From the Editor’s Desk: The emergence of “personalized medicine” in medical care

EDITORIAL From the Editor's Desk: The emergence of "personalized medicine" in medical care Medical students throughout their education are taught to consider the patient as a whole. We are reminded through our course work and by our course instructors that understanding the pathophysiologic basis of disease and responding with clinical interventions are only part of healing a person who is ill. So we must consider what makes both the patient and the disease presenting to us typical. Or better perhaps would be posing the opposite question: what makes this patient and their disease different from others? To be sure, socioeconomic and lifestyle factors, past medical and family histories, medications, etc. all contribute to making each patient unique. As editors, though, we note the emergence of another titratable parameter in this process of "personalization:" genetic constitution. We have invited and published in this issue of the McGill Journal of Medicine, four expert reviews from leaders in the field of an emerging approach to medical care referred to as "personalized medicine." We find them individually well-written and insightful, and complementary en masse. This introductory editorial offers some specific examples of what we feel are the three most important elements of this field as presented by the reviews herein: molecular diagnosis, treatment prediction, and prognosis-making. With this structure, we hope to equip the reader with a bird's-eye view of "personalized medicine," elements of which will be further developed by the four invited expert reviews herein. We must note that there is no indexed entry for "personalized medicine" in the 16th Edition of Harrison's Principles of Internal Medicine, and that this is very much an evolving field. In early January, 2007, a PubMed search for "personalized medicine" returned 532 results, over 80% of which were published after 2000. Our goal is thus to involve our readers in this dialogue, by way of introduction, and to empower them to help chart a course for personalized medicine. Personalized medicine aims to consider the genetic constitution of a patient and their disease in the process of diagnosis, prognosis, and predicting treatment response. The process begins with molecular analysis of the disease entity and patient's genetic constitution, upon which further subtype diagnosis can sometimes be made. The utility of molecular diagnosis is exemplified by defining colorectal cancer subtypes based on tumorigenic pathways of genetic instability. It is understood that characteristic serial mutations frequently underlie the progression of a …