Childhood secondary ALL after ALL treatment.

Data on secondary acute lymphoblastic leukaemia (sALL) following ALL treatment are very rare. However, the incidence might be underestimated as sALLs without a significant lineage shift might automatically be diagnosed as relapses. Examination of immunoglobulin and T-cell receptor gene rearrangements brought a new tool that can help in discrimination between relapse and sALL. We focused on the recurrences of childhood ALL to discover the real frequency of the sALL after ALL treatment. We compared clonal markers in matched presentation and recurrence samples of 366 patients treated according to the Berlin-Frankfurt-Munster (BFM)-based protocols. We found two cases of sALL and another three, where the recurrence is suspicious of being sALL rather than relapse. Our proposal for the 'secondary ALL after ALL' diagnostic criteria is as follows: (A) No clonal relationship between diagnosis and recurrence; (B) significant immunophenotypic shift--significant cytogenetic shift--gain/loss of a fusion gene. For the sALL (A) plus at least one (B) criterion should be fulfilled. With these criteria, the estimated frequency of the sALL after ALL is according to our data 0.5-1.5% of ALL recurrences on BFM-based protocols. Finally, we propose a treatment strategy for the patients with secondary disease.

Value of intravenous 6-mercaptopurine during continuation treatment in childhood acute lymphoblastic leukemia and non-Hodgkin's lymphoma: final results of a randomized phase III trial (58881) of the EORTC CLG.

Between November 1990 and November 1996, EORTC Children Leukemia Group conducted a randomized trial in de novo acute lymphoblastic leukemia and lymphoblastic non-Hodgkin's lymphoma patients using a Berlin-Frankfurt-Munster protocol to evaluate the monthly addition of intravenous 6-mercaptopurine (i.v. 6-MP) (1 g/m(2)) to conventional continuation therapy comprising per oral MTX weekly and 6-MP daily. Only during the first 18 months of the randomization period, 6-MP p.o. was interrupted for 1 week after each i.v. 6-MP. A total of 877 patients was randomized to either no i.v. 6-MP (Arm A) or additional i.v. 6-MP (Arm B). A total of 217 relapses (91 in Group A vs 128 in Group B) and 13 deaths in CR (5 vs 8) were reported; a total of 134 patients (55 vs 79) died. The median follow-up was 7.6 years. At 8 years, the disease-free survival rate was lower (P=0.005) in Arm B (69.1% (s.e.=2.2%)) than in Arm A (77.9% (s.e.=2.0%)), and the hazard ratio was 1.45 (95% CI 1.12-1.89). In conclusion, as delivered in this study, i.v. 6-MP was detrimental to event-free survival.

Results of 58872 and 58921 trials in acute myeloblastic leukemia and relative value of chemotherapy vs allogeneic bone marrow transplantation in first complete remission: the EORTC Children Leukemia Group report.

The first EORTC (European Organization of Research and Treatment of Cancer) acute myeloblastic leukemia (AML) pilot study (58872) was conducted between January 1988 and December 1991. Out of 108 patients, 78% achieved complete remission (CR), and event-free survival (EFS) and survival rates (s.e., %) at 7 years were 40 (5) and 51% (6%), respectively. It indicated that mitoxantrone could be substituted for conventional anthracyclines in the treatment of childhood AML without inducing cardiotoxicity. The aim of the next EORTC 58921 trial was to compare the efficacy and toxicity of idarubicin vs mitoxantrone in initial chemotherapy courses, further therapy consisting of allogeneic bone marrow transplantation (alloBMT) in patients with an HLA-compatible sibling donor or chemotherapy in patients without a donor. Out of 177 patients, recruited between October 1992 and December 2002, 81% reached CR. Overall 7-year EFS and survival rates were 49 (4) and 62% (4%), respectively. Out of 145 patients who received the first intensification, 39 had a sibling donor. In patients with or without a donor, the 7-year disease-free survival (DFS) rate was 63 (8) and 57% (5%) and the 7-year survival rate was 78 (7) and 65% (5%), respectively. Patients with favorable, intermediate and unfavorable cytogenetic features had a 5-year EFS rate of 57, 45 and 45% and a 5-year survival rate of 89, 67 and 53%, respectively.

Granulocyte colony-stimulating factor in induction treatment of children with non-Hodgkin's lymphoma: a randomized study of the French Society of Pediatric Oncology.

PURPOSE: To determine whether granulocyte colony-stimulating factor (G-CSF; lenograstim) decreases the incidence of febrile neutropenia after induction courses in treatment of childhood non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Patients were randomized to receive (G-CSF+) or not receive (G-CSF-) prophylactic G-CSF, 5 microg/kg/d, from day 7 until an absolute neutrophil count > or = 500/microL was sustained over 48 hours, after two consecutive induction courses of cyclophosphamide 1.5 or 3 g/m(2), vincristine 2 mg/m(2), prednisone 60 mg/m(2)/d x 5, doxorubicin 60 mg/m(2), high-dose methotrexate 3 or 8 g/m(2), and intrathecal injections (COPAD[M]) on protocols LMB89, LMT89, and HM91 of the French Society of Pediatric Oncology. RESULTS: One hundred forty-eight patients were assessable, 75 G-CSF+ and 73 G-CSF-. Although duration of neutropenia less than 500/microL was 3 days shorter in G-CSF+ patients (P = 10(-4)), incidence of febrile neutropenia (89% v. 93% in the first course, 88% v. 88% in the second course), durations of hospitalization and antimicrobial therapy, percentages of infections, mucositis, and transfusions were not significantly different. Although the percentage of G-CSF+ patients commencing the following course on day 21 was significantly higher (84% v 68% after the first and 57% v. 38% after the second course; P <.05), the median delay between the two courses was only 1 day less in G-CSF+ patients (median delay after first COPAD(M), 19 v. 20 days, P =.01; after second, 21 v. 22 days, P = not significant). Remission and survival rates were similar in both arms. CONCLUSION: This study demonstrates that G-CSF did not decrease treatment-related morbidity, nor increase the dose-intensity in children undergoing COPAD(M) induction chemotherapy for NHL.

Etoposide and carboplatin: a highly effective combination in relapsed or refractory Wilms' tumor--a phase II study by the French Society of Pediatric Oncology.

PURPOSE: Since we had previously demonstrated encouraging efficacy of etoposide in patients with relapsed or refractory Wilms' tumor (WT), the likely synergism between etoposide and platinum compounds prompted us to conduct a phase II study of a combination with carboplatin. PATIENTS AND METHODS: Twenty-six relapsed or refractory WT patients were included in a phase II study of two courses of combination etoposide 100 mg/m2/d for 5 days and carboplatin 160 mg/m2/d for 5 days, with a 21-day interval between the two courses. Initial stages were I (n = 2), II (n = 8), III (n = 6), IV (n = 6), V (n = 3), and unknown (n = 1). Sites of diseases were lung(s) (11 patients), abdomen-pelvis or liver or primary tumor (six patients), and multiple (eight patients). Histology was unfavorable in three of 26 patients. RESULTS: Complete response (CR) was documented in eight patients and partial remission (PR) in 11 (overall response rate, 73%). Stable disease (SD) was observed in five patients and progressive disease (PD) in two. Thrombocytopenia (grade IV) was the major toxicity, and platelet transfusions were required in all but two patients. Grade III anemia and grade III to IV neutropenia were seen in 19 and 23, respectively, of 25 assessable first courses. Venoocclusive disease of the liver was fatal in one child who had undergone irradiation to the whole abdomen, 8 weeks before study. CONCLUSION: Combination etoposide and carboplatin has impressive activity in refractory or relapsed WT at the cost of high-grade hematologic toxicity, especially thrombocytopenia. It is of great interest in second-line therapy, since eight of 26 patients are still alive in continuous CR (median follow-up duration, 40 months; range, 24 to 56). This combination deserves further investigation as first-line or consolidation treatment.

Systemic effect of intrathecal methotrexate during the initial phase of treatment of childhood acute lymphoblastic leukemia. The European Organization for Research and Treatment of Cancer Children's Leukemia Cooperative Group.

PURPOSE: The in vivo response to prephase corticosteroid therapy for 1 week has been described as a major prognostic factor in childhood acute lymphoblastic leukemia (ALL). Patients with less than 1,000 blasts/microL at day 8 are considered responders and have a better prognosis. This prephase therapy is usually considered as an evaluation of glucocorticoid sensitivity. In fact, it also includes one intrathecal (IT) injection of methotrexate (MTX). In this study, we try to clarify the influence of this injection of IT MTX on the response to the prephase therapy. PATIENTS AND METHODS: This retrospective study analyzed the response to prephase therapy in 1,044 children with ALL entered onto the European Organization for Research and Treatment of Cancer (EORTC) trial 58881 of the Children's Leukemia Cooperative Group (CLCG). Analysis was restricted to 732 cases with an initial blast count greater than 1,000/microL. The following variables were tested to analyze response to prephase therapy: age, sex, evaluated risk factor (RF), blast count on day 0, actual dose of prednisolone administered, immunophenotype (T v non-T), and day of IT MTX. For statistical analysis, the variable day of IT MTX (D) was stratified into three groups: group 1 if D less than 2, group 2 if D > or = 2 but < or = 6, and group 3 if D greater than 6. RESULTS: All variables tested had a significant influence on response to the prephase therapy. This was especially true for IT MTX: 90.4% responders in group 1, 76.9% in group 2, and 70% in group 3 (P < .001). Immunophenotype was also a major predictor of response to the prephase: 88% responders in B-lineage ALL versus 56.2% in T-lineage ALL. IT MTX had a significant influence in B-lineage ALL (96% responders in group 1, 90% in group 2, and 79% in group 3; P < .001), whereas the influence could not be detected in T-lineage ALL. CONCLUSION: These results clearly demonstrate a therapeutic systemic effect of low doses of IT MTX in childhood ALL, and response to prephase therapy should not be considered as an in vivo test for cortico-sensitivity only. Earlier use of IT MTX leads to a higher percentage of responders.

High-dose melphalan, etoposide, and carboplatin followed by autologous stem-cell rescue in pediatric high-risk recurrent Wilms' tumor: a French Society of Pediatric Oncology study.

PURPOSE: The three-drug combination of melphalan (M), etoposide (E), and carboplatin (C) followed by autologous stem-cell (ASC) rescue has been evaluated prospectively by the French Society of Pediatric Oncology (SFOP) in pediatric high-risk recurrent (HRR) Wilms' tumor (WT) patients with chemotherapy-responsive disease. PATIENTS AND METHODS: From October 1988 to October 1994, 29 patients with HRR WT were treated in nine SFOP centers. Two additional patients with stage IV anaplastic WT were consolidated in first complete response (CR) with the same regimen and have been studied separately. The regimen consisted of M 180 mg/m2 for 1 day, E 200 mg/m2/d for 5 days, and C at a daily targeted area under the concentration-time curve (AUC) of 4 mg x min/mL for 5 days. ASCs were reinfused 48 hours after M. RESULTS: Twelve of 28 assessable patients with HRR WT are still in continuous CR at a median of 48.5 months (range, 36 to 96) after consolidation. Disease-free survival (DFS) and overall survival (OS) estimated by the Kaplan-Meier method at 3 years were 50%+/-17% and 60%+/-18%, respectively. Sixteen patients relapsed at a median of 8.5 months (range, 3 to 53) after consolidation. Toxicity data are available in 31 grafted patients. Grade III and IV toxicities included hematologic side effects (n=31), hemorrhage (n=8), mucositis (n=24), diarrhea (n=12), renal disorders (n=8), and pneumonitis (n=3). CONCLUSION: The adverse prognostic factors (APF) used to select patients for this dose-intensive chemotherapy define children with very-poor-risk recurrent WT. Despite high treatment-related toxicity, about half of these patients remain disease-free at 3 years. Patient outcome is statistically better when high-dose chemotherapy (HDCT) is performed as early as the second CR or partial response (PR). Novel therapeutic approaches with innovative preparative regimens are warranted for the remaining high-risk patients.

Value of high-dose cytarabine during interval therapy of a Berlin-Frankfurt-Munster-based protocol in increased-risk children with acute lymphoblastic leukemia and lymphoblastic lymphoma: results of the European Organization for Research and Treatment of Cancer 58881 randomized phase III trial.

PURPOSE: The European Organization for Research and Treatment of Cancer 58881 study was designed to test in a prospective multicentric randomized trial the value of high-dose (HD) intravenous (IV) cytarabine (Ara-C) added to HD IV methotrexate (MTX) to reduce the incidence of CNS and systemic relapses in children with increased-risk acute lymphoblastic leukemia (ALL) or stage III and IV lymphoblastic lymphoma treated with a Berlin-Frankfurt-Munster (BFM)-based regimen. PATIENTS AND METHODS: After completion of induction-consolidation phase, children with increased-risk (risk factor > 0.8 or T-lineage) ALL or stage III and IV lymphoblastic lymphoma were randomized to receive four courses of HD MTX (5 g/m(2) over 24 hours every 2 weeks) and four intrathecal administrations of MTX (Arm A) or the same treatment schedule with additional HD IV Ara-C (1 g/m(2) in bolus injection 12 and 24 hours after the start of each MTX infusion) (Arm B). RESULTS: Between January 1990 and January 1996, 653 patients with ALL (593 patients) or lymphoblastic lymphoma (60 patients) were randomized: 323 were assigned to Arm A (without Ara-C) and 330 to Arm B (with Ara-C). A total of 190 events (177 relapses and 13 deaths without relapse) were reported, and the median follow up was 6.5 years (range, 2 to 10 years). The incidence rates of CNS relapse were similar in both arms whether isolated (5.6% and 3.3%, respectively) or combined (5.3% and 4.6%, respectively). The estimated 6-year disease-free survival (DFS) rate was similar (log-rank P =.67) in the two treatment groups: 70.4% (SE = 2.6%) in Arm A and 71.0% (SE = 2.5%) in Arm B. The 6-year DFS rate was similar for ALL and LL patients: 70.2% (SE = 1.9%) versus 76.3% (SE = 5.6%). CONCLUSION: Prevention of CNS relapse was satisfactorily achieved with HD IV MTX and intrathecal injections of MTX in children with increased-risk ALL or stage III and IV lymphoblastic lymphoma treated with our BFM-based treatment protocol in which cranial irradiation was omitted. Disappointingly, with the dose schedule used in this protocol, HD Ara-C added to HD MTX, although well tolerated, failed to further decrease the incidence of CNS relapse or to improve the overall DFS.

Mitoxantrone and high dose Ara-C for the treatment of ANLL in childhood: a pilot study of the EORTC CLCG (EORTC 58 872).

Since January 1988, 91 children with ANLL have been treated with a polychemotherapy regimen containing Mitoxantrone (MTZ), excluding other anthracyclines. Induction consisted of Ara-C, MTZ, and VP 16. Consolidation lasted 6 weeks with Vincristine, MTZ, Ara-C and 6-thioguanine (6TG), and was followed by 2 intensification courses combining High-dose Ara-C with respectively MTZ or VP 16. Maintenance therapy associated 6TG, Ara-C and MTZ up to a cumulative dose of 150 mg/m2. 91 patients are evaluable: 70 (76.9%) achieved complete remission, 59 (64.8%) after induction alone. There were 7 early deaths, 5 deaths in complete remission, and 17 relapses. Major toxic side effects were observed during the consolidation phase, mainly infectious complications, and the median duration of neutropenia was 82 days in this phase, leading to decrease the MTZ dose from 10 to 8 mg/m2. The event-free survival at three years is 38%. Cardiac toxicity is presently absent in children without previous cardiopathy.

Deletion of chromosomal region 13q14.3 in childhood acute lymphoblastic leukemia.

Deletion of the 13q14 chromosomal region is frequent in B cell chronic lymphocytic leukemia (B-CLL) and is believed to inactivate a tumor supressor gene (TSG) next to RB1. We studied microsatellite markers spanning the 13q14 chromosomal region in 138 children with acute lymphoblastic leukemia (ALL). Allelic loss was demonstrated in six cases (4.3%). Deletion did not include RB1 in two cases. In five patients, the deleted region overlapped that described in B-CLL. A sixth patient harbored a smaller deletion, slightly more telomeric than minimal deleted regions reported in B-CLL. Apparent differences in the delineation of the minimal deleted region could be due to the fact that the putative TSG is a very large gene, with some deletions affecting only a part of it. Our present findings suggest that at least some of its exons lie within a region of less than 100 kb more telomeric that previously thought.

Long-term results of three randomized trials (58831, 58832, 58881) in childhood acute lymphoblastic leukemia: a CLCG-EORTC report. Children Leukemia Cooperative Group.

We present here the long-term results of three randomized clinical trials conducted on children with newly diagnosed acute lymphoblastic leukemia (ALL) between 1983 and 1998 by the Children Leukemia Cooperative Group (CLCG) from EORTC. In study 58831/32, the overall event-free survival (EFS) rates (+/- s.e.) at 6 and 10 years were 66% +/- 1.8% and 65% +/- 1.8%, respectively, and the risk of isolated central nervous system (CNS) relapse was 6% +/- 1% and 7% +/- 1%, respectively. In patients with a standard risk of relapse the omission of cyclophosphamide had no adverse effect on disease-free survival rates at 10 years (trial 58831). In medium- and high-risk patients the omission of radiotherapy did not increase the risk of CNS or systemic relapse (trial 58832). In study 58881 (1989-1998) the overall EFS rate at 8 years was 68.4% +/- 1.2% and the risk of isolated CNS relapse was 4.2%+/-0.5%. In this trial which adressed three randomized questions, the following results were obtained: the combination of cytarabine at high doses with methotrexate at high doses during interval therapy did not improve prognosis. The addition of 6-mercaptopurine iv during maintenance increased the risk of late relapse. E. coli asparaginase was more toxic and has a higher efficacy than Erwinia asparaginase. Leukocyte counts >100 x 10(9)/l, specific genetic abnormalities, a poor initial response to steroids or a high level of minimal residual disease at early time points were consistently associated with an adverse prognosis in the 58881 trial.

High-dose thiotepa and hematopoietic stem cell transplantation in pediatric malignant mesenchymal tumors: a phase II study.

The prognosis of metastatic malignant mesenchymal tumors (MMT) remains poor. Given the chemosensitivity of these neoplasms, a phase II study of high-dose thiotepa (HDT) was performed to evaluate the efficacy of this drug in this particular subset of pediatric tumors. Between 1986 and 1998, 18 patients, previously treated with conventional therapy for metastatic or refractory MMT, entered the study. Thiotepa was administered at a daily dose of 300 mg/m2 for 3 consecutive days. Hematopoietic stem cell rescue, consisting of bone marrow transplantation or peripheral stem cell transplantation, was performed 2 days after completion of HDT. A response exceeding 50% was observed in 6/18 patients (response rate 33%). Toxicity was severe but never led to death. HDT used at a dose of 900 mg/m2 yields measurable anti-tumor activity in previously treated patients. The next step in these particularly poor prognosis metastatic MMT will be to investigate HDT combined with other drugs, known to be efficient at high doses.

Virus recovery from stools of patients undergoing bone marrow transplantation.

Diarrhea in marrow transplant recipients is a frequent complication attributable to non-infectious events such as acute GVHD or infectious events such as viral gastroenteritis. Rotavirus and enteric adenovirus are the most frequent viral pathogens. To determine the frequency of these infections, we prospectively examined the stool specimens of 94 patients who underwent autologous BMT (34 cases) or allogeneic BMT (60 cases). Stool specimens were examined from patients twice weekly. Nineteen of the 94 patients were infected with viral pathogens. This study showed: (1) an incidence of viral gastroenteritis identical in autologous and allogeneic BMT (20%), (2) a persistent risk despite treatment in laminar air flow rooms, (3) a significant association with severe acute GVHD, and (4) a significant risk of multiple viral infections in autologous BMT recipients. Rotavirus and adenovirus are a cause of enteritis involvement in patients undergoing BMT and they may be underdiagnosed and confused with GVHD. Screening of stool specimens after BMT should be directed to prevention and treatment of these viral infections to decrease the morbidity and mortality associated with BMT.

[Clostridium perfringens septicemia in drug-induced aplasia]. / Septicémie à Clostridium perfringens au cours d'une aplasie chimio-induite.

Septicemia due to Clostridium perfringens during the course of acute leukemia is rare and often lethal particularly in childhood. Antibiotherapy is necessary but polymorphonuclear activity recovery is helpful. This can be done through transfusion or administration of colony stimulating factors. Here is a new case of such a septicemia in a 12 year-old female treated for acute lymphoblastic leukemia. Of particular interest is the favourable outcome despite a high risk situation.

[Angiomatoid fibrous histiocytoma: a rare pathologic entity]. / Histiocytome fibreux angiomatoïde: une entité rare.

Angiomatoid fibrous histiocytoma is an unusual tumor, affecting primarily young adults who develop local disease with favorable prognosis. This contrasts with the aggressive natural history of malignant fibrohistiocytoma. We report case of a 9-year-old girl who presented with a tumor mass of soft tissues with an unusual deep location, thereby with non distinctive clinical features. Surgical treatment was performed.

[Autoimmune thrombopenic purpura. Therapeutic modalities]. / Purpura thrombopénique auto-immun. Modalités thérapeutiques.

TOP PRIORITY: Preventing hemorrhage is the number one priority in the treatment of idiopathic thrombocytopenic purpura. There are three main treatments: corticosteroids, intravenous immunoglobulins and splenectomy. CORTICOSTEROIDS: The main effects of corticosteroids are to reduce platelet phagocytosis, counteract mechanisms leading to inhibited thrombopoiesis, limit vascular fenestration and endothelial fragility, and immuno-depression. Corticosteroids are usually started at 1 to 2 mg/kg/day for 2 or 3 weeks before rapidly tapering off to final withdrawal after 3 or 4 weeks. IV IMMUNOGLOBULINS: Administered by intravenous injections, immunoglobulins saturate the Fc fragment of the IgGs on the surface of the macrophages, neutralize antiplatelet antibodies, and inhibits synthesis of antiplatelet autoantibodies. Treatment cost is high as is the risk of adverse effects. SPLENECTOMY: The most effective long-term treatment, splenectomy is particularly useful when platelet sequestration, as identified by radiolabeling occurs mainly in the spleen. OTHER THERAPIES: Anti-D immunoglobulins (limited availability), danazol or immuno-suppressors have a beneficial effect which disappears after withdrawal. INDICATIONS: Essential elements are the risk of hemorrhage (low or nil above 30000 platelets/mm3), its severity, patients status (childhood cases usually resolve spontaneously) and prognosis factors (idiopathic thrombocytopenic purpura is a benign disorder).

[Infection and cancer: general information and specific questions]. / Infection et cancer: notions générales et questions actuelles.

The main risk factors of infectious complications in cancer patients result from immune deficiency more or less related to cancer. Prognosis is related to the type and grade of the underlying disease. Prospective studies should be conducted to update data on the frequency of infections, morbidity and mortality (expert agreement). Prospective studies are needed to follow the epidemiology in cancer patients, particularly in neutropenic patients (expert agreement). Prospective studies should be conducted to determine prognosis factors allowing precise recognition of "low-risk" neutropenic patients with fever who could benefit from home care (expert agreement). When infection is suspected, the first criterion determining the therapeutic attitude concern signs of gravity requiring emergency care (septic shock). Beyond this situation, the first criterion determining the therapeutic attitude is the severity of the neutropenia. Microbial diagnosis is essential for initiating and later adapting anti-infectious treatment as well as for assessing efficacy.

Characteristics of endobronchial primitive tumors in children.

Primary endobronchial tumors are rare in children and they include a broad spectrum of lesions. The aim of this study was to determine the characteristic features, treatments and outcomes of these tumors. We report a retrospective analysis of all patients treated for endobronchial tumor in nine French hospitals between 1990 and 2010 and a comparison of the results with those reported in the medical literature. Twelve tumors were reported: five low grade muco epidermoid carcinomas, two inflammatory myofibroblastic tumors, two hemangiomas, one anaplastic large cell lymphoma, one carcinoid tumor, and one juvenile xanthogranuloma. The mean age of the patients was 7.5 ± 3.5 years. The most common sign revealing the disease was persistent atelectasis or recurrent pneumonia (eight cases). The other revealing signs were a persistent bronchospasm (three cases) and hemoptysis (one case). The clinical presentation, biology, serum tumor markers, and chest X-ray abnormalities were not specific to a particular histological diagnosis. Chest CT scan revealed the presence of an endobronchial tumor in 11 cases. Nine tumors could be diagnosed from a biopsy obtained by video endoscopy. Complete surgical resection was performed in seven patients. Bronchoscopic removal was performed in five cases and was successful in three. There were no deaths. Endobronchial tumors are rare in childhood and their histology is diverse. Chest CT scan and per-endoscopic endobronchial biopsies are required for diagnosis, when possible. Surgical or endoscopic treatment should be discussed by a multidisciplinary team. Despite the multiple etiologies, the prognosis of these tumors is good if diagnosis is early and if resection is complete. Long-term recurrences have been described, so long-term follow-up of these children is recommended.

NOTCH1 and FBXW7 mutations have a favorable impact on early response to treatment, but not on outcome, in children with T-cell acute lymphoblastic leukemia (T-ALL) treated on EORTC trials 58881 and 58951.

Risk-adjusted treatment stratification in T-cell acute lymphoblastic leukemias (T-ALLs) is currently based only on early response to chemotherapy. We investigated the prognostic implication of hyperactivation of NOTCH pathway resulting from mutations of NOTCH1 or FBXW7 in children with T-ALL enrolled in EORTC-CLG trials. Overall, 80 out of 134 (60%) patients were NOTCH+ (NOTCH1 and/or FBXW7 mutated). Although clinical presentations were not significantly associated with NOTCH status, NOTCH+ patients showed a better early response to chemotherapy as compared with NOTCH- patients, according to the rate of poor pre-phase 'responders' (25% versus 44%; P=0.02) and the incidence of high minimal residual disease (MRD) levels (11% (7/62) versus 32% (10/31); P=0.01) at completion of induction. However, the outcome of NOTCH+ patients was similar to that of NOTCH- patients, with a 5-year event-free survival (EFS) of 73% and 70% (P=0.82), and 5-year overall survival of 82% and 79% (P=0.62), respectively. In patients with high MRD levels, the 5-year EFS rate was 0% (NOTCH+) versus 42% (NOTCH-), whereas in those with low MRD levels, the outcome was similar: 76% (NOTCH+) versus 78% (NOTCH-). The incidence of isolated central nervous system (CNS) relapses was relatively high in NOTCH1+ patients (8.3%), which could be related to a higher propensity of NOTCH+ leukemic blasts to target the CNS.