Practical Precision Medicine is about striving for better medicine.
But it means different things to different people.
For patients, it promises fewer “trial and error” therapies and fewer side effects, especially fatal ones.
The New England Journal reported the tragic case of a 2-year old boy with obstructive sleep apnea who underwent a routine, outpatient adenotonsillectomy. After an uncomplicated surgery, the parents were sent home with a prescription for acetaminophen with codeine. Unknown to the physicians, he had a functional duplication of the CYP2D6 allele, the enzyme that turns codeine into morphine. Practically, this resulted in a lethal dose of morphine in his blood.
If a genetic test for this were available in the right place, at the right time, could it have prevented this tragedy?
For patients, practical precision medicine also means new therapies and hope.
Case in point, the remarkable story of one woman’s ordeal with pancreatic cancer detailed at Georgetown’s Lombardi Cancer Center website. When standard chemotherapy failed, genetic testing identified an experimental therapy (PARP inhibitor) that made her cancer disappear.
For providers, Precision Medicine is somewhat of a mixed bag. Some of this genetic testing is old news. For years they have been testing for Prothrombin mutation, Factor V Leiden or HIV 1 genotype. In this case, it is not called Precision Medicine; it is simply called routine clinical practice.
The challenge for clinicians lies in the evidence that Precision Medicine directly improves outcomes. Examples of therapies that made sense, were widely used, and then proved harmful (for example hormone replacement therapy to prevent first heart attack or stroke) litter the history of medicine. There are always more tests to order. However, the issue is determining which tests pass beyond the standard of “it makes sense it should work” and actually improve outcomes when studied in a rigorous manner.
The Precision Medicine journey has already begun, meaning different things to different individuals but inevitably bettering the practice of medicine.