A new cancer treatment study has revealed that combining chemotherapy with radiation treatment substantially prolonged the lives of patients suffering from certain brain tumors.

While previous studies revealed that adding chemo to radiation can slow the progression of certain brain tumors with or without surgical operation, the latest long-term follow-up study reveals that the combination can also extend patients lifespan.

All participants taking part in the study were being treated for grade 2 gliomas, which are tumors that manifest in the brain's glial cells. Researchers noted that this type of brain cancer grows relatively slowly and accounts for about five to 10 percent of all primary brain tumors in adults.

The latest study involved 251 patients who were recruited from 1998 through 2002. All participants at the start of the study were diagnosed with grade 2 astrocytoma, oligoastrocytoma, or oligodendroglioma, and most were between the ages of 18 and 39. Participants were randomly assigned to receive either radiation only or a combination of radiation and chemotherapy.

The results showed that patients who received a combination of radiation therapy and chemotherapy lived 5.5 years longer in median overall survival compared to those who just received radiation therapy. The median overall survival was 13.3 years for patients who received radiation therapy plus chemotherapy and 7.8 years for those who received only the radiation therapy.

The study also revealed that combining radiation therapy with chemotherapy significantly increased the rate of progression-free survival with 51 percent of the group that received radiation therapy plus chemotherapy, and 21 percent of the group that received radiation therapy alone surviving progression-free 10 years after treatment.

"This phase 3 trial showed a survival benefit among patients with grade 2 glioma who were treated with radiation therapy plus chemotherapy, as compared with those who received radiation therapy alone," the researchers wrote.

"The treatment effect appeared to be largest in patients with oligodendroglioma or oligoastrocytoma and in patients with IDH1 R132H mutations. The differences in survival cannot be explained on the basis of treatment after tumor progression because patients who received radiation therapy alone had a shorter time to progression and more therapeutic interventions after progression than did those who received radiation therapy plus chemotherapy," they added.

The findings were published in the April 7 issue of the New England Journal of Medicine.