Personalized rational medicine for all

Electrospray needle of a mass spectrometer

As a medical student at the last century’s end, I was taught to practice evidence-based medicine, to use the scientific method instead of the largely anecdotal, experiential practice of the physicians that came before. At this century’s beginning, medicine has begun yet another tectonic shift, termed personalized medicine.

Striving to use information about individual patients to their own benefit is probably as old as medicine itself. But I quickly learned, first as a resident and now as a Hematology and Oncology fellow at Children’s Hospital Boston, that accurate diagnosis remains challenging and perfect treatment, elusive. Frequently, we are not confident in knowing a patient’s exact disease, and treat using therapies that work better for some people than others without being able to predict the outcome.

Whereas Hippocrates described dozens of human conditions, today’s diseases number in the thousands, with the OMIM database alone listing more than 2,700. And the numbers keep growing: some diseases like cancer are so varied that they may be virtually as unique as we are ourselves.

Uncovering the crucial parts of a patient’s medical history and disease biology, performing just the right test to confirm the correct diagnosis and picking the best treatment can become overwhelming. But rapid improvements in technology can now help us make more rational choices.

The first is information technology, where the pace of progress is thrilling: just look at the thousands of patients sharing information at patientslikeme, reporting which treatments work and which don’t, and the hundreds of medical apps for the iPhone. These platforms, along with patient-controlled health records and sites like TuAnalyze (for patients with diabetes) are letting patients capture their own detailed medical histories. In the future, these histories will become essential to diagnosis and care.

At the same time, recent advances in molecular profiling are helping us classify disease and understand treatment in ever more specific ways. Mass spectrometry is an especially powerful tool, with its simultaneous abilities to identify biomolecules and measure them in amounts that defy intuition (one part per quintillion, that’s 1,000,000,000,000,000,000!). Recently, I worked with the Children’s Proteomics Center and Emergency Department, using “mass spec” to find biomarkers of appendicitis, a common surgical emergency that often escapes correct diagnosis, even by seasoned physicians. Our team found accurate markers in a simple urine sample, and a clinical trial is testing their performance as a diagnostic test. Several new collaborative projects are seeking diagnostic markers of Kawasaki disease, kidney tumors, neuroblastoma and leukemia, hoping to identify not only accurate diagnostic approaches, but also causes of diseases that can be targeted with new treatments. Early results are promising!

The ability to not simply define a generic disease or treatment, applying imperfectly to many people, but to define an individual’s disease and treatment, in just the right way, would allow us to deliver cures with assurance, not mere expectation. To conclude — with confidence — that a mysterious constellation of symptoms is a real disease with defined causes, specific diagnostic tests and effective treatment is to practice medicine that’s not only personal, but fundamentally rational.