Nozomi Hirai

Prophylactic Intra-arterial Administration of Fasudil Hydrochloride for Vasospasm Following Subarachnoid Haemorrhage

PURPOSE We evaluated patients treated with prophylactic intra-arterial administration of fasudil hydrochloride (IAF) after subarachnoid haemorrhage (SAH). MATERIALS AND METHODS Between August 1998 and December 2012, 92 patients with aneurysmal SAH were treated with IAF for angiographic vasospasm without ischemic symptoms after their follow-up angiography. Patients comprised 50 women and 42 men, aged 24-83 (mean 56.6) years. IAF consisted of 15 mg of fasudil hydrochloride dissolved in 20 ml physiological saline and injected through a catheter during approximately 15 min, after diagnostic angiography. The clinical outcome was evaluated using the Glasgow Outcome Scale (GOS) at discharge and ischemic lesions resulting from vasospasm were assessed on computed tomography (CT) scan at discharge. RESULTS Forty-eight patients underwent surgical clipping and 44 patients underwent endovascular coiling. Angiographic improvement was observed in all patients (100 %). At discharge, 76 (83.0 %) of 92 patients showed good recovery on GOS. Nine patients developed progression of delayed ischemic neurological deficits (DIND) and three of these patients had ischemic lesions on CT scans. No patient had any significant changes in vital signs or any other adverse effects resulting from IAF. CONCLUSION IAF therapy was safe and effective for patients with vasospasm following SAH. Prophylactic IAF therapy may prevent symptomatic vasospasm.

Abstract 774: Notch pathway activation predicts resistance to bevacizumab therapy in glioblastoma

Glioblastoma, the most common adult glioma, is associated with a dismal prognosis. Treatment with bevacizumab has not significantly prolonged overall patient survival times. Glioblastoma resistance to angiogenesis inhibitors is attributed to multiple interacting mechanisms. We have thus embarked on a comprehensive effort to detecting expression signatures that are associated with response to the therapy and these signatures may allow prospective selection of patients with high likelihood of responding to therapy. Notch signaling pathway is an evolutionarily conserved pathway that plays an important role in multiple cellular and developmental processes including cell fate decision, differentiation, proliferation, survival, angiogenesis and migration. Analysis of The Cancer Genome Atlas expression dataset identified a group (43.9%) of tumors with proneural signature showing high Notch pathway activation. In this study, we compared CD133, Notch, and VEGF expressions in histological sections of primary and recurrent glioblastomas after radiotherapy and chemotherapy. Tumor samples were collected from 27 patients at the time of tumor recurrence. We used immunohistochemical techniques to compare expression of CD133, Notch-1 and VEGF. Expressions of CD133-, Notch-1-, and VEGF-positive glioma cells were higher in recurrent glioblastoma after radiotherapy and chemotherapy. To determine the clinical importance of Notch-1 expression in glioblastoma, we analyzed 15 patients who had received bevacizumab therapy followed by a second surgery at recurrence. OS was significantly longer in cases with Notch-1 negativity (8.8 months) than in those with Notch-1 positivity (6.8 months). Electron microscopic observation of two autopsy cases revealed the effects of blood vessel normalization in Notch-1 positive glioblastoma. Electron microscopic images confirmed the presence of pericytes surrounding the vascular endothelium. Autopsied tumors exhibited marked proliferation of Notch-1 and VEGF positive cells around vessels. In tumor angiogenesis, vascular endothelial growth factor and Notch signaling induce sprouting angiogenesis and recruitment of vascular endothelial cells such as tip cells, stalk cells, and phalanx cells. Fully mature phalanx cells are in close contact with pericytes. These findings indicate that bevacizumab treatment promotes vascular normalization by recruiting mature pericytes and associated with resistance to bevacizumab therapy in glioblastoma with high Notch pathway activation. Citation Format: Norihiko Saito, Kazuya Aoki, Nozomi Hirai, Satoshi Fujita, Junya Iwama, Masashi Ikota, Haruo Nakayama, Morito Hayashi, Keisuke Ito, Takatoshi Sakurai, Satoshi Iwabuchi. Notch pathway activation predicts resistance to bevacizumab therapy in glioblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 774. doi:10.1158/1538-7445.AM2017-774