'Stem-cell tourism' needs tighter controls, say medical experts

Stem-cell tourism involvingpatients who travel to developing countries for treatment withunproven and potentially risky therapies should be more tightlyregulated, international health experts said.

With hundreds of medical centres around the world claimingto be able to repair damaged tissue in conditions such asmultiple sclerosis and Parkinson's disease, tacklingunscrupulous advertising of such procedures is crucial.

These therapies are advertised directly to patients with thepromise of a cure, but there is often little or no evidence toshow they will help, or that they will not cause harm, the 15experts wrote in the journal Science Translational Medicine.

Some types of stem cell transplant mainly using blood andskin stem cells have been approved by regulators after fullclinical trials found they could treat certain types of cancerand grow skin grafts for burns patients.

But many other potential therapies are only in the earlieststages of development and have not been approved byinternational regulators.

"Stem cell therapies hold a lot of promise, but we needrigorous clinical trials and regulatory processes to determinewhether a proposed treatment is safe, effective and better thanexisting treatments," said one of the 15, Sarah Chan ofBritain's University of Edinburgh.