The recent increase in survival for children with cancer is due to more patients taking part in clinical trials, according a British study.

But the authors warn that future improvements could be at risk if European trial regulations are not simplified.

The study, published in the journal Annals of Oncology, found that the sharp increase was linked to the establishment of the UK Children's Cancer Study Group (UKCCSG - now the Children's Cancer and Leukaemia Group) in 1977, which aimed to set up a portfolio of national and international trials for the majority of children's cancers.

The greatest improvements were seen in children with germ cell tumours (a form of cancer that develops in the testes and ovaries) and hepatoblastoma, a rare liver tumour.

While just over in one in four (28 per cent) of young patients diagnosed with cancer between 1966 and 1970 survived for five years, the figure had risen to nearly four in five (79 per cent) by 2005.

Between 1978 and 2005 two-thirds of children diagnosed with cancer in Britain had a cancer type for which there was an open national or international clinical trial.

Study author Charles Stiller, from the University of Oxford's Childhood Cancer Research Group, said: "The results of our study show that improvements in childhood cancer survival match those reported by the relevant clinical trials that were running between 1978 and 2005.

"During this time there has been an increasing number of patients in trials, with around 90 per cent of all children with many types of cancer enrolled, and this has been made possible by specialist children's cancer units."

He said that although trends in childhood cancer survival had been reported in relation to improvements in treatment in the UK, this was the first time that population-based survival had been looked at in relation to available clinical trials at the time.

Professor Peter Johnson, Cancer Research UK's chief clinician, welcomed the research.

"This study shows that the huge improvements in survival following cancers in childhood have come directly from the clinical trials that have been carried out," he said.

"But it is vital that we continue this work, and that the systems in place for the organisation and regulation of trials do not slow up the progress we are making."

The European Commission this week announced a review of the European Clinical Trials Directive, a move "strongly welcomed" by a Cancer Research UK spokesperson.

Emma Greenwood, the charity's policy manager, said: "We've been working closely with the European Commission throughout the consultation process, and we're pleased to see that many areas we were concerned with look to have been addressed.

"We hope the proposed changes will make it easier for cancer patients and the public to take part in world-class research throughout the UK and Europe. We'll now be working closely with our researchers and other organisations to take a closer look at the revisions to ensure the proposals are as helpful as possible and taken forward quickly."

Source: CRUK