Drug Therapy for Brain & Spine Tumors
Drug therapy is an important element of an effective care plan for most malignant brain and spine tumors. A variety of drugs are now available that act in different ways to inhibit brain and spine cancers. The Brain and Spine Tumor Program includes two board certified, fellowship-trained neuro-oncologists — neurologists with specialized training in using drug therapies to treat neurological cancers.
Patients in the Brain and Spine Tumor Program who require infusion services can receive their therapy at the Day Hospital. This unique outpatient clinic at the Froedtert & the Medical College of Wisconsin Clinical Cancer Center provides patients with the highest level of care in a comforting treatment setting.
Drug Therapy for Malignant Glioma
More than half of all primary malignant brain tumors are malignant gliomas. This category includes glioblastoma multiforme (GBM), one of them most aggressive brain cancers. Currently, GBMs and other malignant gliomas are treated with two different drugs: Temodar and Avastin.
The first-line therapy for GBMs and other malignant gliomas is the oral drug temozolomide (Temodar). Temodar damages the DNA of tumors cells, which prevents them from multiplying. Typically, patients receive small daily doses of Temodar during their course of radiation therapy. After radiation is complete, the patient takes a higher dose for five days in a row every 28 days, on average for a year. Temodar is a very well tolerated drug, and many patients work and travel during their therapy period.
When a malignant glioma recurs, a patient may benefit from bevacizumab (Avastin), a “targeted” drug that slows the growth of cancer by inhibiting the development of new blood vessels that tumors need to survive and grow. Patients receive Avastin by infusion once every two weeks, typically for one year.
Other Rare Primary Brain Tumors
Chemotherapy is also part of the treatment plan for less common primary brain tumors, including medulloblastoma, pineoblastoma and ependymoma. For these cancers, surgical removal and radiation therapy can be followed by a combination of chemotherapy drugs.
Brain Tumor Gene Testing in Drug Therapy
For several years, breast cancer physicians have been able to use “genetic markers” within individual breast tumors to choose the most effective drug therapies. Recently, the science of tumor genetics has begun to provide similar tools to brain cancer treatment.
Currently, brain tumor markers are not being used to determine specific drug therapies, but they are helping physicians make decisions about prognosis and the timing of drug treatments. Two tumor gene profile tests are now available: MGMT and 1P19Q.
All GBM tumors now undergo testing for a specific genetic alteration — methylation of the promoter regions of the tumor cell’s MGMT gene. If this alteration is present, the tumor will likely be responsive to Temodar chemotherapy. A patient’s MGMT status can assist medical decision making in two ways.
First, it can support a decision to maintain Temodar therapy for a patient with a favorable MGMT status even if imaging studies do not show a good response. (Radiation therapy can cause inflammation around a brain tumor, which can make MRI scans look as though the tumor is not responding to medication.) Second, it can support a decision to change therapy strategies for a patient with an unfavorable MGMT. (Knowing that a certain patient is less likely to respond to Temodar will help physicians consider switching to a different drug sooner.)
Oligodendroglioma is a slow-growing malignancy that accounts for approximately 3 percent of brain tumors. Researchers have discovered that oligodendroglioma tumors with certain chromosome deletions (the short arm of chromosome 1 and the long arm of chromosome 19) have a very good prognosis. Neuro-oncologists are still determining how to use this information in treatment planning. Currently, it provides another piece of information to help physicians interpret patient progress.
Drug Therapy for Brain and Spine Metastases
There are only a small number of drugs that can be used for patients with metastatic tumors — cancer that has spread to the brain or spine from other parts of the body. For many patients with brain or spine metastases, enrolling in a clinical trial can provide access to investigational drugs that have the potential of providing therapeutic benefit. The Brain and Spine Tumor Program at Froedtert & the Medical College of Wisconsin is a leader for national clinical trials for these new drug options. For a complete list of current drug trials, visit our clinical trials section.
Managing Overall Patient Health
Patients with brain and spine tumors can experience a number of health problems that are related to their cancer. In addition, chemotherapy drugs can cause a variety of side effects. Neuro-oncologists manage their patient’s overall health and individual response to drug treatment.
Brain tumors can disrupt the normal flow of electrical signals within the brain, leading to seizures. Approximately 30 percent of brain tumor patients have experienced one or more seizures by the time of their diagnosis. Another 30 percent will have a seizure at some time as their disease progresses. All patients who have had a seizure are placed on an anti-seizure medication (one that will not interact with the patient’s chemotherapy or render it less effective). Medical management greatly reduces the risk of seizure, and most patients become seizure-free.
Chemotherapy Side Effects
Drug side effects vary widely, and they depend on the specific chemotherapy agent used and the individual patient. Some drugs are tolerated better than others. For most patients, nausea can be prevented with medications. Constipation can be managed through the use of a bowel regimen. Treatment options are also available for fatigue, diarrhea and other potential side effects.
Low Blood Count
Radiation therapy and chemotherapy can cause low blood counts (low levels of red blood cells, white blood cells and blood platelets). This increases the risk of infection, bleeding and other complications. Patients who are on chemotherapy undergo weekly blood tests to allow physicians to monitor their blood counts and intervene if necessary. If a patient’s red blood cells or platelets reach a critical level, blood transfusion can be an option. If the white blood cell count is too low, a drug called filgrastim (Neupogen) can be effective at boosting white cell production.
Patients with a low white blood cell count are at a higher risk of infection — anything from urinary tract infection to pneumonia to sepsis. The care team closely monitors all chemotherapy patients for signs of an infection. Suspected infections typically require evaluation in the emergency department and often hospitalization.
Blood Clots, Deep Vein Thrombosis
All cancer patients are at an increased risk for blood clots. (Cancer tends to make the blood “stickier,” and many patients are less mobile, which further contributes to clotting risk.) All neurological cancer patients and their families receive education on deep vein thrombosis (DVT), a clot that usually forms in the leg. Signs of DVT include a swelling of the calf (usually in just one leg) that is tender, painful or red.
DVTs are evaluated with ultrasound and managed with blood thinner medications. If a DVT breaks free, it can travel through the bloodstream to the lungs, causing a pulmonary embolism (PE), which can be life-threatening. Patients who experience symptoms of PE (such as chest pain or shortness of breath) should be evaluated in the emergency department.