The call comes after their analysis of 32 English-language websites showed that the information provided was of extremely variable quality, that many endorsed unproven therapies and some were even dangerous.
In a paper published today in Annals of Oncology[1], researchers from the Plymouth Peninsula Medical School in the UK said that their survey findings were somewhat reassuring as most of the evaluated websites did provide valuable and reliable information, especially for the prevention of cancer, and most were of medium quality.
However, some issued information on complementary and alternative medicine (CAM) that was misleading. "These websites promoted and discussed CAM treatments for which no compelling safety and efficacy data exist," said Professor Edzard Ernst, Professor of Complementary Medicine. "Generally speaking, the 'cancer cures' discussed on these websites are not supported by good scientific evidence. Other sites are outright dangerous as they advise patients against using conventional therapies."
He said that it was not the intention to deny that cancer patients can feel empowered and be supported by accessing health information on the internet. But, 600 million people worldwide currently access the Internet and public awareness needed raising about the usefulness of the information. The content of some websites also required further evaluation.
The survey, by Professor Ernst and colleague Ms Katja Schmidt, evaluated 32 of the most popular websites appearing on eight commonly used search engines between December 2002 and January 2003 and awarded them points on a scale from 0 to 14. The objective was to assess the quality and to identify the most popular forms of CAM currently discussed.
"Two websites stood out for their excellent quality, both scoring 14 – Quackwatch and Bandolier." said Ms Schmidt. "Two listed the HON code of approval[2] – the US National Cancer Institute Cancer Facts, and Quackwatch."
The survey also scored the sites for whether their information could harm patients. Three of the 32 fell into the two high-risk categories by overtly discouraging patients from using conventional cancer care.
Ms Schmidt said: "Overall, 16% provided information that discouraged patients from using conventional treatment, 3% discouraged patients from adhering to clinicians' advice, 91% provided opinions, experiences and factual details and 22% provided mainly commercial details."
Of the total CAM therapies advertised, 118 were for cure, 88 for palliative/supportive care and 59 for prevention. The researchers carried out extensive literature searches in scientific and medical databases to assess the evidence of the top five CAM modalities suggested for preventative, curative and palliative care.
They concluded of the recommended therapies that:
- Coenzyme Q10, one of the most frequently discussed, did not seem to warrant a positive recommendation as the evidence to date was far from compelling;
- There was insufficient evidence for shark cartilage – frequently recommended as a cancer 'cure' – with the only published clinical study failing to produce encouraging results;
- Clinical trials for laetrile, which contains the toxic compound amygdalin, had found no relevant benefit for cancer patients;
- The Gerson diet was not supported by convincing evidence – one study reporting a six-fold increase in 5-year survival for melanoma compared to rates reported in the medical literature was too methodologically flawed to allow any firm conclusions;
- A review of all 10 randomised controlled trials for mistletoe – an often advocated CAM – found no good evidence for an effect on cancer progression or quality of life.
However, advice on palliative/supportive care fared better with at least some evidence to back meditation for improving quality of life, acupressure and acupuncture for preventing chemotherapy-related nausea and vomiting, and massage for decreasing stress, anxiety, depression and pain.
"Raising Internet users' awareness as to what a good website contains is an important and timely task for researchers and health-care providers," said Professor Ernst. "Further research needs to identify and assess larger number of websites promoting CAM for cancer. It would also be interesting to know the numbers of cancer patients who use information from such sites or buy CAM for cancer online.
"Our analysis has shown that many websites are not as reliable as one would hope. In the interests of cancer patients we should find ways of minimising the potential harm such misinformation may cause.
"Cancer charities and other independent organisations should investigate and introduce a code similar to the HON code, which would give the public some guidance on the reliability and status of the information on CAM sites."
[1] Assessing websites on complementary and alternative medicine for cancer. Annals of Oncology. 15. Pp 737-746.
[2] HON code: Health on the Net Foundation Code of Conduct (HONcode) is a set of rules that hold website developers to basic ethical standards in presenting information and helps readers to know the source and the purpose of the data. The organisation has been granted NGO status by the Economic and Social Council of the United Nations. Its code has been adopted by over 3,000 websites worldwide.
The Peninsular Medical School is a joint School of the Universities of Exeter and Plymouth. Research is a vital part of the School's activities and is carried out in biomedical, clinical education and health services areas, which map National Health Service (NHS) needs and priorities. Website: www.pms.ac.uk
Notes:
1. Annals of Oncology is the monthly journal of the European Society for Medical Oncology.
Please acknowledge the journal as the source in any reports.
2. Annals of Oncology website: http://www.annonc.oupjournals.org
PDF of this article available from Margaret Willson.
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Annals of Oncology