Neuroblastoma: validation of the INRG classification system in a small series.

PURPOSE: In 2009, the International Neuroblastoma Risk Group (INRG) published a new classification system of the childhood neuroblastic tumors. In this work, we present the results of the application of this new classification system in our patients. METHODS/PATIENTS: We conducted a retrospective analysis of the patients diagnosed with a neuroblastic tumor in our center in the last 20 years. We classified them according to the new classification and performed a survival analysis based on the Kaplan-Meier method and Mantel-Cox test. RESULTS: The five-year event-free survival (5-year EFS) was 95.8, 80.8, 50 and 45.9% for the very low, low, intermediate and high-risk groups. Mantel-Cox test showed statistically significant differences between these risk groups (p = 0.002). CONCLUSION: The 5-year EFS for the different risk groups was similar to the expected by the INRG. Therefore, this classification allows us to predict the evolution of this tumor and apply the correct intensity of treatment.

Análisis de GATA1 en los trastornos mieloproliferativos asociados a la trisomía 21 / GATA1 analysis in myeloproliferative disorders associated to trisomy 21

Introducción: La enfermedad mieloproliferativa transitoria neonatal y la leucemia aguda megacarioblástica del síndrome de Down se consideran manifestaciones distintas de la misma enfermedad. La mayoría de casos de enfermedad mieloproliferativa transitoria no requiere tratamiento mientras que la leucemia aguda megacarioblástica del síndrome de Down se caracteriza por una elevada sensibilidad a la quimioterapia, lo que ha llevado a la reducción en la intensidad de dosis de tratamiento administrada. Ambas entidades comparten mutaciones específicas en los exones 2 y 3,1 del factor de transcripción GATA1. Pacientes y métodos: Hemos analizado los hallazgos biológicos incluyendo la presencia de mutaciones de GATA1 en cuatro pacientes con enfermedad mieloproliferativa transitoria neonatal (2) y leucemia aguda megacarioblástica (2) incluyendo un paciente fenotípicamente normal portador de un mosaicismo para la trisomía 21. Resultados: En los cuatro casos hemos encontrado la presencia de una clona GATA1 mutante y en tres de ellos se describe una mutación puntual en el exón 2 de dicho gen. Dada la heterogeneidad fenotípica de los blastos megacariocíticos y el bajo porcentaje de estos elementos, la detección de mutaciones en GATA1 resultó de gran utilidad para establecer el diagnóstico. Además, sucesivos resultados normales del análisis mutacional de GATA1 permitieron establecer la remisión molecular en 2 pacientes. Conclusiones: Concluimos que el análisis mutacional de GATA1 es una herramienta útil para el diagnóstico y manejo de los trastornos mieloproliferativos asociados a la trisomía 21 (AU)

Introduction: Neonatal transient myeloproliferative disorder and acute megakaryoblastic leukaemia of Down syndrome are considered different manifestations of the same disease. In most cases, transient myeloproliferative disorders require no treatment, while acute megakaryoblastic leukaemia of Down's syndrome is characterised by an increased sensitivity to chemotherapy and its treatment should be adapted with a reduction in dose intensity. Both entities share specific mutations at exón 2 of the transcription factor GATA1. Patients and methods: We analysed biological features and GATA1 mutations in 4 patients with transient abnormal myelopoiesis (2) and acute megakaryoblastic leukaemia (2) including one phenotypically normal trisomy 21 mosaicism. We found abnormal GATA1 mutated clones in each case, and a specific point mutation at exón 2 was detected in three cases. Given the heterogeneous phenotype of megakaryoblastic blasts and the low percentage of blasts at presentation, the recognition of GATA1 mutations was helpful for diagnosis. In addition, molecular remission was established in 2 patients after subsequent normal mutational GATA1 analysis. Conclusions: We conclude that GATA1 mutational study is a useful tool for the diagnosis and management of trisomy 21 associated myeloproliferative disorders (AU)

[GATA1 analysis in myeloproliferative disorders associated to trisomy 21]. / Análisis de GATA1 en los trastornos mieloproliferativos asociados a la trisomía 21.

INTRODUCTION: Neonatal transient myeloproliferative disorder and acute megakaryoblastic leukaemia of Down syndrome are considered different manifestations of the same disease. In most cases, transient myeloproliferative disorders require no treatment, while acute megakaryoblastic leukaemia of Down's syndrome is characterised by an increased sensitivity to chemotherapy and its treatment should be adapted with a reduction in dose intensity. Both entities share specific mutations at exón 2 of the transcription factor GATA1. PATIENTS AND METHODS: We analysed biological features and GATA1 mutations in 4 patients with transient abnormal myelopoiesis (2) and acute megakaryoblastic leukaemia (2) including one phenotypically normal trisomy 21 mosaicism. We found abnormal GATA1 mutated clones in each case, and a specific point mutation at exón 2 was detected in three cases. Given the heterogeneous phenotype of megakaryoblastic blasts and the low percentage of blasts at presentation, the recognition of GATA1 mutations was helpful for diagnosis. In addition, molecular remission was established in 2 patients after subsequent normal mutational GATA1 analysis. CONCLUSIONS: We conclude that GATA1 mutational study is a useful tool for the diagnosis and management of trisomy 21 associated myeloproliferative disorders.