Timothy Caulfield: Genetics and personalized medicine—where’s the revolution?

tim_caulfieldThis blog is part of a series of blogs linked with BMJ Clinical Evidence, a database of systematic overviews of the best available evidence on the effectiveness of commonly used interventions.

I started my academic career in the early 90s working on the policy issues associated with something called the “genetic revolution,” which we were constantly told (by researchers, government, and the media) was just around the corner. As a result of this impending seismic shift, we needed to ready ourselves for all the profound social implications—or so the story (and the arguments for grant money) went.

Since then, the claims that we are in the middle of a genetic revolution have come at a steady pace, but the nature of alleged, near-future, healthcare transformation have evolved. First it was going to be gene therapy (it didn’t really pan out as planned). Then it was highly predictive disease genes (ditto). And now the revolution has taken the form of personalized medicine, also known as personalized genetics, personalized genomics or, in accordance with the latest semantic tweak, precision medicine.

At times it feels like an uncoordinated and desperate scramble to find some kind of “revolutionary” application for a field that has received a great deal of public attention and research funding. Alas, as with the past promises of genetically driven paradigm shifts, personalized medicine seems just as unlikely to result in widespread revolutionary changes.

Don’t get me wrong. Good things will happen, knowledge will increase and new therapies will emerge. But there is little reason to suspect that the promised cost-saving, life-extending, population-health-improving revolution will unfold as suggested by the many vocal advocates (who include researchers, media, research institutions and the President of the United States). And remember, what has been promised is a revolution (which the Oxford dictionary defines as a “dramatic and wide-reaching change in conditions, attitudes, or operation”—a pretty high standard), not a slow and iterative evolution (AKA: how science usually works).

My favourite example of the disconnect between the rhetoric of revolution and, well, reality, is in the realm of lifestyle change (this is a topic I’ve written about before). A key part of the push for personalized medicine is the belief that genetic information will facilitate healthy lifestyle change. It will, as Obama suggested in his last State of the Union address, provide us all with the “personalized information we need to keep ourselves and our families healthier.” It will be empowering, so says the Director of the National Institutes of Health, Francis Collins.

The theory behind this “revolutionary” idea is that genetic risk information will cause us all to exercise more and stop eating too much. We’ll quit smoking and drinking to excess. And we will discover what unique and special things we should do to stay healthy (answer: don’t smoke, exercise, eat a balanced diet, watch your weight, wear your seatbelt, sleep). This is an idea that is absolutely everywhere. It is, for example, part of the marketing strategy for virtually every direct-to-consumer genetic testing company. Get your genes tested, these companies promise, and you will feel the urge to start running with your dog.

Unfortunately, there is absolutely no good evidence to support the idea that providing genetic risk information will have this kind of revolutionary impact. (And, by the way, nor is there evidence that it is needed—see above noted parenthetical “answer”.) On the contrary, all the available research points in the opposite direction. Studies have found that providing genetic risk information will not, long-term, help people quit smoking or lose weight. It will not encourage them to get cancer screening. And, more damning, it will not help individuals at risk for diabetes adopt a healthy lifestyle, even when that personalized, genetically informed advice is provided by experts. A 2013 study concluded: “Diabetes genetic risk counselling with currently available variants does not significantly alter self-reported motivation or prevention program adherence for overweight individuals at risk for diabetes.”

I could go on and on.

To be fair, there are a few studies that suggest behaviour can be tweaked, but the tiny effect size of these studies—is so small and underwhelming that they can hardly be held up as an example of a healthcare “revolution”, especially since the body of evidence suggests otherwise.

Yes, hype is a natural part of the scientific process. It can raise interest in a field and can help to build communities and mobilize needed resources. But the hype in this domain has been unrelenting. And many have noted that there are potential downsides. It has been suggested, for example, that the hype in the biosciences may lead to, among other harms:

• Unrealistic patient and public expectations;
• The premature implementation and/or overuse of technologies;
Inaccurate public representations of the state of the science;
• A misrepresentation of the value of a technology, and thus a co-opting of the “patient voice” (as seems to have occurred with some screening technologies);
• A less than constructive allocation of research resources;
• The skewing of policy priorities away from needed public health initiatives;
• The complication of healthcare funding decisions (e.g. “regulatory capture”);
• The confusion of ethical concerns and the associated policy debates (ethics hype);
• And the facilitation of a market for unproven products and services.

So let’s stop with the revolution language. And let’s recognize the harm that it can do. This is not a revolution in any reasonable sense of the word. This is science unfolding as science usually does. Slowly.

Timothy Caulfield is a Canada Research Chair in Health Law and Policy at the University of Alberta, a Trudeau Fellow and the author of “Is Gwyneth Paltrow Wrong About Everything?: When Celebrity Culture And Science Clash” (Penguin, 2015). He would like to thank Tania Bubela, Chris McCabe, Robyn Hyde-Lay and Maeghan Toews for their comments on this piece.

Competing interests: None declared.

  • David_Colquhoun

    This post hits the nail on the head. Congratulations to Tim Caulfield for cutting through the hype and telling the truth.