Speaker: Randy Jensen

Title: Imaging brain tumor hypoxia, angiogenesis and exploiting this for potential therapeutic measures

Abstract:

Malignant glial tumors are thought to have large proportions of hypoxic tissue that contribute to their resistance to radiation, chemotherapy and ultimate poor prognosis. The oxygenation status of a tumor is also a factor in the regulation of gene expression for the malignant progression of tumors. We have compared molecular markers of hypoxia, apoptosis, cellular proliferation, and microvascular density in patients with varying grades of glioma in a retrospective manner. This is correlated with preop imaging. We are currently undertaking a prospective study that accomplishes this in more comprehensive model. We found the cellular proliferation index and microvascular density was significantly higher in higher-grade gliomas as was the microvascular density. This correlated with markers of hypoxia and vascularity including VEGF, CA IX, GLUT-1, and HIF-1. We have preliminary results for measures of apoptotic index and preoperative imaging measures of “peritumoral edema”. Our prospective study examines the correlation between preoperative imaging including MR spectroscopy, diffusion and perfusion imaging with similar markers from tumor specimens from 4 specific regions within newly diagnosed malignant gliomas. These findings will be cross referenced to overall survival. We believe that an understanding of the ability to predict tumor hypoxia, vascularity and proliferation could be used to maximize therapeutic measures such as radiation and chemotherapy. In addition, hypoxia driven therapies could be developed and targeted to these regions including the ability to use these measures to determine response to therapy.

Randy Jensen M.D. Ph.D.

Associate Professor

Dept of Neurosurgery

Huntsman Cancer Institute