Dr. Perry: Glioblastoma is a very difficult disease to treat, and patients that have recurrent tumours have very few treatment options available. At Sunnybrook Hospital in the Odette Cancer Centre we have the opportunity to be involved with a new strategy for treatment, and that is giving daily doses of chemotherapy, rather than traditional cycles which are much less frequent.
We were able to see in some of our patients that giving chemotherapy daily had advantages in terms of tumour control and patients’ quality of life. So, we wanted to create a much larger study to prove those findings across all Canadian centres. Dr. Perry: What I’m showing you now are before and after pictures from the very first patient that we treated at Sunnybrook hospital with daily temozolomide.
These are both MRI scans of a 42 year-old woman who had a recurrent tumour. The recurrent tumour is seen here in white, and on the scan this would measure about 3 by 4 cm in size. And after 4 months of daily temozolomide, you can see that white area is gone. What this is is a resolution of the aggressive part of her brain cancer on this scan, and what we call a complete response.
And this was so encouraging that we started to treat other patients at Sunnybrook, and it led to the rescue trial. So the results were very encouraging, we treated over 120 patients in 11 different brain tumour centres across Canada and we were able to see the highest, so far, reported rate of tumour control in patients with recurrent glioblastoma.
The advantage of this treatment is that it’s oral, so it’s just a pill that’s taken at home, and the side effects are extremeley uncommon and very easy to treat and manage in the clinic. So compared to the other options available, temozolomide given daily for these patients has the advantage of being much less toxic, and at least as active, or more active, in controlling their tumour.
One of the advantages of temozolomide is that it can be given in a variety of different schedules–and what we mean by that is different doses over different number of days, and it can be very well tolerated in these different schedules, but it’s one of the only chemotherapy drugs we can administer every day. As I said before, it’s a pill, so we can give this to patients to take at home, rather than having them come to a cancer centre or a treatment centre on a daily basis, and we think by giving it daily, it’s attacking the blood vessels within a tumour so that’s called antiangiogenic therapy,
and in the results of our study we determined that there’s a particular resistance protein, and I don’t want to make this too complicated but there’s a particular protein present in tumours that creates resistance to traditional therapy drugs, and it looks like the daily administration of temozolomide overcomes that in a way that no other drug has been shown to do so far.
I think it’s important to still emphasize that this is a very difficult disease to treat, and although this is very effective, it still isn’t going to be a cure for many, if any, of our patients and we desperately need to invest in our resources and to continue to raise funds and raise awareness for brain tumours throughout this country, so that more research like this can happen in Canada