What’s new in adult brain and spinal cord tumor research and treatment?
There is always research going on in the area of brain and spinal cord tumors. Scientists are looking for causes and ways to prevent these tumors, and doctors are working to improve treatments.
Researchers are looking for changes inside brain tumor cells to see if they can be used to help guide treatment. For example, doctors have found that patients with oligodendrogliomas whose cells are missing parts of certain chromosomes (known as a 1p19q co-deletion) are much more likely to be helped by chemotherapy than patients whose tumors do not.
Imaging and surgery techniques
Recent advances have made surgery for brain tumors much safer and more successful. Some of these newer techniques include:
- Functional magnetic resonance imaging (fMRI, described in “How are brain and spinal cord tumors in adults diagnosed?”). This technique can help identify important functional areas of the brain and how close they are to the tumor.
- Magnetic resonance spectroscopic imaging (MRSI, described in “How are brain and spinal cord tumors in adults diagnosed?). In this approach, specially processed MRS information is used to make a map of important chemicals involved in tumor metabolism. This is being developed to help surgeons direct their biopsies to the most abnormal areas in the tumor and to help doctors direct radiation and evaluate the effects of chemotherapy or targeted therapy.
- Fluorescence-guided surgery. For this approach, the patient drinks a special fluorescent dye a few hours before surgery. The dye is taken up mainly by the tumor, which then glows when the surgeon looks at it under special lighting from the operating microscope. This lets the surgeon better separate tumor from normal brain tissue.
- Newer surgical approaches for some types of tumors. For example, a newer approach to treat some tumors near the pituitary gland is to use an endoscope, a thin tube with a tiny video camera lens at the tip. The surgeon passes the endoscope through a small hole made in the back of the nose to operate through the nasal passages, limiting the potential damage to the brain. A similar technique can be used for some tumors in the ventricles, where a small opening in the skull near the hairline serves as the point of endoscope insertion. The use of this technique is limited by the tumor’s size, shape, and position.
Some newer types of external radiation therapy let doctors deliver radiation more precisely to the tumor, which helps spare normal brain tissue. Techniques such as 3-dimensional conformal radiation therapy (3D-CRT), intensity modulated radiation therapy (IMRT), and proton beam therapy are described in the section “Radiation therapy for adult brain and spinal cord tumors.”
Newer methods of treatment planning are also being studied. For example, image-guided radiation therapy (IGRT) uses a CT scan done just before each treatment to better guide the radiation to its target.
Along with developing and testing new chemotherapy drugs, many researchers are testing new ways to get chemotherapy to the brain tumor.
Many chemotherapy drugs are limited in their effectiveness because the tightly controlled openings in the brain capillaries, sometimes referred to as the blood-brain barrier, prevents them from getting from the bloodstream to the brain. Researchers are now trying to modify some of these drugs by putting them in tiny droplets of fat (liposomes) or attaching them to molecules that normally cross the blood-brain barrier, to help them work better. This is an area of active research and clinical trials.
For another newer method called convection-enhanced delivery, a small tube is placed into the tumor in the brain through a small hole in the skull during surgery. The tube extends through the scalp and is connected to an infusion pump, through which drugs can be given. This can be done for hours or days and may be repeated more than once, depending on the drug used. This method is still being studied in clinical trials.
Other new treatment strategies
Researchers are also testing some newer approaches to treatment that may help doctors target tumors more precisely. This could lead to treatments that work better and cause fewer side effects. Several of these treatments are still being studied.
Several vaccines are being tested against brain tumor cells. Unlike vaccines against infections, these vaccines are meant to help treat the disease instead of prevent it. The goal of the vaccines is to stimulate the body’s immune system to attack the brain tumor.
Early study results of vaccines to help treat glioblastoma have shown promise, but more research is needed to determine how well they work. At this time, brain tumor vaccines are available only through clinical trials.
Tumors need to create new blood vessels (a process called angiogenesis) to keep their cells nourished. New drugs that attack these blood vessels are used to help treat some cancers. One of these drugs, bevacizumab (Avastin), has been approved by the FDA to treat recurrent glioblastomas because it has been shown to slow the growth of some tumors.
Other drugs that impair blood vessel growth, such as sorafenib (Nexavar) and trebananib, are being studied and are available through clinical trials.
Growth factor inhibitors
Tumor cells are often very sensitive to proteins called growth factors, which help them grow and divide. Newer drugs target some of these growth factors, which may slow the growth of tumor cells or even cause them to die. Several of these targeted drugs are already used for other types of cancer, and some are being studied to see if they will work for brain tumors as well.
Hypoxic cell sensitizers
Some drugs increase the oxygen content in tumors, which might make tumor cells more likely to be killed by radiation therapy if they are given before treatment. These types of drugs are now being studied to see if they can improve treatment outcomes.
Electric treatment fields
The NovoTTF-100A system is approved by the FDA to treat glioblastomas that are no longer responding to other treatments. To use this device, the head is shaved and 4 sets of electrodes are placed on the scalp. The electrodes are attached to a battery pack and are worn for most of the day. They generate mild electric currents that are thought to affect tumor cells in the brain more than normal cells. In a clinical trial, people using the device lived about as long as those getting further chemotherapy, although they reported a better quality of life because of fewer side effects.
Last Medical Review: 03/05/2014
Last Revised: 03/05/2014