Companies may bring genetic scans direct to consumers

The American consumer seems to be growing weary of TV ads for erectile dysfunction drugs.

The American consumer seems to be growing weary of TV ads for erectile dysfunction drugs. Even the jokes on late night TV seem stale. However, the ads are not likely to disappear because they have proven extremely effective in swaying consumers toward medications they may or may not need. This leaves doctors in the position of explaining complex prescription topics to pre-sold consumers. These discussions are likely to get even more difficult now that direct-to-consumer (DTC) marketing has entered the genomic age.

Most of us are equipped to deal with patient questions regarding the latest “purple pill” advertised during commercials on the big game last Saturday. But are we ready to answer questions about nutrigenetics, DNA-based chronic-disease-susceptibility testing, or whole genome scans? Unlike medications, patients can access most of these tests without a physician's order. DTC marketing of genetic testing is not only legal but essentially unregulated. There is no requirement that it have any clinical utility (does the test do any good for the patient or society?) before it is marketed.

Further, many tests are offered without even the benefit of oversight by Medicare's Clinical Laboratory Improvement Amendments (CLIA) program, which brings even the tests' analytic validity (does the test reproducibly measure what it claims to measure?) into question. Where FDA or Medicare rules do exist, enforcement has been inconsistent. Recently, the FDA ventured into the arena with draft guidance for complicated genetic tests that include internal interpretation mechanisms called “In Vitro Diagnostic Multivariate Index Assays.” However, controversy remains over which tests are covered, and in what setting, especially regarding home-brew tests developed by a hospital laboratory, for example. The bottom line for the consumer and health care provider is caveat emptor.

How bad can this be? In 2006, the Government Accountability Office (GAO), a federal watchdog for fraud and abuse, examined the field of nutrigenetic testing. It purports that genetic testing can be used to select a diet that will allow you to live a thousand years without needing Botox. What did the GAO find? “The results from all the tests GAO purchased mislead consumers by making predictions that are medically unproven and so ambiguous that they do not provide meaningful information to consumers.” Hardly a ringing endorsement.

Most of us, even without being savvy about genetics, would have recognized this stuff as snake oil. Someday, nutrigenetic testing may become scientifically valid and clinically useful, but someday is not today.

However, the distinctions are not always so clear. Recent DTC campaigns targeted audiences for hereditary breast and ovarian cancer syndrome. Good or bad? It's hard to tell. Certainly heightened awareness of these serious disorders is valuable, but is it driving demand for unneeded and expensive testing?

2007 saw a bounty of new genomic discoveries about the genetics of common diseases. For reputable testing companies, these discoveries make extremely tempting product development opportunities, tests that might just sell themselves to lots and lots of people. One can imagine the internal debate: “Who wouldn't want to know their risk of developing diabetes based on their genes? How many people are out there who might benefit from the test? Just about everyone?”

It will come as no great shock that genetic testing for diabetic predisposition is already on the market, as are genetic tests for the predisposition to several other common complex diseases. Do we know how these tests perform prospectively? Do we know if they are appropriate in all populations? Do we know if the knowledge from testing makes people healthier or saves health care dollars? Not yet. To paraphrase a colleague, “We need to be able to distinguish what we know from what makes sense.” Poorly thought out genetic testing will be expensive and may have serious consequences for individuals and society.

Soon, marketing individual gene tests for susceptibility to chronic disease will be old news. Large and well-funded companies are releasing plans to market “whole genome scans,” complete with an interpretation. This amounts to DTC marketing of the genetic equivalent of a full-body CT scan. Even the genetics community is having difficulty coming to grips with the implications. Undoubtedly, some patients will undergo this type of testing, and we will be asked to help make sense of the results. Do some research on these complex topics (you can start here) before being confronted by a patient with questions. This is a new frontier for everyone.