For two decades, most cancer genetic testing centered around looking for mutations of the BRCA1 and BRCA2 genes, both well known for increasing the risk for breast cancer.
That is still an integral part of genetic testing. But it’s only a part. Today, hereditary (passed down in families) cancer genetic testing does much more than look for BRCA1/2 mutations, says Rocky Mountain Cancer Centers certified genetic counselor Laura Brzeskiewicz. There are now nearly 100 genes which are linked to an increased risk for cancer.
New discoveries of genes linked to cancer, the emergence of targeted therapies, along with lower costs and greater willingness of insurance companies to cover the tests have paved the way for recent expansion of genetic testing, Ms. Brzeskiewicz says.
Now, she says, genetic testing is a frequent component of cancer treatment and management.
In the past, there were two very important reasons for hereditary cancer genetic testing:
- To help a patient determine risk for developing a new cancer
- To determine if family members were at elevated risk for cancer
But in recent years, a third reason has been added to that list: Genetic testing may help determine cancer treatment.
As more personalized targeted cancer treatments become available, determining whether a patient’s cancer is due to an abnormal gene can help oncologists devise treatment plans.. “For certain patients, medical oncologists are asking for genetic testing ASAP because it could change the chemotherapy treatment plan or surgical decisions,” Ms. Brzeskiewicz says.
For example, women diagnosed with ovarian cancer who have a BRCA mutation may benefit from treatment with relatively new therapies such as Lynparza or Rubraca. These drugs are part of an emerging class of drugs known as poly (ADP-ribose) polymerase, or PARP, inhibitors. PARP helps repair DNA when it becomes damaged. Blocking PARP may help keep cancer cells from repairing their damaged DNA, causing them to die.
At Rocky Mountain Cancer Centers, genetic testing now is rarely limited to BRCA genes, but instead looks for abnormalities in as many as 80 genes, Ms. Brzeskiewicz says.
There are several factors that make someone a candidate for genetic testing, Brzeskiewicz says. Those include:
- Breast, colon, uterine, or prostate cancer diagnosis under age 50
- Three or more family members diagnosed with breast, ovarian, prostate, colon, uterine, or pancreatic cancer in any combination
- Ovarian cancer in a patient or family member
- Ashkenazi Jewish heritage
- Diagnosis of triple negative breast cancer
- Male breast cancer
- Metastatic prostate or breast cancer
“Genetic counseling is a vital component of genetic testing,” Ms. Brzeskiewicz says. “In fact, many insurance companies now require genetic counseling as a condition of covering the cost of testing,” she says. That’s important, because genetic counselors can help interpret results in the context of the patient’s personal and family history. They also help create a plan with the goal of helping to reduce cancer risk, both for the individual and for members of their family.
Ms. Brzeskiewicz predicts that genetic testing will continue to grow, unlocking more and more information on cancer genetics and tumors, and playing a greater role in determining treatment. “This field is expanding so rapidly it’s important to have genetics experts, like we have at Rocky Mountain Cancer Centers, to ensure you have the most up-to-date genetic testing and personalized management and treatment plans.”