Pascale Schneider

Myelodysplasia and leukemia of Fanconi anemia are associated with a specific pattern of genomic abnormalities that includes cryptic RUNX1/AML1 lesions

Fanconi anemia (FA) is a genetic condition associated with bone marrow (BM) failure, myelodysplasia (MDS), and acute myeloid leukemia (AML). We studied 57 FA patients with hypoplastic or aplastic anemia (n = 20), MDS (n = 18), AML (n = 11), or no BM abnormality (n = 8). BM samples were analyzed by karyotype, high-density DNA arrays with respect to paired fibroblasts, and by selected oncogene sequencing. A specific pattern of chromosomal abnormalities was found in MDS/AML, which included 1q+ (44.8%), 3q+ (41.4%), -7/7q (17.2%), and 11q- (13.8%). Moreover, cryptic RUNX1/AML1 lesions (translocations, deletions, or mutations) were observed for the first time in FA (20.7%). Rare mutations of NRAS, FLT3-ITD, MLL-PTD, ERG amplification, and ZFP36L2-PRDM16 translocation, but no TP53, TET2, CBL, NPM1, and CEBPα mutations were found. Frequent homozygosity regions were related not to somatic copy-neutral loss of heterozygosity but to consanguinity, suggesting that homologous recombination is not a common progression mechanism in FA. Importantly, the RUNX1 and other chromosomal/genomic lesions were found at the MDS/AML stages, except for 1q+, which was found at all stages. These data have implications for staging and therapeutic managing in FA patients, and also to analyze the mechanisms of clonal evolution and oncogenesis in a background of genomic instability and BM failure.

Use of Recombinant Human Granulocyte Colony-Stimulating Factor to Increase Chemotherapy Dose-Intensity: A Randomized Trial in Very High-Risk Childhood Acute Lymphoblastic Leukemia

PURPOSEnTo determine whether the use of a recombinant human granulocyte colony-stimulating factor ([G-CSF] lenogastrim) can increase the chemotherapy dose-intensity (CDI) delivered during consolidation chemotherapy of childhood acute lymphoblastic leukemia (ALL).nnnPATIENTS AND METHODSnSixty-seven children with very high-risk ALL were randomized (slow early response to therapy, 55 patients; translocation t(9;22) or t(4;11), 12 patients). Consolidation consisted of six courses of chemotherapy; the first, third, and fifth courses were a combination of high-dose cytarabine, etoposide, and dexamethasone (R3), whereas the second, fourth, and sixth courses included vincristine, prednisone, cyclophosphamide, doxorubicin, and methotrexate (COPADM). G-CSF was given after each course, and the next scheduled course was started as soon as neutrophil count was > 1 x 10(9)/L and platelet count was > 100 x 10(9)/L. CDI was calculated using the interval from day 1 of the first course to hematologic recovery after the fifth course (100% CDI = 105-day interval).nnnRESULTSnCDI was significantly increased in the G-CSF group compared with the non-G-CSF group (mean +/- 95% confidence interval, 105 +/- 5% v 91 +/- 4%; P <.001). This higher intensity was a result of shorter post-R3 intervals in the G-CSF group, whereas the post-COPADM intervals were not statistically reduced. After the R3 courses, the number of days with fever and intravenous antibiotics and duration of hospitalization were significantly decreased by G-CSF, whereas reductions observed after COPADM were not statistically significant. Duration of granulocytopenia was reduced in the G-CSF group, but thrombocytopenia was prolonged, and the number of platelet transfusions was increased. Finally, the 3-year probability of event-free survival was not different between the two groups.nnnCONCLUSIONnG-CSF can increase CDI in high-risk childhood ALL. Its effects depend on the chemotherapy regimen given before G-CSF administration. In our study, a higher CDI did not improve disease control.

Carboplatin before and during radiation therapy for the treatment of malignant brain stem tumours: a study by the Société Française d'Oncologie Pédiatrique.

Childhood malignant brain stem tumours have a very poor prognosis with a median survival of 9 months despite radiotherapy. No chemotherapy has improved survival. However, carboplatin has been reported to have activity in glial tumours as well as antitumour synergy with radiation. Our aims were to test the response rate of these tumours to carboplatin alone and to evaluate the efficacy on survival of carboplatin alone followed by concurrent carboplatin and radiotherapy. Patients younger than 16 years with typical clinical and radiological presentation of infiltrating brain stem tumour, as well as histologically-documented cases in the atypical forms, were eligible. Two courses of carboplatin (1050 mg/m2 over 3 days) were administered initially. This treatment was followed by a chemoradiotherapy phase including five weekly carboplatin courses (200 mg/m2) and conventional radiotherapy. 38 eligible patients were included. No tumour response was observed after the initial phase. This schedule of first-line carboplatin followed by concurrent carboplatin and radiotherapy did not improve survival.

Multicenter randomized trial of chewing gum for preventing oral mucositis in children receiving chemotherapy.

The properties of saliva led us to hypothesize that the salivary flow increase induced by gum chewing might protect the oral mucosa from lesions due to cancer chemotherapy. We conducted a multicenter randomized trial to evaluate the efficacy of chewing gum in preventing oral mucositis in 145 children receiving chemotherapy regimens expected to induce WHO grade 3-4 oral mucositis in at least 30% of patients. Patients were allocated at random to standard oral care with or without 5 gum pieces per day. No overall reduction in severe oral mucositis occurred in the gum arm (51%) compared with the standard arm (44%). VIDE, COPADM, and multidrug intensive chemotherapy caused severe oral mucositis in 75% of patients in both arms. In patients receiving less toxic regimens, a decrease in WHO grade 1-4 oral mucositis was noted in the gum arm compared with the standard arm (49% vs. 72%, P=0.03). In the multivariate analysis, the risk of oral mucositis was related only to the type of chemotherapy regimen, suggesting that further strategies for preventing oral mucositis could be mainly based on these criteria.

French Multicenter 22-Year Experience in Stem Cell Transplantation for Beta-Thalassemia Major: Lessons and Future Directions

Although hematopoietic stem cell transplantation (HSCT) offers curative potential for beta-thalassemia major (beta-TM), it is associated with a variable but significant incidence of graft rejection. We studied the French national experience for improvement over time and the potential benefit of antithymocyte globulin (ATG). Between December 1985 and December 2007, 108 patients with beta-TM underwent HSCT in 21 different French transplantation centers. The majority of patients received a matched sibling transplant (n = 96) and a busulfan- and cyclophosphamide-based conditioning regimen (n = 95), also with ATG in 57 cases. Ninety-five of the 108 patients survived, with a median follow-up of 12 years. Probabilities of 15-year survival and thalassemia-free survival after first HSCT were 86.8% and 69.4%, respectively. Graft failure occurred in 24 patients, 11 of whom underwent a second HSCT. The use of ATG was associated with a decrease in rejection rate from 35% to 10%. Thalassemia-free survival improved significantly with time, reaching 83% in the 54 patients undergoing HSCT after 1994 (median time of HSCT). In view of the increased risk of graft rejection after matched sibling HSCT, current French national guidelines recommend, for all children at risk for beta-TM, the systematic addition of ATG to the myeloablative conditioning regimen and special attention to optimize transfusion and chelation therapy in the pretransplantation period.

Excellent prognosis of late relapses of ETV6/RUNX1-positive childhood acute lymphoblastic leukemia: lessons from the FRALLE 93 protocol.

Background The prognosis of patients with relapses of ETV6/RUNX1-positive acute lymphoblastic leukemia remains to be evaluated, particularly with regards to the frequency of late relapses. We performed a long-term, follow-up retrospective study to address the outcome of patients with ETV6/RUNX1-positive leukemia relapses. Design and Methods Among the 713 children tested for ETV6/RUNX1 enrolled into the FRALLE 93 protocol, 43 ETV6/RUNX1-positive patients relapsed (19.4%). Most were initially stratified in the low or intermediate risk groups. The median follow-up after relapse was 54.2 months. All but three received second-line salvage therapy and 16 underwent allogeneic transplantation. Results ETV6/RUNX1 had a strong effect on overall survival after relapse (3-year survival= 64.7% for positive cases versus 46.5% for negative cases) (P=0.007). The 5-year cumulative incidence of relapse was 19.4% and testes were more frequently involved in ETV6/RUNX1-positive relapses (P=0.04). In 81.4% of cases the relapses were late, early combined or isolated extramedullary relapses. The 5-year survival rate of patients with ETV6-RUNX1-positive acute lymphoblastic leukemia relapses reached 80.8% when the relapse occurred after 36 months (versus 31.2% when the relapse occurred earlier). In univariate analysis, female gender was associated with a poor survival, whereas site of relapse, age at diagnosis, leukocytosis and consolidation strategy had no effect. In multivariate analysis, only the duration of first remission remained associated with outcome. Conclusions We found an excellent outcome for patients with ETV6/RUNX1-positive leukemia relapses that occurred more than 36 months after diagnosis. The duration of first complete remission may, therefore, be a guide to define the treatment strategy for patients with relapsed ETV6/RUNX1- positive leukemia. Key words: ETV6/RUNX1, childhood leukemia, acute lymphoblastic, prognosis, relapse.

Deep intronic hotspot variant unraveling rhabdoid tumor predisposition syndrome in two patients with atypical teratoid and rhabdoid tumor

About one third of patients with rhabdoid tumors (RT) harbor a heterozygous germline variant in SMARCB1. Molecular diagnosis therefore keeps a crucial place in the diagnosis of RT, and genetic counseling should be systematically recommended. However, immunohistochemistry has progressively replaced molecular tools to assess the status of SMARCB1 in tumors; the necessity of analyzing SMARCB1 status in the tumor may thus be less considered by neuropathologists and pediatric neuro-oncologists. In the present manuscript as aforementioned, we report on two patients with bifocal RT in the first month of life and in whom no germline variant was initially found in the SMARCB1 coding sequence. Careful analysis of SMARCB1 status in the tumors revealed that only one of the two inactivating hits was found in the coding sequence. By sequencing the tumor cells RNA, we were able to detect an insertion with an abnormal sequence, due to the same intronic variant of SMARCB1, which led to the exonisation of the first intron. This cryptic variant was absent in the germline DNA of both patients. Of note, we previously reported one patient with the same deep intronic variant in the germline in a soft tissue RT. To our mind, this additional report on two patients clearly demonstrates that this intronic variant is a new hotspot that should now be systematically added to the germline screening of SMARCB1. We therefore recommend searching for and cautiously interpreting germline analysis if SMARCB1 has not been extensively studied in the tumor.

A Pharmacokinetic and Pharmacogenetic Analysis of Osteosarcoma Patients Treated With High‐Dose Methotrexate: Data From the OS2006/Sarcoma‐09 Trial

Growing evidence suggests that polymorphisms of genes coding for transporters or enzymes may partially explain the large between subject variability reported for methotrexate (MTX) pharmacokinetics (PK). This prospective study aimed to develop a population PK‐pharmacogenetic model to evaluate the part of between‐subject variability due to single‐nucleotide polymorphisms (SNPs) in transporters and enzyme genes implicated in MTX distribution and elimination. MTX concentrations and 54 SNPs (located in ABCB1, ABCC1, ABCC2, ABCC3, ABCC4, ABCG2, SLC19A1, SLCO1B1, and UGT1A1 genes) were analyzed in patients treated with MTX included in the OS2006/sarcoma‐09 trial (a multicenter, open‐label, phase III trial, ClinicalTrials.gov. Identifier: NCT00470223). PK data were analyzed using the nonlinear mixed‐effect modeling software program Monolix. The influence of each SNP was evaluated using a stepwise procedure under additive, recessive, or dominant genetic model. The likelihood ratio test was used to test the effect of each SNP on PK parameters. Overall, 187 patients with 7898 MTX blood concentrations were included in the PK‐pharmacogenetic analysis. A 2‐compartment model adequately described the data. Although high‐dose MTX dosing recommendations in pediatric patients are currently based on body surface area, body weight was more predictive of clearance between‐subject variability than body surface area. The most significant polymorphism associated with MTX clearance was rs13120400 (on the ABCG2 gene) under the recessive genetic model (P < .0001). GG genotype carriers for rs13120400 appeared to have a moderate decrease in MTX exposure compared to AA or GA carriers.