Thanks to celebrities like Angelina Jolie and Christina Applegate coming forward with their genetic test results, knowledge about two breast cancer genes, BRCA1 and BRCA2, has greatly increased among the general public. While these two genes contribute to a significant proportion of inherited breast cancer cases, more recent studies have supported what researchers have suspected for years: there are other genes that are also linked to inherited breast cancer risk.
One gene currently gaining popularity due to a newly published article in the New England Journal of Medicine is called PALB2. Mutations in this gene increase a woman’s chance to develop breast cancer to up to 58 percent. They also increase the risk for other cancers, such as pancreatic or ovarian cancer, however exact risk estimates remain under study. PALB2, along with BRCA1, BRCA2 and multiple other genes related to breast and other cancers, can now be tested together via multi-gene panel tests.
“The goal of genetic testing is to help patients who have cancer and to prevent cancer in their relatives,” says Jamie Mushlin, certified genetic counselor with the Main Line Health Cancer Risk Assessment and Genetics Program, "Having the ability to test hereditary cancer families for multiple cancer-related genes saves both time and money and increases the chances we might find an answer.”
While physicians and patients are encouraged to consider such broader genetic tests, Terri McHugh, DO, Medical Director, suggests this should be done with caution.
“Even though having information about cancer risk can be helpful, exact risk estimates and effective risk management strategies are still being investigated for many genes being analyzed through multi-panel tests.”
Additionally, Dr. McHugh says there is an increased chance for an uncertain, or inconclusive, test result when so many genes are tested.
“Multi-gene panel tests highlights the importance of both pre- and post-test genetic counseling by someone with specialized training in genetics and with current knowledge of reputable testing laboratories, test options, gene information and insurance implications,” states Cristina Nixon, another certified genetic counselor within the program. “Incorrect test ordering or misinterpretation of genetic findings can result in false reassurance or needless interventions.”
Fortunately, most insurance companies cover the cost of genetic counseling and testing and many will support additional genetic testing in individuals previously testing negative for the BRCA or other cancer-related genes. While genetic testing is not appropriate for everyone, it’s advisable for consideration by individuals with a personal or family history of any of the following: breast or colorectal cancer diagnosed at age 50 or younger; ovarian cancer at any age; male breast cancer; two or more relatives with breast, pancreatic cancer, uterine, or colorectal cancer at any age.
For more personalized guidance, contact a genetic counselor in the Cancer Risk Assessment and Genetics Program at 484.565.GENE (484.565.4363).
Rachael Brandt, PhD, LCGC is a licensed certified genetic counselor at Main Line Health.