January 2002 • Volume 8 • Number 1
Rise to challenges posed by genetic screening
BY TONI LAPP
The ability to genetically screen for diseases far outpaces the ability to treat such conditions as breast cancer, Alzheimer's disease and prostate cancer. Plenary speaker and FP Howard Brody, M.D., Ph.D., issued that warning to attendees at the 23rd annual Conference on Patient Education here on Nov. 18.
Evidence should include the physician's hunches and the patient's wishes, as well as data from randomized clinical trials.Such a disconnect should prompt physicians to view genetic tests in the larger framework of evidence-based medicine, suggested Brody, professor of family practice and philosophy at Michigan State University, Lansing.
In fact, genetic tests for breast cancer, Alzheimer's disease and prostate cancer "are not ready for prime time," said Brody, noting that the companies that own the tests are the source of data on the tests' accuracy.
One concern is that money, not science, is driving the push toward genetic testing, said Brody. He foresees a future in which companies with vested interests in genetic testing will go directly to patients, much as direct-to-consumer advertising is now being conducted. Physicians should arm themselves with evidence-based knowledge in preparation for this, said Brody.
Yet evidence-based medicine need not exclude "clinical hunches" and patient values, said Brody. Medical information should be managed so that the best available evidence is used to guide treatment decisions. That evidence should include the physician's hunches and the patient's wishes, as well as data from randomized clinical trials, he said.
Problematic is the fact that not all physicians are on the same page with evidence-based medicine. One example Brody cited of medical practice not following evidence: starting to give mammograms to women at age 40, regardless of the screening's proven effectiveness for women that young. (AAFP recommends counseling women ages 40 to 49 about risks and benefits of mammography and clinical breast exam, and offering mammography and clinical breast exam every one or two years to women ages 50 to 69.)
Another concern Brody has is the misguided belief among the public that screening itself confers some sort of protection against a disease. Some patients are shocked when a test actually comes back positive, thinking that they had somehow earned "gold stars" by being screened, said Brody.
One concern about genetic testing that's not being addressed is the implication for family members, said Brody. Physicians must acknowledge that disclosures made about a person's bloodline affect the whole family. To illustrate, he pointed to the descendants of Sally Hemings and Thomas Jefferson. Because one or two descendants consented to genetic tests, revelations concerning all family members were made public. "What gave us the right to know?" Brody asked.
He suggested that a "family covenant" be made before going through genetic screening. Such a document would be negotiated among family members with the help of a physician. Family members who "opt in" set conditions and are privy to the knowledge that comes out. However, the concept of a covenant is lagging behind advances in genetic testing. "Where we most need the covenant is where we have the least expertise," said Brody.
FP Report is published by the AAFP News Department.
Copyright © 2002 by American Academy of Family Physicians.
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