Results of a National Institutes of Health (NIH)-supported clinical trial suggests that patients with low-grade glioma, a form of brain tumor, can live longer if they receive both chemotherapy and radiation.

Researchers conducted the study on 251 individuals with low-grade glioma who were either over 40 years old or had not completed the surgical removal of tumor. After completing surgery and radiation therapy, the subjects were divided into two groups.

The first group stopped treatment after their radiation therapy while the second group received six cycles of chemotherapy called PCV. Patients in the second group received three drugs: CCNU (C), procarbazine (P) and vincristine (V).

The researchers found a big improvement in the overall survival of the subjects who received the PCV chemotherapy and radiation therapy, compared to those who only received radiation therapy. Those who received both radiation and PCV chemotherapy had 13.3 years average survival time while those who received radiation therapy alone had 7.8 years average survival time, a huge difference of 5.5 years.

"Patients who are deemed appropriate candidates for radiation therapy should be encouraged to receive chemotherapy as well, understanding both the potential benefits and risks," said study investigator Edward Shaw, a radiation oncologist at Wake Forest School of Medicine in Winston-Salem, North Carolina.

Jeff Abrams, clinical director of NCI's Division of Cancer Treatment and Diagnosis said that the results of the study show the potential benefits of combining available treatments. "These findings also are an example of how combining available treatments can produce a significant improvement in clinical outcome," he said.

Unfortunately, while the chemotherapy drugs used in the trial are commercially available, PCV chemotherapy is linked with some toxicities. It reduces white blood cells counts, for instance, which could lead to increased infection risks so trial investigators recommend that it should only be utilized by a physician who is experienced with managing its unwanted side-effects.

Radiation has its risks as well. Low-grade glioma is the most prevalent form of pediatric brain tumor and giving radiation to children's developing brain has been associated to a number of adverse long-term effects, such as those that affect cognitive development and endocrine function.

"We strongly recommend treatments that are less likely to cause long-term effects and second cancers," said Peter Manley, of the Brain Tumor Center at Dana-Farber/Boston Children's. "According to our analysis, radiation was the most common factor linked to differences in mortality among long-term survivors."