Elderly patients with glioblastoma live longer with chemoradiation using temozolomide
Prof James Perry - University of Toronto, Toronto, Canada
I’m here on behalf of my colleagues from the Canadian Cancer Trials Group and the intergroup mechanism through EORTC and TROG to present the results of our randomised controlled trial at a plenary session here at ASCO 2016.
Can you tell us what the medicines that you’re working with were as solo therapies and how they’re being used in combination?
We studied radiation therapy following surgical resection for newly diagnosed patients with glioblastoma who were over the age of 65. We tested radiation therapy alone or radiation therapy with temozolomide chemotherapy. Temozolomide is an capsule that’s given daily with radiation and then monthly adjuvant cycles following.
How are the patient cohorts divided?
The patients were all over the age of 65 with surgically confirmed glioblastoma. From the statistical point of view we stratified at randomisation according to their age group, according to their performance status, so the ECOG 0, 1 or 2, according to the centre that they come from and the degree of surgery. We found that those variables were equally distributed between the groups when we looked at the final data.
What kind of results did you find from the trial and were there any predictive markers that you could associate with the results?
The results from the overall trial were very pleasing. The overall survival was improved, as was progression free survival for all patients in the trial. We looked at a very particular subgroup of patients, those patients that had MGMT promoter methylation which is a test done on the brain tumour tissue from the time of surgery. Patients that have MGMT methylation are known to benefit from temozolomide chemotherapy so we expected that we would see more benefit in those patients and we did. The magnitude of that benefit surprised us somewhat because in those patients we saw essentially a doubling of the average median survival time in those patients.
When it came to the patients, you mentioned how they were stratified, were there any limits to their access to the treatments?
One of the challenges with older patients is that they frequently have issues with mobility and many times don’t have caregivers near at hand to be able to make the trip to a cancer centre to receive radiation which is an outpatient treatment. The one advantage of our approach, using the shorter schedule, is that it was 15 days of treatment rather than 30. So that becomes a lot more approachable for patients and obviously could easily have an economic advantage – it’s half the treatment in terms of visit time etc.
When it comes to taking these results forwards, do you think they could be incorporated into standard of care or be used to benefit other patients groups outside of the elderly cohort?
What’s important about this is that temozolomide is obviously a marketed drug, we’ve studied it in an older patient group. So these results are immediately applicable in clinical practice so I think that that will continue to happen immediately after this meeting.
And for patients? I was speaking with someone at AACR recently who was researching glioblastoma in children under the age of 7 and some of the extensions they were doing to the quality of life there and overall survival were small but important. Do you think this could be brought forward to younger age groups or people at the extreme of age distribution.
Yes, the question of age is an important one. Children’s glioblastoma is relatively rare, so it’s the most common type of cancer in adults, it’s one of the least common paediatric brain malignancies. They are completely different diseases so if you look at genomic analyses they’re completely different. So temozolomide chemotherapy is already used in children but doesn’t have as nearly as much impact as it does in adults unfortunately.