Immune checkpoint inhibitors in MITF family translocation renal cell carcinomas and genetic correlates of exceptional responders.

BACKGROUND: Microphthalmia Transcription Factor (MITF)family translocation renal cell carcinoma (tRCC) is a rare RCC subtype harboring TFE3/TFEB translocations. The prognosis in the metastatic (m) setting is poor. Programmed death ligand-1 expression was reported in 90% of cases, prompting us to analyze the benefit of immune checkpoint inhibitors (ICI) in this population. PATIENTS AND METHODS: This multicenter retrospective study identified patients with MITF family mtRCC who had received an ICI in any of 12 referral centers in France or the USA. Response rate according to RECIST criteria, progression-free survival (PFS), and overall survival (OS) were analyzed. Genomic alterations associated with response were determined for 8 patients. RESULTS: Overall, 24 patients with metastatic disease who received an ICI as second or later line of treatment were identified. Nineteen (82.6%) of these patients had received a VEGFR inhibitor as first-line treatment, with a median PFS of 3 months (range, 1-22 months). The median PFS for patients during first ICI treatment was 2.5 months (range, 1-40 months); 4 patients experienced partial response (16,7%) and 3 (12,5%) had stable disease. Of the patients whose genomic alterations were analyzed, two patients with mutations in bromodomain-containing genes (PBRM1 and BRD8) had a clinical benefit. Resistant clones in a patient with exceptional response to ipilimumab showed loss of BRD8 mutations and increased mutational load driven by parallel evolution affecting 17 genes (median mutations per gene, 3), which were enriched mainly for O-glycan processing (29.4%, FDR = 9.7 × 10- 6). CONCLUSIONS: MITF family tRCC is an aggressive disease with similar responses to ICIs as clear-cell RCC. Mutations in bromodomain-containing genes might be associated with clinical benefit. The unexpected observation about parallel evolution of genes involved in O-glycosylation as a mechanism of resistance to ICI warrants exploration.

Combined therapy in children and adolescents with classical Hodgkin's lymphoma: A report from the SFCE on MDH-03 national guidelines.

Hodgkin's lymphoma (HL) in children and adolescents is highly curable, but children are at risk of long-term toxicity. The MDH-03 guidelines were established in order to decrease the burden of treatment in good-responder patients, and this report should be considered a step toward further optimization of treatment within large collaborative trials. We report the therapy and long-term outcomes of 417 children and adolescents treated according to the national guidelines, which were applied between 2003 and 2007 in France. The patients were stratified into three groups according to disease extension. Chemotherapy consisted of four cycles of VBVP (vinblastine, bleomycin, VP16, prednisone) in localized stages (G1/95 pts/23%), four cycles of COPP/ABV (cyclophosphamide, vincristine, procarbazine, prednisone, adriamycin, bleomycin, vinblastine) cycles in intermediate stages (G2/184 pts/44%) and three cycles of OPPA (vincristine, procarbazine, prednisone, adriamycin) plus three cycles of COPP in advanced stages (G3/138 pts/33%). Radiation therapy of the involved field was given to 97% of the patients, with the dose limited to 20 Gy in good responders (88%). With a median follow-up of 6.6 years, the 5-year event-free survival (EFS) and overall survival (OS) were 86.7% (83.1-89.7%) and 97% (94.5-98.1%), respectively. EFS and OS for G1, G2, and G3 were 98% and 100%, 81% and 97%, and 87% and 95%, respectively. Low-risk patients treated without alkylating agents and anthracycline had excellent outcomes and a low expected incidence of late effects. Intensification with a third OPPA cycle in high-risk group patients, including stage IV patients, allowed for very good outcomes, without increased toxicity.

[Multidisciplinarity, education, and training in pediatric oncology-hematology]. / Multidisciplinarité et formation des spécialistes à l'oncologie et à l'hématologie maligne pédiatrique.

INTRODUCTION: According to the European Society of Pediatric Oncology (SIOPE) standard of care guidelines, high-quality care of children and adolescents with cancer needs to be delivered by well-trained multidisciplinary teams in specialist centers working with designated shared-care local centers in a so-called hub-and-spoke model. The Diplôme Inter-Universitaire d'Oncologie Pédiatrique (DIUOP) is the only European training program in pediatric oncology in French for all physicians involved in care of patients with pediatric malignancies. In agreement with the SIOPE syllabus, the DIUOP is composed of training courses (120h), on-site practical training in a specialist center, and a research project to be defended before an examining board. METHOD: All graduates received a questionnaire to describe their current professional position. A comprehensive PubMed analysis retrieved all papers published form DIUOP research projects. RESULTS: From 2000 to 2011, 290 physicians were trained: 242 pediatricians, 21 surgeons, and 19 radiation therapists. Eight had another specialty including imaging, hematology, and pathology. Ninety-two were initially trained outside of France: 50% in Europe (mainly in Italy, Belgium, and Switzerland), 42% in Africa and the Middle East, and 8% in South America. Of the 266 graduates, 74% answered the questionnaire, and 90% of them take care of children and adolescents with cancer. Sixty-nine articles, i.e., one out of four research projects, were published in 34 journals with a median impact factor of 3.5 (0-22.6), 85% in English. CONCLUSION: DIUOP is the only French-speaking European education program providing a high-quality, professionalizing, and comprehensive multidisciplinary training program for French and international specialists taking care of children and adolescents with cancer.

SPRED1, a RAS MAPK pathway inhibitor that causes Legius syndrome, is a tumour suppressor downregulated in paediatric acute myeloblastic leukaemia.

Constitutional dominant loss-of-function mutations in the SPRED1 gene cause a rare phenotype referred as neurofibromatosis type 1 (NF1)-like syndrome or Legius syndrome, consisted of multiple café-au-lait macules, axillary freckling, learning disabilities and macrocephaly. SPRED1 is a negative regulator of the RAS MAPK pathway and can interact with neurofibromin, the NF1 gene product. Individuals with NF1 have a higher risk of haematological malignancies. SPRED1 is highly expressed in haematopoietic cells and negatively regulates haematopoiesis. SPRED1 seemed to be a good candidate for leukaemia predisposition or transformation. We performed SPRED1 mutation screening and expression status in 230 paediatric lymphoblastic and acute myeloblastic leukaemias (AMLs). We found a loss-of-function frameshift SPRED1 mutation in a patient with Legius syndrome. In this patient, the leukaemia blasts karyotype showed a SPRED1 loss of heterozygosity, confirming SPRED1 as a tumour suppressor. Our observation confirmed that acute leukaemias are rare complications of the Legius syndrome. Moreover, SPRED1 was significantly decreased at RNA and protein levels in the majority of AMLs at diagnosis compared with normal or paired complete remission bone marrows. SPRED1 decreased expression correlated with genetic features of AML. Our study reveals a new mechanism which contributes to deregulate RAS MAPK pathway in the vast majority of paediatric AMLs.

Expression of CD34 and CD7 on human T-cell acute lymphoblastic leukemia discriminates functionally heterogeneous cell populations.

Leukemia-initiating/repopulating cells (LICs), also named leukemic stem cells, are responsible for propagating human acute leukemia. Although they have been characterized in various leukemias, their role in T-cell acute lymphoblastic leukemia (T-ALL) is unclear. To identify and characterize LICs in T-ALL (T-LIC), we fractionated peripheral blood cell populations from patient samples by flow cytometry into three cell fractions by using two markers: CD34 (a marker of immature cells and LICs) and CD7 (a marker of early T-cell differentiation). We tested these populations in both in vitro culture assays and in vivo for growth and leukemia development in immune-deficient mice. We found LIC activity in CD7(+) cells only as CD34(+)CD7(-) cells contained normal human progenitors and hematopoietic stem cells that differentiated into T, B lymphoid and myeloid cells. In contrast, CD34(+)CD7(+) cells were enriched in LICs, when compared with CD34(-)CD7(+) cells. These CD34(+)CD7(+) cells also proliferated more upon NOTCH activation than CD34(-)CD7(+) cells and were sensitive to dexamethasone and NOTCH inhibitors. These data show that CD34 and CD7 expression in human T-ALL samples help in discriminating heterogeneous cell populations endowed with different LIC activity, proliferation capacity and responses to drugs.

[Hodgkin disease and autoimmunity in children: 11 case reports]. / Maladie de Hodgkin et auto-immunité chez l'enfant : à propos de 11 observations.

The association of lymphoma and autoimmune manifestations has been predominantly studied in adults affected by non-Hodgkin lymphoma. Few publications exist in the literature concerning Hodgkin lymphoma, particularly in children and adolescents. The objectives of this study were to define the characteristics of the link between Hodgkin disease and autoimmunity in childhood. The present 25-year retrospective study was conducted in all centers affiliated with the French Society of Paediatric Oncology (SFCE). Eleven children with Hodgkin disease presented manifestations of disimmunity preceding or following their diagnosis. Four patients had thrombocytopenic purpura, the remaining 7 each had a different autoimmune pathology: lupus syndrome, antiphospholipid syndrome with transient ischemic attack, Evans syndrome, leukocytoclastic vasculitis, autoimmune hemolytic anemia, autoimmune thyroiditis, and juvenile idiopathic arthritis. Lymphoma relapse occurred in 3 patients. Two children died, death being directly attributed to the autoimmune disease in 1 case. Our data suggest that development of autoimmunity is related to significant morbidity. Possible pathophysiological mechanisms include lymphocyte proliferation secondary to chronic inflammation, cell-mediated immune deficiency in Hodgkin disease, molecular mimetics, and antineoplastic phenomena are discussed. A study with a larger patient population is needed to identify the group of children at high risk of autoimmunity for whom additional investigations and modified therapy may be indicated.

[Is there a risk of steroid-induced adrenal deficit after induction treatment of acute lymphoblastic leukemia?]. / Existe-t-il un risque de déficit corticotrope au décours du traitement d'induction d'une leucémie aiguë lymphoblastique ?

The occurrence of eight cases of adrenal deficit in children hospitalized for acute lymphoblastic leukemia (ALL) led us to conduct a prospective study from May 2006 to May 2007 to better characterize this corticoid-induced adrenal deficit. Forty of the 48 patients hospitalized for ALL were given a low-dose Synacthen test (1 µg), a mean 7 days after the induction phase. An adrenal deficit was diagnosed in 27 patients (67.5%). No significant clinical or hematological difference was identified between the "with deficit" (n = 27) and "without deficit" (n = 13) groups. The diagnosis of adrenal deficit was not more common for children who had received dexamethasone (13/19) or prednisone (14/21), or for those who had (19/29) or had not (8/11) experienced corticoid toxicity during induction. The clinical signs suggesting adrenal deficit were identical in the two groups and none of the children presented an acute episode. In biological terms, only hypoprotidemia was significantly more common in patients with adrenal deficit (p = 0.0004). Of 13 patients with a deficit at the end of the induction who had received a 2nd low-dose Synacthène(®) test before intensification no. 1, 3 weeks on average after the end of corticotherapy, only two still had a deficit. Thus, corticoid-induced adrenal deficit is a common complication in children treated for ALL, although it is not highly symptomatic. Most of these children recover normal adrenal function before intensification no. 1, but it does not eliminate the risk of a secondary deficit after other courses of corticotherapy. Systematic repeated Synacthène(®) tests in common practice among children treated for ALL does not seem justified. However, the results of this study encouraged us to propose a hydrocortisone substitution to children treated for ALL in the event of stress.

[Inherited thrombocytopenias]. / Les thrombopénies génétiques.

Secondary causes of thrombocytopenia as immunologic thrombopenia purpura, or ITP, are far more common than inherited causes, which even as a group, are rare. Nevertheless, diagnosis is important and progress made in uncovering the molecular basis of these disorders has contributed greatly to our knowledge of these diseases. Inherited thrombocytopenias are a heterogeneous group of disorders. Different criteria have been suggested to classify the forms, such as the inheritance mechanism and the platelet volume as well as the associated platelet dysfunctions or clinical abnormality. This paper describes the clinical and biological data, and current knowledge of the molecular findings of inherited thrombocytopenia, allowing a diagnostic approach to these diseases.

SPRED1 germline mutations caused a neurofibromatosis type 1 overlapping phenotype.

OBJECTIVE: Germline loss-of-function mutations in the SPRED1 gene have recently been identified in patients fulfilling the National Institutes of Health (NIH) diagnostic criteria for neurofibromatosis type 1 (NF1) but with no NF1 (neurofibromin 1) mutation found, suggesting a neurofibromatosis type 1-like syndrome. METHODS: 61 index cases with NF1 clinical diagnosis but no identifiable NF1 mutation were screened for SPRED1 mutation. RESULTS: We describe one known SPRED1 mutation (c.190C>T leading to p.Arg64Stop) and four novel mutations (c.637C>T leading to p.Gln213Stop, c.2T>C leading to p.Met1Thr, c.46C>T leading to p.Arg16Stop, and c.1048_1060del leading to p.Gly350fs) in five French families. Their NF1-like phenotype was characterised by a high prevalence of café-au-lait spots, freckling, learning disability, and an absence of neurofibromas and Lisch nodules in agreement with the original description. However, we did not observe Noonan-like dysmorphy. It is noteworthy that one patient with the p.Arg16Stop mutation developed a monoblastic acute leukaemia. CONCLUSIONS: In our series, SPRED1 mutations occurred with a prevalence of 0.5% in NF1 patients and in 5% of NF1 patients displaying an NF1-like phenotype. SPRED1 mutated patients did not display any specific dermatologic features that were not present in NF1 patients, except for the absence of neurofibromas that seem to be a specific clinical feature of NF1. The exact phenotypic spectrum and the putative complications of this NF1 overlapping syndrome, in particular haematological malignancies, remain to be further characterised. NIH diagnostic criteria for NF1 must be revised in view of this newly characterised Legius syndrome in order to establish a specific genetic counselling.

Mutations in NALP12 cause hereditary periodic fever syndromes.

NALP proteins, also known as NLRPs, belong to the CATERPILLER protein family involved, like Toll-like receptors, in the recognition of microbial molecules and the subsequent activation of inflammatory and immune responses. Current advances in the function of NALPs support the recently proposed model of a disease continuum bridging autoimmune and autoinflammatory disorders. Among these diseases, hereditary periodic fevers (HPFs) are Mendelian disorders associated with sequence variations in very few genes; these variations are mostly missense mutations whose deleterious effect, which is particularly difficult to assess, is often questionable. The growing number of identified sporadic cases of periodic fever syndrome, together with the lack of discriminatory clinical criteria, has greatly hampered the identification of new disease-causing genes, a step that is, however, essential for appropriate management of these disorders. Using a candidate gene approach, we identified nonambiguous mutations in NALP12 (i.e., nonsense and splice site) in two families with periodic fever syndromes. As shown by means of functional studies, these two NALP12 mutations have a deleterious effect on NF-kappaB signaling. Overall, these data identify a group of HPFs defined by molecular defects in NALP12, opening up new ways to manage these disorders. The identification of these first NALP12 mutations in patients with autoinflammatory disorder also clearly demonstrates the crucial role of NALP12 in inflammatory signaling pathways, thereby assigning a precise function to this particular member of an emerging family of proteins whose putative biological properties are currently inferred essentially through in vitro means.

[A pediatric case of Alveolar Soft Part Sarcoma]. / Sarcome alvéolaire de la langue: un cas pédiatrique.

INTRODUCTION: Alveolar Soft Part Sarcoma (ASPS) is a rare malignant tumor arising from skeletal muscles and occurring usually in young adults. It is a solid chemo resistant tumor. At time of diagnosis the disease is usually advanced and lung metastasis are present in 65% of the cases. The translocation (X; 17), producing an ASPL-TFE3 transcript fusion which is detected on tumoral cells wall, is specific of ASPS. The curative treatment is surgical. CLINICAL REPORT: We report the case of a child with an ASPS of the tongue and lung metastasis. DISCUSSION: This report presents two particularities. Firstly this type of sarcoma is very exceptional in a 2-year-old child. Secondly ASPS is not usually susceptible to chemotherapy.

Age and high-dose methotrexate are associated to clinical acute encephalopathy in FRALLE 93 trial for acute lymphoblastic leukemia in children.

The objective of the study was to assess acute neurotoxicity associated with triple intrathecal therapy (TIT)+/-high-dose methotrexate (HD MTX) in children with acute lymphoblastic leukemia (ALL). 1395 children were enrolled on FRALLE 93 protocol from 1993 to 1999. Lower-risk group (LR, n=182) were randomized to weekly low-dose MTX at 25 mg/m(2)/week (LD MTX, n=81) or HD MTX at 1.5 g/m(2)/2 weeks x 6 (n=77). Intermediate-risk group (IR, n=672) were randomized to LD MTX (n=290) or HD MTX at 8 g/m(2)/2 weeks x 4 (n=316). Higher-risk group (HR, n=541) prednisone-responder patients received LD MTX and cranial radiotherapy. HR group steroid resistant cases were grafted (autologous or allogenic). TIT (MTX, cytarabine and methylprednisolone) was given every 2 weeks during 16-18 weeks and every 3 months during maintenance therapy in LR and IR patients. 52 patients (3.7%) developed neurotoxicity. Isolated seizures: n=15 (1.1%), peripheral and spinal neuropathy: n=17 (1.2%) and encephalopathy: n=20 (1.4%). Age >10 years was significantly associated with neurotoxicity (P=0.01) and use of HD MTX is associated with encephalopathy (P=0.03). Sequels are reported respectively in 60 and 33% of spinal neuropathy and encephalopathy cases. Current strategies tailoring risk of neurological sequels has to be defined.