The short answer
Most cancer is not inherited. But a minority runs in families because of a passed-down gene change. A pattern of certain cancers may be a reason to ask about genetic counseling.
Most cancers are not caused by an inherited gene change.
About 5 to 10 percent of cancers are linked to a gene passed down in a family.
Several close relatives with the same or related cancers can be a clue.
Cancer at a young age can also suggest an inherited risk.
Choose how you want to read this
The whole article, with every detail and caution.
This page is for anyone with cancer in the family who wonders about their own risk. It explains when family history matters and how genetic counseling can help.
The short answer
Some cancer runs in families, but most does not. Most cancers happen without an inherited cause. Still, family members can share genes, habits and surroundings that affect risk.
When family history matters more
About 5 to 10 percent of all cancers are thought to come from a harmful gene change passed down from a parent. The NCI and CDC list patterns that may point to an inherited risk:
- Cancer at a younger age than usual, such as uterine, breast, or colorectal cancer before age 50.
- Two or more relatives on the same side of the family with breast, uterine, or colorectal cancer.
- Cancer in both of a pair of organs, such as both breasts.
- A cancer type that often points to an inherited gene change, such as breast cancer in a man, or ovarian cancer in a female relative.
- A relative already known to carry a gene change that raises cancer risk.
Some backgrounds carry higher odds of an inherited syndrome. Ashkenazi Jewish or Eastern European ancestry is one. Two of the better-known syndromes are hereditary breast and ovarian cancer syndrome and Lynch syndrome.
Shared genes and shared habits
Families share more than genes. They often share a home, a diet, and habits around exercise, tobacco, and alcohol. All of those affect cancer risk. So cancer can seem to cluster in a family even when no inherited gene is involved.
Genetic counseling
If your family history raises questions, a genetic counselor can review it with you. NCI generally recommends genetic counseling before any genetic testing for inherited cancer risk. A counselor can explain what testing would and would not tell you. A positive result means higher risk, not certainty. When possible, NCI advises that testing begin with a relative who has already had cancer. The choice to test is yours.
Sources
Common questions
If a parent had cancer, will I get it?
Not necessarily. Most cancers are not inherited. Family members can share genes, habits and surroundings that affect risk, so family history is worth sharing with your doctor.
How much cancer is inherited?
Estimates suggest roughly 5 to 10 percent of cancers are linked to an inherited gene change passed down through a family.
What patterns suggest an inherited risk?
Clues include cancer before age 50, two or more relatives on the same side with related cancers, breast cancer in a man, or ovarian cancer in a female relative. A genetic counselor can weigh these.
What does genetic counseling do?
A genetic counselor reviews your family history, explains what testing can and cannot show, and helps you decide whether genetic testing is right for you.
Questions to ask your doctor
Being prepared helps you get the most out of your appointments. Save or print these questions.
Tap a question to save it to your list (kept on this device).
Talk with a trained specialist or navigator
Cancer Explained provides educational guidance, but does not replace trained specialists, social workers, or your medical team.
Talk to a trained cancer information specialist
Free, confidential assistance from NCI Cancer Information Service via phone, chat, or email.
Contact your oncology team
Locate after-hours contact numbers, portal messages, or urgent triage phone lines.
Find a patient navigator
Get one-on-one help with appointments, logistics, translation, and care coordination.
Find a genetic counselor
Discuss inherited mutation risk, family history, and genetic testing options.
Find an oncology social worker
Access emotional counseling, family support groups, and mental health resources.
Find a financial navigator
Locate copay assistance foundations, grant programs, and lodging/travel support.
Find a clinical-trial specialist
Search matching studies and speak with NCI trial information specialists.
Get urgent help
Fever of 100.4°F (38°C) or higher during chemo, severe pain, or trouble breathing: call your cancer care team right away, day or night. Call 911 for an emergency.
Know someone who needs this?
Plenty of people are looking for something like this and do not know where to start. If this would help a friend or someone you love, send it on — we have written an opening line so you do not have to stare at an empty message. You can change every word of it.
Your message is written and sent in your own email or messaging app — we never see who you send it to, and nothing is added to any list.
Plain-language explanation of the published sources cited on this page. AI-assisted, source-checked, not clinician-reviewed.
Written by: Cancer ExplainedSources last checked: 2026-10-02 what this meansLast updated: 2026-10-02Next planned review: 2028-07-14
Review details and limits
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status — Source checked. This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
General education. Low-risk educational or organizational content. Medical facts are cited to authoritative sources.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Words to know
Tap any term to see what it means.
Knowledge check
0 of 5 answered
This self-assessment checks understanding of educational content only. It is not medical advice.
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Read more about our editorial process, our use of AI, and our corrections policy.
Spotted a problem? Report an error — a factual mistake, broken or outdated source, confusing wording, or anything that seems unsafe. Please do not include names, medical record numbers, dates of birth, addresses, or other identifying medical information in your report.
After using this page, do you understand what to do next?
Anonymous — we only record the answer, never who gave it.