Newswise, September 8, 2015 — Only half of brain cancers
actually start in the brain. The rest – as in the case of former president
Jimmy Carter – are metastatic tumors from cancer that originated elsewhere in
the body.
Dr. Brad Zacharia, director of neuro-oncology and
skull-base surgery at Penn State Hershey Medical Center, said between 15 and 30
percent of patients who have cancer will develop metastases to the brain at
some point during the course of their disease.
Lung cancer and breast cancer – two of the most common cancers – are
most likely to metastasize to the brain.
Once brain cancer is discovered, treatment
varies based on a number of factors. Those include the location of tumors, the
size and number of tumors and how the patient’s disease elsewhere in the body
is being controlled.
“There is a lot to consider,” Zacharia
said.
When the cancer appears as a single lesion
causing symptoms such as weakness or language confusion – and it is located in
a place considered safe or accessible for surgery – surgical removal is often
the best course of action.
Gamma knife radiosurgery is a noninvasive,
outpatient procedure that allows doctors to treat a number of lesions in a
single day by targeting the tumors with high doses of radiation.
Sometimes, surgery is used to remove
larger lesions and followed up with gamma knife radio surgery.
“This is really a revolution in the way
these tumors are managed,” Zacharia said. “We can directly target a multitude
of small and difficult to access lesions with incredible accuracy and efficacy
in a non-invasive way. In select cases, it has been shown to be equally as
effective as surgery.”
A new therapy just starting at Penn State
Hershey is laser ablation, a minimally invasive surgery in which doctors guide
a small laser into the tumor and use heat from the laser to target it directly.
Patients go home the following day.
“It has been tolerated very well and can
be used in difficult-to-access tumors or those that have undergone radiation
and recurred,” Zacharia said.
Patients who are very ill and cannot
tolerate directed therapy – or who have many lesions in inaccessible locations
– may benefit from general radiation to the brain.
Because general radiation can produce
cognitive side effects with time, Zacharia said doctors may try to avoid that
course of treatment for younger patients: “The targeted therapies have gotten
so good that we are getting away from using that.”
Unlike other types of cancer, chemotherapy
is not usually effective for brain tumors – especially metastatic ones –
because of a blood barrier that protects the brain, Zacharia said.
The two types of tumors that originate in
the brain are gliomas, which are inside the brain and can range from benign to
malignant, and meningiomas, which are benign and slow-growing tumors outside
the actual brain substance.
Zacharia said a brain tumor is not always
the death sentence many people think it is.
“We have good techniques and it’s not as
dire as people think,” he said.
“From a neurosurgery standpoint, we have
gotten pretty good at managing these patients with our arsenal of therapies and
advances.”
The Medical Minute is a weekly health news feature
produced by Penn State Milton S. Hershey Medical Center. Articles feature the
expertise of Penn State Hershey faculty physicians and staff, and are designed
to offer timely, relevant health information of interest to a broad audience
