Most people believe it is acceptable to use individual cancer patients' details to help research, a survey has found.
Data is used to compare cancer treatments
Eight out 10 people backed the compulsory use of such data without first seeking consent - provided there were tight rules governing its use.
The data is currently collected, but experts fear data protection legislation threatens the practice.
The poll of almost 3,000 people, funded by the charity Cancer Research UK, appears in the British Medical Journal.
The research was designed to find out if people would be concerned that allowing their details to be logged by the National Cancer Registry, which was set up to collect data for research, would be an invasion of their privacy.
The data held on the register enables researchers to compare the effectiveness of cancer diagnosis and treatment in different areas of the UK, and to assess UK performance with that of other countries.
It is also used by the Department of Health to inform its cancer policy.
However, routine data collection has been under threat from various bodies because of different interpretations regarding laws governing data and confidentiality.
The General Medical Council has published guidance stressing the need to protect patient confidentiality.
And the NHS Code of Practice on Confidentiality says it cannot be assumed that patients are happy for identifiable information about them to be used for anything except their own medical care.
The survey results showed:
- 81% said holding details of their name and address in the registry would not be an invasion of their privacy
- 88% said they had no objection to their postcode details being held
- 87% said being invited to take part in a research study would not be an invasion of privacy
However, most people who responded said data should only be used in strict confidence for research by recognised bodies.
Professor Michel Coleman, of the London School of Hygiene and Tropical Medicine, who worked on the study, said it was "patronising and unjustified" to assume patients were unhappy for identifiable information about them to be used for anything except their own medical care.
He said: "This survey shows categorically that the vast majority of people do want their personal health information to be shared for the collective good, if it could lead to improvements in the diagnosis and treatment of cancer."
Professor John Toy, medical director of Cancer Research UK, said: "These results strongly challenge the assumption that the public does not want personal information about cancer health to be registered.
"Just as cancer patients unselfishly want their experiences to help determine the best care for future patients so this study clearly shows the general public shares the same marvellous generosity of spirit."
In a statement, the GMC said it had never opposed legislation in relation to cancer registration.
"We fully accept that it is the role of Parliament to decide when it is appropriate for information to be collected for the public good, irrespective of individual patients' wishes.
"Where such a decision has not been taken, we believe that, wherever practical, patients should be informed about how their data is used and - if this includes information which identifies them - given an opportunity to agree or object."