Portland, Ore. -- Like an armed guard, the blood-brain barrier in the human body works to keep dangerous chemicals out of the central nervous system. Unfortunately, this same barrier also can keep chemotherapy drugs away from deadly brain tumors. In the early 1980s, Oregon Health Sciences University researchers made national headlines when they found a way to outsmart this natural defense mechanism in the brain. Following years of additional research, OHSU scientists now are releasing the encouraging results of a long-term study involving patients who have beaten the odds thanks to chemotherapy assisted by blood-brain barrier disruption. The results of the study are published in the January edition of the journal Neurosurgery.
OHSU scientists studied 74 people with central nervous system lymphomas who were treated with enhanced chemotherapy through blood-brain barrier disruption (BBBD) and had not previously undergone radiation therapy. Overall, 42 percent of these patients survived five years or more. That compares with a 9 to 22 percent five-year survival rate for patients treated with a combination of radiation therapy and non-enhanced chemotherapy. A total of 48 patients (65 percent) exhibited complete responses and a disappearance of their brain tumors on a CT scan following BBBD-enhanced chemotherapy.
In addition to frequent physical examinations, patients underwent neurophsychological tests to measure various mental functions, including attention, concentration, motor skills, and immediate and delayed memory recall. Based on these tests, a total of 36 patients demonstrated no cognitive loss or impairment caused by their chemotherapy treatment. To this point, no other known studies have measured so comprehensively the long-term mental impact of brain tumors treated with BBBD-enhanced chemotherapy.
More than 15 years ago, OHSU neurosurgeon Edward A. Neuwelt, M.D., pioneered a unique method for outwitting the blood-brain barrier. Neuwelt found the introduction of a concentrated sugar solution caused a temporary disruption of the barrier allowing for the passage of chemotherapy drugs. Neuwelt, who is now director of the Blood-Brain Barrier Program at OHSU, says this study shows the long-term effectiveness of the enhanced chemotherapy approach. "For years, many people considered a brain tumor an immediate death sentence," said Neuwelt. "That's not necessarily true any more. Five years after their initial treatment, many of our patients with central nervous system lymphoma are living normal, happy lives with little or no cognitive impacts."
The Blood-Brain Barrier Program at OHSU has long been considered a national leader in neurological chemotherapy research. The program combines basic science, research and comprehensive care to treat patients with brain tumors. Since its creation in 1981, the Blood-Brain Barrier Program at OHSU has treated more than 400 patients and performed 4,750 blood-brain barrier disruptions.
Journal
Neurosurgery