Patients with a grade 2 type of brain tumor called glioma, who receive combined radiation therapy (RT) and chemotherapy, survive longer than those who receive RT alone, according to a new study published in the New England Journal of Medicine.

Even though stage 2 glioma only makes up 5 to 10 percent of all brain tumors, it is responsible for progressive neurologic symptoms and premature death in almost all patients with this type of brain tumor.

Researchers at Mayo Clinic in Rochester, Minnesota, evaluated 251 patients with stage 2 glioma who were involved in the RTOG 9802 trial from October 1998 to June 2002. The patients were considered to be at high risk because they were 40 years old or older or had incomplete surgical removal of their tumor.

The study involved a network of investigators across the U.S. and Canada who worked through the National Cancer Institute’s National Clinical Trials Network. It could only have been conducted through a publicly-funded national clinical trials network, according to the lead author.

The patients were randomly placed into one of two groups — RT plus six cycles of procarbazine, lomustine and vincristine (PCV) chemotherapy or RT alone. Prior to the patients receiving treatment, the researchers performed a pathology review on tumor samples and prepared samples for correlative lab studies to assess mutational status and identify prognostic variables.

After 11.9 years, 67 percent of the patients presented with tumor progression and 55 percent of the patients died. The patients in the RT plus PCV chemotherapy group had a median survival rate of 10.4 years and the RT alone group had a median survival rate of four years.

Furthermore, the ten-year, progression-free survival rate for patients in the RT plus PCV chemotherapy was 51 percent and the rate for the RT group was 40 percent.

However, treatment toxicity was greater in the RT plus PCV chemotherapy group. The most common toxicities were fatigue, anorexia, nausea and vomiting, which were mostly grade 1 and 2 in severity, with the exception of grade 3 and 4 neutropenia.

An article published in the Journal of Clinical Oncology in April 2014 stated that the traditional research on RT focuses on improving technical delivery through more precise targeting in order to minimize the toxicity of normal tissues.

Previous studies have also demonstrated that combined RT and chemotherapy has improved survival compared to RT or chemotherapy alone when treating gliomas. Research has also recommended the combination for treating locally-advanced cancers of the head and neck, lung, esophagus, breast, stomach, pancreas and rectum.

Other studies have shown that combined RT and chemotherapy also allows for organ conservation with high cure rates in cancers of the breast, larynx and anus and sarcomas of the extremities.

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