Decades of scientific research have culminated in new techniques for anticipating, diagnosing and treating disease. Precision medicine — a system for disease prevention and treatment that takes individual variability in genes, lifestyle and the environment into account — is emerging as a promising approach in the fight against cancer and other serious diseases.
The basic premise of precision medicine is that a physician can look at an individual's genotypic information to understand his or her disease on a molecular level and use clues in genetic variation to identify the most effective course of action. These genes can reveal, for example, if a person has a higher likelihood of developing certain diseases and how that individual might respond to certain medications.
Here are nine questions — and answers — about this emerging field.
1. What is precision medicine?
Precision medicine is defined as "using an individual patient's genotypic information in his or her clinical care," according to a research paper published in Genetics in Medicine. Precision medicine involves a molecular diagnosis of a disease and a medical plan personalized to be most effective based on your DNA and unique genetic variations.
A molecular diagnosis does not define a disease by its signs and symptoms, as we always have, but through its molecular and environmental causes.
The practice of precision medicine can be both reactive and preemptive. On the reactive side, if a patient presents with a certain diagnosis, providers can look at that patient's genetic makeup to anticipate if/how the patient would react to certain medications. By looking at this information and assessing the efficacy of medications on an individual level, providers can eliminate the trial-and-error process of prescribing medication and treatments. Doing so can cut down costs and quicken the time to recovery.
In the discussion of population health, precision medicine can be leveraged to identify an individual's risk of developing a certain disease. This allows him or her to make behavioral changes to help stave off or delay the onset of a disease. If a person has a predisposition to develop heart disease and the predisposition is made apparent in their genetic information, he or she can take steps to reduce the likelihood of heart disease developing.
2. Does precision medicine go by any other name?
Yes: Personalized medicine, individualized medicine and genomic medicine are also common names.
3. When did precision medicine make its debut?
Shortly after the genome was mapped in 2003. The achievement was the result of decades of genetic research, beginning with American geneticist Alfred Sturtevant's first gene map of the fruit fly in 1911.
Researchers of the Human Genome Project, an international, collaborative research program under the National Institutes of Health, deciphered the human genome in three primary ways: determining the sequence of all of the bases in our genome's DNA; creating maps that show the locations of genes for major sections of all of our chromosomes; and producing "linkage maps," through which inherited traits and conditions are tracked over generations.
The International Human Genome Sequencing Consortium published the first draft of the human genome in February 2001. The first draft contained an important finding: significantly fewer human genes than previously thought. Researchers identified 20,500 genes, compared with prior estimates of 50,000 to as many as 140,000. The full genomic sequence was published in April 2003.
Since then, precision medicine has been most widely used in treating patients with cancer. Providers use molecular testing on patients with certain types of cancers to choose treatments that boost chances of survival. Precision medicine has also been used for diagnostics and treatment decision-making for other conditions, such as epilepsy, certain childhood diseases, some pregnancy conditions, cardiology and infectious disease.
"Precision medicine will work its way into many, perhaps most, areas of medicine. I think it’s going to happen in stepwise fashion," said David B. Goldstein, PhD, director of the Institute for Genomic Medicine at ColumbiaUniversityMedicalCenter in New York City. "There will be some branches of medicine where genomics will be much more important. If you're going to be an oncologist or neurologist, it will be part of virtually every day's work in the clinic."
4. Didn't President Obama talk about precision medicine a year ago in his State of the Union address?
Yes.In his 2015 State of the Union address, President Obama announced the Precision Medicine Initiative, dedicating $215 million in fiscal year 2016 to advancing genomics.
Of that funding, $130 million was allocated to the NIH to build a national research cohort of at least 1 million U.S. participants/volunteers. Anyone living in the U.S. can participate. Volunteers undergo a standard physical exam and provide a biological sample such as blood, urine or saliva. They are asked to use the findings from these samples and share information — such as medical records, profiles of their genes, environmental and lifestyle data, etc. — that will be used in research and data efforts related to precision medicine. Researchers will be able to access data from this cohort to advance progress in developing more effective treatments and prolonging health. Participants also get to access their results and data from the study.
NIH aims to begin enrolling participants in 2016 and reach one million volunteers within three to four years, but hopes to continue to enroll participants beyond 1 million. For fiscal year 2017, President Obama requested $309 million from Congress to scale up the initiative.
5. How much does precision medicine cost?
The cost of sequencing a genome has dramatically decreased over the years. Mapping the first genome took 15 years and cost $3 billion. In 2010, it cost roughly $15,000. In the past two to three years, the cost fell to the $1,000 to $4,000 range, and innovators are consistently trying to develop mapping solutions with the lowest price tags. For example, last fall, one genome scientist made news for developing a $250 test.
That cost has fallen per sequencing, but DNA results are needed for large groups of people to learn the relationship between genes and medicine. The financial implications of precision medicine at large are still difficult to forecast. If drugs are tailored to specific populations, those prices will be higher, but costs may also be saved when people stop taking drugs that aren't most effective for them.
6. What do physicians generally think of precision medicine?
The Obama administration's national cancer "moonshot" initiative, which is largely based on precision medicine, has spurred optimism and excitement among consumers that a cure for cancer is within reach. While medical researchers and scientists will readily accept the extra $1 billion in funding the administration has proposed for the initiative, many physicians are not prepared to put the principles of precision medicine into practice.
This is in part due to skepticism of the loftiness of the goal, but also a result of a lack of genetics expertise among physicians, many of whom went to medical school before the human genome was sequenced in 2003. In theory, general practitioners could turn to specialists to fill knowledge gaps related to genetics, but this could be difficult depending on where they live. Additionally, the pace of genetics research and new developments is difficult to keep up with, even if physicians are engaged in education efforts.
Additionally, different types of hospitals have different outlooks on precision medicine. A survey from data warehousing company Health Catalyst found 71 percent of academic medical centers said precision medicine will play a significant role in their organizations in the next five years, but 68 percent of non-academic hospitals and health systems said precision medicine will not play a role.
7. Consumers can now order genetic tests from direct-to-consumer companies. How does this typically go over with physicians?
Many primary care physicians are unwilling or unable to communicate with their patients about the results of genetic tests, especially when patients obtain them from consumer facing companies such as 23andMe.
According to patient anecdotes described in a study from the Impact of Personal Genomics Study Group, patients who attempted to discuss their genetics test results with their physicians often felt the appointment was too rushed. Some indicated the physician lacked adequate understanding of genomics to properly advise them, while others described their provider as explicitly cynical of the tests' reliability. In a survey by the Impact of Personal Genomics Study Group, about 18 percent of patients said they were "not at all satisfied" with their experience sharing the test results with their physicians.
8. What are some other challenges of precision medicine?
Individual privacy is a key concern in precision medicine. Even though information in the cohort will be de-identified, the stored data is highly personal and sensitive.
Additionally, precision medicine can challenge how individuals perceive health risks and how they act after learning this new information. Take Angelina Jolie, for example. The actress underwent a double mastectomy in 2013 after learning she carried a gene mutation (BRCA1) that put her at a greater risk of developing breast and ovarian cancer. Though she was not diagnosed with cancer, she went forth with the procedure as a preventive measure.
Sarah Kliff, then health reporter for The Washington Post and now senior editor at Vox, wrote just because it is now possible to determine an individual's susceptibility to certain types of cancer doesn't always mean it should be done. "Figuring out which women should have the expensive screening for a relatively rare genetic mutation is a vexing task. Researchers have no bright line between the portion of the population that is and is not at risk."
Ms. Kliff also pointed to drafted recommendations from the United States Preventive Services Task Force that recommend against widespread BRCA screening, finding it would produce "no net benefit." The task force underscores the appropriateness of such testing, saying they do not believe the screening to be appropriate for women without a history of cancer.
In March 2015, Ms. Jolie wrote about her decision to remove her ovaries and fallopian tubes after a physician identified several markers that "taken together…could be a sign of early cancer."
It's important to note, though, and Ms. Jolie clarifies this herself, that she did not undergo the double mastectomy or the bilateral salpingo-oophorectomy simply because she carried the mutated BRCA1 gene. In her case, three women in her family died from cancer, and she proceeded with the surgeries after consulting with physicians and surgeons.
9. What hospitals/health systems are pioneering precision medicine?
The NIH tapped Nashville, Tenn.-based VanderbiltUniversity to head a precision medicine pilot program and enroll 79,000 volunteers toward its 1 million goal by the end of 2016. Other hospitals and health systems are investing in and initiating independent precision medicine programs, including but not limited to:
- Dana-Farber Cancer Institute (Boston)
- Phoenix Children's Hospital
- NewYork-Presbyterian (New York City)
- NorthShoreUniversity HealthSystem (Chicago)
- Children's Hospital of Philadelphia
- Geisinger Health System (Danville, Pa.)
- Hospital Corporation of America
- Mayo Clinic (Rochester, Minn.)
More articles on precision medicine:
Precision Medicine Initiative: 8 data security recommendations
Senate bill prompts Precision Medicine Initiative action
Biden meets with bipartisan lawmakers to lay path to fund cancer 'moonshot'