Experts predict that around 1.9 million Americans will be diagnosed with cancer in 2023 — and for many of them, there’s no one identifiable cause.
“Most of the time, cancer occurs randomly due to environmental factors over the course of someone’s life,” says Brittanie Shelton, a genetic counselor at UTHealth Houston’s McGovern Medical School. Potential factors include age, lifestyle habits, like smoking, or exposure to carcinogens.
But a cancer diagnosis isn’t always random: Up to ten percent of cancer cases are hereditary. To help people prevent these cases ahead of time, experts have developed methods of predictive genetic testing.
Genetic testing can determine whether you have inherited a genetic variant that might predispose you to developing certain cancers. While testing positive for a certain gene can be disheartening, knowing you carry it can help you be more proactive about preventative care.
Below, learn more about how genetic testing works, when you should consider it and what to do if you test positive for a certain gene.
What is predictive genetic testing?
Predictive genetic testing determines whether you have inherited any genetic variants that may predispose you to developing a certain type of cancer. While these tests look at your genes through either a saliva or blood sample, they can’t identify active cancer cells in the body, says Shelton.
Every genetic variant comes with its own unique risks. According to the National Cancer Institute, more than 50 types of genes associated with cancer risk have been identified. Here are a few cancers that can be hereditary:
- Breast cancer
- Ovarian cancer
- Skin cancer
- Brain cancer
- Colon cancer
- Pancreatic cancer
- Prostate cancer
- Hematologic (blood) cancer
Each gene carries a different level of risk.
For instance, people assigned female at birth have a 13% chance of developing breast cancer in their lifetime. BRCA1 and BRCA2 mutations are associated with a very high predisposition to breast cancer and/or ovarian cancer: Up to 72% of people assigned female at birth that have a BRCA1 mutation will develop breast cancer by the age of 80.
Meanwhile, CHEK2 gene mutations, a more common variant that can predispose an individual to developing breast cancer, puts patients at much more of a moderate risk.
While anyone can theoretically get genetic testing, Shelton says it’s recommended for people who have a family history of cancer. Cancer survivors, or people who are currently facing cancer diagnoses, may also want to test for genetic variants to determine the likelihood of cancer returning or to craft a more targeted treatment plan.
It’s important to go over any test results with a professional, like a genetic counselor. They can help you determine your next steps.
What’s the cost of genetic testing?
Testing can cost anywhere from $200 to a few thousand dollars (especially if you’re getting a multi-gene panel.)
Testing for a specific gene that runs in your family is typically less expensive. In some cases, your insurance company might cover a portion of the cost.
What to do if you test positive
It can be overwhelming to learn you have a higher risk of developing cancer. Every case is unique, so a genetic counselor or medical provider can help you determine how to move forward.
For example, if you test positive for BRCA1 or BRCA2, you might want to get frequent mammograms and other screenings to catch any potential cancerous cells sooner rather than later. However, unfortunately, some cancers, like ovarian cancer, are more difficult to screen for. “Often, when someone is diagnosed, it’s too late to treat,” says Estie Rose, a genetic counselor for JScreen.
For this reason, more and more experts are recommending that people at risk of developing ovarian cancer get their ovaries and fallopian tubes surgically removed.
For other cancers without comprehensive screening tools, such as brain cancer, experts advise patients to be aware of potential symptoms and see a provider if they develop any concerns.
In any case, the ultimate goal of predictive genetic testing is to protect you and your loved ones from advanced cancer. If you undergo genetic testing and test positive for a certain gene, you can alert your family members so they can get checked too.
“Knowing you are positive for a mutation is empowering and possibly life-saving for yourself, and your current and future family members,” says Rose.