What’s this Personalized Medicine You Speak of?
Those of you paying attention to the latest trends in research and medicine have probably been hearing a lot about “personalized” or ”precision” medicine and how it is changing clinical practice. However, for most of the general public, personalized/precision medicine is a relatively new term and many people are not aware of the implications it can have on patient treatment. According to a 2014 poll by KRC Research, 62% of American adults had not heard of personalized medicine. Of those that had heard of personalized medicine, only about 16% believed they were well informed about personalized medicine. So what is personalized medicine, what technologies are driving personalized medicine, and why should we care?
Current medical practice is based around the “standard of care” which is determined as the best course of prevention or treatment for a general population. Take cancer treatment as an example. Across oncology practice, there are standard tests that are performed before a patient is diagnosed with cancer and placed on their first treatment of chemotherapy. If the first treatment doesn’t work the doctor attempts a second treatment, the third treatment, etc. until one of the drugs benefits the patient. It is essentially a trial and error method with the patient’s life literally being on the line.Many doctors will say that they are practicing “personalized medicine” as they are adjusting the treatment as needed to the patient. One could argue that this method of treatment does fit the idea of “personalized medicine” in a loose sense. However, the National Human Genome Research Institute has placed a stricter definition on “personalized medicine” that defines personalized medicine as the practice of medicine that uses a person’s genetic profile to guide decisions made in regard to the prevention, diagnosis, and treatment of disease. Therefore, personalized medicine could only have been practiced by doctors within the past decade if they are following the NHGRI’s stricter definition of personalized medicine.
The goal behind personalized medicine is to screen the patient’s genetic makeup to provide them with the right treatment the first time. Giving the patient the right treatment the first time provides an immense improvement in their quality of life, while eliminating extra treatment burdens to the patient by preventing possible adverse event and multiple doctor visits and treatments, and reducing the healthcare system’s costs. There are numerous success stories of patients benefiting from personalized medicine, especially in the field of oncology. For some drugs, the benefits of genetic testing are strong enough that the FDA has recommended guidelines for how the drug should be administered depending on the genetic makeup of the patient. The list of drugs and recommended genetic testing can be found at this website:
One of the main driving forces behind personalized medicine has been improved technology with Next Generation Sequencing (NGS) leading the way. NGS is essentially a massively parallel sequencing technology that allows the sequencing of a few genes to the entire genome. To put the power of NGS in perspective, it took 13 years for the first human genome to be sequenced at a cost of about $1 billion dollars, today the entire human genome can be sequenced within a week for a couple of thousand dollars. While NGS has rapidly advanced personalized medicine, it has also introduced many questions that the field is trying to address. Two major questions that go hand in hand are what to do with novel mutations and what information needs to be provided to clinicians to guide patient treatment?
Clinically relevant mutations are mutations for which there is strong data to guide prognosis, diagnosis, or treatment. Genetic tests like NGS are commonly used to identify the presence or absence of these clinically relevant mutations within tumors. In the process of assessing the presence/absence of clinically relevant mutations other novel mutations are observed that are currently not considered clinically relevant. Although there is no actionable information from these novel mutations, it does not mean that these mutations could not provide meaningful insight later on. For instance, after a large enough data set is acquired, these novel mutations could sub-classify patients into different outcome or response groups based on genetically similar profiles. Additionally, while data may not suggest a therapy the genetic profile may guide the doctor to enroll the patient in a clinical trial that could be of benefit to the patient.
The field is also still trying to determine what information needs to be provided to the clinician and how responsible are they for keeping up with the numerous amount of research that suggests new links every day. The use of genetics to guide treatment is relatively new, and most physicians are not well versed in the fields of genetic and genomics.
Educating physicians to fully leverage the genetic information available through advanced testing methods is an ongoing effort as testing techniques are advancing rapidly. Companies are appearing specifically to fill this niche; however, it is too early to tell if these companies are providing sufficient support to physicians to advance the adoption of genetic testing before treatment on a routine basis. Ultimately, it will take a physician supported by medical geneticists, genetic counselors, and genomic data scientists to make personalized medicine a true reality.
In the end what does all this mean for the patient? In the 2014 KRC Research survey the large majority (68%-78%) of patients believed that personalized medicine could help choose the treatment that is most likely to be effective, give the patient more control to prevent or treat illness, reduce or avoid treatment side effects, result in less invasive procedures, and help avoid trial and error medicine. All of these are the true goals of personalized/precision medicine that both the physicians and patients can agree upon and when personalized medicine becomes a true reality it will offer patients more choice and influence on how they are treated than ever before.
Personalized Medicine Coalition, KRC Research. US public opinion about personalized medicine: survey shows public optimism about personalized medicine. March 5–16, 2014.