The results, published in the New England Journal of Medicine, found that combining the chemotherapy drug temozolomide with a short course of radiotherapy was more successful than radiotherapy alone in older patients.
Survival almost doubled in just under half of patients (45%), increasing from 7 months in those given radiotherapy alone to 13.5 months in those who received the combined treatment.
This was linked to a molecular marker found in the cancer cells, say the research team. When the marker indicated that cells were unable to repair their DNA, the treatment was more effective.
The study included 562 patients aged 65 to 90.
“We anticipate this combined therapy will be the treatment strategy broadly adopted around the world for patients 65 and older because it makes a significant difference in the course of this terrible disease,” said Laperriere.
Professor Susan Short, a Cancer Research UK expert in brain tumours at the University of Leeds, said that the results would be “practice changing” for the UK.
“They make it clear that we should be using a combination of radiotherapy and the chemotherapy drug temozolomide for elderly patients, a similar approach to what we use in younger patients,” said Short.
“The study also gives more information about the combination of treatments that we didn’t have before.“
The phase 3 randomised trial was the first to investigate combining the drug with radiotherapy in older patients.
For patients under 65, the standard treatment is six weeks of radiotherapy plus temozolomide.
But there is no similar standard of treatment for older people with glioblastoma, a disease that has no cure.
“It’s also reassuring that this patient age group can tolerate this combination.” said Short, commenting on patient reports that the drug did not affect their quality of life.
“The drug is so well tolerated” said Laperriere, “there is no downside in administering it to all glioblastoma patients.”