Dominique Valteau-Couanet

Somatic and germline activating mutations of the ALK kinase receptor in neuroblastoma

Neuroblastoma, a tumour derived from the peripheral sympathetic nervous system, is one of the most frequent solid tumours in childhood. It usually occurs sporadically but familial cases are observed, with a subset of cases occurring in association with congenital malformations of the neural crest being linked to germline mutations of the PHOX2B gene. Here we conducted genome-wide comparative genomic hybridization analysis on a large series of neuroblastomas. Copy number increase at the locus encoding the anaplastic lymphoma kinase (ALK) tyrosine kinase receptor was observed recurrently. One particularly informative case presented a high-level gene amplification that was strictly limited to ALK, indicating that this gene may contribute on its own to neuroblastoma development. Through subsequent direct sequencing of cell lines and primary tumour DNAs we identified somatic mutations of the ALK kinase domain that mainly clustered in two hotspots. Germline mutations were observed in two neuroblastoma families, indicating that ALK is a neuroblastoma predisposition gene. Mutated ALK proteins were overexpressed, hyperphosphorylated and showed constitutive kinase activity. The knockdown of ALK expression in ALK-mutated cells, but also in cell lines overexpressing a wild-type ALK, led to a marked decrease of cell proliferation. Altogether, these data identify ALK as a critical player in neuroblastoma development that may hence represent a very attractive therapeutic target in this disease that is still frequently fatal with current treatments.

Overall Genomic Pattern Is a Predictor of Outcome in Neuroblastoma

PURPOSE For a comprehensive overview of the genetic alterations of neuroblastoma, their association and clinical significance, we conducted a whole-genome DNA copy number analysis. PATIENTS AND METHODS A series of 493 neuroblastoma (NB) samples was investigated by array-based comparative genomic hybridization in two consecutive steps (224, then 269 patients). RESULTS Genomic analysis identified several types of profiles. Tumors presenting exclusively whole-chromosome copy number variations were associated with excellent survival. No disease-related death was observed in this group. In contrast, tumors with any type of segmental chromosome alterations characterized patients with a high risk of relapse. Patients with both numerical and segmental abnormalities clearly shared the higher risk of relapse of segmental-only patients. In a multivariate analysis, taking into account the genomic profile, but also previously described individual genetic and clinical markers with prognostic significance, the presence of segmental alterations with (HR, 7.3; 95% CI, 3.7 to 14.5; P < .001) or without MYCN amplification (HR, 4.5; 95% CI, 2.4 to 8.4; P < .001) was the strongest predictor of relapse; the other significant variables were age older than 18 months (HR, 1.8; 95% CI, 1.2 to 2.8; P = .004) and stage 4 (HR, 1.8; 95% CI, 1.2 to 2.7; P = .005). Finally, within tumors showing segmental alterations, stage 4, age, MYCN amplification, 1p and 11q deletions, and 1q gain were independent predictors of decreased overall survival. CONCLUSION The analysis of the overall genomic pattern, which probably unravels particular genomic instability mechanisms rather than the analysis of individual markers, is essential to predict relapse in NB patients. It adds critical prognostic information to conventional markers and should be included in future treatment stratification.

Alternatively spliced NKp30 isoforms affect the prognosis of gastrointestinal stromal tumors

The natural killer (NK) cell receptor NKp30 is involved in the recognition of tumor and dendritic cells (DCs). Here we describe the influence of three NKp30 splice variants on the prognosis of gastrointestinal sarcoma (GIST), a malignancy that expresses NKp30 ligands and that is treated with NK-stimulatory KIT tyrosine kinase inhibitors. Healthy individuals and those with GIST show distinct patterns of transcription of functionally different NKp30 isoforms. In a retrospective analysis of 80 individuals with GIST, predominant expression of the immunosuppressive NKp30c isoform (over the immunostimulatory NKp30a and NKp30b isoforms) was associated with reduced survival of subjects, decreased NKp30-dependent tumor necrosis factor-α (TNF-α) and CD107a release, and defective interferon-γ (IFN-γ) and interleukin-12 (IL-12) secretion in the NK-DC cross-talk that could be restored by blocking of IL-10. Preferential NKp30c expression resulted partly from a single-nucleotide polymorphism at position 3790 in the 3′ untranslated region of the gene encoding NKp30. The genetically determined NKp30 status predicts the clinical outcomes of individuals with GIST independently from KIT mutation.

Defibrotide for prophylaxis of hepatic veno-occlusive disease in paediatric haemopoietic stem-cell transplantation: an open-label, phase 3, randomised controlled trial

BACKGROUND Hepatic veno-occlusive disease is a leading cause of morbidity and mortality after haemopoietic stem-cell transplantation (HSCT). We aimed to assess whether defibrotide can reduce the incidence of veno-occlusive disease in this setting. METHODS In our phase 3 open-label, randomised controlled trial, we enrolled patients at 28 European university hospitals or academic medical centres. Eligible patients were younger than 18 years, had undergone myeloablative conditioning before allogeneic or autologous HSCT, and had one or more risk factor for veno-occlusive disease based on modified Seattle criteria. We centrally assigned eligible participants on the basis of a computer-generated randomisation sequence (1:1), stratified by centre and presence of osteopetrosis, to receive intravenous defibrotide prophylaxis (treatment group) or not (control group). The primary endpoint was incidence of veno-occlusive disease by 30 days after HSCT, adjudicated by a masked, independent review committee, in eligible patients who consented to randomisation (intention-to-treat population), and was assessed with a competing risk approach. Patients in either group who developed veno-occlusive disease received defibrotide for treatment. We assessed adverse events to 180 days after HSCT in all patients who received allocated prophylaxis. This trial is registered with ClinicalTrials.gov, number NCT00272948. FINDINGS Between Jan 25, 2006, and Jan 29, 2009, we enrolled 356 eligible patients to the intention-to-treat population. 22 (12%) of 180 patients randomly allocated to the defibrotide group had veno-occlusive disease by 30 days after HSCT compared with 35 (20%) of 176 controls (risk difference -7·7%, 95% CI -15·3 to -0·1; Z test for competing risk analysis p=0·0488; log-rank test p=0·0507). 154 (87%) of 177 patients in the defibrotide group had adverse events by day 180 compared with 155 (88%) of 176 controls. INTERPRETATION Defibrotide prophylaxis seems to reduce incidence of veno-occlusive disease and is well tolerated. Thus, such prophylaxis could present a useful clinical option for this serious complication of HSCT. FUNDING Gentium SpA, European Group for Blood and Marrow Transplantation.

Advances in Risk Classification and Treatment Strategies for Neuroblastoma

Risk-based treatment approaches for neuroblastoma have been ongoing for decades. However, the criteria used to define risk in various institutional and cooperative groups were disparate, limiting the ability to compare clinical trial results. To mitigate this problem and enhance collaborative research, homogenous pretreatment patient cohorts have been defined by the International Neuroblastoma Risk Group classification system. During the past 30 years, increasingly intensive, multimodality approaches have been developed to treat patients who are classified as high risk, whereas patients with low- or intermediate-risk neuroblastoma have received reduced therapy. This treatment approach has resulted in improved outcome, although survival for high-risk patients remains poor, emphasizing the need for more effective treatments. Increased knowledge regarding the biology and genetic basis of neuroblastoma has led to the discovery of druggable targets and promising, new therapeutic approaches. Collaborative efforts of institutions and international cooperative groups have led to advances in our understanding of neuroblastoma biology, refinements in risk classification, and stratified treatment strategies, resulting in improved outcome. International collaboration will be even more critical when evaluating therapies designed to treat small cohorts of patients with rare actionable mutations.

Osteosarcoma recurrences in pediatric patients previously treated with intensive chemotherapy.

PURPOSE AND METHODS Between January 1981 and June 1993, 137 children and adolescents were each treated at the Institut Gustave Roussy for an initially nonmetastatic osteosarcoma of the extremities. We report the retrospective analysis of 42 cases of recurrence that occurred in this population. RESULTS The median interval between the diagnosis of the primary osteosarcoma and the first recurrence was 21 months (range, 5 to 60). The site of the first recurrence was limited to the lung in 20 patients, the bone in seven patients, was local in six patients, and was confined to soft tissue in one patient. In eight patients, the first recurrence affected multiple sites. Subsequent recurrences often involved unusual or multiple sites. Management of recurrences included surgery and/or various regimens of second-line chemotherapy, and in one case involved high-dose chemotherapy followed by autologous bone marrow transplantation. Overall survival and event-free survival were, respectively, 36% and 27% at 36 months. At present, 13 patients are alive without evidence of disease. Response of the primary tumor to preoperative chemotherapy, the time between the diagnosis and the first recurrence, and the number of metastatic lesions did not correlate with survival. The survival rate is better in patients with a local or a pulmonary first recurrence. CONCLUSION The most important prognostic indicator at first recurrence seems to be the possible complete resection of disease. Patients not amenable to surgery and patients with a second or a third recurrence have a poor prognosis. The potential benefit of more aggressive treatments such as high-dose chemotherapy and autologous bone marrow transplantation should be investigated for these patients.

Prognostic Factors for Death Due to Invasive Aspergillosis after Hematopoietic Stem Cell Transplantation: A 1-Year Retrospective Study of Consecutive Patients at French Transplantation Centers

BACKGROUND Invasive aspergillosis (IA) is a major cause of death after hematopoietic stem cell transplantation (HSCT). The goal of this retrospective and consecutive survey was to assess prognostic factors of death due to IA after HSCT at the time of diagnosis of IA. METHODS All 64 health care centers affiliated with the Société Française de Greffe de Moelle et de Thérapie Cellulaire were contacted to participate in this study of all proven or probable cases of IA that occurred among HSCT recipients in 2002. Data for 51 cases (41 involving allogeneic HSCT and 10 involving autologous HSCT) were collected from patient records and included diagnostic and therapeutic features of IA, outcome, presence of hematological disease, and transplantation data. Cox models were applied to risk factors for death attributed to IA that were initially identified using the usual tests. RESULTS The proportion of deaths attributed to IA within 4 months after diagnosis was 0.62 (95% confidence interval, 0.47-0.76). Seven factors assessed at diagnosis were determined to be strongly related to death due to IA: age of 12-35 years, dissemination of IA, presence of a pleural effusion, monocyte count of <120 cells/mm3, prolonged administration of steroids within the previous 2 months, receipt of a dose > or =2 mg/kg at the time of diagnosis, and uncontrolled graft-versus-host disease.Conclusions. Our study explored potential risk factors for death due to IA among HSCT recipients as a reference for investigation in larger future studies. These factors should help to identify HSCT recipients who would benefit from more-aggressive antifungal therapies.

Correlation of Early Metastatic Response by123I-Metaiodobenzylguanidine Scintigraphy With Overall Response and Event-Free Survival in Stage IV Neuroblastoma

PURPOSE Metaiodobenzylguanidine (MIBG), specifically taken up in cells of sympathetic origin, provides a highly sensitive and specific indicator for the detection of metastases in neuroblastoma. The aim of this study was to correlate early response to therapy by MIBG scan, using a semiquantitative scoring method, with the end induction response and event-free survival (EFS) rate in stage IV neuroblastoma. PATIENTS AND METHODS Seventy-five children older than 1 year and with stage IV neuroblastoma had 123I-MIBG scans at diagnosis, after two and four cycles of induction therapy, and before autologous stem-cell transplantation. The scans were read by two independent observers (concordance > 95%) using a semiquantitative method. Absolute and relative (score divided by initial score) MIBG scores were then correlated with overall pretransplantation response, bone marrow response, and EFS. RESULTS The pretransplantation response rate was 81%, and the 3-year EFS rate was 32%, similar to a concomitant group of 375 stage IV patients. The median relative MIBG scores after two, four, and six cycles were 0.5, 0.24, and 0.12, respectively. The probability of having a complete response or very good partial response before transplantation was significantly higher if the relative score after two cycles was < or = 0.5, or, if after four cycles, the relative score was < or = 0.24. Patients with a relative score of < or = 0.5 after two cycles or a score of < or = 0.24 after four cycles had an improved EFS rate (P =.053 and.045, respectively). CONCLUSION Semiquantitative MIBG score early in therapy provides valuable prognostic information for overall response and EFS, which may be useful in tailoring treatment.

Busulfan disposition and hepatic veno-occlusive disease in children undergoing bone marrow transplantation

Hepatic veno-occlusive disease (HVOD) is a frequent life-threatening toxicity in patients undergoing bone marrow transplantation (BMT) after the administration of a high-dose busulfan-containing regimen. Recent studies have shown that the morbidity and mortality of HVOD may be reduced in adults by pharmacologically guided dose adjustment of busulfan. We analyzed the pharmacodynamic relationship between busulfan disposition and HVOD in 61 children (median age, 5.9 years) with malignant disease. Busulfan, given at a dose ranging from 16 mg/kg to 600 mg/m2, was combined with one or two other alkylating agents (cyclophosphamide, melphalan, thiotepa). Only 3 patients received the standard busulfan/cyclophosphamide (BUCY) regimen. A total of 24 patients (40%) developed HVOD, which resolved in all cases. A pharmacokinetics study confirmed the previously reported wide interpatient variability in busulfan disposition but did not reveal any significant alteration in children with HVOD. The mean area under the concentration-time curve (AUC) after the first dose of busulfan was higher in patients with HVOD (6,811±2,943 ng h ml−1) than in patients without HVOD (5,760±1,891 ng h ml−1;P=0.10). This difference reflects the higher dose of busulfan given to patients with HVOD. No toxic level could be defined and, moreover, none of the toxic levels identified in adults were relevant. The high incidence of HVOD in children given 600 mg/m2 busulfan may be linked to the use of more intensive than usual high-dose chemotherapy regimens and/or drug interactions. Before the prospective evaluation of busulfan dose adjustment in children, further studies are required to demonstrate firmly the existence of a pharmacodynamic relationship in terms of toxicity and allogeneic engraftment, especially when busulfan is combined with cyclophosphamide. The maximal tolerated and minimal effective AUCs in children undergoing BMT are likely to depend mainly upon the disease, the nature of the combined high-dose regimen, and the type of bone marrow transplant.

Feasibility of ovarian tissue cryopreservation for prepubertal females with cancer.

Loss of fertility is one of the long‐term adverse effects of high‐dose chemotherapy or total body irradiation for cancer, even in children. Ovarian tissue cryopreservation (OTC) may make it possible for survivors of childhood cancer to have children. We evaluated the feasibility of this technique for prepubertal girls.