Family Cancer Syndromes
Some gene changes, also called variants or mutations, that greatly increase cancer risk can be inherited (passed from one generation to the next). When this happens, it is referred to as a family cancer syndrome. You might also hear it described as an inherited cancer syndrome or genetic cancer syndrome.
Types of family cancer syndromes
- Ataxia-telangiectasia (A-T)
- Beckwith-Wiedemann Syndrome (BWS)
- Birt-Hogg-Dubé syndrome (BHD)
- Carney Complex (CNC)
- Cowden Syndrome
- Familial Adenomatous Polyposis (FAP)
- Familial GIST Syndrome
- Hereditary Breast and Ovarian Cancer Syndrome (HBOC)
- Hereditary Retinoblastoma (RB1)
- Li-Fraumeni Syndrome (LFS)
- Lynch Syndrome
- MUTYH-Associated Polyposis (or Familial Adenomatous Polyposis Type 2)
- Neurofibromatosis Type 1 (NF1)
- Neurofibromatosis Type 2 (NF2)
- Peutz-Jeghers Syndrome
Is cancer inherited?
Most cancers are not inherited. Researchers estimate that only about 5% to 10% of cancers are passed down from a parent to their child or children. Most cancers develop due to some kind of change to a person’s genes that happens during their lifetime.
Not every cancer that seems to run in a family is caused by a family cancer syndrome. It’s not uncommon to have many cancers in a family because 1 in 3 people in the United States will develop cancer at some point during their lifetime.
If different family members are diagnosed with the same or similar cancers, it’s very possible they have had shared behaviors or exposures. For example:
- Some families who live together or spend lots of time together are exposed to harmful chemicals known to increase cancer risk, such as tobacco smoke.
- Some families have similar behaviors or habits that can increase their cancer risk, such as a poor diet, lack of physical activity, and excess alcohol use.
How family cancer syndromes happen
Some people are born with a gene change that can cause the gene to not work the way it should. When this happens, the risk of cancer can be higher. Because the gene change is present at birth, it can be passed down from a parent to their child. When several people in the same family share the gene change, certain cancers might be diagnosed more often in that family.
Having one of these gene changes does not mean someone will definitely get cancer. It means their risk may be higher than average. To learn more about how gene changes can lead to cancer, see Genes and Cancer.
How are family cancer syndromes suspected or found
Recognizing a possible family cancer syndrome can be difficult in some situations but easier in others. If a doctor suspects a family cancer syndrome, they usually have noticed certain patterns of cancer in a family, such as:
- Several relatives with the same type or related types of cancer
- Cancers occurring in family members at younger ages than usual
- One family member with more than 1 type of cancer
- Rare cancers occurring in different family members
- More than 1 childhood cancer in siblings
- Certain cancers occurring in a family member who would not usually be affected (like male breast cancer)
- Cancer occurring in families through multiple generations
Certain kinds of benign (not cancer) tumors and medical conditions are sometimes also part of a family cancer syndrome.
If you think you might have a family cancer syndrome
If cancer seems to run in your family, talk to your doctor. They will help you look for specific patterns and details or can refer you to a genetic counselor or specialist. Talking to your doctor about this information can help you understand whether cancer in your family may be due to an inherited gene change, shared lifestyle behavior, or chance.
In the meantime, you can collect some information about your family history. For each case of cancer, try to find out the following information.
Information to collect
When looking at your family medical history as it relates to cancer, use this questionnaire or collect this information:
Who in your family has or had cancer
Cancer in close relatives (like a parent, brother, or sister) is generally more concerning than in more distant relatives. Look at each side of the family separately. Two relatives with cancer on the same side of the family can be more concerning than one on each side.
- Who had cancer and how are they related to you (parent, sibling, grandparent, aunt, uncle, cousin, etc.)?
- Which side of the family are they on (mother’s or father’s side)?
The type of cancer
- What specific kind of cancer did each person have?
- Did multiple relatives have the same type of cancer?
- Did anyone have a rare type of cancer?
- Did anyone have cancers that are known to occur together in inherited cancer syndromes (such as breast and ovarian cancer, or colon and endometrial cancer)?
Age at diagnosis (and age at death, if applicable)
Cancers diagnosed at younger-than-expected ages can sometimes suggest an inherited gene change.
- How old was each relative when first diagnosed?
- How old were they when they died (if they have passed away)?
Patterns or shared risk factors
- Did anyone have more than one type of cancer?
- Did the affected family members share lifestyle risk factors, such as smoking, or environmental exposures?
- Did anyone in the family have genetic testing, and if so, what were the results? Can you get a copy?
Genetic counseling and testing
People with a strong family history of cancer might consider genetic counseling to find out if they have a family cancer syndrome or learn more about their genes.
Sometimes, this helps the person or other family members adjust their lifestyle and plan their healthcare for the future. But genetic testing is not helpful for everyone, so it’s important to talk to your doctor first before seeing a genetic counselor.
Other sources of information
Along with the American Cancer Society, other sources of information and support include:
National Society of Genetic Counselors (NSGC)
Phone: (312) 321-6834
Website: www.nsgc.org
Genetic Support Foundation
Phone: (844) 743-6384
Website: geneticsupportfoundation.org
*Inclusion on this list does not imply endorsement by the American Cancer Society.
- Written by
- References
The American Cancer Society medical and editorial content team
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as editors and translators with extensive experience in medical writing.
Garutti M, Foffano L, Mazzeo R, et al. Hereditary cancer syndromes: A comprehensive review with a visual tool. Genes. 2023; 14(5):1025. doi: 10.3390/genes14051025.
National Cancer Institute (NCI). Genetic Testing for Inherited Cancer Risk. Accessed at www.cancer.gov/about-cancer/causes-prevention/genetics/genetic-testing-fact-sheet on May 8, 2026.
National Cancer Institute (NCI). Physician Data Query (PDQ). Cancer Genetics Overview – Health Professional Version. 2025. Accessed at www.cancer.gov/about-cancer/causes-prevention/genetics/overview-pdq on May 8, 2026.
Sabik EF. Genetic basis of familiar cancer risk: A narrative review. DNA. 2026; 6(1):5. doi.org/10.3390/dna6010005.
Last Revised: May 8, 2026
American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.
American Cancer Society Emails
Sign up to stay up-to-date with news, valuable information, and ways to get involved with the American Cancer Society.
