Radiation/Chemotherapy Combination Ups Glioma Survival Rates

Patients with a low-grade glioma who received radiation therapy (RT) plus chemotherapy experienced a longer progression-free survival and overall survival than patients who received RT alone, according to a new study.

Researchers at the Mayo Clinic, Emory University and other institutions conducted a study involving 251 patients with grade 2 astrocytoma, oligoastrocytoma, or oligodendroglioma who were younger than 40 and had undergone subtotal resection or biopsy, or who were 40 years or older and had undergone biopsy or resection of any of the tumor. The patients were randomly assigned to RT alone or to radiation therapy followed by six cycles of a combination chemotherapy that included procarbazine, lomustine, and vincristine (PCV).

The results showed that at a median follow-up time of 11.9 years, 67% of all enrolled patients were identified as having tumor progression, and 55% of the patients had died. Patients in the RT plus PCV chemotherapy arm had longer median survival times, compared with those who received RT alone (13.3 versus 7.8 years, respectively). Median progression- free survival time for patients receiving RT plus PCV chemotherapy was longer as well (10.4 years), compared to RT alone (four years).

In addition, 10-year progression-free survival rates for patients in the RT plus PCV chemotherapy arm were 51%, compared to 21% percent in the RT alone arm. For both progression-free survival and overall survival distributions, a difference between treatment arms became apparent only after two to four years following randomization. The favorable prognostic variables identified for survival included being in the radiation plus PCV chemotherapy arm and oligodendroglioma histology. The study was published on April 7, 2016, in the New England Journal of Medicine (NEJM).

“Our results indicate that initial radiation therapy followed by PCV is necessary to achieve longer survival in patients with grade 2 glioma, and that salvage therapy at relapse after radiation therapy alone is less effective,” said lead author oncologist Jan Buckner, MD, chair of the department of oncology at the Mayo Clinic Cancer Center. “Radiation therapy plus PCV appears to represent the most effective treatment identified to date for the majority of patients with grade 2 glioma.”

Grade 2 gliomas are relatively uncommon, constituting 5%–10% of all primary brain tumors in adults. They occur most commonly in young adults, and cause progressive neurologic deterioration and premature death.

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Mayo Clinic
Emory University