Experts have warned a massive increase in the number of cancer patients taking part in clinical trials could be threatened by new EU regulations.
The new regulations could affect how much research is carried out
The number of patients taking part in research has grown by over 70% in the last two years.
But experts warn the increase could be lost if the EU regulations on clinical research become law - and say non-commercial research is under most threat.
They say the leap in the number of patients taking part in research is due to the establishment of National Cancer Research Network, which was set up by the government in 2001.
It would be tragic if all that progress were swept away at a stroke by the introduction of bureaucratic and inflexible legislation
Professor Peter Selby, Cancer Research UK
One of the network's aims was to double the number of cancer patients entering clinical trials.
So far, it has increased the numbers recruited for research into cancer treatment each year from 3.75% of adults diagnosed with cancer when it was set up to 6.5% in its second year.
But these improvements could be eroded if the EU Clinical Trials Directive is adopted as UK law, according to Professor Peter Selby of Cancer Research UK.
The regulations are due to come into effect in May next year.
The charity is to be part of a steering group set up by the Department of Health to look at the concerns over the legislation.
Professor Selby will tell scientists attending the British Cancer Research Meeting in Bournemouth on Saturday that the directive would seriously restrict or stop publicly funded clinical trials.
Trials funded by charities and universities would have to follow a set of specific rules, which Cancer Research UK say fail to take into account the systems they and other public bodies already have in place to ensure high-quality research and patient safety.
Professor Selby warned the new systems could double the amount of paperwork needed for trials and quadruple the cost, leading to fewer trials being carried out.
He said much of the research funded by Cancer Research UK was in areas which were of little commercial interest to drugs companies, such as childhood cancers or trials of new combinations of existing treatments and drugs.
Professor Selby said: "The establishment of the network has been a tremendous success, and we're now reaping the rewards with more participants in clinical trials than we've ever had before.
"But it would be tragic if all that progress were swept away at a stroke by the introduction of bureaucratic and inflexible legislation."
Dr Richard Sullivan, Head of Clinical Programmes at Cancer Research UK, said: "The aim of the original European Directive from which this legislation springs - to simplify the process for allowing patients access to clinical trials across Europe - will not be achieved."
He said the charity was pleased to be in discussions with the government, the Medical Research Council and the Medical Healthcare products Regulatory Authority.
But he added: "It is important that the UK legislation is drafted and implemented in the most pragmatic manner to ensure the continuation of publicly funded clinical trials."