Unintended consequences are possible with genetic screening
Uncertainty makes decisions problematic
Interpretation of results of genetic screening tests is potentially problematic for both providers and patients, and misunderstandings can arise regarding their implications. Bioethicists should ensure that patients receive pre-test genetic counseling informing them of:
- what screening for genes can and cannot do;
- the uncertainty or inconsequentiality of test results;
- the risks, benefits, and limits of genetic screening.
Benefits of genetic screening are generally overstated by clinicians, whereas harms and unintended consequences are often understated, according to Evelyne Shuster, PhD, a medical and research ethicist at Veterans Affairs Medical Center in Philadelphia.
"Clinical uncertainty itself is problematic," she says. "Interpretation of results makes for a difficult conversation between doctors and patients, and agonizing decisions for patients."
Patients may be so troubled when confronted with the uncertainty of their results that they may request additional screens, hoping to determine with absolute certainty their risks of developing the disease. "Over-diagnosis, however, may have unintended consequences, such as causing patients to undergo radical treatment that is irreversible," says Shuster.
The role of bioethicists is to ensure that patients receive pre-test genetic counseling that includes the underlying principles of clinical uncertainty and variable genetic expressivity, says Shuster.
Patient counseling can become even more complicated when war metaphors are used, as this terminology suggests that precautionary steps should be taken, argues Shuster. "For example, women’s breasts have been called ticking time bombs’; her body, a battlefield’; and breast cancer gene, the invader,’" she says. "Taking pre-emptive action against breast cancer would be to initiate a radical treatment’ in the absence of a disease, and view a healthy person as a patient before there might be a disease. This is premature, misleading, and damaging."
Treatment intervention to address risk factors can be more radical than intervention for breast cancer itself, says Shuster. The fact that the presence of the BRCA1 gene mutation indicates an elevated risk for breast cancer, not the actual disease itself, can get lost in translation. "It is a risk factor, which, in a significant number of patients will not become cancer. In many others, it will not manifest itself until very late in life," she says.
Consider ethical principles
Patients and their doctors have an obligation to educate themselves about genetic testing and learn how to interpret results with the help of genetic counselors, says Shuster.
The ethical principles which generally guide medical ethicists when they counsel patients and physicians are respect for persons and their rights to autonomous decisions, beneficence, non-maleficence, and fairness, she notes. "Bioethicists must be mindful of how these ethical principles play out in the genetic setting," she says. "People must be informed of what screening for genes can and cannot do, understand the probabilistic nature of most genetic findings and the uncertainty or inconsequentiality of test results, and know the risks, benefits, and limits of genetic screening."
In some cases, early screening for breast cancer genes may not be beneficial, says Shuster. "While raising public awareness of breast cancer may be worthy, it is also critically important to discuss the unintended consequences of early screening and over-diagnosis," she adds. "These oversell the fear of cancer, and the effectiveness of screening as disease prevention."
Ensuring that patients receive competent and comprehensive genetic counseling, and safeguarding the moral integrity of patients’ informed choice based on genetic findings, are the foremost obligations of bioethicists, underscores Shuster. "Patients should be reminded in terms that they can understand that there are no absolute remedies or universal cures for carriers of breast cancer genes," she says.
SOURCE
• Evelyne Shuster, PhD, Veterans Affairs Medical Center, Philadelphia. Phone: (215) 823-4206. E-mail: [email protected].
