Genetic testing, when used prudently, can help physicians and patients make an informed treatment choice together. But when the DNA tests are marketed directly to consumers, they can place an undue burden on our already overloaded medical system. Let’s compare two diametrically opposed approaches to using genetic testing and demonstrate how well-meaning consumers can become costly, burdensome middlemen in health care.
Russel Kaufman, MD
With prostate cancer, genetic testing provides information about the risk of some types of recurrence and can help guide therapy. It informs both the patient and the physician about that risk. The particular advice given to the patient by the physician will depend, in part, on the philosophy and experience of the physician. It’s a complicated issue. A thoughtful explanation can’t be rushed. The pros and cons of a “definitive” treatment of prostate cancer like prostatectomy or radiation need to be explained and put in full context, which includes weighing the risk of recurrence.
Contrast that approach with a person sitting at home reviewing a report from one of the number of direct-to-consumer genetic tests available. You even may have seen 23andme’s “Genetic Health Risk” report, which purports to inform customers of their likelihood of coming down with a host of diseases, including late-onset Alzheimer’s disease and breast cancer.
One thing it doesn’t predict, but I will, is that the test comes with a side serving of heart palpitations. Positive results for heightened risk of a serious disease can only provide anxiety, not peace of mind.
To make matters worse, in March 2018, the FDA approved 23andMe’s test for three specific types of BRCA1/BRCA2 breast cancer gene mutations that are prevalent in Ashkenazi Jewish women, who are typically of Eastern European descent. These mutations are rare in the general population, so there is very little value in testing for them in the general population.
According to the National Cancer Institute, one of the three mutations are present in approximately one in 40 Ashkenazi Jewish women compared with one in 400 in the general U.S. population. The 23andMe test is a much more limited test than most clinical diagnostic lab BRCA tests, which examine the entire gene to determine if there is any deleterious mutation of the BRCA genes that are known to be a marker for elevated breast cancer or ovarian cancer risk. This difference is downplayed by 23andMe in its marketing.
Because only three of the many deleterious mutations in BRCA genes are tested by the 23andMe test, a normal result does not mean a person does not have a predisposition for breast or ovarian cancer. Also, mutations in many other genes besides those affecting the BRCA genes are associated with an elevated risk of breast and other cancers. The 23andMe test doesn’t tell us anything about those mutations. People who order the company’s test and who don’t test positive for its three BRCA mutations may think they are in the clear. They’re not. People who might order this test may have a history of cancer in their family and may be given false assurances.
In the past several weeks, the FDA approved a 23andMe test for hereditary colorectal cancer. It’s a test for an uncommon type of hereditary colorectal cancer, not the more common Lynch syndrome. I see the potential for more false assurance.
And there is a flip side: The very real possibility of a direct-to-consumer test triggering a cascade of unnecessary and costly tests and procedures. A positive result for a mutation may prompt more testing and possibly a biopsy. Some people are going to experience a great deal of needless stress and worry.
Greater awareness of health status and access to care at a lower cost should be everyone’s goal. Fragmented and low-value health care only increases costs without evidence that they improve outcomes. Genetic testing can provide great insights into our health, when used appropriately at the right time and in conjunction with a health care provider who has a thorough understanding of the genetic testing provided.