A group of top scientists in Britain have warned patients to be wary of "extravagant" claims made for "unorthodox" stem cell treatments offered abroad and that some stem cell treatments could be killers.
In a letter to The Times newspaper, the experts while lauding the UK for establishing itself as a world leader in such research, say some foreign therapies, in particular those offered for multiple sclerosis and cosmetic skin treatment, were unproven, not subjected to independent review and could be dangerous.
In Britain, a handful of treatments have been licensed, principally for treating leukaemia and eye and skin disorders, and the group say that while they welcome efforts to translate research findings as quickly as possible into clinical benefits, it should only be done in the context of rigorous scientific scrutiny.
The letter has been signed by 14 medical charities and research funders, including Professor Colin Blakemore, chairman of the UK Stem Cell Funders Forum, Lord Patel, chairman of the steering committee for the UK Stem Cell Bank, and Simon Gillespie, chief executive of the MS Society.
It says among other things that with regard to unorthodox stem-cell treatments, the protocols and results have not been published or subject to independent review, and there is no published evidence to support claims that stem cells can safely repair tissue damage caused by multiple sclerosis.
They say there is in fact concern that these unproven treatments could be dangerous, potentially exposing patients to the risk of uncontrolled and inappropriate tissue generation.
The experts were prompted to raise the issue because of reports of patients travelling abroad, particularly to the Netherlands, for treatment not available in the UK and warn that two such clinics in the Netherlands are already under investigation.
Professor Blakemore says patients who seek unorthodox treatment risked hampering stem cell research as the 'delicately poised field of research' has a difficult ethical background and just one application of maverick stem-cell science that leads to cancer could set back the legitimate field by decades.
Stem cells are undeveloped cells with the ability to become different kinds of tissue and those extracted from embryos less than 14 days old can potentially be directed to grow into any part of the body, from bones to brains.
Scientists hope in future they will be used to develop new treatments for a host of diseases, including currently incurable conditions such as diabetes and Parkinson's.