There is still some confusion surrounding the difference between precision medicine and personalized medicine. Some argue for a strict distinction between the two. For them, using the term “precision medicine” instead of “personalized medicine” offers a more accurate representation of practices involving the customisation of healthcare services.
Others have used the two interchangeably however. The public and mainstream media, as well as industry practitioners and non-profit healthcare and scientific organizations have used a degree of freedom in switching between the two terms.
Drawing the difference between precision medicine and personalized medicine
A 2011 report prepared by a committee of the U.S. National Research Council suggested the use of the term “precision medicine” instead of “personalized medicine.” Note that NRC is the working arm of the United States National Academies responsible for shaping policies and advancing the pursuit of science, medicine, and engineering.
The report defines precision medicine as “the tailoring of medical treatment to the individual characteristics of each patient.” The report added, “It does not literally mean the creation of drugs or medical devices that are unique to a patient, but rather the ability to classify individuals into subpopulations that differ in their susceptibility to a particular disease, in the biology and/or prognosis of those diseases they may develop, or in their response to a specific treatment.”
In explaining the difference between precision medicine and personalized medicine, the report said the latter is susceptible to misinterpretation. Some might regard personalized medicine as a concept that implies the design of unique treatments for each individual. This is not the actual case in practice as iterated in the definition of precision medicine.
An executive at Merck Research Laboratories and geneticist also explained the distinction between the two. In his blog article, Robert M. Plenge, MD, PhD, considered the term “personalized medicine” as synonymous with practices involving basic patient care. According to him, physicians generally make decisions about the best course of treatment based on patient preferences. This should be the actual and most basic definition of personalized medicine.
Plenge also said that there are some burdens associated with personalized medicine. When the Human Genome Project was nearing it completion in 2000, people hoped that the identification of genetic markers would clearly differentiate patients between responders and non-responders. Personalized medicine was a buzzword around this time. This did not happen due to the polygenicity of complex traits.
Gary An, MD, and Yoram Vodovotz, MD, also trace the popularity of the term “personalized medicine” from the assumptions associated with the Human Genome Project. These assumptions revolved around using sequence data and information such as demography, medical histories, and responsiveness to medications to determine therapies that would work best for an individual patient. The assumptions never materialised however. An and Vodovotz said that “precision medicine” has become a more appropriate terminology to describe a healthcare approach involving the analysis of precisely defined subgroups of patients using genomic sequence data and metadata from existing therapies.
Blurring the difference between precision medicine and personalized medicine
Others have used the terms “precision medicine” and “personalized medicine” despite some strict calls to use the former. This is evident in casual and formal discourse, as well as in scientific and non-scientific literatures.
During his 2015 State of the Union Address, President Obama announced an initiative centred on promoting precision medicine. His speech interestingly highlighted how some people use the term “personalized medicine.”
Publications from non-profit organisations have also switched the two terms with a high degree of liberty. For example, an article published online by the American Cancer Society featured “personalized medicine” in its headline. Author Elizabeth Mendes also mentioned that the definitions of precision medicine and personalized medicine seem to be merging.
The patient information website of the American Society of Clinical Oncologists has also used the terms interchangeably throughout its contents. In a specific info page about cancer treatment options, ASCO included personalized medicine in the list. However, some of its blog articles featured “precision medicine” in their headlines.
Note that “personalized medicine” seems an obsolete term based on the arguments by NRC and other physicians. However, organizations such as pharmaceutical companies and scientific communities are still using it in their publication. Companies such as Bayer and Pfizer, for instance, have made information webpages about personalized medicine. Pfizer describes the term as an approach involving the tailoring of drugs to match the genetic variability of diseases.
The Jackson Laboratory, a non-profit biomedical research institution, also uses “personalized medicine” as a term to describe tailoring of healthcare services based on genomics. Other organisations use “precision medicine” such as the National Health Institute and U.S. Food and Drug Administration.
Journals under the Nature Publishing Group and Public Library of Science have also featured articles using either the terms “precision medicine” or “personalized medicine.” There are even journals that are carrying the either of the two. Examples of these are the The Journal of Personalized Medicine of Molecular Diversity Preservation International, Personalized Medicine by Future Medicine, and the Personalized Medicine Universe by the Society of Personalized Medicine; as well as The Journal of Precision Medicine and Advances in Precision Medicine, among others.
However, PHG Foundation has concluded that the two terms have specific meanings. In their position paper, the UK-based health policy think thank suggested that personalized medicine is a more general or broader concept. Under this broad concept are specific concepts such as precision medicine, stratified medicine, and P4 medicine. PHG Foundation is still on the process of reviewing and analysing relevant literatures to come up with a more concrete suggestion as regards the use of these terminologies.
Takeaway: The difference between precision medicine and personalized medicine
The concepts behind precision medicine and personalized medicine are hardly new. But there is a discord among stakeholders regarding their exact definitions and differentiations. One of the probable reasons behind this discord is that the actual application of each concept is relatively new. Another reason is that the overlaps between precision medicine and personalized medicine are very evident that their differences become negligible. Then there are those who consider the debate as nothing but a case of preferential difference.
Further readings: (1) An, Gary and Vodovotz, Yoram. 9 March 2015. What Is “Precision Medicine” — And Can It Work? Elsevier Connect; (2) Mendez, Elizabeth. 3 April 2015. Personalized Medicine: Redefining Cancers And Its Treatment. ACS Research Updates. American Cancer Society; (3) National Research Council. 2011. Toward Precision Medicine: Building a Knowledge Network for Biomedical Research and a New Taxonomy of Disease. ISBN: 978-0-309-22222-8; (4) PHG Foundation. n.d. Many Names For One Concept Or Many Concepts In One Name? PHG Foundation; (5) Plenge, Robert M. 16 March 2013. Personalized Medicine vs. Precision Medicine. Plenge Gen Blog