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New home cancer testing option concerns specialist

23andMe calls FDA approval of its test a milestone. One cancer expert says buyer beware

testing kit
This screen shot from shows a 23andMe kit for sale.
Staff Report | | March 14, 2018

A breast cancer specialist at MUSC Hollings Cancer Center is raising concerns about a newly-approved, direct-to-consumer test by the company 23andMe for genes linked to breast, ovarian and prostate cancer. “While it's a really exciting time in cancer genetics making genetic testing available directly to the consumer, the testing is a bit dangerous, as it is not a comprehensive test for one's cancer risks,” said Sara Giordano.

“Consumers who test will more than likely be left with the wrong impression about their cancer risk. So without consulting a physician or genetic counselor knowledgeable in cancer genetics, the use of this test could carry high risks.”

23andMe recently won approval from the Food and Drug Administration to sell the test that can check for three genetic mutations in two genes, BRCA1 and BRCA2.

Dr. Sara Giordano 
Dr. Sara Giordano 

“23andMe is only testing for 3 out of more than 1,000 BRCA gene mutations most often seen in those of Ashkenazi Jewish descent,” Giordano said.

“Analyzing a person's cancer risk is similar to editing a book. While most commercial companies will spell check the entire book, 23andMe is only checking for the spelling of 3 words in the book. And if those 3 words are spelled correctly, i.e. 3 gene mutations found to be normal, then one may falsely be under the impression that the entire book is spelled correctly. Most people would not benefit from this test.”

23andMe acknowledges that the test does not account for all genetic variants that can raise the risk of cancer and says people should continue recommended cancer screenings. Giordano said that does not necessarily make her more comfortable with it.

"The consumer may not completely understand this fact without consulting first with a doctor or genetic counselor. The reality is that there are many genetic variants in the BRCA gene and other genes as well which can increase one's risk of breast and ovarian cancer," Giordano said.
"It is great that 23andMe helps get people more aware of testing for genetic cancers with genetic testing becoming more widespread, but it can carry risks."
She said she'd prefer that the company offer post-test genetic counseling to consumers.

In a blog on its website, 23andMe calls FDA approval of the BRCA testing a milestone that can help people who would otherwise “fall through the cracks in the current screening system leaving them unaware of their risk.”

It also notes that the FDA reviewed its ability to accurately spot BRCA1 and BRCA2 and found that the company can “report genetic health risk information to customers in a way that could be easily understood.”

SC State and MUSC to study cancer disparities, and more (The Post and Courier, Feb. 26, 2018)

Frankincense tested as possible breast, colon cancer treatment (MUSC News, Oct. 6, 2017) 

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