Stem cells are a source of keen interest because they can be coaxed into becoming almost any type of cell, and thus might offer remedies for many medical problems. But they also carry risk; they can form tumours and migrate to parts of the body where they don't belong.
For the study, the researchers scoured the Internet for businesses engaged in direct-to-consumer marketing of stem-cell procedures. Many of the clinics were in California (113), Florida (104) and Texas (71). Certain cities, including Beverly Hills, New York and San Antonio, were "hotspots." Almost two-thirds of the businesses offered procedures involving stem cells derived from a patient's own fat; almost half performed treatments using bone marrow.
The Food and Drug Administration has approved only a very few stem-cell treatments. In the vast majority of cases, the procedures being conducted in the clinics are not approved, are outside clinical trials and can cost patients thousands of dollars.
The new analysis comes as the debate over regulating stem-cell clinics is intensifying. While some critics say the FDA should crack down on the industry, others say they shouldn't face new restrictions because what they are doing is part of the "practice of medicine".
Michael Werner, executive director of the Alliance for Regenerative Medicine, which represents companies, patient advocates and researchers, said group thinks FDA oversight is critical. He said "the proliferation of the so-called stem cell clinics is potentially harmful because the treatments may not undergo, or have not undergone, the appropriate scientific rigour that takes place in evaluating new technologies and new medical treatments."
But Marc Scheineson, a former top FDA official who advises the Bipartisan Policy Center on medical innovation, said the current FDA regulatory regime is "archaic" and is stifling medical innovation.
As the issue heats up, the FDA has scheduled two public meetings in September to get public comment on draft guidance language on stem cells.
In a statement, the agency said, "In theory, stem cells may advance the treatment of many other diseases or conditions; however, at this time, the value of stem cells as a treatment for most conditions is largely unproven and more information is needed about their potential benefits."
The agency added that it is "concerned that the hope patients have for treatments not yet proven to be safe and effective may leave them vulnerable to unscrupulous providers of stem cell treatments that are illegal and potentially harmful."