In a boost for brain cancer research, an international phase III clinical trial involving Trans-Tasman Radiation Oncology Group researchers and patients has significantly improved survival of elderly patients with glioblastoma (GBM).
The study found that adding temozolomide chemotherapy during short-course radiation therapy, followed by monthly maintenance doses of temozolomide, reduced the risk of death by 33 per cent.
It's the first study to test the combination of temozolomide and radiation therapy in older adults, who account for half of all patients with this disease. While side effects were slightly greater among patients receiving temozolomide, overall quality of life was similar in both patient groups.
Radiation oncologist Dr Mike Fay, Australian Trial Co-Chair and a member of the HMRI Cancer Research Program, said this practice-changing study would help treat elderly patients with glioblastoma.
“It’s a great example of international collaboration answering an important question in an uncommon tumour. It’s important to learn how to best use the cancer treatments we already have available,” he said.
“This study does this by shortening the radiotherapy course and adding temozolomide chemotherapy. It also shows the benefit of testing the tumour to predict the chance of response. In patients who have a specific genetic marker the benefit of temozolomide is significantly reduced.”
Glioblastoma is the most common primary brain cancer in adults and among the top five causes of death due to cancer. The disease kills an estimated 1,000 Australians each year. Glioblastoma occurs primarily in older people; the average age at diagnosis is 64 years.
Co-Chair Dr Claire Phillips said that in the past there had been a tendency to be “gentle” when treating older patients with GBM because the prognosis was thought to be universally dismal and there was a reluctance to subject people to possible side-effects if they are only going to live for a short time.
“This study shows us that the prognosis is poor but perhaps not as bad as is generally believed. Importantly, it provides good evidence that older patients who have GBM, but who are otherwise quite healthy, benefit from moderately aggressive therapy without causing terrible toxicity,” Dr Phillips said.
This international phase III trial was led by the Canadian Cancer Trials Group (CCTG) with collaboration from the European Organization for the Research and Treatment of Cancer (EORTC) and TROG Cancer Research.
Investigators enrolled 562 patients 65 years and older who were newly diagnosed with glioblastoma, with 97 of these patients from Australia and New Zealand.