Doctor Warns Against Complacency Stemming From At-Home Genetic Testing Results

At-home genetic testing is a fun way to learn about family history, but be careful about health results you get.

Knowing if you're at risk for certain cancers should help you prepare for them, right?

"They're doing the tests that they can do because they can do those tests," said Dr. Steven Mamus, with the Cancer Center of Sarasota. "Those are not necessarily the tests that you need."

Mamus said at-home testing doesn't give someone a full picture of their cancer risk.

"The majority of cancers that we know are not caused by a gene, by mutation, something you inherit, they are acquired problems," Mamus said. "So, the fact of the matter is a gene test by definition, is going to pick up a small proportion of patients who potentially might have an increased risk of developing cancer."

Most cancers that can be tested for through genetic testing are very rare.

"For something called hereditary amaladosis, which is extremely rare, and in 40 years I've not seen a single case, so effectively 99% of cancers are really not tested for by this particular testing system," he said.

Testing for the BRCA gene could be helpful for some women, but if the test comes back negative it could give some women a false sense of security.

"The overwhelming majority of breast cancers are not due to BRCA-1 or BRCA-2, which are hereditary pre-disposing gene abnormalities, and the majority of women who do develop breast cancer do not have an obvious genetic cause for it," Mamus said.

He said even if someone does genetic testing, they definitely still need preventative screenings.

"You really would be much better off getting a mammogram and doing screenings as recommended by the American Cancer Society," Mamus said.

He recommended people should continue to talk to their doctors about personal risks, regardless of genetic testing results.

"If you come back with a test that says you have a low risk for something, whether it be heart disease, whether it be diabetes, that doesn't mean no risk."

To know which screenings should be completed, talk with your family doctor.

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