"Glioblastoma is the most malignant brain tumor you can have," said study co-author Dr. David Baskin, professor of neurosurgery with both Houston Methodist Hospital and the Weill-Cornell College of Medicine in New York City.
"It's almost always a death sentence, with median survival of about nine to 15 months, and the quality of life during the last five months is often quite poor.
"Surgery, along with chemotherapy and radiation, is the only current treatment option," he
"This cancer is like an octopus -- it reaches into all parts of the brain [and] you can only ever get some of it out."
However, "this particular gene therapy is better than anything else we have," said Baskin, who also directs the Peak Brain Tumor Center at the Houston hospital.
"By inserting a virus into the tumor, then attacking that virus with medication while also firing up the patient's own immune system, you can get a real one-two punch treatment effect, and prolonged survival."
stressed that the treatment may not be a cure.
"The [survival] numbers still stink," Baskin
"But they're significantly better, which makes this a big advance."
team are slated to present their findings Sunday in Chicago at the annual meeting of the American Society of Clinical Oncology
The result, said Baskin
, is that "suddenly the immune system starts killing anything that might have these proteins.
So you put the Trojan horse virus in.
Then, after you kill the virus the tumor cells explode, causing the immune system to hyper-activate without raising toxicity [to the patient]."
"It's interesting and exciting, because the improvement [in survival] is significant," Baskin
Specifically, one-year survival rose from 57 percent to 67 percent; two-year survival rose from 22 percent to 35 percent; and the number of patients who lived at least three years rose from 8 percent to 19 percent, the study team found.
Overall, average survival improved by about eight months, researchers say.
"We're not saying we have a cure, of course," noted Baskin
SOURCES: David Baskin, M.D., professor, neurosurgery, and director, Kenneth R. Peak Brain Tumor Center, Houston Methodist Hospital, Houston, Texas, and professor, neurosurgery, Weill-Cornell College of Medicine, New York City; Balveen Kaur, Ph.D., professor, neurological surgery, and associate director, Medical Center at the Comprehensive Cancer Center, Ohio State University, Columbus, Ohio; May 31, 2015, presentation, annual meeting, American Society of Clinical Oncology, Chicago, Ill.