Can cancer be passed from parent to child?

Cancer itself cannot be passed down. What can be inherited is a gene change that raises the risk of some cancers, such as a harmful BRCA1 or BRCA2 change.

If my parent had cancer, will I get it?

Not necessarily. Most cancers are not inherited, and even an inherited gene change means a higher risk, not a certainty. Tell your doctor about your family history so they can advise you.

Should I take an at-home genetic test?

NCI notes that at-home tests have many drawbacks and are not generally recommended for checking inherited cancer risk. Ask your doctor whether genetic counselling and testing are right for you.

Is Cancer Hereditary? Genes, Family History and Your Risk

Q: How many cancers are hereditary?

The US National Cancer Institute estimates that up to 10% of all cancers may be caused by inherited genetic changes. Most cancers happen by chance as gene changes build up over time.

Many people worry about cancer when a parent or other relative has had it. The short answer from leading health authorities: cancer itself is not passed down, but an increased risk of some cancers can be. Here is what that means, in plain language.

For information only - this is not medical advice. If you are concerned about your family history, talk to your doctor, who can refer you for genetic counselling if appropriate.

Cancer is a genetic disease - but usually not inherited

The US National Cancer Institute (NCI) explains that cancer is a genetic disease, meaning it is caused by changes in the genes that control how cells grow and multiply. That is not the same as saying it is inherited. According to NCI, cancer-related gene changes can happen because of (NCI: The Genetics of Cancer):

random mistakes in DNA as cells divide;
damage from things in the environment, such as chemicals in tobacco smoke, UV rays from the sun and the human papillomavirus (HPV);
a gene change inherited from a parent.

NCI states that the vast majority of cancers occur by chance, as gene changes build up in cells over many years. That build-up is also part of why cancer becomes more common with age.

What can be passed down

NCI is clear that cancer itself cannot be passed from parents to children, and that the gene changes inside a tumour are not passed on either. What can be inherited is a gene change that increases the risk of cancer, if it is present in a parent's egg or sperm cells. A well-known example is a harmful change in the BRCA1 or BRCA2 genes, which gives a much higher risk of breast and several other cancers.

NCI estimates that up to 10% of all cancers may be caused by inherited genetic changes. Importantly, inheriting such a change does not mean a person will definitely get cancer - it means their risk is higher than average.

Family cancer syndromes

When an inherited gene change gives family members a higher-than-average risk of certain cancers, it is called a family (or hereditary) cancer syndrome. NCI describes these as rare. One example is familial adenomatous polyposis (FAP), caused by changes in the APC gene, which carries a very high chance of colorectal cancer at an early age.

Why cancer can seem to "run in families" without a faulty gene

Not every family with several cases of cancer has an inherited syndrome. NCI gives several other reasons:

Shared environment or habits - for example, smoking or exposure to air pollution in the same household.
Chance - common cancers can affect more than one relative simply because they are common.
Many small effects - a combination of many gene variants that each raise risk only slightly.

Family patterns worth mentioning to a doctor

NCI lists features that can suggest a hereditary cancer syndrome and may make genetic counselling worthwhile (NCI: Genetic Testing for Inherited Cancer Risk):

a relative with a known inherited harmful gene change;
cancer diagnosed at a young age, for example colon cancer before age 50;
several different types of cancer in the same person;
several close relatives (parents, siblings or children) with the same type of cancer, or patterns such as breast and ovarian cancer in the family;
cancer in both of a pair of organs, such as both breasts or both kidneys;
rare cancers, such as breast cancer in a man.

If any of these apply to your family, it is worth writing down who had which cancer and at roughly what age, and taking that to your doctor.

Genetic testing and counselling

Not everyone needs genetic testing. NCI advises that your doctor can help decide whether testing makes sense, and that genetic counselling is generally recommended before testing. A genetic counsellor can explain the possible benefits, drawbacks and limits of a test, and what results might mean for you and your relatives. Where possible, testing often starts with a family member who has had cancer.

NCI also notes that at-home genetic tests have many drawbacks and are not generally recommended as a way to check for inherited cancer risk. Results can be hard to interpret without professional help, and a negative result does not always mean low risk if your family history is strong.

Genetic testing for inherited risk is different from biomarker testing, which looks at gene changes inside a person's tumour to help guide treatment.

If you do have a higher risk

Knowing about a higher inherited risk can help you and your doctor plan. NCI notes that people at higher risk may be advised to have screening earlier or more often than others - see cancer screening explained. The general steps in reducing cancer risk still matter for everyone. For background on how gene changes lead to cancer, read what is cancer?, and if you are preparing for an appointment, our questions to ask your doctor can help.

A family history of cancer is a reason to have a conversation with your doctor, not a reason to panic. Most cancers are not inherited, and a higher risk is not a diagnosis.

Sources

Published and last reviewed: 15 October 2026.

Is cancer hereditary? Genes, family history and risk