Democrat US Senator Edward Kennedy has a type of brain tumor known as a glioma, his doctors told the press yesterday, Tuesday, from Massachusetts General Hospital, Boston, where the 76 year old Kennedy is a patient, but they did not disclose any details of the type and size of tumor, which would help to clarify prognosis.
The Senator was taken into hospital following a seizure last Saturday morning. His doctors said the seizure was caused by a tumor that they have located in the left side of his brain, just above the ear, an area known as the parietal area. Kennedy is in “good spirits”, he is up and walking around, and he has had no further seizures, his doctors told the press.
According to Dr Lawrence Altman, writing in the New York Times, the type, size and grade of a glioma is key information to making a prognosis in this type of cancer.
A glioma is a tumor that affects the glial cells, a type of “scaffolding” and infrastructure support cell that also provides chemicals to the neurons of the brain and nervous system. Glial cells outnumber neurons by 10 to 1. There are four main types of glioma, depending on the type of glial cells involved.
Statistically the most common type of glioma is the astrocytoma, which affects the astrocyte glial cells that are responsible for carrying nutrients and reparing brain tissue, among other things.
The World Health Organization (WHO) classifies astrocytomas by four grades. The poorest prognosis is for grade 4, a glioblastoma multiforme, the most common type of astrocytoma in adults.
Patients with a glioma usually undergo surgery to remove the tumor and then have chemotherapy and radiation therapy. Kennedy’s doctors did not say if he was going to have surgery; and his precise treatment depends on the results of further tests, they said.
The prognosis of a malignant brain tumor depends on many factors, including exactly where it is located in the brain, how easily it can be removed, the age and health of the patient, and the type of treatment. It is unlikely to be curable.
Dr Harald Sontheimer, a neurobiology professor at the University of Alabama told the Boston Herald:
“The overall prognosis for these cancers is quite poor.” If surgery is not an option, it could be less than a year, if it is, and successfully removes the tumor, survival can be as long as five years.
Sontheimer told the paper the five-year survival rate can be as low as 5 to 10 per cent, depending on the grade and location of the tumor.
Susan Chang, brain cancer expert and president of the Society for Neuro-Oncology told Bloomberg reporters in a telephone interview that people with aggressive gliomas live on average for another 1.5 years, while those with more with slow growing tumors live on average for about 4.5 years.
Statistics issued by the American Cancer suggest nearly 22,000 Americans will get brain and central nervous system (CNS) cancers in 2008, and about 13,000 people will die from them.
According to the Central Brain Tumor Registry of the United States (CBTRUS), the prevalence rate for all primary brain and CNS tumors is estimated to be about 130.8 per 100,000 people, and that more than 359,000 Americans were living with a diagnosed primary brain and CNS tumor in 2000, of whom more than 81,000 had a malignant tumor.
Sources: New York Times, Boston Herald, Bloomberg, American Cancer Society, wikipedia, CBTRUS.
Written by: Catharine Paddock, PhD