What
is a Glioma?
A glioma is a cancer of the brain,
or brain tumor, which forms in the
glial cells of the central nervous
system. Glial cells are those that
surround and support nerve cells.
While some brain cancers originate
elsewhere in the body, gliomas originate
in the central nervous system, and
are often called “primary”
brain tumors.
Beyond
the location of their origin, gliomas
have a number of characteristics.
One important characteristic of
malignant gliomas is that they do
not have clearly discernable boundaries,
or are “diffuse.” 1
Even if removed, portions of a glioma
often remain and lead to relapse.
While gliomas do not spread outside
of the central nervous system, it
is common to find multiple gliomas
throughout the brain stem during
relapse phases of the disease.
Gliomas
are disproportionately common among
children, and they are the second
highest cause of cancer death among
young people. Different forms of
gliomas, however, have different
prognoses and treatments. Over 97%
of children with the worst of the
gliomas, diffuse pontine gliomas,
die within three years. 2
Different
Types of Gliomas
There are many different forms of
gliomas, which are categorized by
their location in the brain stem
as well as a number of other criteria.
It is often difficult, however,
to obtain an accurate diagnosis,
as many gliomas appear similar yet
act differently.
In
the future, accurate diagnosis of
specific gliomas will likely become
more important. Currently, however,
the location of the glioma generally
dictates the treatment. Gliomas
occurring in the midbrain, the dorsum
of the medulla, or elsewhere in
the brain stem can often be treated
through surgical removal (in combination
with radiation and chemotherapy),
which dramatically increases the
chances of survival. Some forms
of gliomas, in particular many that
arise in the pons or supratentorial
hemisphere, cannot be removed surgically,
and therefore are treated primarily
with radiation and chemotherapy.
According
to St. Jude, in such cases “the
patients' symptoms often improve
dramatically during or after six
weeks of irradiation. Unfortunately,
problems usually recur after six
to nine months, and progress rapidly.
Survival past 12 to 14 months is
uncommon, and new approaches to
treating these tumors are urgently
needed.” 3
1
Fisher, P.G. & Buffler, P.A. (2005)
“Malignant Gliomas in 2005:
Where to GO From Here?” Journal
of the American Medical Association,
2005; Vol. 293, No.5.
2
Wagner, S., et al (2006) “Treatment
options in childhood pontine gliomas,”
Journal of Neuro-Oncology (2006) 79:
281–287.
3
http://www.stjude.org/stjude/v/index.jsp?vgnextoid=b86c061585f70110VgnVCM1000
001e0215acRCRD&vgnextchannel=bc4fbfe82e118010VgnVCM1000000e2015acRCRD
The Symptoms of Gliomas
Symptoms common across multiple forms
of gliomas include headaches, seizures,
speech or reasoning difficulties,
diminished vision, loss of balance,
nausea, and physical weakness or paralysis.
However, other symptoms arise in line
with the location of the glioma. For
example, a pontine glioma may involve
difficulty swallowing whereas a glioma
in the medulla can be associated with
weakness in the legs and arms.
For
More Information
St.
Jude Children’s Hospital
Children’s
Memorial Hospital
The
Mayo Clinic
The
National Cancer Institute
The
Prayers
from Maria Foundation
is actively funding research into
specific forms of childhood cancer
known as gliomas.