Carsten Friedrich

Recent developments and current concepts in medulloblastoma

Medulloblastoma is the most common malignant brain tumor of childhood. While prognosis has significantly improved in the last decades with multimodal therapy including surgery, radiotherapy, and chemotherapy, one third of patients still succumb to their disease. Further research is needed to find more efficient treatment strategies for prognostically unfavorable patient groups and to minimize long-term sequelae of tumor treatment. This review gives a summary of the current state of treatment concepts including an outlook on the near future. We describe recent advances in the understanding of molecular mechanisms, their potential impact on risk stratification in upcoming clinical trials, and perspectives for the clinical implementation of targeted therapies.

Treatment of young children with CNS-primitive neuroectodermal tumors/ pineoblastomas in the prospective multicenter trial HIT 2000 using different chemotherapy regimens and radiotherapy

BACKGROUND Especially in young children, primitive neuroectodermal tumors of the central nervous system (CNS-PNET) and pineoblastomas are associated with an unfavorable outcome, and only a few prospective trials have been conducted thus far. METHODS From January 2001 through January 2005, 17 eligible children aged <4 years with CNS-PNET not otherwise specified (n = 8), ependymoblastoma (n = 1), or pineoblastoma (n = 8) confirmed by central review were prospectively treated in the trial HIT 2000. In nonmetastatic disease (n = 11), up to 5 postoperative cycles of HIT-SKK systemic multiagent chemotherapy (8 months duration), followed by craniospinal radiotherapy (CSI), were given. In metastatic disease (M1-M3, n = 6), treatment consisted of a shorter induction chemotherapy (2-3 months) with carboplatin and etoposide, followed by tandem high-dose chemotherapy (HDCT) in case of good response to induction. During induction and HDCT, patients received intraventricular methotrexate. CSI was applied to all patients with poor response to induction or residual disease after HDCT and was optional for patients with residual disease before HDCT. RESULTS Five-year event-free survival and overall survival rates ± standard error for all eligible patients were 24% ± 10% and 40% ± 12%, respectively (median follow-up of survivors: 8.3 years). Only one patient with nonmetastatic disease remained free of relapse/progressive disease during induction. Three of 6 patients with metastatic disease responded to induction and received tandem-HDCT, followed by preventive CSI, and remain in continuous complete remission. CONCLUSIONS Short intensive induction chemotherapy followed by tandem-HDCT in young children with CNS-PNET/pineoblastomas seems to be superior to the prolonged and less intensive induction regimen.

Treatment of adult nonmetastatic medulloblastoma patients according to the paediatric HIT 2000 protocol: A prospective observational multicentre study

BACKGROUND Medulloblastoma in adulthood is rare. Knowledge is limited, and the efficacy and toxicity of chemotherapy--especially in nonmetastatic disease--is still elusive. METHODS Seventy adults aged ≥21 years (median age: 28.5 years) with nonmetastatic medulloblastoma were followed as observational patients within the prospective paediatric multicentre trial HIT 2000. Treatment consisted of radiotherapy (35.2 Gy to the craniospinal axis and a boost to 55.2 Gy to the posterior fossa) followed in most patients by maintenance chemotherapy (lomustine (CCNU), vincristine and cisplatin, n=49). RESULTS The implementation of maintenance chemotherapy was feasible. Peripheral neuropathy (74%) and haematotoxicity (55%) during maintenance chemotherapy appear to be more common in adults than in children. At a median follow-up of 3.7 years, the 4-year event-free survival (EFS) and overall survival (OS) rates±standard error (SE) were 68%±7% and 89%±5%. Patients with desmoplastic medulloblastoma and lateral tumour location (n=19) had a lower EFS compared to patients with centrally located desmoplastic tumours (n=10) (p=0.011). Absence of residual postoperative tumour (n=40) was associated to a lower rate of progression/relapse compared to present (n=11) or unknown (n=12) residual tumour status (p=0.006). Lateral tumour location and unknown residual tumour status were independent negative prognostic factors. CONCLUSIONS Maintenance chemotherapy is applicable in adults with nonmetastatic medulloblastoma. Histological subtype and tumour location were newly identified risk factors in this age-group, and should be further analysed in prospective trials.

Molecular stratification of medulloblastoma: comparison of histological and genetic methods to detect Wnt activated tumours

Wnt activation in medulloblastomas is associated with good outcome. Upfront testing and risk‐adapted stratification of patients will be done in future clinical studies. In a cohort of 186 paediatric medulloblastomas our aim was to identify the optimal methods in standard clinical practice to detect this subgroup.

Intraventricular methotrexate as part of primary therapy for children with infant and/or metastatic medulloblastoma: Feasibility, acute toxicity and evidence for efficacy

BACKGROUND To assess feasibility, acute toxicity, and efficacy of intraventricular methotrexate administered as part of the primary therapy in medulloblastoma. METHODS From 2001 to 2007, 240 patients < 22 years from 61 treatment centres were registered. Patients received 2-3 cycles of intraventricular methotrexate with systemic chemotherapy in three different treatment arms of the prospective multicentre trial HIT2000 (150 children > 4 years with metastatic, 59 < 4 years with non-metastatic, 31 < 4 years with metastatic medulloblastoma). RESULTS 211 patients received an intraventricular access device with a subcutaneous reservoir for the application of chemotherapy. Reservoir-associated complications were documented in 57 (27%) patients, mostly due to infection (n = 32) and reservoir malfunction (n = 19), requiring removal in 39 (18%) patients. Acute neurotoxicity likely associated with intraventricular MTX was observed in 9/202 documented patients. Toxicity was usually mild, apart from one therapy-associated death due to toxic oedema followed by seizures. Of 519 treatment cycles including intraventricular methotrexate, 226 (43%) were reduced or omitted, most frequently due to the absence of an intraventricular device. Survival rates were higher in patients receiving ⩾ 75% of the scheduled intraventricular methotrexate dose compared to those receiving < 75% in both univariate and multivariate models (event-free survival (EFS), 61.5 versus 46.2%, p = 0.004; OS, 75.5% versus 60.4%, p = 0.015; hazard ratio: EFS 1.723, p = 0.016; OS 1.648, p = 0.051). CONCLUSION Intraventricular methotrexate therapy was feasible and mostly well tolerated. Infections were the most frequent complication. A higher cumulative dose of intraventricular methotrexate was associated with better survival. Further evaluation of efficacy and late effects is warranted.

Ependymoblastoma of the brainstem: MRI findings and differential diagnosis

Ependymoblastoma (EBL) is a rare malignant CNS tumor of early childhood, listed as a subgroup of primitive neuroectodermal tumors (PNET) in the 2007 WHO Classification of Tumours of the Central Nervous System. Histologically, EBL can be defined by multilayered, mitotically active “ependymoblastic” rosettes with central lumen as a histological hallmark. The prognosis seems to be far inferior to other embryonal CNS tumors, and known clinical and MRI characteristics of EBL are based on scattered case reports. We present and discuss two uncommon cases of histopathologically confirmed ependymoblastoma that both seem to originate from the brainstem. Pediatr Blood Cancer 2014;61:1132–1134.

MRI Characteristics of Ependymoblastoma: Results from 22 Centrally Reviewed Cases

BACKGROUND AND PURPOSE: Ependymoblastoma is a malignant embryonal tumor that develops in early childhood and has a dismal prognosis. Categorized by the World Health Organization as a subgroup of CNS-primitive neuroectodermal tumor, ependymoblastoma is histologically defined by “ependymoblastic rosettes.” Because it is so rare, little is known about specific MR imaging characteristics of ependymoblastoma. We systematically analyzed and discussed MR imaging features of ependymoblastoma in a series of 22 consecutive patients. MATERIALS AND METHODS: Ependymoblastoma cases were obtained from the database of the German multicenter HIT trials between 2002 and 2013. All cases within this study were centrally reviewed for histopathology, MR imaging findings, and multimodal therapy. For systematic analysis of initial MR imaging scans at diagnosis, we applied standardized criteria for reference image evaluation of pediatric brain tumors. RESULTS: Ependymoblastomas are large tumors with well-defined tumor margins, iso- to hyperintense signal on T2WI, and diffusion restriction. Contrast enhancement is variable, with a tendency to mild or moderate enhancement. Subarachnoid spread is common in ependymoblastoma but can be absent initially. There was a male preponderance (1.75:1 ratio) for ependymoblastoma in our cohort. Mean age at diagnosis was 2.1 years. CONCLUSIONS: With this study, we add the largest case collection to the limited published database of MR imaging findings in ependymoblastoma, together with epidemiologic data. However, future studies are needed to systematically compare MR imaging findings of ependymoblastoma with other CNS-primitive neuroectodermal tumors and ependymoma, to delineate imaging criteria that might help distinguish these pediatric brain tumor entities.

Abstract LB-82: Chromosome 1q gain as genetic marker for risk stratification of pediatric ependymoma patients - validation as an adverse prognostic marker in the German multicenter HIT2000 trial.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC In contrast to histopathological grading which varied in respect to its prognostic value between different clinical trials, extent of resection was found to be consistently associated to the clinical outcome. In retrospective series, gain of genetic material of chromosome arm 1q was identified to predict worse outcome. This marker was mainly assessed by FISH analysis which typically showed failure rates of 15-20 % in archival material. To validate this marker in a homogenously treated patient cohort, we analysed chromosome 1qin 209 consecutive cases enrolled into the multicenter trial HIT2000 (postoperative chemotherapy and irradiation, in a sequence depending on age and extent of resection) in which formalin-fixed, paraffin embedded material was available for DNA extraction. By using multiplex ligation-dependent probe amplification (MLPA) for 5 markers located on chromosome 1q and control markers, we were able to analyse 206/209 samples (> 98 %) and found a gain of chromosome 1q in 35 cases (17 %). 135/206 ependymomas were located in the infratentorial region. 35 cases were diagnosed as WHO grade II ependymoma, 171 as anaplastic ependymoma (WHO grade III). Interestingly, only 2 of the 35 WHO grade II ependymomas had 1q gain (5.7%). At a median follow-up of 3.9 years for survivors, patients with tumors showing 1q gain had a significantly lower 4-year overall survival (OS) (±SE) of 58% +/- 9% compared to patients lacking this marker (89% +/- 3%, p=0.002). The distribution of this marker was similar when comparing patients with supra- and infratentorial tumors. Multivariable analysis demonstrated that residual tumor and infratentorial localization were independent risk factors for event-free survival, and gain of chromosome 1q for OS, respectively. In conclusion, we validated chromosomal 1q gain to be a useful independent genetic marker for risk stratification of pediatric ependymoma patients which can be evaluated by MLPA representing a robust, reliable and cost-efficient method. Citation Format: Torsten Pietsch, Evelyn Doerner, Anja zur Muehlen, Natalia Velez-Char, Monika Warmuth-Metz, Rolf-Dieter Kortmann, Katja von Hoff, Carsten Friedrich, Stefan Rutkowski, Andre O. von Bueren. Chromosome 1q gain as genetic marker for risk stratification of pediatric ependymoma patients - validation as an adverse prognostic marker in the German multicenter HIT2000 trial. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-82. doi:10.1158/1538-7445.AM2013-LB-82

Ongoing remission after intensive ALL-type chemotherapy in pediatric intestinal T-cell lymphoma.

A rare case of primary intestinal T‐cell lymphoma (ITL) of an 8‐year‐old boy is reported. Medium‐ to large‐sized tumor cells were βF1+, CD3+, CD8+. TIA‐1+, but CD4−, CD5−, CD30−, CD56−, CD20−, CD79a−, TdT−, consistent with an intraepithelial lymphocyte (IEL) origin. They showed monoclonal rearrangement of the T‐cell receptor γ‐chain and no evidence of EBV infection. No clinical, histologic, laboratory, or genetic evidence of celiac disease was detected. In adults, ITL is often associated with enteropathy and has a very poor outcome. Our patient remains in first remission 30 months after finishing the acute lymphoblastic leukemia protocol COALL‐07‐03 high risk standard. Pediatr Blood Cancer 2010;54:610–612.