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Br J Haematol ; 183(4): 608-617, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30421536


Neurodegenerative (ND) complications in Langerhans cell histiocytosis (LCH) are a late-onset but dramatic sequelae for which incidence and risk factors are not well defined. Based on a national prospective registry of paediatric LCH patients, we determined the incidence rate of clinical ND LCH (cND-LCH) and analysed risk factors, taking into account disease extent and molecular characteristics. Among 1897 LCH patients, 36 (1·9%) were diagnosed with a cND-LCH. The 10-year cumulative incidence of cND-LCH was 4·1%. cND-LCH typically affected patients previously treated for a multisystem, risk organ-negative LCH, represented in 69·4% of cND-LCH cases. Pituitary gland, skin and base skull/orbit bone lesions were more frequent (P < 0·001) in cND-LCH patients compared to those without cND-LCH (respectively 86·1% vs. 12·2%, 75·0% vs. 34·2%, and 63·9% vs. 28·4%). The 'cND susceptible patients' (n = 671) i.e., children who had experienced LCH disease with pituitary or skull base or orbit bone involvement, had a 10-year cND risk of 7·8% vs. 0% for patients who did not meet these criteria. Finally, BRAFV 600E status added important information among these cND susceptible patients, with the 10-year cND risk of 33·1% if a BRAFV 600E mutation was present compared to 2·9% if it was absent (P = 0·002).

Br J Haematol ; 178(3): 457-467, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28444728


The BRAFV600E mutation is reported in half of patients with Langerhans cell histiocytosis (LCH). This study investigated the detection of the BRAFV600E allele in circulating cell-free (ccf) DNA in a paediatric LCH cohort. Children with BRAFV600E -mutated LCH were investigated to detect ccf BRAFV600E at diagnosis (n = 48) and during follow-up (n = 17) using a picolitre-droplet digital PCR assay. At diagnosis, ccf BRAFV600E was positive in 15/15 (100%) patients with risk-organ positive multisystem (RO+ MS) LCH, 5/12 (42%) of patients with RO- MS LCH and 3/21 (14%) patients with single-system (SS) LCH (P < 0·001, Fisher's exact test). The positive BRAFV600E load was higher for RO+ patients (mean, 2·90%; range, 0·04-11·4%) than for RO- patients (mean, 0·16%; range, 0·01-0·39) (P = 0·003, Mann-Whitney U test). After first-line vinblastine-steroid induction therapy, 7/7 (100%) of the non-responders remained positive for ccf BRAFV600E compared to 2/4 (50%) of the partial-responders and 0/4 of the complete responders (P = 0·002, Fisher's exact test). Six children treated with vemurafenib showed a clinical response that was associated with a decrease in the ccf BRAFV600E load at day 15. Thus, ccf BRAFV600E is a promising biomarker for monitoring the response to therapy for children with RO+ MS LCH or RO- LCH resistant to first-line chemotherapy.

Histiocitose de Células de Langerhans/diagnóstico , Proteínas Proto-Oncogênicas B-raf/sangue , Adolescente , Alelos , Biomarcadores/sangue , Sistema Livre de Células/metabolismo , Criança , Pré-Escolar , Monitoramento de Medicamentos/métodos , Quimioterapia Combinada , Feminino , Seguimentos , Glucocorticoides/uso terapêutico , Histiocitose de Células de Langerhans/tratamento farmacológico , Histiocitose de Células de Langerhans/genética , Humanos , Indóis/uso terapêutico , Lactente , Masculino , Mutação , Prognóstico , Proteínas Proto-Oncogênicas B-raf/genética , Sulfonamidas/uso terapêutico , Vemurafenib , Vimblastina/uso terapêutico
J Clin Oncol ; 34(25): 3023-30, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27382093


PURPOSE: Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasia with a broad spectrum of clinical manifestations and outcomes in children. The somatic BRAF(V600E) mutation occurs frequently, but clinical significance remains to be determined. PATIENTS AND METHODS: BRAF(V600E) mutation was investigated in a French LCH cohort. We analyzed associations between mutation status and clinical presentation, extent of disease, reactivation rate, response to therapy, and long-term permanent sequelae. RESULTS: Among 315 patients with successfully determined BRAF status, 173 (54.6%) carried a BRAF(V600E) mutation. Patients with BRAF(V600E) manifested more severe disease than did those with wild-type BRAF. Patients with BRAF(V600E) comprised 87.8% of patients (43 of 49) with multisystem LCH with risk organ involvement (liver, spleen, hematology), 68.6% of patients (35 of 51) with multisystem LCH without risk organ involvement, 43.9% of patients (86 of 196) with single-system LCH, and 42.1% of patients (8 of 19) with lung-involved LCH (P < .001). BRAF(V600E) mutation was also associated with organ involvement that could lead to permanent, irreversible damage, such as neurologic (75%) and pituitary (72.9%) injuries. Compared with patients with wild-type BRAF, patients with BRAF(V600E) more commonly displayed resistance to combined vinblastine and corticosteroid therapy (21.9% v 3.3%; P = .001), showed a higher reactivation rate (5-year reactivation rate, 42.8% v 28.1%; P = .006), and had more permanent, long-term consequences from disease or treatment (27.9% v 12.6%; P = .001). CONCLUSION: In children with LCH, BRAF(V600E) mutation was associated with high-risk features, permanent injury, and poor short-term response to chemotherapy. Further population-based studies should be undertaken to confirm our observations and to assess the impact of BRAF inhibitors for this subgroup of patients who may benefit from targeted therapy.

Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Histiocitose de Células de Langerhans/tratamento farmacológico , Histiocitose de Células de Langerhans/genética , Mutação , Proteínas Proto-Oncogênicas B-raf/genética , Adolescente , Corticosteroides/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Criança , Pré-Escolar , Estudos de Coortes , Resistencia a Medicamentos Antineoplásicos , Feminino , França/epidemiologia , Histiocitose de Células de Langerhans/enzimologia , Histiocitose de Células de Langerhans/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Terapia de Alvo Molecular , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Sistema de Registros , Vimblastina/administração & dosagem
Orphanet J Rare Dis ; 5: 3, 2010 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-20128925


OBJECTIVE: To document the epidemiological, clinical, histological and radiological characteristics of aggressive vascular abnormalities of bone in children. STUDY DESIGN: Correspondents of the French Society of Childhood Malignancies were asked to notify all cases of aggressive vascular abnormalities of bone diagnosed between January 1988 and September 2009. RESULTS: 21 cases were identified; 62% of the patients were boys. No familial cases were observed, and the disease appeared to be sporadic. Mean age at diagnosis was 8.0 years [0.8-16.9 years]. Median follow-up was 3 years [0.3-17 years]. The main presenting signs were bone fracture (n = 4) and respiratory distress (n = 7), but more indolent onset was observed in 8 cases. Lung involvement, with lymphangiectasies and pleural effusion, was the most frequent form of extraosseous involvement (10/21). Bisphosphonates, alpha interferon and radiotherapy were used as potentially curative treatments. High-dose radiotherapy appeared to be effective on pleural effusion but caused major late sequelae, whereas antiangiogenic drugs like alpha interferon and zoledrenate have had a limited impact on the course of pulmonary complications. The impact of bisphosphonates and alpha interferon on bone lesions was also difficult to assess, owing to insufficient follow-up in most cases, but it was occasionally positive. Six deaths were observed and the overall 10-year mortality rate was about 30%. The prognosis depended mainly on pulmonary and spinal complications. CONCLUSION: Aggressive vascular abnormalities of bone are extremely rare in childhood but are lifethreatening. The impact of anti-angiogenic drugs on pulmonary complications seems to be limited, but they may improve bone lesions.

Doenças Ósseas/epidemiologia , Malformações Vasculares/epidemiologia , Doenças Ósseas/diagnóstico , Doenças Ósseas/tratamento farmacológico , Criança , Difosfonatos/uso terapêutico , Feminino , França/epidemiologia , Humanos , Interferon-alfa/uso terapêutico , Estimativa de Kaplan-Meier , Masculino , Estudos Retrospectivos , Malformações Vasculares/diagnóstico , Malformações Vasculares/tratamento farmacológico