Genetic Testing Looks for Cancer Genes in DNA

Now more than ever, genetic testing is widely available and affordable. Genetic testing uses family history and DNA to assess a person’s risk for certain diseases, such as cancer. With appropriate screening, prevention and early treatment, patients and their families can make informed choices about their health and take steps to reduce their cancer risk.

Lorrell White, senior genetic counselor at Baptist Cancer Center, helps patients confirm or rule out a suspected gene mutation. She not only works to determine her patients’ likelihood of developing cancer or passing on cancer genes but also educates patients about human biology and what patients can do if they test positive for a gene mutation.

What is hereditary cancer?

If cancer is present in your family tree, you may be more likely to develop cancer. However, most cancers are related to smoking or other exposures, lack of exercise and an unhealthy diet.

“In general, only about 5 to 10% of cancers are hereditary,” said White. “People in that small percentage inherit an abnormal gene—this doesn’t mean you’ll necessarily get cancer, but it means you’re much more likely to develop certain cancers because you have a hereditary cancer syndrome.”

How does family history play a role in genetic testing?

While genetic testing focuses on understanding an individual’s risk, genetic counselors need to examine the whole family tree. According to White, family histories offer important clues for finding inherited cancer genes.

“The first thing we do at a genetic counseling appointment is assess the patient’s family history,” said White. “We take a three-generation pedigree, which includes siblings, parents, aunts and uncles—all the way back to grandparents.”

In general, those at risk for an inherited cancer gene typically have some clues in their family history. This can include having several close family members who were diagnosed with certain cancers at a young age or with similar types of cancers, multiple primary cancers, rare cancers (such as male breast cancer or ovarian cancer) or a known gene mutation.

“If you fit one or more of these criteria, or if you want to learn more about your risk for genetic disease, talk to your doctor about genetic testing,” said White.

How is genetic testing done?

“Genetic testing can be done by taking a saliva or blood sample,” said White. “Once we send your genetic sample to the lab, it takes about two to three weeks to get the test results back.”

Taking a sample is only part of the process. Genetic counselors also make sure patients understand their options once they receive their test results.

“Genetic counselors have training in genetics, biology, diseases and cancer genes—as well as counseling in general,” said White. “Everybody is different—everybody views information in a different way. For example, some people may be scared to learn this information. Genetic counselors provide clear information and guidance for their patients.”

Why is it important to identify cancer genes early?

According to White, early identification can lead to early prevention and treatment.

“If we know a woman is predisposed to breast cancer, we will start breast imaging at a younger age and perform screening more often than in a woman who does not have a hereditary mutation,” said White. “We can watch patients closer. Hopefully, we’ll identify cancer early so that it’s easier to treat and cure.”

In some cases, when a person has been identified with a hereditary cancer gene, doctors may recommend risk-reducing options, including surgery, medications and other treatments that can lower that person’s risk of developing cancer.

“A woman at high risk for developing breast cancer may decide to have a mastectomy—which is a surgery that removes the majority of the breast tissue,” said White. “She has significantly reduced her risk of breast cancer. It doesn’t mean that she can’t get breast cancer, but now the risk is extremely low.”

Is genetic testing covered by insurance?

Most health insurance companies pay for genetic counseling sessions in which counselors assess family history and determine if genetic testing is necessary. If genetic counselors or doctors recommend genetic testing, patients can check with their group insurance to determine their level of coverage. Most insurance companies have genetic testing criteria for coverage.

“Some patients also worry what their insurance company can do to them if they test positive for a gene mutation,” said White. “State and federal laws protect against insurance premium increases and prohibit employer discrimination based on your genetic information.”

If you’re concerned about your family’s history of cancer, it’s important to carefully weigh the pros and cons of genetic testing to make an informed decision for you and your family. Meeting with a genetic counselor is recommended for anyone considering genetic testing.

Learn more about the Genetic Counseling and Testing Center at Baptist Cancer Center. Find a Baptist doctor by visiting our Find a Physician page.