More than 22,000 Americans are diagnosed each year with a form of brain cancer.
The 2015 death of Beau Biden, son of Vice President Joe Biden, is a reminder that long-term survival remains an elusive goal. Biden was treated with surgery, radiation and chemotherapy after a tumor was discovered in 2013.
Glioblastoma multiforme: aggressive and deadly
Though it’s not clear from news reports which kind of tumor Biden had, brain cancer experts say glioblastoma multiforme is the most aggressive and deadly. Only 10 percent of the 12,000 to 14,000 people annually diagnosed with GBM survive five years, according to the National Cancer Institute.
“The standard of care prolongs survival, but it does not fully destroy the cancer,” according to Dr. Daniela Bota, a neuro-oncologist and director of the UCI Health Comprehensive Brain Tumor Program.
Bota has said advances in immunotherapy in the form of tumor vaccines show promise in extending patients’ lives by eliminating the cancer cells that inevitably remain after surgery.
The announcement of Biden’s death coincided with an update on brain tumor research at the annual meeting of the American Society of Clinical Oncology.
The ReACT clinical trial, which Bota participated in, studied whether the experimental vaccine rindopepimut, which identifies and targets a surface protein called EGFRvIII, can extend patient survival, specifically when combined with bevacizumab. The EGFRvIII protein regulates cell growth and bevacizumab, also known as Avastin, attacks a tumor’s blood supply. ReACT showed an increased survival among relapsed GBM patients who received rindopepimut and bevacizumab.
How does a tumor vaccine work?
Tumor vaccines rely on a patient’s own tumor tissue, which is used to “train” the immune system to identify and kill cancer cells. Bota described the approach when she launched one of several brain tumor vaccine trials at UC Irvine several years ago.
“Our goal is to train the immune system to recognize and attack the cancer,” she said. “Cancer cells are like crabgrass: Once they take root, they’re hard to eradicate, even after brain surgery.”
Think of the vaccine as a personal brain cancer smoothie: Pulverized pieces of a patient’s surgically excised tumor are blended in a laboratory with some of his or her white blood cells. These grow into dendritic cells that, when injected back into the patient, target protein antigens in the tumor and prompt the immune system’s T cells to identify and attack remaining cancer cells.
An earlier trial demonstrated that this vaccine is safe and, in some cases, doubled patients’ median survival after diagnosis from 15 months to about 31 months.
“Everyone responds differently, but immunotherapy has a great chance to be the next leap forward in cancer treatment,” Bota said.