الفهرس 
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Abstract
Gliomas are the most common primary brain tumors in adults. Glioblastoma, WHO grade 4, is the most common type of glioma. IDH1 mutations participate in occurrence and development of glioma. So, IDH1 mutation is an important target for prevention and treatment of glioma. Increasing grades of gliomas correlates with increased cellularity and poorly organized tumor vasculature leading to insufficient blood supply. Hypoxia (through activating Hypoxia-inducible factor-1α) induces changes in the biology of tumor and its micro-environment leading to increased aggressiveness and resistance to chemotherapy and radiation.
In this study 71 glioma cases were included. Median age of patients was about 42 years. 87.3% of cases were adults (more than 18 year old). Females were slightly predominant (52%). Regarding tumor location; 43.7 of gliomas were left sided and 85.5% of the intracranial gliomas were supratentorial. Frontal lobe was the most frequent site for tumors limited to one lobe. The mean largest diameter of the specimens was 4.22 cm. Concerning diagnosis; 26.8% of cases were glioblastomas. Regarding tumor grade; 42.3% were grade 4 gliomas.
IDH1-R132H immunohistochemistry was performed to grade 2,3and 4 astrocytic and oligodendroglial tumors (51 cases). 62.7% of cases were IDH1-mutant. IDH1 mutation was significantly higher with younger age. IDH1 mutation was also significantly noted with lower tumor grade and with absence of necrosis.
HIF1α immunohistochemistry was performed for the studied 71 cases, 73.2% of cases were positive for HIF1α expression. Positive group was divided into three categories (25.4% in +1 score, 32.4% in +2 score and 15.5% +3 score( .
There was a statistically significant positive correlation between HIF1α expression scores and patients’ age, supratentorial location, tumor high grade and presence of microscopic necrosis.
We found a statistically significant association between IDH1-R132H mutation and lower HIF1α expression.