Molecular test for cancer relapse in UK children

Apr 2 2009

A molecular marker used in America to predict whether children with a form of kidney cancer, called Wilms' tumour, are more likely to relapse than other children, could be useful for UK patients.

The study is published in the European Journal of Cancer.

In the UK and most of Europe, doctors give children with Wilms' tumour chemotherapy before surgery to make the tumour easier to remove and to reduce long-term side effects from treatment for this disease. In North America, doctors attempt to remove the tumour before chemotherapy.

The two treatment approaches use different methods to predict whether a child will relapse - the European approach looks at the number of tumour cells that survive the initial chemotherapy, and the North American approach analyses molecular changes in tumour cells that have not been exposed to chemotherapy.

Scientists in this study, funded by Cancer Research UK and undertaken at The Institute of Cancer Research, have analysed over 400 Wilms tumours from UK patients treated in past clinical trials by either immediate surgery or initial chemotherapy for two molecular markers now used in North America.

They found that the American test - which reveals the loss of chromosome 16 - predicted which children were more than twice as likely to relapse and to die from Wilms' tumour.

The risk was the same regardless of the treatment approach that had been used.

Around 20 per cent of Wilms' tumours have the genetic profile that indicates a higher risk of the disease coming back.

Ongoing UK research on tumours from children treated with chemotherapy before surgery will show whether this marker should be added to current methods to predict risk in UK children to determine how much treatment they should receive.

Lead author Professor Kathy Pritchard-Jones, a clinical scientist based at The Institute of Cancer Research and the Royal Marsden Hospital, said: "Unfortunately, children whose tumours contained this 'high-risk' molecular marker were more likely to relapse regardless of the treatment regimen they were given.

"Now we've identified this group of patients in the UK who could benefit from this type of classification, we can begin to develop a more tailored treatment strategy that will help to improve the survival chances for these children."

Around 80 children are diagnosed with Wilms' tumour in the UK each year. Around 95 per cent of kidney cancers diagnosed in children are Wilms' tumours and they are most commonly diagnosed in children under 5 years. Around nine out of ten children with Wilms' tumour are treated successfully.

Kate Law, Cancer Research UK's director of clinical trials, said: "Great progress has been made in improving survival rates for children with Wilms' tumour, but now we need to create more effective ways of assessing the most appropriate treatment for each child.

"This study is another step towards creating personalised treatment for children with this type of cancer, so that all children who receive a diagnosis can be successfully treated with their future prognosis in mind, and with the view to one day finding a way of curing all children with this disease."

http://www.cancerresearchuk.org/