CN-14 * RETROSPECTIVE ANALYSIS OF ISCHEMIC CEREBRAL STROKES IN PATIENTS DIAGNOSED WITH A GLIOBLASTOMA DURING THE COURSE OF A BEVACIZUMAB TREATMENT

Abstract

Bevacizumab is an anti-vascular endothelial growth factor approved in the treatment of recurrent glioblastoma. It prolongs progression-free survival, improes radiologic response and contributes to reduce the dose of dexametha-sonerequired to control peritumoral edema. Arterial and venous thromboem-bolic events represent significant toxicities related to the use of angiogenesis inhibitors. Various mechanisms could be implicated in bevacizumab-related strokes, as cardioembolic, lacunar stroke related to hypertension, deep venous thrombosis passing through a patent foramen ovale, pro-coagulant effect of the underlying glioblastoma and radiation-induced damages on peri-tumoral vessels. The characterization of the risk factors and stroke mechanisms is primordial since bevacizumab is currently used in the treatment of glioblastoma and VEGF receptor tyrosine-kinase inhibitors are actually in clinical trials for malignant gliomas. The prevention and optimal treatment of strokes depend on a precise description of the pathophysiological mechanisms involved. This retrospective study is performed with the collaboration of Roche to evaluate in detail risk factors and stroke mechanisms in the popu-lation of patients diagnosed with a glioblastoma who presented an ischemicce-rebral stroke during the course ofa bevacizumab treatment. The impact of the stroke on the overall survival and the location of the infarct in relation to the tumor emplacement will also be evaluated. This project will be completed in time for the SNO meeting, since we received the official approval from Roche and the ethics committee of Princess Margaret Hospital.