It has recently been discovered that there are at least three subtypes of glioblastoma: proneural, proliferative and mesenchymal. During the course of her study, Liau and her colleagues saw that one group of patients seemed to be responding very well to the vaccine and examined their tumors using a microarray analysis of their DNA. They found that those with a gene expression profile identifying their cancers as mesenchymal responded better to the vaccine.
The finding was surprising, Liau said, because patients with the mesenchymal subtype generally have more aggressive disease and shorter survival than those with the other subtypes. In patients with this type of glioblastoma, several genes that modulate the immune system are dysregulated, meaning they don't work properly. Liau speculates that the vaccine helped replenish the immune system, allowing that subset of patients to more easily fight the brain cancer.
"Glioblastoma remains one of the diseases for which there is no curative therapy and the prognosis for patients with primary malignant brain tumors remains dismal," the study states. "Our results suggest that the mesenchymal gene expression profile may identify an immunogenic sub-group of glioblastoma that may be more responsive to immune-based therapies."
Brad Silver, 41, who grew up in Southern California and now lives in a Cleveland suburb, was diagnosed with glioblastoma in 2003 and was told that he had, at best, two months to live. He was stunned.
"I was 33 years and my wife was seven months pregnant with my son," said Silver, a college water polo instructor. 'I didn't think I was going to live to see my son born, let alone grow up."
Silver sought a second opinion at UCLA and the golf-ball sized tumor in his left lateral lobe was removed. He underwent radiation and chemotherapy and enrolled in the vaccine clinical trial.
|Contact: Kim Irwin|
University of California - Los Angeles