Thursday December 4 2008
The science behind stem cell treatment is still in the early stages
“Patients with debilitating diseases such as multiple sclerosis and Parkinson’s risk being exploited by websites offering expensive stem-cell treatments.” The Times reported. It said that a study had investigated the websites of 19 companies that offer such therapies. Researchers found that most make inflated or over-optimistic claims about the benefits, are not backed by evidence and make little or no mention of the risks involved.
This study highlights the extent of the problem of direct-to-consumer advertising of stem cell therapies.
There are risks in buying anything claiming to have a health benefit over the internet. Stem cell treatment offered by seemingly legitimate clinics is no different. Stem cells are an accepted treatment for blood cancers, but this science is still in its infancy in terms of neurological treatments. The MS Society warns there is no evidence yet that the treatment repairs multiple sclerosis damage.
Anyone considering this sort of treatment is strongly recommended to discuss it with their GP first. The Department of Health has recently released a warning on unproven stem cell treatment.
Where did the story come from?
Darren Lau and colleagues from the Department of Public Health Sciences and Faculty of Law at the University of Alberta in Edmonton, Canada carried out this research. The work was funded by a grant from the Stem Cell Network. The study was published as correspondence in the peer-reviewed science journal, Cell Stem Cell.
What kind of scientific study was this?
The researchers say despite the fact that stem cell medicine is in an immature state, there is still an ‘early market’ for the supposed stem cell therapies, and people are beginning to buy the therapies directly. They believe that direct-to-consumer advertising through the internet is likely to play an important role in how this market develops. This cross-sectional descriptive analysis was aimed at answering three specific questions:
- What sorts of therapies are being offered?
- How are they portrayed?
- Is there clinical evidence to support the use of these therapies?
To investigate this, the researchers took a ‘snapshot’ of online stem cell clinics in August 2007, by carrying out a Google search using the terms ‘stem cell therapy’ or ‘treatment’. This search returned 19 websites claiming to use stem cells to treat the disease. The researchers took the clinics’ uses of the ‘stem cell’ label at face value, meaning that they did not assess if the clinics were truly offering therapies with stem cells.
The researchers noted that the sites often offered other services including cosmetic treatments of otherwise healthy patients or health ‘enhancements’. Importantly, these clinics also gave information on how the stem cells were given to patients.
They also say that it is usually difficult to sort the stem cells from other cells and that it is therefore likely that the ‘stem cell therapies’ referred to by the websites contain numerous other cells in addition to the stem cells.
What were the results of the study?
The researchers found that the most commonly provided stem cells were adult and taken from the patient’s own body (nine websites or 47%). These were followed by stem cells sourced from a foetus, cord blood or embryo. The stem cells were most often obtained from the patient’s bone marrow (seven sites or 37%) and/or blood (five sites or 26%). Some websites did describe getting the stem cells from patient fat, blood or marrow donors, aborted foetuses, patient’s skin, animal tissues and human placental tissue.
The websites claimed that treatments were most commonly administered by infusion into cerebrospinal fluid by lumbar puncture (six sites or 32%). Injection into a vein was equally common. Four websites described procedures for injecting the stem cells into deep body cavities, such as the space around the brain or by injection directly into the spinal cord.
The conditions treated were diverse, including neurological conditions or brain diseases such as multiple sclerosis, stroke, Parkinson’s disease, spinal cord injury and Alzheimer’s disease. The sites also claimed to treat allergies and congenital diseases, mainly cerebral palsy, autism and Duchenne muscular dystrophy.
Regarding the portrayal of risks and benefits, all 19 websites advertised improvement in the disease state as a benefit of therapy and most (14 or 74%) of the sites did not mention particular risks.
The last part of the study was to look for the evidence supporting stem cell treatments. For this, the researchers performed a database search (Pubmed) in July 2008. They looked for human studies that reported the clinical effects of stem cell therapies for any neurological or cardiovascular conditions mentioned 10 or more times by the websites. This search provided a range of trials (mostly randomised controlled trials) of low-level evidence (i.e. varying quality) for neurological conditions and four systematic reviews with meta-analyses for stem cell treatments after heart attack.
All of the systematic reviews reported a small but statistically significant advantage of about 2-3% in a measure of heart function, but the researchers say this was of uncertain clinical importance. For stem cell therapies for multiple sclerosis, Parkinson’s disease, stroke, Alzheimer’s disease, and spinal cord injury they found that the treatments offered on stem cell websites are generally unsupported by the clinical evidence.
What interpretations did the researchers draw from these results?
The researchers concluded that direct-to-consumer portrayal of stem cell medicine is optimistic and unsupported by published evidence. They also suggest that the results have other implications including:
- Providers are making inaccurate claims in their direct-to-consumer advertising.
- Importantly, patients may not be receiving sufficient and appropriate information and may be being put at increased risk.
- Clinics may also be contributing to a public expectation that exceeds what this field of research can reasonably achieve.
What does the NHS Knowledge Service make of this study?
The researchers mention some limitations to the methods that they used to collect the data:
- The information available from websites may not be the same as the information actually shared with patients in the clinic.
- The overall data was collected from a diverse range of clinics. The results cannot therefore be used to evaluate the claims of any particular clinic.
- The researchers did not directly assess the accuracy of the websites’ claims by analyzing the results of treatment they had carried out.
These are valid points. The researchers also say that even if improvements had occurred, it would be impossible to say with confidence that these were due to the treatment. If on the other hand the treatments did not work, then patients would have been subjected to inappropriate risk and the cost of the treatment. The average cost of a course of therapy among the four websites that mentioned costs was $21,500, excluding travel and accommodation for patients and caregivers.
There are well-publicised dangers in buying anything claimed to have a health benefit over the internet. Stem cell treatment offered by seemingly legitimate clinics is no different, especially considering the various sources of the stem cells, the deeply invasive methods in which they can be delivered and the fact that this science is still in its early stages.
New guidelines have just been released by the International Society for Stem Cell Research (ISSCR).
A patient handbook is included that also lists some of the claims made by the websites, those that patients should interpret with caution.