August 3, 2004
Molecular Therapeutics Advance
Against Brain Cancer
New imaging and genetic techniques available only
at Penn for state-of-the-art approaches to brain tumor
(Philadelphia, PA) -- An estimated 41,000 new cases
of primary brain tumors are expected to be diagnosed
in 2004, according to the American Brain Tumor Association.
To further narrow the gap between diagnosis and effective
therapy, physicians at the Hospital of the University
of Pennsylvania now offer several promising
-- and unique to the Philadelphia region -- approaches
to brain tumor treatment, including novel imaging for
oncologic neurosurgery and refined genetic testing for
tumors to better target treatment.
Through enhanced magnetic resonance imaging (MRI), newer
and broader information is helping to better guide tumor
removal. MRI is used to measure the anatomy and metabolism
of tumors. This informs surgeons pre- and post-operatively
with a three-dimensional map of tumor-associated blood
flow to more precisely assess the full extent of tumor
growth versus conventional imaging methods. “This
novel approach helps guide surgery and assessment of
treatment response,” says Donald M. O’Rourke,
M.D., Associate Professor of Neurosurgery.
These novel imaging methods are leading to increased
patient survival by allowing for greater tumor removal
in a safe manner.
Neuroscientists are also ushering in a new era in which
genetics will dictate treatment. In the 1990s researchers
noted that a more favorable prognosis in patients with
certain brain tumors, primarily oligodendrogliomas,
was associated with a deletion of genes on chromosomes
1 and 19. This genetic loss translates into a significant
life-expectancy gain for some patients and is therefore
a robust predictor that post-surgery chemotherapy should
be given to such patients.
Patients with the genetic deletion on chromosome 1 have
a median survival in certain cases of about 10 years
and respond particularly well to chemotherapy given
immediately after surgery. Patients with the deletion
have slower-growing tumors and show a better response
to chemotherapy; whereas, those without the deletion
have relatively faster-growing tumors and are less responsive
to chemotherapy, so radiation therapy is required sooner.
“Given the expected increase in the life-span
of patients with this deletion, there is no need to
give radiation therapy early in their treatment,”
The deletion can only be detected by genetic analysis.
“Under the microscope these tumors can look identical,
so there’s no way of knowing the difference unless
a genetic analysis is performed,” explains O’Rourke.
Having the ability to provide such genetic testing to
determine treatment is of benefit to patients. “The
idea of using a genetic test to predict prognosis and
select therapy, thereby deferring potentially deleterious
treatment is tremendously attractive,” says O’Rourke.
“Penn’s genetic testing is done in-house,
so patients don’t have to wait for the results.”
Further, there is no cost to the patient at this point
since the tests are performed by the Neuro-oncology
Program and supported by the Abramson Cancer Center
at Penn. In addition, there is no requirement for additional
blood samples, so results will be given more quickly
with no need for follow-up visits.
Penn colleagues J. Carl Oberholtzer, MD, PhD,
Department of Neuropathology and Myrna Rosenfeld,
MD, PhD, Department of Neurology and Director
of the Division of Neuro-oncology as well as Jaclyn
Biegel, PhD, Director of Cytogenetics, Children’s
Hospital of Philadelphia, collaborated with O’Rourke
on developing the genetic testing program. Dr. Biegel’s
laboratory performs the genetic test and has significant
experience with genetic testing of brain tumors.
O’Rourke is also Director of the Human Brain Tumor
Tissue Bank at Penn, a unique resource to the region
and one of only a few such dedicated banks in the United
States. Tissue banks allow for the direct evaluation
of human tumors and are one of the best ways to advance
treatment options for gliomas and other human cancers.
O’Rourke’s basic research interests include
finding new treatments for gliomas based on genetic
alterations detected in tumors. He is currently investigating
a variant of the epidermal growth factor receptor that
is present in many primary glioblastomas to better understand
the development of malignancy in the brain and how it
relates to cancer cell division, survival, and movement.
O’Rourke and colleagues are now prepared to discuss
potential surgical and clinical treatments and genetic
evaluation of brain tumor patients. Contact Dr. O’Rourke
at 215-662-3490 for more information.
a printer friendly version of this release,
PENN Medicine is a $2.5 billion
enterprise dedicated to the related missions of medical
education, biomedical research, and high-quality patient
care. PENN Medicine consists of the University of Pennsylvania
School of Medicine (founded in 1765 as the nation’s
first medical school) and the University of Pennsylvania
Health System (created in 1993 as the nation’s
first integrated academic health system).
Penn’s School of Medicine is ranked #3 in the
nation for receipt of NIH research funds; and ranked
#4 in the nation in U.S. News & World Report’s
most recent ranking of top research-oriented medical
schools. Supporting 1,400 fulltime faculty and 700 students,
the School of Medicine is recognized worldwide for its
superior education and training of the next generation
of physician-scientists and leaders of academic medicine.
Penn Health System is comprised of: its flagship hospital,
the Hospital of the University of Pennsylvania, consistently
rated one of the nation’s “Honor Roll”
hospitals by U.S. News & World Report; Pennsylvania
Hospital, the nation's first hospital; Presbyterian
Medical Center; a faculty practice plan; a primary-care
provider network; two multispecialty satellite facilities;
and home health care and hospice.