Medical experts fight to improve prognoses

PUBLISHED : Monday, 10 December, 2007, 12:00am
UPDATED : Monday, 10 December, 2007, 12:00am

The most common type of brain cancer for adults aged over 19 is called glioma. Most adult glioma patients with the disease have an aggressive form of it known as high-grade glioma. Even with treatment, life expectancy of these patients is usually less than 12 to 14 months.

For patients with high-grade glioma, Brigette Ma Buig-Yue, associate professor of the department of clinical oncology, the Chinese University, said surgery remained the primary treatment, followed by radiotherapy. But still less than 10 per cent of patients survived beyond two years after receiving both treatments.

However, if patients received radiotherapy and an oral form of chemotherapy concurrently after surgery, the two-year survival rate rose to 26.5 per cent.

'A pivotal clinical trial has shown that the combined treatment does not significantly increase the toxicity of radiotherapy,' she said.

'Also, the new generation of chemotherapy drugs has fewer side effects and many patients tolerate it well, although it is expensive and patients need to be self-financed.'

Gilberto Leung Ka-kit, assistant professor, division of neurosurgery, department of surgery, University of Hong Kong, said laboratory and clinical studies showed that the new chemotherapy drug, Temozolomide, had shown significant results. But due to its high cost, not all patients could afford it. 'In Hong Kong, only some patients are using the drug,' he said.

For recurrent cases, Professor Ma said, initial studies found that treatment combining chemotherapy and anti-angiogenesis agents produced some remarkable results.

In one clinical study, 30 to 40 per cent of patients had their tumour shrunk, although some suffered from some drug-related side effects. Dr Leung added that pilot trials had had good results.

Statistics show that every year in Hong Kong there are about 200 new adult brain cancer cases.

Brain tumours are generally divided into three categories - 40 per cent of patients have a benign tumour which is curable by surgery; another 40 per cent have malignant tumours; and about 20 per cent have other types of rare cancers, including germinomas and lymphomas.

Professor Ma said investigators are exploring new drugs and treatment techniques, such as conducting stem cell research, and the effectiveness of anti-angiogenesis drugs.

Pathologists and neurosurgeons at the Chinese University are studying the biological factors that may predict the effectiveness of the concurrent use of chemotherapy and radiotherapy in high-grade glioma cases.

Professor Ma said one of the problems of treating high-grade glioma was that most patients were elderly and had other diseases. 'Some older treatment drugs have more side effects. We are trying to reduce the side effects of the treatment by prescribing more friendly drugs for mature patients.

'We also hope to establish academic links with major neurology and oncology centres overseas on the development of new drugs for clinical evaluation.'

On clinical research, Dr Leung said his department is working with local hospitals to collect brain tumour specimens from patients for future laboratory research. This is necessary as each centre treats a small number of cases only and the availability of specimens may become 'diluted' among private and public hospitals.