New genetic test for breast cancer may be unable to keep promises


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Three-dimensional illustration of cancer cells

Our cancer genetics team at UT Southwestern has concerns about a new genetic test that can be ordered over the Internet; a test that analyzes specific genes to determine breast and ovarian cancer risk. Although the test doesn’t measure new genes, the bargain basement price of the new test is certainly new.

The new test will use a sample of saliva to analyze 19 cancer-risk genes, including the two main breast cancer risk genes, BRCA1 and BRCA2. According to the New York Times, a company called Color Genomics plans to sell the test online for $249. That is about one-tenth of the price of other tests now on the market. Is this a case where you get what you pay for?

The affordability of the test will result in more women getting tested. This has the potential to be a good thing. But will those results be accurate? Some of the genetic mutations this test will identify are not fully understood.

Will the women who discover a genetic mutation have the information they need to take action and prevent the disease? Will they have the opportunity to be cared for by a team of experts on hereditary cancers?

With any new genetic test, we strive to understand the science behind it. The patient normally relies on their doctor and genetic counselor to understand the technology and accuracy behind the testing. In the case of multi-gene genetic testing, the science is at early stages.

In a large genetics program like ours at UT Southwestern Medical Center, it’s common for the team of genetic experts to evaluate all laboratories used for testing and only order a test when we understand the limitations and benefits of the test’s technology. A doctor’s office, in consultation with colleagues in the genetics clinic, looks beyond the marketing and the hype of a new test or company.

The Jolie effect

Decisions by Angelina Jolie to have preventive surgeries and reduce her cancer risk have created more awareness about genetic testing. The actress has an extensive family history of cancer, and she took action after a blood test revealed a mutation in the BRCA1 gene. Not all women fall into the same category.

While this new, less-expensive test may be effective at identifying mutations known to lead to breast or ovarian cancer, the steps taken after a mutation is found are equally important. Genetic counseling is an essential part of this process.

The critical question is: Will this kind of test reduce cases of cancer? Making genetic testing widely available is only part of the equation. The testing needs to be reliable, and women need to know what they should do with the results.

Research is under way here at UT Southwestern to study the real-life outcomes of patients who carry a harmful mutation. The steps to take after a mutation is identified are a bigger challenge than simply finding the mutation. If patients are to understand what complex genetic findings mean and what to do about them, they will need to know much more than the sequence of 19 genes.

Sharing information

The New York Times article also mentioned that two prominent laboratories plan to share data in hopes of better understanding the genetic mutations that can lead to cancer. The effort, called BRCA Share, is a wonderful step in the right direction.

One of the worst scenarios is a patient who is actually healthy but believes they have a mutation that could cause cancer. It’s our belief that all clinical genetic data should be shared and vetted by all testing laboratories, including Color Genomics, so these instances are reduced.

If you have questions about genetic testing, please call our Cancer Answer Line at 1-888-980-6050.

Linda Robinson, M.S., C.G.C., also contributed to this article.