By Pat Carragher - August 08, 2023
Inherited mutations in our genes account for 5% to 10% of all cancers. Knowing if you have an inherited cancer risk may offer options for cancer prevention, early detection and personalized treatment. While genetic testing is more affordable and accessible than ever, a new study found that only 6.8% of people diagnosed with cancer were tested for inheritable genetic variants linked to cancer.
The study, published in JAMA, looked at 1.3 million patients in California and Georgia who had been diagnosed with any type of cancer between 2013 and 2019. These patients were linked to genetic testing results from four laboratories that performed the most germline testing for the two states. In that timeframe, just over 93,000 (6.8%) patients underwent genetic germline testing.
“This tells me there’s more work we need to be doing in our community,” said Carolyn Haskins, a certified genetic counselor at Moffitt Cancer Center. “We see these patients every day and we know of certain barriers that we’re attempting to address, but there are things that we need to be doing a better job of.”
Germline testing is a type of testing that looks at genetic mutations that are shared among family members, but it’s not the only type of testing available.
“Many patients will also undergo what’s called ‘somatic testing,’” said Laura Barton, a certified genetic counselor at Moffitt. “This looks at genes specific to their cancer that have mutated. This can be helpful to inform treatment with no impact on family members as these mutations are not passed down.”
According to Barton, fear is one of the biggest barriers keeping patients from seeking genetic testing and counseling.
“Just like a lot of fears it is more related to a lack of understanding of what would happen in a genetic counseling visit,” Barton said. “We’re not going to force them to undergo testing or see information that they don’t want to see. It’s important to understand that talking to a genetic counselor can help you make an informed decision and not one based on fear or assumptions of information.”
"It’s important to understand that talking to a genetic counselor can help you make an informed decision and not one based on fear or assumptions of information."- Laura Barton, Certified Genetic Counselor
In an effort to increase the amount of patients that undergo genetic testing at Moffitt, genetic counselors attend tumor boards, which is a multidisciplinary group of medical professionals who review each patient’s case to determine to best plan of care.
“Even a small increase in the number of people that get tested can have a big impact,” Barton said. “Every patient that tests positive for a mutation has some number of family members who might be at risk for that mutation. Increased testing translates to a higher chance of an earlier diagnosis, which we know leads to the best potential outcomes.”
You can gauge your risk for an inherited cancer gene by looking at your personal and family history. There are some features that may be present in a family that would make an inherited cancer risk more likely. These include:
- Cancer in two or more generations
- Two or more people on the same side of the family with the same type of cancer
- A family member with more than one type of cancer
- Family members diagnosed with cancer at a young age (generally younger than age 50)
- A family member with a rare type of cancer, like ovarian, male breast, metastatic prostate and/or pancreatic cancer
- Certain ethnic backgrounds, like Ashkenazi Jewish ancestry, in which inherited cancer risk may be more common
It’s important to note some cancers may have strong associations with other risk factors aside from genetics. For example, lung cancers diagnosed in people who use tobacco products or smoke or cervical cancer in women who have exposure to the human papillomavirus (HPV).
Genetic counseling and testing may also be a good option if you’ve already been diagnosed with cancer, especially if there are factors to suggest the cancer may be caused by an inherited genetic mutation. Testing can show if you are at risk for other cancers and if other members of your family should be tested.
“Look at Moffitt’s mission statement, to contribute to the prevention and cure of cancer,” Haskins said. “Genetic testing has the potential to impact not just the prevention of cancer, but also in treating it in the most personalized way.”