAPERED BEVACIZUMAB AND MAINTENANCE THERAPY WITH CELECOXIB AND FENOFIBRATE

Recurrent ependymomas have a dismal prognosis (2 year survival rates 29% OS and 23% EFS) and are relatively resistant to conventional chemotherapy. We previously reported five relapsed ependymoma patients treated with a MEMMAT based metronomic antiangiogenic combination therapy. All patients are currently alive, including four patients who were multiply relapsed with at least three recurrences. These four patients received between 44–52 weeks of therapy with minimal toxicity. Three had recurrent disease within an average of 44 months (median 42 months) after discontinuation of therapy. One patient who received the following tapering bevacizumab schedule: q3 weeks x 3, q4 weeks x 4 and q5 weeks x 5 followed by maintenance therapy with fenofibrate and celecoxib is in complete remission 12 months post treatment. This regimen was well tolerated with good quality of life in this patient population. Our results suggest that the chosen anti-angiogenic drug combination prolonged the time to progression in these multiply relapsed patients and thus may be particularly beneficial for patients with recurrent ependymoma. Tapered bevacizumab and maintenance therapy with celecoxib and fenofibrate may be modifications worth further investigation for prolonged disease free survival in relapsed ependymoma patients.

EPEN-37. TREATMENT OUTCOME OF RECURRENT EPENDYMOMA IN CHILDREN IN NORTHERN EGYPT

INTRODUCTION 1/3 of Ependymoma patients will develop recurrence with only 25% are long term survivors. Treatment is usually between surgery, radiotherapy or combinations. PATIENTS AND METHODS Retrospective review of children with recurrent Ependymoma in northwest of Egypt between 2005 and 2019 in Alexandria School of medicine records. RESULTS 27 patients were identified 19 of them after 2010. The median age is 9.7 years (1.5–19), with 16 males and 11 females. Pathology were 11 grade II Ependymoma and 16 anaplastic Ependymoma. 16 had gross residual disease after 1st surgery and 22 received radiotherapy initially at median dose of 53.5 Gy, 4 patients received suboptimal radiotherapy. The initial site was14 supratentorial tumors and 13 infratentorial. Median time to recurrence is 27.6 months(3–84), and recurrences were 17 local and 9 CSF disseminated, and one patient had recurrence at the scar with lung metastasis. At a median follow up of 56.6 months 14(51.8%) are still alive. Treatment was surgery only in 6(4 alive) radiotherapy alone in 2(1alive), combined in 15(9 alive) and 4 patients received neither. The best outcome were in patients with late local relapse treated with complete resection and CSI after 2010. Radiotherapy dose was between 54 to 57.3 Gy and one patient developed reirradiation injury at brain stem. 5 of the 14 living patients is having toxicity in form of hearing aids (4) and low TSH(1). CONCLUSION Aggressive treatment of recurrent Ependymoma with surgery and radiotherapy is feasible and about half of the patients are salvageable.

EPEN-06. CHEMOTHERAPY OF RECURRENT EPENDYMOMA: LONG-TERM RESPONSE ONLY IN FEW CASES

INTRODUCTION The efficacy of chemotherapy in recurrent ependymoma is unclear. We present results from the German HIT-REZ-studies. METHODS 137 patients were analyzed regarding the treatment with chemotherapy at first recurrence, the time from first relapse to progression (PFS) and to either time-point of death or last follow-up (OS). Tumor response evaluation was based on MRI and clinically; molecular data was available in 80. RESULTS In our cohort, 96 patients (20 supratentorial, 73 infratentorial, 3 spinal) received chemotherapy during first recurrence: 49 (51.0%) temozolomide (TMZ) monotherapy, 12 (12.5%) HIT-SKK regime, 9 (9.4%) carboplatin/etoposide (CE) and 26 (27.1%) other combinations. In 19.8% (26.5% in TMZ), chemotherapy was administered prior to surgery (neoadjuvant), which resulted in tumor progression in 78% (85% in TMZ). Gross-total resection was achieved in 86% without neoadjuvant chemotherapy and in 74% (69% in TMZ) with neoadjuvant treatment. Switching to trofosfamide/etoposide (TE) after surgery and unresponsiveness to TMZ showed further progression in all cases of tumor-residuum after surgery. Regarding 1-year-PFS, treatment with HIT-SKK (50.0%±14.4%) or CE (55.6%±16.6%) was advantageous over TMZ (30.2%±6.7%). However, 5-y-OS was lower in CE (19.0% ±16.8%) than in TMZ (39.8%±7.7%) and HIT-SKK (42.9%±8.7%). Long-term control was seen in individual cases of TMZ, HIT-SKK and CE, with TMZ providing longest response of 72 months. CONCLUSION Neoadjuvant TMZ has no significant advantage regarding PFS. However, in few cases chemotherapy prevented progression after incomplete resection. Difficulties in response evaluation and variability in therapies hinder conclusions. Supported by the German Children’s Cancer Foundation

EPEN-05. CLINICAL AND GENETIC EVOLUTION OF EPENDYMOMA EXPOSED FROM A MULTI-RECURRENCE GIRL CASE

Ependymomas are glial brain tumors accounting for approximately 2~3% of all primary tumors of the central nervous system (CNS), and 12% of all pediatric intracranial tumors. To better understand the evolution process of ependymomas, we studied the clinical, pathological and genetic development of a rare girl case with repeatedly recurrent ependymoma. This girl was diagnosed as ependymoma at age of 9 years old, and experienced 7 times tumor relapse and received 9 times surgeries but finally ceased at 19 years old with multiregional recurrences. The pathological characteristics, radiographic images and therapeutic strategies of the patient were all retrieved. Molecular markers confirmed the diagnosis of anaplastic ependymoma based on the updated WHO guideline for CNS tumors. Whole-genome sequencing (WGS) was performed to elucidate the landscape of mutation signatures and to identify potential driver mutations along the tumor progression. The seven tumor specimens showed a highly branched evolutionary pattern. There were six gene mutations found in 5 of the 7 specimens (PCDHA4, PCDHA8, SEC14L6, SETD2, RIOK2, and SLCO2A1) and three in 6 of 7 the samples (RYR1, SNX25, DSC2). Strikingly, there was one gene, ADGRL3, which was found to be consistently mutated in the entire disease progression process. Our findings therefore suggest that ADGRL3 might play roles in the disease progression of ependymoma patient.

EPCO-34. CLINICAL AND GENETIC EVOLUTION OF EPENDYMOMA

Ependymomas are glial brain tumors accounting for approximately 2~3% of all primary tumors in central nervous system (CNS), and 12% of all pediatric intracranial tumors. To better understand the evolution process of ependymomas, we studied the clinical, pathological and genetic development of a rare girl case with repeatedly recurrent ependymoma. This girl was diagnosed as anaplastic ependymoma at age of 9 years old, and experienced 7 times tumor relapse and received 9 times surgeries but finally ceased at19 years old with multiregional recurrences. The pathological characteristics, radiographic images and therapeutic strategies of the patient were all retrieved. Molecular markers confirmed the diagnosis based on the updated WHO guideline for CNS tumors. Whole-genome sequencing (WGS) was performed to elucidate the landscape of mutation signatures and to identify potential driver mutations along the tumor progression. The seven tumor specimens showed a highly branched evolutionary pattern. There were six gene mutations found in 5 of the 7 specimens (PCDHA4, PCDHA8, SEC14L6, SETD2, RIOK2, and SLCO2A1) and three in 6 of 7 the samples (RYR1, SNX25, DSC2). Strikingly, there was one gene, ADGRL3, which was found to be consistently mutated in the entire disease progression process. Our findings therefore suggest that ADGRL3 might play roles in the disease progression of ependymoma patient.

A Phase II Study of Dose-Dense Temozolomide and Lapatinib for Recurrent Low-Grade and Anaplastic Supratentorial, Infratentorial, and Spinal Cord Ependymoma

Background No standard medical treatment exists for adult patients with recurrent ependymoma and prospective clinical trials in this population have not succeeded because of its rarity and challenges in accruing patients. The Collaborative Ependymoma Research Network (CERN) conducted a prospective phase II clinical trial of dose-dense temozolomide and lapatinib, targeting the unmethylated MGMT promoter status and increased expression of ErbB2 (HER2) and ErbB1 (EGFR) in ependymomas. Methods Patients age 18 or older with histologically proven and progressive ependymoma or anaplastic ependymoma were eligible and received dose-dense temozolomide and daily lapatinib. The primary outcome measure was median progression-free survival (PFS). Landmark 6- and 12-month PFS and objective response were measured. Serial assessments of symptom burden using the MDASI-BT/MDASI-SP were collected. Results The 50 patients enrolled had a median age of 43.5 years, median Karnofsky Performance Status of 90, and a median of 2 prior relapses. Twenty patients had grade III, 16 grade II, and 8 grade I ependymoma. Half had spinal cord tumors; 15 had a supratentorial tumor, 8 infratentorial, and 2 had disseminated disease. Treatment was well tolerated. The median PFS was 7.8 months (95% CI 5.5,12.2); the 6-and 12-month PFS rates were 55% and 38%; with 2 complete and 6 partial responses. Measures of symptom burden showed reduction in moderate-severe pain and other disease-related symptoms in most patients. Conclusions This treatment, with demonstrated clinical activity with objective responses and prolonged disease control associated with disease-related symptom improvements is an option as a salvage regimen for adult patients with recurrent ependymoma.