Experts warn against “tourist trap” stem cell therapies

Hundreds of clinics around the world are offering unproved and potentially dangerous stem cell treatments to desperate patients willing to travel thousands of miles in the hope of successful treatment.

A group of UK specialists says that patients are mortgaging their houses and raising tens of thousands of pounds from their communities to pay for stem cell treatments. They are attracted by promotional material on the internet for treatments for which there is no evidence of benefit other than patients’ testimonials. The clinics attract patients with conditions such as multiple sclerosis, Parkinson’s disease, and degenerative retinal conditions for which conventional treatments have temporary or limited effectiveness.

Tighter regulation in the European Union will be introduced in 2011 under the Advanced Tissues Directive, but such clinics are a “global issue,” said Chris Mason, professor of regenerative medicine at University College London and a member of the group.

He identified three potential sources of harm for patients: physical, psychological, and financial. “We too often forget the psychological effects that ‘stem cell tourism’ can have,” he said at a press conference. “Patients dealing with the stress of a serious condition already have to go back to their communities and explain where the £30 000 they raised to send the patient to the clinic went.” It was not surprising, he added, that in these circumstances patients reported treatment to be a success.

Physical adverse effects of unproved stem cell treatments were under-reported, Professor Mason said. One widely reported case, he said, concerned an unnamed Israeli boy who was given intracerebellar and intrathecal injection of human fetal neural stem cells for ataxia telangiectasia who later developed multifocal brain tumours (PLoS Med 6(2):e1000029, doi:10.1371/journal.pmed.1000029). Another case concerned a woman with systemic lupus erythematosus who developed a renal tumour after receiving bone marrow stem cells.

He said that patients have an unrealistic sense of risk, because they believe that if clinicians are offering a treatment “there must be something in it,” even though evidence of effectiveness is lacking.

“I get dozens of emails and phone calls from desperate patients every week,” he said. “I say they need to seek as many expert opinions as they can on stem cell therapy. There is good evidence only for haematopoietic stem cells used to treat leukaemia, lymphoma, and some other haematological conditions and in the treatment of damaged corneas.”

Peter Coffey, professor of cellular therapy and visual sciences at University College London, said, “I have pulled my hair out and made some strong comments warning about stem cell tourism, but people still go for these unlicensed therapies. They all use some sort of procedure with the potential to cause some sort of problem.

“In clinical trials of these treatments there needs to be evidence of safety and of some potential for benefit. But these treatments are offered in private clinics in Germany, China, and throughout the world where research regulations don’t apply.”

Kieran Breen, director of research at the Parkinson’s Disease Society, said, “There is no evidence that stem cell therapy works to halt or slow progression of Parkinson’s disease.” He said he had tried to contact the XCell-Center in Germany, which carries out autologous stem cell transplantations in patients with Parkinson’s disease (BMJ 2009;339:b2967, doi:10.1136/bmj.b2967), to see whether it had evidence to support its treatment, “but they won’t take calls from me.”

Claims from the clinic that 30-40% of patients benefit from treatment were consistent with a placebo effect, he added.