Med School's Hot New Field: Personalized Medicine

Dr. Bernadine Healy explores the hot new trend.


Doctoring one on one: University of Chicago Medical Center.

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What propels most students into medicine is the desire to relieve human suffering with knowledge, judgment, and skill. Noble aspirations quickly sour, however, when insurance companies deny care over the phone or when faceless bureaucrats penalize doctors' discretionary decisions on what's best for their patient based on some standardized guidelines. As pediatrician Mark Vonnegut stated recently in the New England Journal of Medicine, "U.S. doctors today have less and less to say about the care of their patients. All the complex lessons they learned in medical school are being swept aside for template care." Not much longer, I hope. Template care is increasingly at odds with the emergence of personalized medicine, a new discipline driven by the exploding knowledge of the human genome that guides treatment tailored to the individual patient. And this is what today's medical students will be practicing tomorrow.

Look at cancer, which offers a glimpse of what's to come. The wide arrays of genes that mastermind cancer have become targets for drug design. Herceptin, for example, counters a gene that occurs in 20 to 30 percent of women with breast cancer and makes it especially aggressive. For these women, Herceptin is lifesaving. For women who would not benefit and would face only side effects, the drug is avoided. This is what we want for every therapy. But the development of such personalized medicine requires that physicians actively integrate genomics into all fields, reaffirming the time-honored tenet that doctors always consider what's special about an individual patient as opposed to the textbook case.

Care would be easy if people fit some standard mold. When the sequence of the human genome was published in 2001, scientists pointed to our common humanity, with people being more similar than different. But seven years and a mountain of research show the opposite—an astonishing level of individual variety. In fact, Science magazine declared human genetic variation as the No. 1 breakthrough of 2007.

Thanks to ever better, faster, and cheaper sequencing technology, researchers have shown the many ways our 25,000 or so genes can vary. One little glitch—a misspelling, a hunk of DNA lost or added, or a gene altered by interplay with other genes or molecules—can affect disease susceptibility or treatment. Already, researchers have tied genetic differences to many diseases, including diabetes, heart failure, autism, restless leg syndrome, multiple sclerosis, and rheumatoid arthritis. Imagine this in medical practice. Knowing your patient's risk early on would bring more targeted prevention. And by knowing that some patients are more likely than others to become infected with certain viruses or other pathogens, patient care would be improved, as would the public-health management of epidemics—such as identifying priority groups for vaccination.

Case by case. It's downright humbling for physicians to learn that some patients with illnesses we label and treat as the same are just plain different and should not be expected to respond to standard therapy. These patients have not failed treatment; treatment has failed them. And so follows the mantra of the emerging personalized medicine industry in the hunt for personalized diagnostics and therapeutics: right treatment, right patient, right time—not one size fits all.

To the pharmaceutical industry, personalized medicine poses limitless opportunities. To insurers and government payers, it offers increased quality at lower cost, since treatments that don't work are not used. To patients, it's better care.

The medical establishment has been slow to catch on. As Ralph Snyderman, former chancellor at Duke University Medical Center, puts it, "physicians haven't yet grasped this as the great new wave in the practice of medicine." Although a few medical schools, including Duke, have developed programs in personalized medicine, they are scarce, as are the ranks of medical professionals trained in genetics.