Brain tumour treatment on the cusp of revolution, conference hears

Brain tumours account for only two per cent of cancer deaths but they are the fourth most important type of tumour in terms of life years lost, as they disproportionately affect younger people.

In fact, survival rates for high-grade cerebral glioma -- the most aggressive late-stage form of the disease -- average less than one year.

But according to Prof Andrew Kaye, head of the department of surgery at the University of Melbourne, the next decade will see major advances in treatments for brain tumours that could turn around the statistics and extend the lives of sufferers.

"It's disheartening that treatment of gliomas is still so poor... despite the best therapies available," Kaye told delegates at the Australian Neuroscience Society's annual conference this week.

Kaye said one reason that surgery, radiotherapy and chemotherapy failed to eradicate the tumour was due to the tendency of brain tumours to infiltrate brain tissue in a zone around the tumour mass known as the invasive edge. In 80 per cent of patients, he said, the tumours recur locally, unlike other cancers where recurrence is usually due to metastasis.

But researchers are slowly making headway against the disease. "We now have a much better understanding of the genetic events and molecular events in the genesis of a tumour," Kaye said.

"In the progression from normal brain tissue to a low-grade tumour to a high-grade tumour there are increasing chromosomal abnormalities. There is no doubt that in 10 years' time we will identify tumours by their chromosomal abnormalities."

Increased understanding of the changes that take place in a tumour cell will lead to more effective treatments, Kaye said. One of the more important changes in tumour cells is upregulation of the EGF receptor -- seen in the majority of patients with cerebral glioma.

In the next six months, Kaye hopes to initiate Phase I studies to look at a new therapy targeting the EGF receptor developed at the Ludwig Institute for Cancer Research.

Kaye has also been involved in the testing of photodynamic therapy (PDT). In this technique a sensitising molecule administered and taken up by cancer cells, then a laser is used to activate the sensitizer and trigger a toxic reaction that kills the cell. In trials at the Royal Melbourne Hospital, photodynamic therapy has been demonstrated to significantly extend the median survival times of patients with medium and high-grade gliomas, with 25 per cent of patients surviving for more than five years.

"It doesn't cure but it slows down the recurrence," Kaye said.

Kaye believes that ultimately a multi-pronged attack on tumours will be required, targeting multiple biological mechanisms and events.