Combination therapy found best for low-grade brain tumors
New clinical trial findings provide further evidence that combining chemotherapy with radiation therapy is the best treatment for people with a low-grade form of brain cancer. This research was published in the International Journal of Radiation Oncology Biology Physics (2015; 91(3): 497-504).
The phase 2 study found that patients with low-grade gliomas and at high risk for tumor recurrence have an overall survival of 73% after 3 years when treated with radiation plus temozolomide, a chemotherapy drug. This is compared with a 3-year survival rate of 54% for historical controls treated with radiation alone.
These findings come from a study co-led by a researcher at Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James) in Columbus and researchers at the University of Maryland in College Park and at London Regional Cancer Program in Ontario, Canada.
"The most effective treatment for these rare tumors is currently controversial at best," said Arnab Chakravarti, MD, chair and professor of Radiation Oncology and co-director of the Brain Tumor Program at the OSUCCC – James. Chakravarti is the trial's translational research national study chair.
"Many of these high-risk low-grade gliomas progress to grade III and IV tumors over time, so identifying the best treatment strategy is critical to ensure that patients have the best outcomes," said Chakravarti, who is also the Max Morehouse Chair in Cancer Research at Ohio State.
"Our study reports that combining radiation with temozolomide-based chemotherapy appears to improve clinical outcome compared to historical controls treated by radiation alone. This may prove critical in killing enough tumor cells to prevent progression to stage IV disease, or glioblastoma multiforme, over time."
Low-grade gliomas represent less than 1% of all human tumors in the United States. The average survival times vary depending on the tumor's structural, molecular, and genetic features. (One form of high-risk low-grade glioma has an average overall survival of approximately 5 years.)
The study's 3-year progression-free survival rate was 59%. Grade 3 adverse events occurred in 43% of patients; grade 4 events occurred in 10% of patients.
Chakravarti and his lab are currently conducting molecular studies to identify more specifically which low-grade glioma patients benefit from temozolomide.