Genetic testing "running way ahead" of ethics
Patients — and their doctors — misunderstand results
If genetic testing reveals a woman has a 60% chance of developing breast cancer in her lifetime, what good does this information do for a patient?
"To have a genetic marker does not entail that you will get a disease. Patients need to understand that clearly," says Kenneth W. Goodman, PhD, professor and director of the University of Miami (FL)'s Bioethics Program.
"Patients often interpret an increase in risk probability to equal 100%."
Goodman says that physicians and patients both need to understand that the information acquired in most genetic testing is probabilistic, and that "genetic disease" is actually an amalgam of heredity, environment, lifestyle, and other factors.
"The technology is running way ahead of the answers to ethical questions that are raised by the ability to get this information," says Robert W. Marion, MD, chief of the section of child development in the department of pediatrics at Albert Einstein College of Medicine in Bronx, NY.
The whole genome sequencing test "is moving into the limelight," says Marion, and is already giving individuals information about their susceptibility to disease.
"When the costs decrease, it can become an everyday test we do in the clinic," Marion says. "When that happens — and it will happen within a number of years — there are all kinds of ethical questions that need to be answered. But the fact is, the test is going to go primetime before we have the answers."
Patients need to know the risks, benefits, and alternatives to genetic testing, and this will require improvement in everyone's "genetic literacy," according to Goodman.
"Physicians and others have duties to safeguard personal information, to ensure that the consent process is adequate to the task, and to ensure they are adequately educated to practice in a genomic world," says Goodman. Here are some other ethical issues to consider:
• Patients may misunderstand their risk.
"Genetic information is probabilistic. Before anything is communicated, patients need to understand that important fact," says Goodman.
If a patient finds out he has a genetic predisposition to diabetes, says Marion, this information doesn't really provide him with any definitive answers. "Not only do individuals have trouble understanding this and knowing what to make of it, but doctors do as well," he says.
Some genetic testing is already being misused by physicians who don't really understand that the results are not definitive, and are based on a probability, adds Marion. He gives the example of an internist who treated an 85-year-old woman for bronchitis, and without obtaining consent, did a genetic test for susceptibility for coronary artery disease.
"During a follow-up visit, he told the patient that she had a high probability of developing coronary artery disease, and asked her if she wanted to start on a medication to prevent it," he says. "That is complete misuse of this technology."
• Patients need to give informed consent.
This means that clinicians need to understand the probabilistic nature of genomic information, and be able to communicate effectively about it, according to Goodman.
"Informed or valid consent is still the mother of all ethical issues," he says. "Consent is not a courtesy, it is a necessity. The 'informed' part of informed consent has never been more important."
Shift to prevention
To some extent, says Marion, physicians already know a lot of information about a patient's susceptibility to disease even without genetic testing, such as the need for patients with a family history of coronary artery disease to take their cholesterol levels very seriously because they're at increased risk.
"The gift of whole genome sequencing is going to be to use that information, in addition to family history and other factors, to help individuals make choices to lead healthier lives," he says.
The testing can help physicians determine whether a patient truly needs to take medications to lower cholesterol levels, adds Marion, which may have significant side effects that may alter the patient's ability to lead a healthy life.
Genetic testing reflects a sea change in the way medicine is practiced, "moving from reaction to prevention," adds Marion.
"At the present time, we wait for patients to develop symptoms of disease and react with treatment," he says. "With whole genome sequencing, we will be able to predict who is going to develop symptoms, and take steps to prevent it."
Sources
- Kenneth W. Goodman, PhD, Professor and Director, Bioethics Program, The University of Miami (FL). Phone: (305) 243-5723. Email: [email protected]
- Robert W. Marion, MD, Section of Child Development, Department of Pediatrics, Albert Einstein College of Medicine in Bronx, NY. Phone: (718) 430-8521. Email: [email protected]
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