Pharmacogenomics in Clinical Practice: Where Do We Go From Here?

In an interview with Medscape, Mark J. Ratain, MD, Professor of Medicine at the University of Chicago and Founding Director of the University's Center for Personalized Therapeutics, pointed out that pharmacogenomic testing needs to move from the realm of reflex lab testing to part of the physical exam….

“I think we need to take genetic testing out of the domain of laboratory testing and move it to the domain of physical examination. It can then be one more piece of information for the physician to consider and we wouldn't need to focus on the cost.”

“There are a lot of things we do during a physical examination that have never been demonstrated to be cost-effective. Physicians look at their patients' toes as part of an annual physical. Have you ever seen a study that shows that looking at your toes is cost-effective?”“We need to conceptualize genetic testing as a part of the physical exam rather than as a laboratory test that needs to be ordered so you can have the information at the time you are seeing the patient. For example, if you're starting a patient on warfarin, or you are considering whether to start him on warfarin, and you already know that he is going to metabolize warfarin a lot more slowly or that he's going to be a lot more sensitive to it, you can take that into account in the same way you would probably use a lower dose if your patient were frail or elderly. That is where I think the field needs to move.”

“The solution is one that we are piloting here, which is to genotype all patients for all polymorphisms that may affect drug response. You'll then have the results when you need them and your costs will be much lower than doing each test as a one-off laboratory test.
In the current system, you see the patient and want to prescribe a drug, and you say to yourself, ‘Maybe I should order a pharmacogenetic test. But I don't know how to do that, I don't know how long it is going to take to get results, and I don't know if my patient is going to get reimbursed for it. Oh, who cares. I am just going to prescribe the drug.'

“Unless someone says that you can't prescribe the drug without doing the test, or unless we change the way we look at how pharmacogenomic testing should be incorporated into clinical practice, the system is unlikely to change.”