Brain cancer is a relatively uncommon type of cancer, accounting for only 1 percent of new cancer diagnoses. More commonly, brain tumors arise because a patient’s cancer has metastasized, or spread, from other primary tumor(s).
The most common cancer in adults that originates in the brain is glioblastoma, which is characterized by the uncontrolled proliferation of glial cells, known as the “supporting cells” of the nervous system. Traditionally, metastatic brain tumors and brain cancer have been treated with surgery and radiation and/or chemotherapy, but researchers are investigating other therapies in the hopes of increasing survivorship and life expectancy.
Targeted therapies and immunotherapy are in a phase of discovery that is more promising than any preceding brain cancer research, David Reardon, MD, and Patrick Y. Wen, MD, of Dana-Farber Cancer Institute’s Center for Neuro-Oncology, explained in a recent Facebook Live Q&A. Biologically-based targeted therapies target the molecular changes in cancer cells that cause tumors to grow; immunotherapy stimulates the immune system to fight tumors, for example, through checkpoint inhibitor drugs in combination with engineered viruses and vaccines that attack tumors. These treatments have the potential to benefit patients with primary brain cancer tumors and brain metastases.
“It is a promising time in brain cancer research,” Reardon said.
Reardon and Wen are overseeing clinical trials that focus on these treatments, and they explained the crucial role that clinical trials play in improving patient outcomes.
“Until recently, there were not a lot of trials for low grade gliomas, one of the most common types of primary brain tumors, but this has completely changed. This is a really exciting area,” Wen said. “70 to 80 percent of low-grade gliomas have a molecular change called an IDH mutation, and so now there are a lot of studies using drugs that block the mutant IDH.”
“The results of these trials are starting to emerge, and in some of these patients, we are very sure that these drugs stop the tumors from growing,” Wen further explains. “They don’t cause shrinkage of the tumor, but they stop them from growing. Since these drugs are very well tolerated, this potentially is a new approach to treating these patients.”