Preventive medicine has been a fixture in healthcare for decades. The proactive approach to patient care includes screenings for hypertension and diabetes, colonoscopies and mammograms to detect cancer early, and taking an in-depth look at your family’s medical history. The goal is to prevent the development of disease or at least to catch it early when it can be more effectively treated.
A newer tool in preventive medicine goes even deeper, to see whether you’re more likely to develop certain conditions due to your genetic makeup. One such screening is the Precision Health Genetic Screen, offered to UNC Health patients as part of the UNC School of Medicine’s Program for Precision Medicine in Health Care. Jonathan Berg, MD, PhD, director of the program, says that if the screen shows someone is predisposed to a disease such as cancer, doctors can adapt their care for that patient.
“With this knowledge, people can take advantage of early screenings, medical interventions or potentially even surgery to prevent the development of health problems in the future,” Dr. Berg says.
For example: Mutations in certain genes can result in a diagnosis of Lynch syndrome, which predisposes a person to a few types of cancer, including colorectal cancer. People with Lynch syndrome often begin colonoscopies much earlier than people at average risk: in their 20s rather than their 40s. In this case, the information that a person is predisposed to cancer leads to earlier screening, which can be lifesaving.
Women with mutations in the BRCA1 or BRCA2 genes are at higher risk for breast and ovarian cancers. Some women ultimately choose to have prophylactic (preventive) removal of the breasts and/or ovaries to virtually eliminate their risk of getting those types of cancer.
The Genetic Screening Process
The Precision Health Genetic Screen requires a blood sample, which is then sent to a lab for testing. The test screens the patient’s DNA for disease-causing variants, specifically looking at 11 genes known to be associated with the following conditions: breast cancer, ovarian cancer, prostate cancer, colorectal cancer, uterine cancer and high cholesterol.
Most cases—90 to 95 percent—of cancer and high cholesterol are sporadic and not due to a rare hereditary condition, Dr. Berg says. But sometimes, these diseases are caused by changes, or variants, in those 11 genes. The screening scans the person’s DNA to determine whether a person has such a variant.
It takes around four weeks for test results to come back, and most of the time, there’s no cause for concern.
“We expect that 95 to 97 percent of screenings for these variants will come back normal, and no disease-causing variants in these genes will be identified,” Dr. Berg says.
In the case of a negative, or normal, test result in which no variants are found, the information will be shared with the patient via their My UNC Chart account and also provided to their physician. Dr. Berg says it is important to remember that even though your genetics may not have predisposed you to develop these conditions, it is still important to complete all routine screenings. These diseases can—and most often do—occur without a specific genetic trigger.
If a patient receives a positive test result, in which one or more variants are found, they will receive a phone call from a genetic counselor.
“The genetic counselor will explain the result, the condition it is associated with, and give some context about what it means,” Dr. Berg says. “From there we recommend a follow-up visit with the genetic medicine team to obtain a more detailed family history, talk about additional testing of family members, and what other follow-ups need to be done.”
It’s important to note that a positive result does not mean a person is guaranteed to develop the condition. And when a person is empowered with information, he or she can take proactive steps to reduce risk.
“One of the most important features of this screening is potentially identifying these highly actionable health conditions before someone comes to the hospital with an advanced form of disease like metastatic cancer,” Dr. Berg says. “We’re trying to find these rare hereditary conditions that can occur without many symptoms early in someone’s life and progress to severe disease before they are caught.”
More Benefits to Genetic Screening
Genetic screening also can be impactful to the people who share your genes: your family. Dr. Berg says there is a multiplier effect with these tests. If the screening identifies variants in your DNA, you can share those results with family members, who can then take action with that information if they choose.
The results of this screening will be part of a patient’s private, protected medical record—unlike commercial screenings available that you might see advertised online or on TV. This means only the people you wish to share the results with, such as your physician, will be able to see them.
Genetic screening is open to people 18 years and older who currently have a physician within the UNC Physicians Network. This screening is not for people who have already been diagnosed with one of the conditions mentioned. If a patient has a strong family history of cancer or heart disease, more specific diagnostic testing may be a better option; talk to your provider.