Family History and the Risk for Breast or Ovarian Cancer
But if someone in your family has had breast or ovarian cancer, your chances of getting those cancers may be higher. And if you have 2 or 3 relatives who have had these cancers, your chances may be even higher.
If you have a family history of breast or ovarian cancer, it may be important to you to find out how high your risk is so that you can decide whether to do something to lower that risk, like take medicine or have surgery.
The best way to find out about your risk is to talk to your doctor. But you can get some idea of how high your risk is by knowing your family history and understanding how it relates to breast and ovarian cancers.
What is a family history?
Having a family history means that you have one or more blood relatives with breast or ovarian cancer.
- They may be relatives who have died or relatives who are still alive.
- They may be first-degree relatives (parents, sisters, brothers, and children).
- Or they may be second-degree relatives (aunts, uncles, nieces, nephews, and grandparents), or third-degree relatives, which includes first cousins.
Some family histories are stronger than others. Here's what determines whether your family history is strong:
- How closely related you are to relatives with breast or ovarian cancer. Cancer in first-degree relatives increases your risk the most.
- How many of your relatives had or have one of these cancers. The more relatives there are, the stronger your family history.
- How young these relatives were when they were diagnosed. Having any relatives who were diagnosed before age 50 adds to your risk.
- Whether you have both breast and ovarian cancer in your family. Having both adds to your risk.
- Whether you have a father or brother who had breast cancer. Breast cancer in men is rare, but when it happens in your family, it adds to your risk.
- Whether you have an Ashkenazi Jewish heritage. Breast and ovarian cancer rates are much higher among Ashkenazi Jews (Jews whose ancestors came from Eastern Europe).
In the tables below, the figures are only rough estimates from research studies. Lifetime risk means the chance that you will get these cancers sometime during your life. These numbers may not apply to you, but they can give you an idea of how high your risk may be.
About 12 out of 100 women will get breast cancer.footnote 1
1 first-degree relative with breast cancer
About 24 out of 100 women will get breast cancer.footnote 2
2 first-degree relatives with breast cancer
About 36 out of 100 women will get breast cancer.footnote 2
See a picture that may help you understand how much having a family history can increase your risk for breast cancer.
About 1 out of 100 women will get ovarian cancer.footnote 3
1 first-degree relative with ovarian cancer
About 5 out of 100 women will get ovarian cancer.footnote 3
2 or more relatives with ovarian cancer
About 7 out of 100 women will get ovarian cancer.footnote 3
See a picture that may help you understand how much having a family history can increase your risk for ovarian cancer.
Your doctor will ask about at least three generations of your family history and tell you how much it affects your risk. Your doctor may also send you to a genetic counsellor, someone who is trained to help people understand their risks for certain diseases.
What is a BRCA gene change?
Sometimes a very strong family history is caused by a mutated gene that runs in the family.
BRCA1 and BRCA2 are genes that normally help control cell growth. But an inherited change, called a mutation, in one of these genes makes you much more likely to get breast and ovarian cancers. BRCA (say "BRAH-kuh") stands for BReast CAncer. A BRCA gene test is a blood test that can tell you and your doctor whether you have one of these changed genes.
Having a BRCA gene change is rare. Most women with a strong family history of breast or ovarian cancer don't have a BRCA gene change.
Before you have a gene test, you will need to see a genetic counsellor. Counselling will help you make an informed decision about whether to have a BRCA gene test. It is often covered by insurance, but check with your insurance company to find out for sure.
You may be more likely to have a BRCA gene change if you:footnote 4
- Were diagnosed with breast cancer before age 50.
- Have had breast cancer in both breasts.
- Have had breast cancer and ovarian cancer.
- Have one or more male family members who have had breast cancer.
- Have multiple cases of breast cancer in the family.
- Have at least one family member who has had BRCA-related cancer.
- Are an Ashkenazi Jew (a Jewish person whose ancestors came from Eastern Europe).
In the table below, the figures are only rough estimates from research studies. These numbers may not apply to you, but they can give you an idea of how high your risk may be.
Breast cancer risk
Ovarian cancer risk
About 12 out of 100 women will get breast cancer sometime during their lives.
About 1 out of 100 women will get ovarian cancer sometime during their lives.
BRCA1 gene carriers
About 55 to 65 out of 100 will get breast cancer by age 70.
About 39 out of 100 will get ovarian cancer by age 70.
BRCA2 gene carriers
About 45 out of 100 will get breast cancer by age 70.
About 11 to 17 out of 100 will get ovarian cancer by age 70.
In the table above, the range for BRCA gene carriers is very broad. That's because different studies have had different results. More study is needed to get a clearer idea of what the risk is for women who have a BRCA gene change.
Pictures may help you understand these numbers better. See the following pictures to get a better idea of how much a BRCA gene change increases your risk for:
If you are worried that you may have a BRCA gene change, talk to your doctor.
- Breast Cancer Risk: Should I Have a BRCA Gene Test?
How can you find out what effect your family history has on your risk?
The best way to find out is to see your doctor. Your doctor will ask you for as much information about your relatives as you can give (for example, what kind of cancer they had, if any; how old they were when they were diagnosed; and, if they have died, how old they were when they died).
People often don't have a lot of information about all of their relatives. The more you can find out, the better your doctor can help you figure out how strong your family history is.
Your doctor may send you to a genetic counsellor, who can help you learn how high your cancer risk is. After counselling, you may decide to have a BRCA gene test.
The discovery of a genetic disease that is not causing symptoms now (such as breast cancer or Huntington's disease) should not affect your ability to gain employment, but it may affect your ability to get private health insurance coverage, life insurance, disability insurance, or long-term care insurance. Results will not affect your health coverage under your provincial health plan. For more information on the risks of genetic discrimination in Canada, talk with your doctor or contact the Canadian Coalition for Genetic Fairness at 1-800-998-7398. Or visit its website at www.ccgf-cceg.ca.
Finding out how high your risk is can help you make important decisions about your health. Some women decide to take extra steps to prevent breast and ovarian cancer, such as having checkups more often, taking anti-cancer medicine, or having surgery to remove the breasts, the ovaries, or both.
Health Tools help you make wise health decisions or take action to improve your health.
- National Cancer Institute (2010). SEER Stat Fact Sheets: Breast from SEER Cancer Statistics Review, 1975-2007. Bethesda, MD: National Cancer Institute. Available online: http://seer.cancer.gov/statfacts/html/breast.html.
- American Cancer Society (2013). Breast cancer: Early detection. Available online: http://www.cancer.org/cancer/breastcancer/moreinformation/breastcancerearlydetection/index.
- National Cancer Institute (2012). Ovarian Cancer Prevention PDQ-Health Professional Version. Available online: http://nci.nih.gov/cancertopics/pdq/prevention/ovarian/healthprofessional.
- U.S. Preventive Services Task Force (2013). Risk assessment, genetic counseling, and genetic testing for BRCA-related cancer in women: U.S. Preventive Task Force recommendation statement. U.S. Preventive Services Task Force. http://www.uspreventiveservicestaskforce.org/uspstf12/brcatest/brcatestfinalrs.htm. Accessed March 6, 2014.
- National Cancer Institute (2016). BRCA1 and BRCA2: Cancer risk and genetic testing. National Cancer Institute. http://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet. Accessed April 6, 2016.
Primary Medical Reviewer Sarah Marshall, MD - Family Medicine
Anne C. Poinier, MD - Internal Medicine
Kathleen Romito, MD - Family Medicine
Adam Husney, MD - Family Medicine
Elizabeth T. Russo, MD - Internal Medicine
Specialist Medical Reviewer Kirtly Jones, MD - Obstetrics and Gynecology
Wendy Y. Chen, MD, MPH, MD, MPH - Medical Oncology, Hematology
Current as ofJune 16, 2017
Current as of: June 16, 2017
Author: Healthwise Staff
Medical Review: Sarah Marshall, MD - Family Medicine & Anne C. Poinier, MD - Internal Medicine & Kathleen Romito, MD - Family Medicine & Adam Husney, MD - Family Medicine & Elizabeth T. Russo, MD - Internal Medicine & Kirtly Jones, MD - Obstetrics and Gynecology & Wendy Y. Chen, MD, MPH, MD, MPH - Medical Oncology, Hematology
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