Mutação do gene da Isocitrato Desidrogenase 1 e a relação com o prognóstico e a sensibilidade ao tratamento com radioterapia em gliomas difusos

Abstract

Introduction: In 2014, 256,000 new cases of Central Nervous System (CNS) tumors were diagnosed, in Brazil estimated 11,320 new cases were diagnosed in 2018. Gliomas accounted for 20% of cases and 80% of malignant tumors. Mutations in the isocitrate dehydrogenase 1 (HDH1) gene are present in more than 80% of the oligodendrogliomas and oligoastrocytomas grades II, III and glioblastomas and have been found more comprehensively in patients. Radiotherapy has played a key role in the treatment of gliomas and as an antihypertensive therapy. Methodology: The study evaluated 20 patients diagnosed with glioma after radiotherapy at Hospital de Clínicas Federal University of Uberlândia between 2005 and 2016. Histological blocks with tumor tissue of the patients were submitted to the TMA technique, followed by HE staining for histological confirmation and immunohistochemistry to observe the status of the IDH1 mutation. Statistically, a significance level of 5% (p <0.05) was used, the survival curves were estimated using the Kaplan-Meier method and Cox proportional azar Regression using SPSS software v.21. Results: The IDH1 mutation was found in 45% of the patients. The analysis of the variables did not present more univariate without adjustments than the variables compatible with the were: advanced age, diagnosis of high grade infiltrative glioma, radiotherapy dose <3060 c and absence of mutation in the HDI. Identification of the IDH1 mutation was identified as an updating factor in the univariate analysis, conferring survival benefit to the mutated patients (p = 0.020), but did not remain as an independent variable in the multivariate evaluation. What is a way of making a difference between sex, an anatomical location of the lesion, and an extent of surgical resection in relation to overall survival. There was an increased incidence of death in patients receiving low doses of radiotherapy (p = 0.001). Conclusion: Mutated patients who were submitted to high doses of radiotherapy showed a trend of better survival when compared to patients without the mutation and who received low doses of radiotherapy.