AAAS Experts Say Inexpensive Gene Screens Will Have Strong Impact on Personalized Medicine
Within the next two years, people will be able to get their entire genome sequenced for less than $1000, a feat that could accelerate customized medical treatments, experts said at a recent AAAS colloquium on personalized medicine.
It’s an impressive technical breakthrough, but physicians, policymakers and others at the event are already worried about a 21st century blitz of lawsuits, ethical quandaries, and logistical issues stemming from inexpensive genome screening.
“We’ve got a 10-mile-wide asteroid heading toward us,” predicted Hank Greely, a Stanford University law professor. “We don’t have a clue how we’re going to handle it.”
The conference, co-sponsored by the Food and Drug Law Institute, the Sandra Day O’Connor College of Law at Arizona State University, and the Mayo Clinic, was the third personalized medicine colloquium organized by AAAS in 2009-2010. The series brought together scientists, lawyers, physicians, and policymakers to discuss the future of personalized medicine, but the 8-9 March event offered a unique perspective on how personalized medicine is practiced today.
“This meeting, more so than the previous two colloquia, revealed the still enormous gap between our ability to generate large volumes of data and to offer patients targeted treatments,” said Mark S. Frankel, director of the AAAS Scientific Freedom, Responsibility & Law program. “Closing that gap is probably the greatest challenge we face in achieving a level of personalized medicine that makes a real difference in health care.”
Genes vs. Proteins
Doctors are already using genetic data and other technologies to tailor treatments for their patients, many speakers noted. Despite these advances, personalized medicine remains “a very slow train,” said Lee Hartwell, who received the 2001 Nobel Prize in Medicine. “Not a lot of information has come out of all that data.”
Personalized medicine is deeply tied to genetic screening, but scientists are finding out that truly predictive genetic markers are relatively scarce, said Hartwell, co-director of the Center for Sustainable Health at Arizona State University. At the same time, he suggested, the risk of disease associated with these markers often isn’t large enough to help doctors make clinical decisions.
“I don’t have a lot of hope of taking your DNA sequence and predicting your disease susceptibility,” he said. “Family history is still a better predictor than that for most common diseases.”
Protein biomarkers—not genes—are more relevant to physicians, said Hartwell, while noting that promising biomarkers are “piling up, but not going anywhere” outside of the lab. He urged the research community to conduct a “bake-off” among biomarkers to determine which are most useful clinically.
Protein biomarkers are much more useful than genes for the doctor in intensive care who needs to know whether a drug is causing a patient’s kidneys to shut down, agreed Prasad Devarajan, CEO of the Dialysis Unit at Cincinnati Children’s Hospital. It’s a problem that’s “crying out for personalized medicine,” he said, since drug toxicity varies considerably from patient to patient. Devarajan’s studies of the protein NGAL, which detects kidney poisoning days before the usual blood tests, are one example of how biomarkers can be used to tailor real-life treatments, he said.
Steve Perlmutter, a Phoenix ophthalmology surgeon attending the colloquium, was encouraged by the possibilities outlined by Devarajan and others. “Right now, medicine is a blunt tool,” he said, “and anything you can do to treat people in a specific way and minimize their risks is good to hear.”
But Perlmutter is also a first-year law student at Arizona State, and he is skeptical that patients will be able to control their personal medical records without specific and strong guidelines to protect the data. “My fear,” he admitted, “is that insurance companies will break down walls to get this information.”
Legal and Logistical Obstacles
Some patients are pushing personalized medicine forward by sharing their personal medical histories and experiences willingly in online communities such as PatientsLikeMe, said Paul Wicks, the site’s research and development director. Participants use the site to plan a personal treatment strategy, Wicks said, but the pooled, anonymous information from the site is also helping researchers and physicians.
Patients “want to make these kinds of contributions,” agreed Hartwell, “but the thing that keeps them from doing so is the threat of losing their health insurance or losing their job.”
Physicians also face new challenges in managing the flood of information. For Donald McAlpine, an assistant professor of psychiatry at the Mayo Clinic, the trove of genetic data related to antidepressant medication is a “scouting report” that “makes prescribing more complex, but ultimately better.” McAlpine underscored the point by unfurling a scroll of genetic variations so long that it spilled over the edge of the podium. “All this information is hard for the busy clinician to manage,” he noted wryly.
But he and others suggested that the matter has serious ramifications. “Health care professionals are likely the most vulnerable to liability risks associated with personalized medicine,” said Gary Marchant, a professor of law and life sciences at Arizona State University. Most doctors lack training in genetics, he said, but they may soon encounter patients who argue that their doctors should know about genetic information when prescribing drugs or tests.
New Medicine, Old Problems
The “worried, wealthy, and well” are the patients most likely to seek genome screening, Offit and others suggested, pushing aside patients with fewer resources and more pressing health problems.
A “spit test”—the irreverent name given to some commercial genome screening packages—could turn up 150 genetic variations of clinical interest, according to Greely. Even if physicians only spent two minutes discussing each item, he calculated, they would need five hours with the patient. Most doctor visits now last less than eight minutes, and patients still walk away with questions, Greely said. Widespread genome screening would “overwhelm our already-strained systems.”
Paying for this expertise is another logistical hurdle, said Marc Williams, director of the Intermountain Healthcare Clinical Genetics Institute. Medicare, the largest U.S. health insurer, does not cover most “preventive” genome screening tests, he noted, a fact that has slowed its coverage by private insurers.
Hopes for a new era of personalized medicine, the speakers concluded, must be tempered by the realities of cost and other systemic issues that affect medical breakthroughs as they make their way from bench to bedside.
“Personalized medicine will not be a reality,” said Katherine Hunt, coordinator of the Mayo Clinic’s Genetic Counseling Program, “without an appreciation of how to integrate its clinical components within our existing health care structure, and all the challenges that go along with such integration.”
Watch presentations by selected speakers from the Colloquia Series on Personalized Medicine.
Learn more about the projects of the AAAS Scientific Freedom, Responsibility & Law program.