The U.S. Food and Drug Administration recently granted the first marketing authorization for a cancer genetic testing panel.
Kevin Hughes, M.D., an MUSC Hollings Cancer Center doctor who is among those leading efforts to develop protocols for hereditary cancer, said that although the news doesn’t alter what’s already happening at Hollings, he hopes that it will bring more awareness to the possibilities of genetic testing.
Hughes is director of the Hollings Hereditary Cancer Clinic, one of a handful of such clinics across the country. He noted that a small percentage of cancers – about 10% – are hereditary, meaning the person inherited a genetic mutation that can lead to cancer.
But, he said, the vast majority of people walking around with these genetic mutations have no idea that they have them or that they’re at heightened risk of developing cancer.
“Genetic testing is critical to find people who have mutations in order to decrease the morbidity and mortality of cancer,” he said.
Hollings tests cancer patients for up to 84 genetic mutations. Finding a mutation may alter a patient’s management, in an effort to decrease the risk of cancer or to find it at an earlier and more easily treatable stage; it also alerts Hughes and his team to reach out to the patient’s family members so that they can be tested.
The test granted marketing authorization by the FDA, the Invitae Common Hereditary Cancers Panel, is one of multiple such tests available for doctors to use. The marketing authorization enables the company to market the test but doesn’t prevent other tests from being used. Anticipating that more such tests will seek marketing authorization, the FDA created a new regulatory classification just for these types of tests.
The Invitae test must be ordered by a doctor. Hughes said that having genetic counselors and providers experienced with the nuances of genetic testing is critical.
“Interpreting the genetic test is not necessarily easy to do,” he said. “If you’re going to be doing the test, you’d like to have an idea of what to do with the results when you get them back, so having a physician, a nurse practitioner, genetic counselor or physician assistant who understands what the test is and what the results mean can be very helpful in order to make sure the patient gets the right information.”
Not all cancer-causing mutations are the same. Some have a much higher likelihood of causing cancer, so the provider must understand when to recommend action, such as a preventive removal of the ovaries, and when to recommend less aggressive actions, such as additional or different screening tests from what’s recommended for the general population.
That’s where the Hollings Hereditary Cancer Clinic comes in for patients at MUSC Health. Providers across the system who order genetic tests can refer patients with mutations to the clinic for counseling about their options and long-term follow-up. Hughes, a breast cancer surgeon, equated it to what happens when he orders a test that comes back with results out of his area of expertise.
“I order CT scans of the abdomen all the time, but I have no idea how to treat an adrenal mass,” he said. “I don’t say, ‘I don’t want to order a CT scan in case it finds an adrenal mass.’ I say, ‘If I get an adrenal mass, I’m going to send it to the urologist, and they’ll figure it out.’” The same can be said for unusual cancer risk mutations.
Hughes’ team is also getting referrals from MUSC’s In Our DNA SC research program. This community health research project tests for three types of genetic mutations, including two that can cause cancer and one that can cause high cholesterol. Hughes said the program flags about 15 participants with mutations each month.
In addition to helping people to understand their risks and decide upon the course of action they prefer, the Hereditary Cancer Clinic is also, in a way, its own research project.
Now, there’s a large cohort of patients with genetic mutations who are being followed and screened according to the existing guidelines, he said.
“Are the guidelines correct? Because the guidelines are basically an opinion by experts of what should be done, but they’ve not really been tested. So we’re testing them at the population level – if you do exactly what the guidelines say, do you get best outcomes?” Hughes explained.
As this clinic and similar ones gather data, they may make recommendations to change the guidelines.
Caitlin Allen, Ph.D., an implementation scientist at Hollings who works with the Hereditary Cancer Clinic, and a team of Hollings researchers recently published in the American Journal of Preventive Medicine an outline of the process of setting up the clinic. Hughes expects that more cancer centers will begin to establish hereditary cancer clinics because it’s becoming clear that, as testing is becoming more available, people who find they have genetic mutations are not getting the proper long-term follow-up.
“Our goal is to be able to help the next new clinic and say, ‘Here is a cookbook of how you build a hereditary cancer clinic,’ so that the next center that does this can do it relatively easily.”