الفهرس 
TitleOnly 14 pages are availabe for public view
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Abstract
Low tumor oxygenation, also known as hypoxia, constitutes a major concern for brain cancer patients, since it promotes cancer cell spreading (invasion) into the healthy brain tissue in order to evade this adverse microenvironment. Tumor invasion not only constitutes a major obstacle to surgery, radiotherapy, and chemotherapy, but it is also the main cause of death in brain cancer patients. Understanding how hypoxia triggers cancer cells to become invasive is paramount to developing novel and more effective therapies against this devastating disease.
The aim of the study was to assess hypoxia markers HIF-1α and VEGF levels in brain cancer patients before and after radiotherapy.
This study included 73 subjects divided into two main groups:
group I: 30 healthy subjects age and sex matched as a control group.
group II: 43 brain cancer patients were subdivided into:
Glioblastoma subgroup: composed of 23 brain cancer patients (18 glioblastoma and 5 brain metastasis)
Meningioma subgroup: composed of 20 Meningioma patients.
Summary, C onclusion & Recommendations
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Our results showed that:
HIF-1α was significantly increased in all Brain Cancer Patients either before or after radiotherapy when compared to their corresponding control values. Moreover, serum HIF-1α significantly increased after radiotherapy treatment when compared to before treatment.
In Glioblastoma subgroup, HIF-1α significantly induced after radiotherapy treatment when compared to before treatment. On the other hand, this parameter significantly decreased after radiotherapy when compared to before treatment in Meningioma subgroup.
Regarding VEGF, it was significantly increased in all Brain Cancer Patients either before or after radiotherapy when compared to their corresponding control values. Moreover, their serum levels were significantly increased after radiotherapy treatment when compared to before treatment.
In Glioblastoma subgroup, VEGF significantly induced after radiotherapy treatment when compared to before treatment. On the other hand, this parameter significantly decreased after radiotherapy when compared to before treatment in Meningioma subgroup.
Both HIF-1α and VEGF serum levels after radiotherapy treatment were significantly higher in glioblastoma subgroup than in meningioma subgroup. Insignificant difference was found in serum HIF-1α and VEGF between the two subgroups before radiotherapy.
Summary, C onclusion & Recommendations
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6.2 Conclusion
According to the present study, we can conclude the followings:
In poor prognosis glioblastoma BCPs, serum HIF-1α and VEGF levels are significantly increased either before or after radiotherapy when compared to their corresponding control values. In addition, these biomarkers significantly induced after exposure to radiotherapy treatment suggesting treatment failure and radioresistance.
In meningioma BCPs, serum HIF-1α and VEGF levels are significantly increased in serum before radiotherapy when compared to their corresponding control values. Moreover, serum biomarkers significantly decreased after radiotherapy treatment when compared to before treatment. The decrease in hypoxia biomarkers after radiotherapy indicating meningioma tumors are radiosensitive and respond well to irradiation.
6.3 Recommendations
The expression of HIF-1α and VEGF should be one of the indicators in the protocol for postoperative radiotherapy in brain cancer patients.
Monitoring HIF-1α and VEGF levels in peripheral blood after radiotherapy may reflect treatment efficacy after surgical removal of the tumor.
Further clinical and experimental trials suggest the combination of ionizing radiation with antiangiogenic therapy and therapeutic approaches designed to overcome tumor hypoxia are in need to improve the efficacy of radiotherapy in GB patients.