Sobrevida de los pacientes con astrocitoma de alto grado que expresan el antígeno Ki67, atendidos en un hospital de pediatría / Survival of patients with malignant astrocytomas according to the expression of Ki67 antigen in a pediatric hospital

Antecedentes: Los pacientes pediátricos con astrocitomas de alto grado con mismas histologías presentan respuestas diferentes a idéntico tratamiento. Es necesario identificar los factores que influyen en el pronóstico y respuesta al mismo. La sobreexpresión de la proteína Ki67 se ha asociado con respuestas poco favorables. El objetivo fue determinar si la expresión de este antígeno influye en la sobrevida de los pacientes con astrocitoma de alto grado del Hospital de Pediatría del Centro Médico Nacional Siglo XXI. Métodos: Se incluyeron pacientes con astrocitoma anaplásico o glioblastoma multiforme atendidos entre 1995 y 2005. Por inmunohistoquímica se determinó la expresión del antígeno Ki67 en las muestras de tejido tumoral y se correlacionó con la histología tumoral y la sobrevida de los pacientes. Resultados: De 21 pacientes, 12 sobreexpresaron el antígeno Ki67. No se encontró asociación estadísticamente significativa entre la sobreexpresión del antígeno Ki67 y la sobrevida, aunque sí clínica. Se encontró asociación estadísticamente significativa entre la sobreexpresión del Ag Ki67 y el grado de malignidad del tumor. La edad menor de 11 años resultó un factor de mal pronóstico. La sobrevida global fue de 49 % a 120 meses. Conclusiones: La edad menor de 11 años fue un factor de mal pronóstico en los pacientes estudiados con astrocitoma o glioblastoma multiforme. La sobreexpresión del antígeno Ki67 está asociada con la histología y pareciera tener relación con la sobrevida de los pacientes pediátricos con astrocitoma.

BACKGROUND: Pediatric patients with malignant gliomas and same histological diagnosis respond distinctly to treatment. It is thus necessary to determine other factors that may influence the response to treatment and survival. Over expression of the Ki67 protein has been associated with poor treatment response. The aim of this study was to determine if the expression of this antigen influences survival of patients treated for malignant gliomas in the CMN SXXI Pediatrics Hospital. METHODS: We included patients with anaplasic astrocitoma or glioblastoma multiforme seen at our hospital between 1995 and 2005. We determined the expression of Ki67 by immunohistochemistry and correlated the findings with tumor histology and patient survival. RESULTS: Of the 21 patients studied, 12 overexpressed antigen Ki67. There was no significant association between over expression of Ki67 and survival, although we observed a clinical association. Over expression of Ki67 correlated with more aggressive histology. Being under the age of 11 was a poor prognostic factor. Overall survival was 49% at 120 months. CONCLUSIONS: Being young (under 11 years) is a marker of poor prognosis among pediatric patients with anaplasic astrocytoma or glioblastoma multiforme. Overexpression expression of antigen Ki67 is associated with histology and may be associated with poor survival among patients treated in our hospital.

Impacto da adição da temozolamida à radioterapia no tratamento de crianças portadoras de tumor de tronco cerebral / Impact of the addition of temozolomide to radiotherapy in the treatment of children with brain stem tumors

OBJETIVO: Analisar o impacto da adição da temozolamida à radioterapia em tumores de tronco cerebral em crianças. MATERIAL E MÉTODO: Entre 2000 e 2005 foram analisadas, retrospectivamente, 64 crianças com tumor do tronco cerebral. Dessas crianças, 32 receberam temozolamida(grupo 1) e 32 não a receberam (grupo 2). RESULTADOS: A idade mediana no grupo 1 foi de 8,2 anos e no grupo 2 foi de 7,5 anos. A localização tumoral era predominantemente difusa (53%) emambos os grupos. Todos os pacientes receberam radioterapia com doses superiores a 50 Gy. No grupo1 foram ministrados nove ciclos, em média, de quimioterapia (3û14 ciclos). O tempo de progressão de doença foi de 7,9 meses no grupo 2 versus 13,8 meses no grupo 1. A sobrevida global foi de 8,8 meses (0,3û30,9 meses) no grupo 1 e de 14,6 meses (4,3û33 meses) no grupo 2. CONCLUSÃO: A utilização da temozolamida após a radioterapia proporcionou aumento da sobrevida, deseis meses em média, nos pacientes pediátricos com tumor do tronco cerebral.

OBJECTIVE: To analyze the impact of adding temozolomide to radiotherapyin pediatric brain stem tumors. MATERIAL AND METHOD: Between 2000 and 2005, 64 children with brain stem tumor were analyzed: 32 received temozolomide (group 1) and 32 did not(group 2). RESULTS: The median age of patients in group 1 was 8.2 year-old and in group 2 was 7.5 year-old. The predominant tumoral localization was diffuse (53%) in both groups. All of the patients were submitted to radiotherapy. In group 1, the median number of temozolomide cycles was 9 (3û14 cycles). Time of disease progression was 7.9 months in group 2 versus 13.8 months in group 1. Overall survival was 8.8 months (0.3û30.9 months) in group 1 and 14.6 months (4.3û33 months) in group 2. CONCLUSION: In our institution,adding temozolomide to radiotherapy increased the overall survival in approximately six months in brain stem pediatric tumors.