Scientists may be close to finding a successful treatment for an aggressive form of brain cancer, according to research published Monday from the University of Zurich.
Current treatment for glioblastoma (GB), the most common and most aggressive form of brain cancer, only extend patient survival, making the cancer "virtually incurable," according to the study. Treatment doesn't eliminate the cancer because tumors have a way to counterattack the immune system's cancer-fighting T cells. But by using a two-pronged drug therapy approach, the researchers were able to completely eliminate the brain tumors in mice.
The tumor (dark region, left) in this mouse brain was eradicated (arrowhead, right) with a novel drug cocktail, according to a Journal of Experimental Medicine study. (vom Berg et al., 2013)
"We wanted to establish whether we can actually elicit an immune response to a tumor growing within the brain," said lead researcher Burkhard Becher, in a statement.
The team simultaneously injected the mice with a T cell-boosting protein called interleukin-12 (IL-12) and another drug that blocks an inhibitory function within the T cell.
When the team only used interleukin-12 to treat the mice, there was a 25 percent survival rate. But when they combined that treatment with the drug that blocks T cells that self-regulate (and can limit their own immune response), the survival rate jumped to 80 percent in the test animals.
"In light of the data presented here, a combination therapy consisting of systemic checkpoint blockade and local administration of IL-12 is a highly promising candidate for swift clinical translation in GB," the study says.
According to the National Cancer Institute, there are about 12,000 new cases of glioblastoma diagnosed each year in the United States, and most patients survive for just 14 months following diagnosis.
Glioblastoma is particularly difficult to treat, according to the NCI, because by the time it is discovered, cancerous cells have already moved away from the tumor and into other parts of the brain.
It's possible for patients to have surgery to remove parts of the tumor, followed by radiation therapy, but some cancerous cells "inevitably remain behind after surgery and if left unchecked will eventually kill the patient," according to the NCI.
"Although these measures may delay disease progression for a while, they cannot prevent it, and death usually occurs within months," the NCI said on its website.
The researchers hope to begin a clinical trial as soon as possible to determine if the treatment will be similarly effective in human cancer patients.
"We are cautiously optimistic but it's time that we adopted completely new strategies to really get to grips with this fatal tumor," Becher said.