Monday, 21 November 2016

Precision medicine, personalized medicine and person-centred medicine

Cristina Roure

In recent years we have frequently heard about personalized medicine referring to the use of our growing understanding of genetic variability in medicine for prevention strategies, more accurate and safer diagnoses and more effective treatments for each individual.

I must confess that the use of the "personalized" adjective referring to the individualization of treatments based on the genetic characteristics of each person has always caused me some discomfort, because I think that a person is much more than a set of genetic information, however accurate it may be.

For this reason I was happy to hear the term precision medicine in relation to the new initiative of the Obama Administration announced in his discourse of State of the Nation on January 20th, 2015.

The term comes from a document prepared by the National Research Council: "Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease" (1). The term personalized medicine widely used even for advertising purposes has been avoided, and has been replaced by precision medicine in order to avoid a misinterpretation that may imply that the treatments would be personally designed and synthesized for unique patients. Instead he wanted to convey a broader concept that would include precision in tailoring the therapies for subpopulations defined by genomics.

The initiative has been presented as a bold and promising pioneering effort in a new research model that will revolutionize medicine in the short and long term (2). Recruiting a longitudinal cohort of 1 million volunteers who will be researched not only on their sequencing of the entire genome but also on their electronic health records, their lifestyle, diet, exercise and environmental exposure among others, through ongoing monitoring and personalized feedback by smartphone and smartwatch. As Francis Collins, Director of the National Institutes of Health says "the genes load the gun, but the environment triggers it" (3). I invite you to learn more about this huge project through the YouTube channel "Precision Medicine Initiative".

Not everyone shares the enthusiasm for the initiative, some sceptics denigrate it as sensationalist and argue that it might be preferable to devote these resources to reduce inequities in the system or to the promotion of exercise and diet can that dramatically reduce the risk of diseases such as diabetes but obviously it would not sound as "sexy" as ‘precision medicine’ (4).

It’s true that most current treatments are designed for the "average patient" and that this approach of "one size fits all" causes the treatments to be very effective for some but not for others who must bear the cost of toxicity in exchange for zero profit and a non-negligible cost for the system. Precision medicine and the use of big data has undeniable potential and will certainly help us take decisions in a context of less uncertainty. However, no database, however big, will tell us exactly what each person needs or wants. This avalanche of data and information makes people’s judgment, intuition, motivation, preferences and values  even more valuable.

When it comes to taking important decisions about our health, or our lives, data and information are not sufficient because often the things we can measure are not exactly the things we care about most. Each individual, independently of the precision with which their genotype and phenotype is known and of how deeply they understand the risks they face, will still take decisions based on their life, their social context, values, preferences and emotions; areas in which the individual is the expert. Allow me to say that I believe that this medicine centred on the person in a context of shared clinical decision is the true personalized medicine, and it seems to me at least as much or even more "sexy" than precision medicine.

Obviously precision medicine and medicine centred on the individual or customized medical care are not exclusive but complementary, but we should not confuse them.  Dr. Aronson, a geriatrician and professor at the University of California at San Francisco, in an interesting article that I discovered thanks to a post by Jordi Varela on this blog, said that we have prioritized medical care to the detriment of health, at least with regards to the complex and frail patients (5). Now with the avalanche of data that is coming we should be alert not to prioritize information to the detriment of people.

  1. Committee on a Framework for Development of a New Taxonomy of Disease, National Research Council. Toward Precision Medicine : Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease. Washington, DC; National Academies Press; 2011.
  2. Euan, A., C. V. R. B. Falk. The Precision Medicine Initiative: A New National Effort. JAMA 2015; 313: 
  3. Collins F, Varmus H. A New Initiative on Precision Medicine. N Engl J Med 2015; 372:793-795.
  4. Rubin R. Precision Medicine: The Future or Simply Politics? JAMA 2015; 313:1089-91.
  5. Aronson L. Necessary Steps: How Health Care Fails Older Patients, And How It Can Be Done Better. Health Aff March 2015; 34:528-532.

No comments:

Post a Comment