Tumors on the Brain
August 25, 2009 marked the day that America, and most importantly Massachusetts, lost one of its greatest senators, Ted Kennedy. Kennedy was diagnosed with a type of brain cancer called glioblastoma multiforme (GBM) in May 2008 after suffering from a seizure. GBM is a tumor formed in the glial, or supportive, brain cells; there is no current evidence for a genetic predisposition to this type of cancer. The American Cancer Society believes that 21,000 Americans are diagnosed with brain tumors, and about 10,000 are GBMs. They are the most aggressive and common type of brain tumor, which are resistant to many types of treatments. Only 3% of patients diagnosed with these tumors generally survive five years after diagnosis.
Almost two years after Kennedy’s death, doctors are using the drug Avastin to treat GMBs. Avastin blocks the growth of new blood vessels, a necessary component for the survival of tumors. In one study conducted on Dennis Sugrue, physicians thread a fine tube through his blood vessels and into his head to spray the drug on the location where the tumor had been cut out. They did this experiment because the tumor began growing back even after treatment with surgery, radiation, and chemotherapy. The FDA has approved the use of this drug on GMB, based on the results of 2 phase II clinical trials that showed reduced tumor size in the patients, but it can only be administered after a prior treatment is performed on the tumor.
One of the biggest challenges facing the treatment of GBM is the blood-brain barrier, a separation of the circulating blood and the brain’s extracellular fluid. It occurs along the capillaries and prevents the diffusion of many cells into the brain. Dr. John Boockvar, a brain surgeon at New York-Presbyterian/Weill Cornell, is administering the Avastin to Mr. Sugrue by first injecting mannitol, a drug that opens the blood-brain barrier, and then flooding the tumor with the drug. In the future, other drugs may be combined with Avastin to combat GBM. Although it is unknown whether it improves disease-related symptoms or survival in people under this treatment, it is promising. Mr. Sugrue’s tumor has decreased in size and his treatment is still an ongoing process.
Although the survival rate for GBM is very low, it is unfortunately the reason why there is a push to try more treatments and expand experimental trials. One can only hope that this treatment leads to more breakthroughs, and more patients like Mr. Sugrue will be able to live longer, healthier lives.