Newswise, June 29, 2017-- – A brain tumor was the furthest thing from Kathy
English’s mind that day in 2003 when she walked into a neurologist’s office.
She’d had some uncontrolled sinus issues, so her doctors had ordered a variety
of tests, including an MRI. When she arrived to get the MRI results, the
neurologist said he had not yet had a chance to look at them himself.
“He said we’d look at them
together,” English recalled. “As he looked over the scan, he pointed out a
small abnormality, a tumor which he described as a meningioma. Then he saw
another one. And another. By this time, I was getting pretty worried.
Ultimately, he found 12, and now I was really worried.”
A meningioma is a usually benign,
slow-growing tumor. While referred to as a brain tumor, it actually does not
grow from brain tissue but rather from the meninges, layers of tissue which
cover the brain. Still, 12 meningiomas are not to be taken lightly.
Markert, who is professor and chair
of the Department of Neurosurgery in the UAB
School of Medicine, says meningiomas are
relatively rare, but certainly not unheard of. He followed English for several
years, and when one of the tumors began to grow, he surgically removed it,
along with eight others that were easily accessible.
Two more were later eliminated
through a gamma knife radiation procedure. Markert continues to monitor the
others. Through it all, English never had any symptoms, other than a
bucket-full of anxiety.
“It was like knowing you have bugs
on your head … ‘Get them off! Get them off!’” she said. “It’s so reassuring to
know that I’m being treated and monitored by some of the top brain tumor people
in the nation.”
Her experiences made English
something of a brain tumor expert herself, certainly enough to realize
something was not right when her husband, John, became dizzy and off-balance
after bending over to unplug a computer cord.
He’d had a couple of bad headaches
in the previous weeks, and that evening in the fall of 2016, there was
something obviously wrong.
“We ruled out stroke pretty quickly,
and our physician ordered an MRI,” English said. “The results came back —
astrocytoma. A brain tumor. We were stunned.”
Two days later, John English was in
Markert’s office, and in less than two weeks, had surgery to remove a Grade 2
tumor. His recovery has been robust, and he knows he is lucky.
“While we never anticipated having a
second person in the family with a brain tumor, Kathy’s experiences made us
proactive,” John said. “My prognosis is so much better due to the quick
recognition of the tumor, and the quick response by UAB.”
The Englishes did not consider
themselves prime candidates for brain tumors. Both are pescatarians
(individuals who add fish to a vegetarian diet) who stay fit and keep a close
eye on their health.
“The scientific community still has
much to learn in order to predict the onset of a brain tumor or who is at
risk,” said Markert, who holds the James Garber Galbraith Endowed Chair of
Neurosurgery at UAB and is a senior scientist in the Comprehensive Cancer
Center.
“Some, called primary tumors, arise
in the brain. Others are called metastatic tumors, which arise elsewhere in the
body and migrate to the brain.”
The good news, Markert says, is that
the landscape for brain tumor therapy is much better now than ever before.
“A diagnosis of a malignant brain
tumor is still devastating, but we’ve come a long way,” he said. “The horizon
is very bright for the development of even more impactful treatments in the
very near future.”
Markert credits improved imaging
with some of that optimism. Improvements in neuroimaging can now reveal much
more information about the makeup of tumors.
“We used to classify tumors based
simply on their microscopic appearance,” Markert said.
“We are now able to look at
mutations within tumor cells, and we’ve found that certain sets of mutations
are associated with different tumor types and subtypes. This really is
precision medicine, as we can now tailor therapy based on our better
understanding of the genetic signature of an individual tumor.”
A new oral chemotherapy agent called
temozolomide is a good example. It is effective on some tumors, but others are
resistant to the drug. Advances in genetic testing can predict which patients
will respond best to the drug and which will not.
Another new agent, aminolevulinic
acid, or 5-ALA, is used in a fluorescence imaging technique. The drug is
absorbed into tumors and causes them to glow when viewed on an MRI. Surgeons
can then better visualize the tumor, especially at its boundaries with healthy
cells.
Those boundaries are usually
indistinct, and the line between tumor and healthy tissue can be blurred. 5-ALA
helps guide surgeons as they attempt to remove as much of a tumor as possible
while leaving healthy tissue intact. 5-ALA is expected to be approved for use
by the FDA in the near future.
New technology will soon be in place
at UAB, such as intraoperative MRI scanning, where surgeons will have the
ability to do real-time MRI scans in the operating room during surgery.
Another advance, also based on
improved MRI use, will employ lasers surgically inserted into the tumor to
precisely destroy tumor cells with heat energy.
Markert says proton therapy, an
option over traditional radiation technology and coming to UAB in 2019, can be
a valuable tool for pediatric tumors or tumors situated close to delicate
structures such as the brain stem or optic nerve.
Another promising therapy has been
under investigation in Markert’s lab for years. In 2001, Markert and his
colleagues published initial results of a first-generation genetically
engineered herpes virus as a therapy to destroy brain tumors.
A second generation virus, known as
M032, is currently undergoing clinical trials. The virus infects tumor cells
and replicates, while leaving healthy cells alone.
The act of viral replication in the
tumor kills the infected tumor cells and causes the tumor cell to act as a
factory to produce new viruses. As the tumor cell dies, progeny viruses are
released from the cell.
These viruses infect other tumor
cells in the vicinity and continue the process of tumor killing. The virus also
causes the patient’s own immune system to attack the tumor.
“This process, especially combined
with advances in immunotherapy, presents a very promising approach to treating
tumors,” Markert said.
Markert explains that the body’s
immune system is designed to patrol for foreign cells in the body, including
mutated cancer cells. The immune system’s killer T cells have an off-switch,
known as a checkpoint.
The checkpoint is usually turned
off, keeping T cells from attacking healthy cells. It turns on — again, usually
— in the presence of a foreign cell, prompting T cells to attack. But tumor cells
are very good at fooling the checkpoint so it remains in the off position.
Drugs known as checkpoint inhibitors
are under development which would turn the checkpoint on, stimulating the T
cells to attack the tumor.
“One approach we are considering now
is a combination of viral and immunotherapy,” Markert said.
“The viral therapy using our
modified herpes virus should produce a vibrant immune response, followed by
introduction of the checkpoint inhibitors, which would turn on the checkpoints
and activate individual T cells.”
Markert is excited about the future
of brain tumor research and treatment. As a leading academic medical center
home of one of the nation’s Comprehensive Cancer Centers, and the state’s leader in personalized medicine,
UAB is primed to be at the forefront of new discovery.
“We have a remarkable array of
talent here, in radiation oncology, hematology/oncology, neurology,
neurosurgery, and other fields,” he said. “We have an outstanding research
enterprise in both adult and pediatric brain tumors. It’s an exciting time to
be in this field.”
Brain cancer is not the most
prevalent kind of cancer — breast and lung cancer top the list; but malignant
brain tumors can be particularly devastating.
The National Cancer Institute
predicts 33,800 new cases in 2017. The NCI also estimates that 16,700 Americans
will die of brain cancer this year.
“We are turning a corner, but there
are still too many people who die from brain tumors each year,” Markert said. “These
patients and their families are very courageous people. We owe it to them to
find better treatments.”
The Englishes had two firsthand
experiences to convince them to continue to be proactive and involved in their
health care.
“Pay attention to your body, and if
something unusual happens, don’t blow it off,” John said. “Be aggressive in
following up. We are two people who paid attention to our medical issues and,
as a result, got the right care to provide us the best possible outcomes.”