Adult patients with low-grade glioma had a better chance for survival if they received chemotherapy, in addition to their course of radiotherapy, according to new research from the Radiation Therapy Oncology Group (RTOG) presented this week at the Society for Neuro-Oncology's 13th annual meeting in Las Vegas.
RTOG is a National Cancer Institute (NCI)-funded national clinical trials group and is administered by the American College of Radiology (ACR).
“In this RTOG study, we found that patients who survived at least one year from the completion of their treatment had much better survival and progression-free survival rates if they received chemotherapy in combination with radiotherapy,” said lead author Edward G. Shaw, MD, of the Wake Forest University School of Medicine in Winston-Salem, N.C. “This is the first multi-center prospective clinical trial to suggest a benefit from adjuvant therapy in this patient population.”
The researchers enrolled 251 patients, who were entered from academic and community-based sites in the United States and Canada from 1998 until 2002. They randomized high-risk low-grade glioma patients to receive either six weeks of radiotherapy alone or six weeks of radiotherapy followed by six cycles of chemotherapy consisting of procarbazine, CCNU and vincristine.
The RTOG investigators found that for patients who survived at least one-year post treatment, the risk of death was reduced by 43 percent and progression-free survival was reduced by 64 percent.
With a median follow-up of 5.9 years, Shaw and colleagues found that the overall five-year survival rate was 72 percent for the patients who received the additional chemotherapy, compared to 63 percent for those who received radiotherapy alone. The five-year progression-free survival rates were 63 vs. 46 percent.
“With two-thirds of the patients still alive at five years we look forward to the long-term follow-up results for this study as well as analysis of the 1p19q genetic codeletion data,” said RTOG Group Chair Walter J. Curran, Jr., chair of the department of radiation oncology in the Emory School of Medicine in Atlanta.