According to a recent article published in The Lancet, radiation therapy directly following surgery improves progression-free survival, when compared to delayed radiation therapy in patients with slow-growing brain cancer. Early radiation, however, does not improve overall survival in these patients.
There are several types of cancers that originate in the brain; each is classified according to the specific cell that becomes cancerous, the speed at which the cancer grows, and how far it has spread in the brain. Fast-growing or aggressive cancers are referred to as high-grade, while slower growing brain cancers are referred to as low-grade. Surgery, followed by radiation therapy, is the standard treatment for low-grade brain cancers that have not spread extensively throughout the brain. However, the optimal timing of radiation therapy for low-grade brain cancers is not known. Radiation therapy can be administered following surgery (early radiation) in an attempt to kill cancer cells that may remain following surgery. It can also be administered when there are signs of cancer progression (delayed radiation).
The European Organization for Research and Treatment of Cancer (EORTC) Radiotherapy and Brain Tumor Groups conducted a clinical trial to directly compare early and delayed radiation therapy in patients with low-grade brain cancers. They recently published long-term follow-up of this trial. This trial included 314 patients with low-grade brain cancer who were treated at 24 medical centers in Europe. All patients were treated with surgery and then received either early radiation therapy (157 patients) or delayed radiation therapy (157 patients). Patients treated with early radiation had no disease progression for an average of 5 years, while the group treated with delayed radiation saw progression in about 3 years. However, the average overall survival was not different between the two groups (approximately 7 years). Patients treated with early radiation therapy had better seizure control compared to those treated with delayed radiation therapy.
The researchers concluded that early radiation therapy extends time without cancer progression, but does not lengthen overall survival time compared to delayed radiation therapy in patients with low-grade brain cancer. The researchers commented that quality of life parameters had not been studied in this trial, and future studies should evaluate quality of life in this setting so treatment decisions may be made accordingly. Patients with low-grade brain cancer may wish to speak with their physician about their individual risks and benefits of different radiation schedules.
Reference: van den Bent M, Afra D, de Witte O, et al. Long-term efficacy of early versus delayed radiotherapy for low-grade astrocytoma and oligodendroglioma in adults: the EORTC 22845 randomized trial. The Lancet. 2005. Early on-line publication. DOI:10.1016/S0140-6736(05)67070-5. Accessed August 2005. Available at: http://www.thelancet.com/journals/lancet/article/PIIS0140673605670705/fulltext.