Ask The Expert/FAQs

Other Frequently Asked Questions:

	Q.	What are brain tumors?
	Q.	What is the difference between primary and secondary type brain tumors?
	Q.	What are common brain tumor symptoms?
	Q.	How are brain tumors diagnosed?
	Q.	How are brain tumors treated?
	Q.	Are brain tumors becoming more common?
	Q.	Are women or men more likely to develop brain tumors?
	Q.	Is there a link between hormones and brain tumors?
	Q.	Are there any risk factors for brain tumors?
	Q.	Can cell phones cause brain tumors?
	Q.	Are brain tumors genetic?
	Q.	What causes brain tumors?
	Q.	What is the difference between a grade IV astrocytoma, a malignant glioma and a glioblastoma multiforme (GBM)?
	Q.	How do you know if chemotherapy will work for treating a glioma?
	Q.	Are there other potential molecular markers that might prove useful for choosing therapy?
	Q.	Is the UC Irvine brain tumor program involved in clinical brain tumor research?
	Q.	Is the UC Irvine Comprehensive Brain Tumor Program involved in basic science brain tumor research?

Q. What are brain tumors?

A. Brain tumors are abnormal or uncontrolled growth of cells in, or around the brain. They can be benign (non-cancerous) or malignant (cancerous).

Q. What is the difference between primary and secondary type brain tumors?

A. Primary tumors originate in, or around the brain. Those that arise from the brain are often called parenchymal or axial tumors. Most parenchymal tumors that arise from the support cells (glia), or electrical cells in the brain, are generically termed “gliomas.” Some gliomas include ependymomas, medulloblastomas, astrocytomas, oligodendrogliomas and glioblastoma multiforme.

Primary tumors that arise from around the brain are called extra-parenchymal, extra-axial or skull base tumors. They include meningiomas, pituitary tumors, cranial nerve schwannomas and craniopharyngiomas.

In 2007, there were an estimated 20,500 new cases of the brain and spinal cord cancers and 12,740 deaths resulting from primary tumors. In Orange County, it is estimated that more than 200 new parenchymal primary brain tumors and 120 new skull base tumors are diagnosed every year.

Secondary or metastatic brain tumors spread to the brain through the blood stream from another area in the body (for example, the lung or breast). They are, by far, the most common type of brain tumors. Their annual incidence is more than five times greater than primary brain tumors. It is estimated that more than 1,200 new patients with metastatic brain tumor are diagnosed in Orange County every year.

Q. What are common brain tumor symptoms?

A. Common early general symptoms include seizures, headaches, nausea or vomiting, change in personality, common habits or even confusion.  More specific symptoms often relate to tumor location and can include weakness, new sensations or reduced sensation on one part of the body, imbalance and changes in speech or peripheral vision. These symptoms can often be confused with a stroke.

Skull base tumors commonly effect cranial nerve function and symptoms often include double vision, facial numbness, hearing loss, ringing in the ears and difficulty swallowing.  Pituitary tumors can interrupt normal menstrual patterns or lead to discharge of milk from the breasts.

Q. How are brain tumors diagnosed?

A. Diagnosing a brain tumor usually involves several steps. Your doctor will likely perform a neurological exam, which includes checking your vision, hearing, balance, coordination and reflexes. Depending on the results of that exam, your doctor may request one or more of the following tests:

• Computerized tomography (CT) scan. A CT scan uses a sophisticated X-ray machine linked to a computer to produce detailed, two-dimensional images of your brain. A special dye may be injected into your bloodstream after a few CT scans are taken. The dye helps make tumors more visible on X-rays. A CT scan generally takes less than 10 minutes.
  
  

• Magnetic resonance (MR) imaging. This scan uses magnetic fields and radio waves to generate images of the brain. MR scans are particularly useful in diagnosing brain tumors. Sometimes a special dye is injected into your bloodstream during the procedure. The dye often makes tumors easier to distinguish from healthy tissue.
  
  

• Angiogram. This test involves injecting a special dye into your bloodstream. The dye, which flows through the blood vessels in your brain, can be seen on X-ray. This test helps show the location of blood vessels in and around a brain tumor.
  
  

• X-rays of your head and skull. An X-ray of your head may show alterations in skull bones that could indicate a tumor. It may show calcium deposits, which are sometimes associated with brain tumors. However, a routine X-ray is a far less sensitive test than are brain scans.
  
  

• Other brain scans. Other tests, such as magnetic resonance spectroscopy (MRS), functional MR scanning, diffusion tensor imaging (DTI), single-photon emission computerized tomography (SPECT) or positron emission tomography (PET) scanning, help doctors gauge brain activity by studying brain metabolism and chemistry and blood flow within your brain. These scans can be combined with standard MR images to help doctors understand the effects of a tumor on brain activity and function, help surgeons determine if a tumor can safely be removed and help guide surgeons at surgery. However, doctors don't typically use them to make an initial diagnosis of brain tumor.
  
  
• If your doctor sees what appears to be a brain tumor on a brain scan, especially if there are multiple tumors, he or she may test for cancer elsewhere in your body before making a definitive diagnosis. Letting your doctor know of a prior history of cancer, even many years earlier, is important.

Q. How are brain tumors treated?

A. Treatment strategies are based on the kind of tumor, the stage of the cancer and the needs of the patient. Treatment usually consists of surgery for biopsy and/or resection, radiation therapy, chemotherapy, stereotactic radiosurgery, experimental therapies — or a combination of treatments.

Q. Are brain tumors becoming more common?

A. The incidence of brain tumors is rising in the United States. This may be due to the general aging of our population since brain tumors become more common with age. The increase in incidences may also result from better screening and detection methods for brain tumors. Because of the increased use of MR scans for screening, it has become easier to detect small brain tumors before they become symptomatic. In addition, medical advancements have helped patients with various forms of cancer live longer. These cancers may spread to the brain over time. Finally, the increase in brain tumor incidences maybe on the rise due to the increased incidence of HIV infection which now accounts for more than 50 percent of cases of primary central nervous system lymphoma.

Q. Are women or men more likely to develop brain tumors?

A. In general, men and women have the same risk for brain tumors.  However, there are some exceptions.  Men are three times more likely to get a rare malignant germ cell tumor called germinoma and nearly twice as likely to be diagnosed with glioma.  Women are three times more likely to get meningioma, a benign tumor.

Q. Is there a link between hormones and brain tumors?

A. The only primary brain tumor clearly linked to hormones is meningioma which is three times more common in women, can present or grow during pregnancy, and whose cells often express progesterone receptors (estrogen receptors less likely).  As a result, we strongly advise women with known meningiomas not to take hormone replacement therapy for osteoporosis, especially preparations containing progesterone.

Q. Are there any risk factors for brain tumors?

A.The most studied and recognized risk factor for brain tumor is a history of radiation therapy.  Patients who undergo radiation therapy for pituitary tumors run a less than three percent risk of developing another type of brain tumor 10 years after exposure.  Even low radiation doses to the scalp as a child can increase the risk of developing a benign skull base tumor over the course of a person’s natural life span.

Q. Can cell phones cause brain tumors?

A. The majority of studies looking at this issue so far have not confirmed a relationship between cell phone use and the development of brain tumors.  An exception is a study looking at old fashioned high energy “brick” cell phones where a slight increase in benign tumors of the hearing ear (vestibular schwannoma) on the side of cell phone usage was noted.  It would appear that the greatest risk arising from cell phone use is the risk of automobile accident and injuring from driver distraction.  We recommend using a low energy cell phone and use a separate ear piece away from the energy source just in case.

Q. Are brain tumors genetic?

A.Brain tumors are associated with certain spontaneous and inheritable genetic disorders, but these pre-disposing conditions account for less than two percent of all brain tumors. The history of a brain tumor in a first degree relative (parent, brother, sister or child) will slightly increase your chance of having a brain tumor compared with the general population. Genetic syndromes associated with brain tumors include:

• Neurofibromatosis type 1 or NF1 – the most common inheritable genetic condition in man occurs is present in 1 in 4000 people. Arising from loss of a tumor suppressor gene on chromosome 17 (17q11.2) that normally codes for a protein called neurofibromin. Patients with NF1 are prone to develop optic nerve gliomas, brain and spinal cord gliomas and astrocytomas and ependymomas, as well as spinal neurofibromas and schwannomas.
  
  
• Neurofibromatosis type 2 or NF2 is present in one in 100,000 people. Arising from loss of a tumor suppressor gene on chromosome 22 (22q11.2) that normally codes for a protein called merlin or schwannomin. Patients with NF2 are prone to develop bilateral vestibular schwannomas, meningiomas and spinal schwannomas.
  
  
• Von Hippel Lindau (VHL) is a neurocutaneous genetic syndrome with a tumor suppressor defect on chromosome 3 (3p25-26). Patients with VHL are prone to develop hemangioblastomas of their cerebellum and spinal cord as well as vascular lesions on their retina.
  
  
• Tuberous Sclerosis is present in one in 10,000 people. It is a neurocutaneous genetic syndrome with a tumor suppressor gene defect on chromosomes 9 and 11 (9q34 &11q). Paients with tuberous sclerosis are prone to developing subependymal giant cell astrocytomas (SEGA’s) and cortical tubers.
  
  
• Meningiomatosis is a poorly characterized genetic disorder with molecular errors noted on either chromosome 22 or 17. Patients with meningiomatosis develop multiple meningiomas over time.
  
  
• Schwanomatosis is a newly recognized neurocutaneous genetic disorder with molecular abnormalities on chromosome 22.  Patients with shcwanomatosis are prone to develop schwannomas on multiple cranial nerves as well as spinal schwannomas.
  
  
• Multiple Endocrine Neoplasia or MEN 1 is a genetic syndrome with the molecular defect on chromosome 11 (11q13). Patients with MEN 1 develop pituitary adenomas, parathyroid tumors and pancreas tumors.
  
  
• Li-Fraumeni syndrome is a rare genetic disorder involving chromosome 17 (17p13.1). The defect leads to abnormalities in CHEK2 & TP53 resulting in p53 function deficiencies. Patients with Li-Fraumeni syndrome are prone to develop brain astrocytomas.
  
  
• Gorlin syndrome is a rare genetic disorder involving chromosome 9 (9q22.3-31). Patients with Gorlin syndrome are prone to develop medulloblastomas.
  
  
• Turcot syndrome, also known as glioma polyposis syndrome, is a rare gentic disorder with a molecular defect on chromosome 5 (5q21-22). Patients with Turcot syndrome are prone to develop astrocytomas, medulloblastoma and glioblastoma multiforme.

Q. What causes brain tumors?

A. Less than two percent of brain tumors result from a genetic disorder. Another even smaller percentage of cases are caused by prior radiation therapy or chemotherapy.  A rare form of primary brain tumor known as primary central nervous system lymphoma (PCNSL) is associated with HIV infection.  However, the overwhelming majority of brain tumors arise for reasons that are unknown.

Q. What is the difference between a grade IV astrocytoma, a malignant glioma and a glioblastoma multiforme (GBM)?

A. Brain tumor names can be quite confusing.  Tumors that arise from the support cells in the brain are called gliomas. They can be low grade malignancies (low grade gliomas) or more aggressive high grade gliomas (malignant gliomas). Ependymomas, medulloblastomas, oligodendrogliomas and astrocytomas are all gliomas arising from different types of support cells, or glia. Like all gliomas, astrocytomas can be low grade malignancies (low grade astrocytomas), mid-grade malignancies (anaplastic astrocytomas) or high grade malignancies (glioblastoma multiforme or GBM).

Another way of describing this increasing grade of aggressiveness is with a number grading system from I-IV, with grade four being the most malignant. Depending on the context, grade IV astrocytoma, malignant glioma and GBM can all be used to describe the same tumor.

Q. How do you know if chemotherapy will work for treating a glioma?

A. The predictive science for response to therapy is still inexact.  However, best current evidence suggests that certain specific molecular markers from the brain tumor can predict greater responsiveness to chemotherapy. For anaplastic oligodendrogliomas, loss of heterozygosity on specific regions of chromosomes 1 and 19 (1p, 19q) is our best current marker for greater chemotherapy responsiveness. For malignant astrocytomas (anaplastic astrocytoma and glioblastoma multiforme or GBM – grades III & IV astrocytoma), methylation (chemical silencing) of the promoter region for a gene called MGMT is our best current marker for greater responsiveness to temazolamide chemotherapy.

Q. Are there other potential molecular markers that might prove useful for choosing therapy?

A. Tailoring therapies using molecular markers is an active area of ongoing brain tumor research. However, for certain therapies, identifying target molecules and/or pathways is likely important.

Q. Is the UC Irvine Comprehensive Brain Tumor Program involved in clinical brain tumor research?

A.The UC Irvine Comprehensive Brain Tumor Program is actively involved in two types of clinical brain tumor research. The first is advancing the field through clinical trials of the latest leading-edge clinical therapies. The second involves systematic clinical outcomes studies for different brain tumor types and brain tumor therapies utilizing our IRB approved prospective outcomes database.

Q. Is the UC Irvine Comprehensive Brain Tumor Program involved in basic science brain tumor research?

A. The UC Irvine Comprehensive Brain Tumor Program is actively involved in both translational basic science brain tumor research as well as molecular biology brain tumor research. Translational efforts include those led by Dr. Daniela Bota in the Chao Family Comprehensive Cancer translational research laboratory and Dr. Mark Linskey and the Beckman Laser Institute studying applications of modulated imaging to investigate brain tumor imaging and intraoperative mapping. Molecular biology efforts include those lead by Dr. Yi-Hong Zhou at the Brain Tumor Research Laboratory. Dr. Zhou is studying the PAX6 tumor suppressor pathway. In addition, Drs. Zhou and Linskey are exploring the differential biology of tumor stem cells versus the main tumor cell population and the molecular modeling of brain tumor patient prognosis.

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