Is Cancer Hereditary? What You Need to Know About Your Genetic Risks

Worried cancer runs in your family? Discover who should consider genetic counseling and testing, and what the results can mean for you.

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Updated September 23, 2025

By Gina Kovacs, GCA, Program Coordinator, Genetics, Penn Medicine | Virtua Health Cancer Program

When someone in your family is diagnosed with cancer, you may be afraid that you or other family members could be at risk. Certain cancers can be inherited. But this isn't usually the case.

All cancers are thought to stem from genetic mutations that develop over a person’s lifetime. These are different from inherited genetic alterations that can be passed down from parent to child.

Inherited alterations or mutations are present at birth and throughout an individual's lifetime. Inherited mutations can increase an individual's chance of developing certain types of cancer, but are thought to play a role in only a small number of all cancer diagnoses.

Who should have cancer genetic counseling and testing?

Some factors that may make you a good candidate for genetic counseling or testing are as follows:

If you and/or multiple first-, second-, or third-degree family members (your parents, grandparents, aunts, uncles, cousins, siblings, or children) were diagnosed with certain cancers—especially breast, ovarian, colorectal, uterine, or pancreatic.
If you or any close family member was diagnosed with cancer at a younger-than-expected age or with a rare cancer such as male breast cancer.
If any close family member has already undergone genetic testing and is positive for a genetic mutation linked to a hereditary cancer syndrome.
If you experience clinical features that indicate an increased risk of a hereditary cancer syndrome. For example, if multiple colon polyps are discovered during a colonoscopy.

Understanding genetic testing for hereditary cancer syndromes

Understanding hereditary cancer is a major focus of researchers around the globe, and as new findings emerge, the cancer genetics field grows.

The genetic testing environment has changed dramatically in just the last decade. Testing done five to 10 years ago may not be considered comprehensive based on current knowledge. Today, genetic testing labs can evaluate more than 50 genes related to hereditary cancer syndromes.

Virtua provides genetic counseling and testing for some of the best-understood hereditary cancer syndromes, including:

Hereditary breast and ovarian cancer syndrome: BRCA1 and BRCA2 genes, which are linked to breast and ovarian cancer, as well as prostate and pancreatic cancers.
Lynch syndrome: Also known as hereditary nonpolyposis colorectal cancer (MSH2, MLH1, MSH6, PMS2, and EPCAM genes), Lynch syndrome is linked to colorectal, endometrial, ovarian, pancreatic, stomach, and brain cancers, among others.
Cowden syndrome: The PTEN gene, which is linked to breast, thyroid, and endometrial cancers, among others.
Li-Fraumeni syndrome: The TP53 gene, which is linked to breast, blood, bone, and brain cancers, among others. We understand that a mutation of this gene is linked to many early-onset cancers, but it’s very rare.

What should you do if you test positive for hereditary cancer syndrome?

If a patient has genetic testing and tests positive for an alteration in one of these genes, the impact can be significant—for both the patient’s care and their family members.

If a woman is diagnosed with breast cancer, she might want to undergo genetic testing immediately so she can make decisions about surgical treatment. If it’s found that she has an alteration in one of the breast cancer genes, she might decide to have a bilateral mastectomy (surgical removal of both breasts) instead of a more conservative lumpectomy. This is because some of the high-risk breast cancer genes increase the risk of a second new breast cancer.

Genetic testing can also have important implications for future generations. For example, a patient who has three daughters recently tested positive for one of the BRCA genes. Now her daughters can have genetic counseling and testing to determine their breast and ovarian cancer risk. If they’re positive as well, they should start screening at age 25 with breast MRI.

Advanced tumor screening at Virtua

Lynch syndrome screening is a test used at Virtua on all colorectal or endometrial cancers. When a Virtua surgeon removes a colorectal or endometrial cancerous tumor, the tissue is tested for characteristics indicating an increased risk for Lynch syndrome. If the tumor has those features, it’s noted in the patient’s pathology report. This alerts the physician to refer them to Virtua’s cancer genetic testing and counseling program for genetic assessment and possible testing.

Virtua experts provide insights into your genetic cancer risks

To learn more about whether your personal or family medical history is concerning for hereditary cancer syndromes, call 856-247-7373 to schedule a telehealth cancer genetic counseling appointment.