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
USA
medrnell
nyp
View drug information on Tarceva.