Christelle Dufour

Vemurafenib in pediatric patients with BRAFV600E mutated high-grade gliomas

We present three pediatric patients with BRAFV600E mutant high‐grade gliomas treated by vemurafenib on a nominative authorization level at our institution. One patient with anaplastic ganglioglioma experienced confirmed partial tumor response and significant clinical improvement and she is alive 20 months after start of treatment. A second patient with ganglioglioma responded transiently to re‐introduction of vemurafenib after immunotherapy. Pharmacokinetic studies suggest that maximum concentration and exposure of vemurafenib at steady‐state is dose‐dependent and similar in children to that reported in adults. These cases suggest that BRAFV600 is an oncogenic driver in pediatric gliomas. Further exploration in clinical studies is ongoing. Pediatr Blood Cancer 2014;61:1101–1103.

High frequency of germline SUFU mutations in children with desmoplastic/nodular medulloblastoma younger than 3 years of age.

PURPOSE Germline mutations of the SUFU gene have been shown to be associated with genetic predisposition to medulloblastoma, mainly in families with multiple cases of medulloblastoma and/or in patients with symptoms similar to those of Gorlin syndrome. To evaluate the contribution of these mutations to the genesis of sporadic medulloblastomas, we screened a series of unselected patients with medulloblastoma for germline SUFU mutations. PATIENTS AND METHODS A complete mutational analysis of the SUFU gene was performed on genomic DNA in all 131 consecutive patients treated for medulloblastoma in the pediatrics department of the Institut Gustave Roussy between 1972 and 2009 and for whom a blood sample was available. RESULTS We identified eight germline mutations of the SUFU gene: one large genomic duplication and seven point mutations. Mutations were identified in three of three individuals with medulloblastoma with extensive nodularity, four of 20 with desmoplastic/nodular medulloblastomas, and one of 108 with other subtypes. All eight patients were younger than 3 years of age at diagnosis. The mutations were inherited from the healthy father in four of six patient cases in which the parents accepted genetic testing; de novo mutations accounted for the other two patient cases. Associated events were macrocrania in six patients, hypertelorism in three patients, and multiple basal cell carcinomas in the radiation field after age 18 years in one patient. CONCLUSION These data indicate that germline SUFU mutations were responsible for a high proportion of desmoplastic medulloblastoma in children younger than 3 years of age. Genetic testing should be offered to all children diagnosed with sonic hedgehog-driven medulloblastoma at a young age.

Clinicopathologic prognostic factors in childhood atypical teratoid and rhabdoid tumor of the central nervous system: a multicenter study.

The objective of this study was to describe the clinical and pathologic features and to identify prognostic factors in patients with atypical teratoid/rhabdoid tumors (AT/RT) of the central nervous system (CNS).

Testicular function of survivors of childhood cancer: a comparative study between ifosfamide- and cyclophosphamide-based regimens.

PURPOSE This study aimed at comparing gonadal toxicity of ifosfamide versus cyclophosphamide received during childhood. METHODS The evaluation was based on basal FSH measurement. LH and testosterone were also measured in most of the patients. One hundred patients had received ifosfamide and 59 had received cyclophosphamide. RESULTS Median age at treatment was 11.2 years. The median interval since treatment was 10.7 years (range 4.1-20.2) and median age at evaluation was 21.4 years (17.5-36.1). The median dose of ifosfamide and of cyclophosphamide was 54 g/m(2) (18-114) and 8.3 g/m(2) (4.6-22), respectively. All but two males had normal testosterone levels. FSH was abnormal in 28/59 patients (47.5%) after receiving cyclophosphamide and was within the normal range in 94/100 patients (94%) after receiving ifosfamide. CONCLUSIONS These results show that ifosfamide is associated with a lower risk of gonadal damage than cyclophosphamide. The risk of abnormal FSH increased with the cumulative dose of cyclophosphamide.

End of life care in adolescents and young adults with cancer: Experience of the adolescent unit of the Institut Gustave Roussy

BACKGROUND Cancer is the third leading cause of death in adolescents and young adults (AYA). Little is known, however, about how end-of-life unfolds for those who die of progressive disease. In order to better evaluate the specific needs of these patients, we performed this study providing baseline information about end-of-life care patterns for AYA in our department. PATIENTS A standardised form was used to collect data concerning all 45 patients treated for a malignancy in the Paediatric and Adolescent Oncology Department at the Gustave Roussy Institute, and who had died of progressive disease above 13 years of age, over a two-year period. RESULTS The main diagnoses were sarcomas and brain tumours. Previous cancer-directed treatment included a median of 3 different chemotherapy regimens, high-dose chemotherapy with haematopoietic stem cell support for 13% and radiotherapy for 40%. One in every four patients had been enrolled in a clinical trial at diagnosis. Median survival was 18 months after the diagnosis and 7 months after the first relapse/progression. During the last week of life, the median number of physical symptoms was 4, mostly pain and dyspnoea. Frequent psychological symptoms were sadness, anxiety, fear and guilt. End-of-life care included transfusions, artificial nutrition, corticosteroids, pain control, sedation but also palliative chemotherapy. The median time spent in hospital during the last month of life was 16 days. Most patients had died in hospital. CONCLUSIONS The terminally ill adolescent displays notable challenges to care providers and requires a holistic approach with the help of a multidisciplinary team.

A case report of pseudoprogression followed by complete remission after proton-beam irradiation for a low-grade glioma in a teenager: the value of dynamic contrast-enhanced MRI

A fourteen years-old boy was treated post-operatively with proton therapy for a recurrent low-grade oligodendroglioma located in the tectal region. Six months after the end of irradiation (RT), a new enhancing lesion appeared within the radiation fields. To differentiate disease progression from radiation-induced changes, dynamic susceptibility contrast-enhanced (DSCE) MRI was used with a T2* sequence to study perfusion and permeability characteristics simultaneously. Typically, the lesion showed hypoperfusion and hyperpermeability compared to the controlateral normal brain. Without additional treatment but a short course of steroids, the image disappeared over a six months period allowing us to conclude for a pseudo-progression. The patient is alive in complete remission more than 2 years post-RT.

Prognostic classification of pediatric medulloblastoma based on chromosome 17p loss, expression of MYCC and MYCN, and Wnt pathway activation

Pediatric medulloblastoma is considered a highly heterogeneous disease and a new strategy of risk stratification to optimize therapeutic outcomes is required. We aimed to investigate a new risk-stratification approach based on expression profiles of medulloblastoma cohorts. We analyzed gene expression profiles of 30 primary medulloblastomas and detected strong evidence that poor survival outcome was significantly associated with mRNA expression profiles of 17p loss. However, it was not supported in independent cohorts from previously published data (n = 100). We speculated that this discrepancy might come from complex conditions of two important prognostic determinants: loss of tumor suppressors (chromosome 17p) and high expression of oncogenes c-myc (MYCC) or N-myc (MYCN). When patients were stratified into 5 or 7 subgroups based on simultaneous consideration of these 2 factors while defining the Wnt group as independent, obviously different survival expectancies were detected between the subgroups. For instance, predicted 5-year survival probabilities ranged from 19% to 81% in the 5 subgroups. We also found that age became a significant prognostic marker after adjusting for 17p, MYCC, and MYCN status. Diminished survival in age <3 years was more substantial in subgroups with high expression of MYCC, MYCN, or 17p loss but not in other subgroups, indicating that poor survival outcome might be synergistically affected by these 3 factors. Here we suggest a more tailored subgrouping system based on expression profiles of chromosome 17p, MYCC, and MYCN, which could provide the basis for a novel risk-stratification strategy in pediatric medulloblastoma.

Smarcb1 Deficiency in Tumors From the Peripheral Nervous System: A Link Between Schwannomas and Rhabdoid Tumors?

Background:Inactivation of SMARCB1 tumor-suppressor gene was originally described as highly specific for rhabdoid tumors (RTs). Nevertheless, recent reports have illustrated that SMARCB1 alterations also characterize other tumors; in particular, some familial schwannomatosis and epithelioid malignant peripheral nerve sheath tumors, both from peripheral nervous system (PNS) origin, lack BAF47 expression. To document the putative role of SMARCB1 in PNS, we reviewed PNS tumors referred to our institution for a molecular analysis of SMARCB1 because of histologic features compatible with RT. Methods:Clinicopathologic, radiologic, and molecular characteristics were detailed for the 12 cases showing loss of expression and/or biallelic inactivation of SMARCB1. The status of the NF2 gene, likely to synergize with SMARCB1 in PNS tumors, was also analyzed. Results:Patients’ age ranged from 0 to 45 years (median age, 6.6 y). Neurological symptoms were observed in 7/12 cases with radiologic features evoking a neuroblastic tumor in 6 cases and a peripheral nerve tumor in 4 cases. The mean delay before diagnosis was 3 months. Histologic examination revealed rhabdoid features in 11/12 tumors. All tumors showed a complete loss of SMARCB1 expression. Interestingly, adjacent nervous proliferation resembling neurofibromas were observed in 3 cases, suggesting a multistep transformation. Three tumors harbored a hemizygous deletion at the NF2 locus, but all NF2 sequences were normal. Conclusions:We report the first series of PNS RT. In patients with aggressive PNS tumors, RT should be suspected, and anti-SMARCB1 immunohistochemical analysis should be performed. SMARCB1 inactivation, occasionally associated with NF2 deletion, might have oncogenic effects in peripheral nerves.

Clinical Features and Treatment of Pediatric Somatotropinoma: Case Study of an Aggressive Tumor due to a New AIP Mutation and Extensive Literature Review

Context: Pediatric somatotropinoma is uncommon but usually more aggressive than in adults, creating therapeutic challenges. No treatment guidelines are available. Objectives: To describe the features of pediatric somatotropinomas and to assess therapeutic strategies based on an extensive literature review. Design: We describe a pediatric case of aggressive somatotropinoma with an AIP mutation. We identified 137 pediatric somatotropinoma cases published between 1981 and 2010, and found 41 cases with AIP mutations in the main review. Results: We found a slight male preponderance (59%). Median age was 9 years at symptom onset and 14 years at diagnosis. Macroadenomas accounted for 90% of the tumors; 2/3 of the children had hyperprolactinemia at diagnosis. The first-line treatment was pharmacotherapy in one third and surgery in 2/3 of the patients. Pegvisomant was used in 7 patients and produced significant improvement in 4. The male preponderance was higher in the subgroup with AIP mutations. Mutations leading to severe protein abnormalities were more common than reported in adults. Conclusion: Higher invasiveness and tumor volume in pediatric somatotropinomas require complex treatment combinations, which produce variable results. Pegvisomant is an effective drug whose usefulness in children remains to be determined. Genetic screening, particularly for AIP mutations, should be performed routinely.

Clinical, Imaging, Histopathological and Molecular Characterization of Anaplastic Ganglioglioma

Anaplastic ganglioglioma (AGG) is a rare and malignant variant of ganglioglioma. According to the World Health Organization classification version 2016, their histopathological grading criteria are still ill-defined. The aim of the present study was to assess the clinical, imaging, histopathological, and molecular characteristics and outcomes of AGGs in a large consecutive and retrospective adult and pediatric case series. Eighteen patients with AGGs (13 adults and 5 children) were identified (14 de novo and 4 secondary) from a cohort of 222 gangliogliomas (GG) (8%) treated at our institution between 2000 and 2015. AGGs represented a very aggressive disease with poor outcome (median progression-free survival, 10 months; median overall survival, 27 months). They were located in the temporal lobe only in 22% and presented with seizures (44%) or increased intracranial pressure (44%) at diagnosis. Concerning histopathological and molecular data, they shared morphological characteristics and BRAF V600E mutation (39%) with their benign counterparts but also showed hTERT promoter mutation (61%), p53 accumulation (39%), ATRX loss (17%), or p.K27M H3F3A mutation (17%). AGGs are malignant neoplasms requiring aggressive oncological treatment. In the perspective of targeted therapies, AGGs should be screened for BRAF V600E, hTERT, ATRX, and mutations of histone genes.