Mary Katherine Melroy, 40, was relieved when a mammogram in November 2020 found that the lump she found in her breast was not a cause for concern. What was worrisome, however, was her risk assessment score for developing breast cancer.
She was referred to the High-Risk Breast Evaluation Clinic at MUSC Hollings Cancer Center, where she met with a genetic counselor and completed tests to look for clues that may have put her at greater risk of developing an inherited form of breast cancer. Then she discovered she had a pathogenic mutation in the CHEK2 gene and a 25% to 39% chance of developing breast cancer in her lifetime — more than double the risk of the average American woman. The mutation also increases her risk of developing colon and thyroid cancer.
Rather than panic, Melroy was comforted by the news. It gave her the answers she was looking for when her mother was diagnosed with breast cancer 10 years ago at the age of 58.
“It was actually a relief because it made sense,” said Melroy, who never understood how breast cancer can affect someone as small, healthy and fit as her mother. “It gave me no fear to know that I had this mutation. It put the ball in my court to do what I had to do.”
Melroy set out to investigate her mutation and found that opting for a bilateral mastectomy — a surgery that removes both breasts — could reduce her risk of breast cancer by up to 5%. After watching her mother struggle with the side effects of chemotherapy, she decided she wanted to do everything she could to reduce her risk of experiencing the same. She plans to have the surgery by the end of 2021.
Knowing she has an increased risk of cancer gives Melroy strength, as she feels she has options to shape her future.
“As an adult, there are very few things I feel I have under control, but this is one piece of the puzzle of my health that I can take control of. I’d rather have surgery than twice a year. going to screening because I would feel like we were just waiting to find something,” said Melroy, who also plans to talk to her doctor about early colon cancer screening.
“You can do as much as you have the knowledge. A lot of people are scared at the thought of getting genetically tested, but what I find terrifying is looking at what happened to my mother.”
A hot topic
At Hollings, the demand for genetic testing has increased by 422% in the past year. In response, the genetic counseling program is the largest it has ever been, with a total of six counselors, two of whom provide full-time on-site services to Hollings patients.
While the popularity of genetic testing took off in 2013 after a Supreme Court case that allowed more than one company to test for certain genetic mutations, it is becoming more common as testing guidelines expand to more people. It is now recommended that all patients with high-risk pancreatic, ovarian and prostate cancer be referred for testing, and work is underway to include all breast cancer patients.
According to Libby Malphrus, one of Hollings’ onsite counselors, Hollings’ ability to grow with demand is something that makes it unique.
“There is a national shortage of genetic counselors. The access people have to genetic counselors at Hollings is huge and something most major health care systems are aiming for,” says Malphrus. “We have a large number of counselors and different ways we can deliver that service, including through telemedicine, which is a huge asset.”
As the program continues to grow, genetic counseling is currently only available to current cancer patients or those who are at high risk of developing cancer based on their family history. For patients who already have cancer, genetic testing can help determine their treatment plans, from determining which surgical techniques to use to how aggressively to treat the cancer.
It can also determine whether they are at risk of developing other types of cancer and whether their relatives may need more supervision.
While the information found could potentially be life-saving for cancer patients and their families, Charly Harris, the program’s other full-time genetic counselor, reminds patients that testing also carries risks.
“When someone is diagnosed with cancer, they don’t want to think about whether there are other cancers that they may be at risk for. Their diagnosis is often already a big surprise to them, so adding in additional cancer risks may be too much information at that point,” said Harris, noting that Hollings’ counselors meet with patients prior to testing to discuss the pros and cons. .
Malphrus added: “It’s hard enough for individuals to fight their diagnoses and see the emotional impact on their families without thinking they could pass that gene on to their children. That’s heavy information, that’s why we don’t want that.” someone assumes they should be tested just because they have cancer.”
Melroy understands that the information found during her tests affects not only her own health, but also that of her sisters, brother and children. She is already planning to have her 6-year-old daughter tested when she is old enough.
While the technology used in genetic testing continues to grow in speed and efficiency, Malphrus and Harris recognize that much is still unknown about how to use the results. Finding a mutation by testing more genes isn’t helpful if counselors don’t know what that mutation means.
That’s why it’s important for patients to have testing done by a genetic counselor trained in medical genetic testing, as opposed to companies that offer direct-to-consumer DNA testing. Direct-to-consumer testing only examines a small number of genes, providing an incomplete picture of potential health risks. The test at Hollings examines up to 84 genes known to be associated with an increased risk of cancer.
Why cancer studies still matter
While certain cancers, such as breast and ovarian cancer, are more strongly associated with hereditary factors than others, most cancers are not inherited. In fact, only 5% to 10% of breast cancers and 20% to 25% of ovarian cancers are hereditary. That is why it is important to have regular cancer screenings, regardless of the results of genetic testing.
“People often think, ‘I don’t have a family history, so it won’t happen to me,'” Harris said. “I always remind my patients that they still have the general population risk of all cancers. Just because we’ve lowered the risk of hereditary cancers doesn’t mean they don’t need to be screened.”
Individuals can lower their risk of cancer through lifestyle choices such as maintaining a healthy weight and diet, exercising regularly, avoiding smoking, and keeping up with their preventive care. In addition, getting the HPV vaccine can protect against six types of cancer.
Although Harris and Malphrus both started genetic counseling because of their love of science, they agree that the most rewarding part of their job is giving patients a sense of control over something they often think they can’t change. .
“Genetics is complicated and is only getting more complex,” says Malphrus. “It’s worth being that bridge between science and medicine and helping people make informed choices that are best for themselves and their families.”