Mar 8, 2016 - ideas, and whatever difference might exist between them will not matter for the ... according to the principle âactions speak louder than words.
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PERSONALIZED AND PRECISION MEDICINE Alex Gamma
In Search of a Definition There are two prevalent characterizations of “personalized“ or “precision” medicine (PM; the abbreviation “PM” will refer to both of these terms, as they describe the same or very similar ideas, and whatever difference might exist between them will not matter for the purposes of this chapter). Their common core is the idea that medical treatment should be tailored to the individual characteristics of each patient in order to be maximally effective, precise, and free of side effects. Where they differ is in their view regarding which kind of patient characteristics should determine the choice of treatment. There is a broad definition that considers any kind of feature of an individual—biological, psychological, environmental—as potentially valuable in guiding treatment decisions (Anonymous, 2012; Buford and Pahor, 2012; Wolpe, 2009). The more typical view, however, is that essentially the molecular biology and, within that, the genetic profile of a person determines the optimal treatment (Ginsburg, 2001; Meyer, 2012; Personalized Medicine Coalition, 2015; Sweet and Michaelis, 2011). In this view, medical interventions can be tailored to individuals by tailoring them to their genetic constitution. The difference between these two characterizations matters because the “genetic” version makes a strong assumption that the broad version doesn’t: that a person’s genome in principle contains all the disease information necessary to derive an optimal treatment. Because this assumption may not hold, the definition of PM is sometimes extended into the broad version, which includes all kinds of non-genetic disease predictors. However, when asking which version of PM should be the subject of analysis, we must consider the fact that, whereas broad PM may sometimes be advertised, genetic PM is practiced. In other words, the broad version may be upheld as the image of PM, but what is actually done in labs around the world is primarily molecular biology and bioinformatics, the software-based management and analysis of genomic data (Ginsburg, 2001; Lesko, 2007; Schleidgen et al., 2012). PM should be evaluated according to the principle “actions speak louder than words.” If PM is what PM does, we should go with the genetic version. This raises the question of the ontological status of (genetic) PM. Some have described it as a new model (Hudis, 2007; Wikipedia, 2015), philosophy (Anonymous, 2012; Buford and Pahor, 2012; Wolpe, 2009), or even paradigm (Ginsburg, 2001; Lesko, 2007) of medicine. These terms seem a bit overblown. The best that can be said about PM is that it is a vision for an improved medicine, whose plausibility is to be evaluated. It must therefore be treated as something other than a medical reality, as is for example the treatment of bacterial infections by antibiotics or
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