What is it, what does this term cover?
Personalized Medicine is a field still rapidly evolving. Accordingly, scientists and medical doctors coined and used quite a number of different definitions. The bottom line of all these definitions is taking quantitative measurable personal information characterizing individual patients or patient groups into account in medical decisions.
However, doctors have also been using qualitative information about patients for that purpose much longer. This kind of information includes the impressions doctors get from physical examination of patients, descriptions of symptoms or in case of psychiatry, the general impression the patient left in therapeutic sessions. This is very important for a holistic patient care but is not part of the definition of P4-medicine and, therefore, will not be a focus of this blog.
A whole lot of new quantitative measures emerged more recently and MDs can obtain them via laboratory analyses of body liquids or tissue samples from the patients. Technologies looking at all molecular measurements in one field (e.g. the genomic DNA-sequence of a tissue sample, called the genome, all proteins present in as sample, called the proteome, etc) are collectively termed -omics (genomics, proteomics, etc) and represents the latest addition to quantitative medicine. The definition given by the NIH focuses on these quantitative aspects:
A form of medicine that uses information about a person’s genes, proteins, and environment to prevent, diagnose, and treat disease.
While this is a widely used definition, there are a few issues remaining with that definition in my mind. The first quite obviously is the fact that all qualitative observations are ignored as mentioned above, which does not sit well with practicing doctors as this is currently one of their major assets in determining how to treat a patient. The second issue is the strong emphasis of personalized medicine on diagnosis and treatment of disease. However, many controversies may disappear by recognizing personalized medicine as a complement to traditional medicine, not a replacement.
As outlined last week I will use another also widely used definition of personalized medicine as guideline in this blog. The P4-medicine definition from Leroy Hood from the Systems Medicine Institute in Seattle. The four Ps stand for: preventive, predictive, personalized, and participatory. Especially the first of these terms, preventive, aims at applying personalized measures to prevent disease and keep people healthy instead of letting them become diseased patients. This part has also been called “scientific wellness”, with “scientific” representing the quantitative measures of wellness. This will be the first topic to be discussed in more detail.
Therefore, I prefer a more inclusive definition of personalized medicine, such as this one:
A form of lifestyle intervention or medicine that uses all available information about a person’s status, including quantifiable measures such as genes, proteins, and environment to achieve lasting wellness and prevent, diagnose, and treat disease.
What’s coming up next?
Next week we will start with the first P4 topic, “Preventive”. I will start with a reflection on the term “health” as currently the major definition is the absence of clinically apparent disease. However, with respect to quantitative medicine this is definitely no accurate or sufficient.