Surgeons Tackle Life-Threatening Brain Tumors In Two Clinical Trials

Main Category: Neurology / Neuroscience
Also Included In: Clinical Trials / Drug Trials
Article Date: 02 Aug 2006 - 0:00 PDT

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Neurosurgeons Dr. John Boockvar and Dr. Theodore Schwartz are studying in clinical research trials how to improve the prospects of patients with brain tumors such as glioblastoma (GBM) and anaplastic astrocytoma (AA). GBM and AA are particularly lethal and aggressive cancers that tend to grow back and spread throughout the body even after surgeons remove the initial tumor.

Patients with a GBM tumor survive, on average, only nine to 12 months after diagnosis, and those with an AA tumor fare only slightly better, with a life expectancy of three to four years.

What makes these tumors particularly difficult to treat is that surgeons cannot remove every tiny cancerous cell in the brain, and chemotherapy, typically the post-surgery treatment to kill remaining cancer cells, is only partially effective since the brain is separated from the bloodstream by the blood-brain barrier*.

In their clinical trials, Drs. Schwartz and Boockvar both surgically remove the tumor, but after this, their approach differs. Dr. Boockvar uses Tarceva, a drug in pill form designed to slip through the blood-brain barrier, while Dr. Schwartz uses TP-38, a drug in liquid form that he infuses into the brain through catheters.

Tarceva is a "small molecule" drug. Its structure is diminutive enough to slip between endothelial cells and clever enough to stick to the surface of cancer cells. Tarceva prevents proteins on the cells' surface known as epidermal growth factor from binding with growth factors or proteins in the blood and setting off a chemical process that allows the cells to multiply. The cancer cells are first kept from multiplying and then eventually destroyed by the drug.

TP-38, on the other hand, belongs to a class of drugs known as immunotoxins. These drugs seek out cancer cells and destroy them with a toxin. TP-38 cannot slip through the blood-brain barrier so Dr. Schwartz employs catheters and an emerging technique known as convection-enhanced delivery (CED) to deliver the drug into the brain.

Several days after the tumor is removed, Dr. Schwartz performs a second surgery. He drills tiny holes in the skull for access and, using a computer-imaging system for guidance, gently slides catheters into the brain, positioning them so their outflow encircles the tumor site. Pumps attached to the catheters then infuse medication continuously over a period of several days. During that time, the patient needs to stay in the hospital but can walk around or engage in other light activity.

Patients in Dr. Boockvar's trial will take one tablet once a day in cycles that can extend to up to 12 months.

Patients interested in the trials, please contact (866) NYP-NEWS.

About the doctors:

Dr. Theodore Schwartz is director of the Center for Epilepsy Surgery, Brain Tumors, Minimally-Invasive Skull Base and Pituitary Surgery, and an associate professor of neurological surgery at Weill Cornell Medcial College. He is also an associate attending neurological surgeon at NewYork-Presbyterian Hospital/Weill Cornell Medical Center.

Dr. John Boockvar is director of the Neurosurgical Laboratory for Translational Stem Cell Research, and the Alvina and Willis Murphy Assistant Professor of Neurological Surgery at Weill Cornell Medical College. He is also an assistant neurological surgeon at NewYork-Presbyterian Hospital/Weill Cornell Medical Center.

From Weill Cornell Medical College Science Briefs

Joan and Sanford I. Weill Medical College of Cornell University
525 East 68th Street, Box 144
New York, NY 10021
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http://www.med.cornell.edu
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