Understanding Your Cancer Risk with Genetic Testing

You often hear people say that their cancer ‘came out of nowhere.’ But the truth is that, in many cases, cancer does leave a calling card in the cells of our bodies. In fact, it’s estimated that millions of Americans are carrying a genetic predisposition to cancer around with them right now, and many of them have no idea. But thanks to advances in what’s called predictive genetic testing, it is possible to detect those calling cards in the form of inherited gene mutations well before they become a problem. Here’s how it works.

Predictive genetic testing is used to look for inherited gene mutations that might put a person at higher risk of getting certain kinds of cancer. It’s typically recommended for individuals who:

• have a strong family history of certain types of cancer: If their test reveals they have an inherited mutation, they can pursue additional screening tests to look for cancer early, or even take steps to try to lower their risk
• have been previously diagnosed with cancer: While not appropriate for everyone who has had cancer, genetic testing is recommended if there’s reason to believe the initial cancer was the result of an inherited mutation or if the cancer was diagnosed at a young age or is uncommon.  
• have family members known to have an inherited gene mutation that increases their risk of cancer: A test will help them determine if they need to have more frequent cancer screening tests or change their lifestyle to reduce their risks. In some cases, individuals found to have an inherited risk may even choose to take more dramatic measures, including surgery, to eliminate all risk of developing certain cancers.

The process of getting predictive genetic testing begins with genetic counseling, typically offered through a Familial Cancer Program, such as the one found at Dartmouth Hitchcock’s Cancer Center. Patients considering testing meet with a board-certified genetic counselor who can help them understand what test results might mean, their risk of developing cancer, and what they can do about the risk. The decision to have testing and what steps to take after are entirely up to the patient.

Should an individual decide to move forward with testing, a collection kit will be mailed to their home. After providing a sample of cells collected through saliva or a cheek swab, the kit is mailed back to the genetic testing laboratory. Once the results are received (often 2-3 weeks later), the individual again meets with the genetic counselor to review the results and options. It’s important to note that testing does not always provide clear answers, which is why meeting with a genetic counselor is essential.

If you have questions about genetic testing, talk to your healthcare provider. In addition, the American Cancer Society has a wealth of information related to the many choices and implications of testing available online. Click the links below to learn more.

Understanding Genetic Testing for Cancer Risk

What Should I Know Before Getting Genetic Testing?

What Happens During Genetic Testing for Cancer Risk?

Themarge Small, MD, FACOG, is an obstetrics & gynecology specialist at SVMC.