Genetic Testing and Cancer: What You Need to Know

Many factors can influence cancer risk, from lifestyle and diet to environmental exposures, and sometimes the genes you inherit from your parents.

Since 1990, when geneticist Mary-Claire King, Ph.D., proved that breast cancer ran down family lines, scientists have added ovarian, uterine, colon and prostate cancer to the list of inheritable cancers, along with less common conditions including leukemia and cancers of the kidney, brain, stomach and eyes.

“We can test for mutations in more than 140 genes linked to cancer, says Loren Yates, a licensed, board-certified genetic counselor at Doylestown Health. “Genetic testing is not about whether or not you have the gene. It’s about whether you have a genetic mutation — an error in your DNA language that reduces your body’s ability to protect you against certain cancer risks,” explains Loren.

According to the National Cancer Institute, inherited genetic mutations contribute to 5 – 10 % of all cancers. “A mutation can run in an entire bloodline, affecting siblings and the next generation, but having a genetic mutation does not mean you’re going to get cancer,” says Loren. “It means that naturally your risk is higher. You can live your life with a genetic mutation and never get cancer, but you can also have a negative result for all mutations and still get cancer.”

Genetic testing is optional. Anyone interested in knowing more about their personal risk for cancer can participate. Some reasons for testing include:

• Diagnosis or strong family history of breast, prostate, ovarian or colorectal cancer
• Diagnosis or strong family history of uterine or colorectal cancer before age 65
• Ethnicity that carries a higher risk for mutation

Benefits of Genetic Testing

Awareness opens the door to early detection and prevention of cancer. “You can adjust your lifestyle, share the information with family members and trace the genetic risk. Testing allows you to rule out family members who don’t have the mutation and monitor those who do more closely,” Loren says.

Making a Difference

“Genetic counselors will help provide guidance in a variety of areas where we can make a difference with a patient or patient’s family members,” says Loren. Personalized recommendations may include:

Lifestyle changes — Everyone, including people with a genetic risk for cancer, can improve their odds by adopting healthy habits such as good nutrition and weight management, regular exercise, using sunscreen and not smoking.

Screening early and often — Early detection leads to better outcomes. A person who has an increased risk for cancer may begin screenings earlier or have them more often than the average person. For example, a woman with the mutation for breast cancer may begin annual screening with MRI at age 25, when the average woman has her first mammogram at age 40, according to Loren.

Prophylactic surgery — Prophylactic surgery is removing a healthy organ as a preventive measure when the potential to reduce cancer risk is greater than the risk of surgery. For example, a person may opt to have their stomach removed if they discover they have inherited a mutation that points to an 80% chance of getting a stomach cancer that is extremely difficult to detect.

Identifying the best treatment — Genetic testing can be an important part of treatment planning, as scientists have found that cancers associated with certain genetic mutations respond better to specific medications.

Doylestown Health’s Cancer Risk and Genetics Program

Doylestown Health patients have direct access to the Cancer Risk and Genetics Program. Call 267.885.1864 to schedule an appointment with a genetic counselor.