The role of apoptosis, cell proliferation index, bcl-2, and p53 in glioblastoma prognosis

Abstract

-Glioblastoma is the most common neuroectodermic tumor. It is also the most malignant one. Many genetic changes are found in glioblastomas, among them, the presence of oncoproteins p53 and blc-2, as well as a high mitotic level and the presence of apoptosis. The utility of such findings through immunohistochemistry for the prognosis of patients remains uncertain. Our objectives in this study were to verify the presence of apoptosis, blc-2, p53, and the proliferative index (MIB-1), through immunohistochemistry, in 30 glioblastomas obtained by surgical resection between August 2000 and August 2001, as well as correlations between those immunohistochemical variables and the patient's age and survival time. Correlations between immunohistochemical variables themselves were also examined. For correlation calculations, Pearson's and Spermann's correlations were used and the time of survival was calculated with the Kaplan-Meier method. Results: No correlation was found between immunohistochemical variables and survival time.There was also no correlation between those variables and the patients' age.A moderate inverse correlation was found between the apoptotic index (AI) and the mitotic index (MI) (p = 0.058), besides an inverse correlation between blc-2 and MI. Conclusion: Our study has not demonstrated any of the examined immunohistochemical findings as having a predictive value in the prognosis of glioblastomas.A reverse correlation was found between AI and MI, which has already been demonstrated by a few studies, as well as an inverse correlation between blc-2 and MI. This finding can demonstrate blc-2 as having a pro-apoptotic role in this group of tumors.KEY WORDS: glioblastoma, apoptosis, p53, bcl-2, MIB-1, prognosis.O papel da apoptose, do índice de proliferação celular, bcl-2 e p53 no prognóstico dos glioblastomas RESUMO -O glioblastoma é o tumor neuroectodérmico mais comum e também o mais maligno. Muitas são as alterações genéti-cas encontradas nos glioblastomas, entre elas, a presença de oncoproteínas p53 e bcl-2, além de elevado índice mitótico e a presença de apoptose. A utilidade desses achados, através da imuno-histoquímica, no prognóstico dos pacientes ainda permanece incerta. Nossos objetivos neste estudo foram verificar a presença de apoptose, bcl-2, p53 e o índice proliferativo (MIB-1), através de imuno-histoquímica, em 30 glioblastomas obtidos através de ressecção cirúrgica entre agosto de 2000 e agosto de 2001 e também as correlações entre estas variáveis imuno-histoquímicas e a idade dos pacientes e o tempo de sobrevida.Também pesquisamos as correlações entre as variáveis imuno-histoquímicas entre si. Para os cálculos de correlação utilizamos Correlação de Pearson e Spearmann e a sobrevida foi calculada através do método de Kaplan-Meier. Resultados: Não houve correlação entre as variáveis imuno-histoquímicas e o tempo de sobrevida.Também não houve correlação entre estas variáveis e as idades dos pacientes. Encontramos correlação inversa de grau moderado entre o índice apoptótico (IA) e o ...

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