Genetics and cancer: why testing can aid prevention

Mar 11, 2017

No one wants to talk about cancer. A disease that has taken the lives of so many, even the word itself has an ominous connotation. But as much as we don’t want to talk about it, new genetic technology suggests that starting the conversation about your family’s cancer history might be in everyone’s best interest.

In her new book, "A Cancer in the Family: Take Control of your Genetic Inheritance," Dr. Theodora Ross addresses how our family’s medical history plays a role in our health. To shed some light on the genetics of cancer, as well as genetic counseling, Ross spoke with “Take Care” to explain the importance of knowing your family history. Ross, a cancer geneticist, is director of University of Texas Southwestern Medical Center’s cancer genetics program.

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First and foremost, Ross says that while you may feel there’s nothing you can do about an impending cancer diagnosis, knowing is always better than not knowing. Ross herself was hesitant to find out about her own genetics, even though she's a cancer expert and has a family history of the disease, including a sister with breast cancer. But when she developed a melanoma in 2004, she decided it was time to talk to a geneticist and a genetic counselor.

Ross attributes her hesitation to “truthiness,” which occurs when we want something to be true. Often when it comes to health, we ignore or deny potential problems. We don’t go to doctors when we’re healthy, we don’t want to believe there could be a problem, and so we don’t look.

But Ross says knowing the family history of a patient is an important step in prevention, and helps not only the patient, but researchers too. Genetic counselors can go to physicians and obtain medical records, which gives researchers more data to work with, and gives patients an accurate understanding of their family history.

According to Ross, the most common genetically inherited cancer syndrome is Lynch syndrome, which occurs when there is a mutation in mismatched repaired genes. This mutation will lead to a predisposition to colon, endometrial, ovarian, pancreatic, and other cancers. The kicker? Only 5 percent of people with this syndrome actually know they have it, and it’s common. About one in 300 have it, says Ross. And if they knew, they could carry out preventative measures such as frequent colonoscopies and check-ups.

Comprehensive genetic testing is becoming cheap enough, according to Ross, for people to seek out this information at a reasonable cost. Genetic counselors, she says, have an incredible ability to connect with their patients while providing them with the information they need to make the most of their genetic history. Talking about cancer in the family can be a scary conversation, but it’s crucial, says Ross, to aid in our efforts towards prevention.