Inheriting a cancer gene mutation doesn't mean you will get cancer
Cancer is caused by a change in a cell. Many types of cancer have a hereditary link, meaning you can inherit a risk for getting that cancer. These are the types of cancers that may run in families. For example, you may have heard of BRCA1 and BRCA2 genes. A person who inherited a genetic mutation in one of these genes has an increased risk of breast and ovarian cancer. There is a long list of cancers that in some cases have a genetic link; some of the more common types are breast, colon, gastric, uterine, prostate, pancreatic and thyroid cancers. Most people who have one of those cancers do not inherit an increased risk. And many people who do inherit one of those mutations do not develop that cancer.
So how do you know what to do? Would genetic testing be beneficial? A genetic counselor can provide guidance. Consider talking to a genetic counselor if:
- You have a personal or family history of cancer
- Several of your close relatives have had the same type of cancer (for example a grandmother, mother and aunts)
- You or a close family member has had more than one type of cancer, or have had cancer that was diagnosed at an unusually young age
Below you can find information about several types of cancer that have a hereditary link.
Hereditary Breast and Ovarian Cancer
We know more about some hereditary cancers than others. For example, five to 10 percent of women with breast cancer and up to 25 percent of women who have ovarian cancer have a genetic mutation that may have played a role. Besides the BRCA1 and BRCA2 genes there are many other genes that relate to breast and ovarian cancer risk as well. Depending on the particular gene, there may be risks of other cancers to consider as well. These genes also may impact men, since males who carry these mutations are more likely to get breast cancer.
Consider visiting a genetic counselor to ask about an inherited risk of breast or ovarian cancer if any of the following apply to you:
- You have a family history, meaning:
- You have more than one close relative on the same side of the family with breast, prostate, pancreatic or colon cancer, or one close relative with ovarian cancer
- A genetic mutation has been identified in your family
- You have been diagnosed with breast cancer and:
- You are under 50 years old
- You have an aggressive type of cancer called triple negative breast cancer that was diagnosed when you were younger than 60 years old
- You have metastatic breast cancer
- You have been diagnosed with ovarian cancer at any age
- You have been diagnosed with pancreatic cancer at any age
- You have been diagnosed with an aggressive or metastatic prostate cancer at any age
- You are of Ashkenazi (Eastern European) Jewish background with a personal or family history of breast cancer, ovarian, pancreatic or prostate cancers
- You are a man who has been diagnosed with breast cancer or have a close relative with male breast cancer
Learn more about breast cancer risk
Download the BRCA Fact Sheet
Learn more about ovarian cancer risk
Bright Pink has developed an online tool to assess your risk for hereditary breast and ovarian cancer.
Learn more about Bright Pink's online tool
Other Hereditary Cancers
There are other cancers that can have a genetic link, including colon, uterine and thyroid cancer.
- Colon cancer
About 10 percent of all colorectal cancers are inherited. Two of the more well-known types of inherited colon cancer are Lynch syndrome (hereditary nonpolyposis colorectal cancer) and familial adenomatous polyposis (FAP). Many other genes have been found that increase the risk of colon cancer. There likely are other forms of inherited cancer, but scientists have not yet identified the genetic mutations responsible.
- Thyroid cancer – The vast majority of people who have papillary thyroid cancer (PTC) – the most common form of thyroid cancer – did not inherit the risk. People with very aggressive PTC and those with the more rare follicular or medullary types are more likely to have inherited the risk. Medullary thyroid cancer is one of the most aggressive of this type of cancer and is strongly associated with mutations in the RET gene. Learn more about thyroid cancer.
- Uterine cancer - About five percent of all uterine cancer is inherited. The most common cause of inherited uterine cancer is Lynch syndrome. Uterine cancer may also be caused by other more rare hereditary cancer syndromes, including Cowden syndrome.
How Testing Can Help
If you have an inherited risk for a specific type of cancer, genetic testing may help you make decisions about prevention or treatment. There are a number of ways genetic testing for cancer is helpful:
- Screening – There are special screening tests available for some cancers. For example, if you learn you are at higher risk for breast cancer, you might choose to begin having mammograms when you are younger, or have more advanced screening tests, such as a breast MRI. If you are at higher risk for colon cancer, you may begin getting colonoscopy screening at an earlier age and more frequently. If you are at higher risk for prostate cancer, you can undergo regular screening with a blood test called the prostate specific antigen (PSA) test at an earlier age. The same holds true for many other cancers as well. When cancer is caught earlier, treatment is usually more effective.
- Lifestyle changes – Being told you have an increased risk for cancer might help encourage you to quit smoking, drink less alcohol, eat healthier and exercise more, all of which can decrease your risk.
- Prophylactic surgery – Some people who learn they have a genetic predisposition to develop breast cancer may choose to have their breasts or ovaries removed, which significantly decreases their risk of cancer. Actress Angelina Jolie made headlines when she chose to undergo surgery to remove her breasts, and later her ovaries, after learning she had inherited the BRCA1 mutation from her mother, who died of ovarian cancer.
- Personalized treatment – Some cancers don’t respond to traditional treatments, but do benefit from targeted therapies. The earlier you learn a cancer is caused by a specific gene, the earlier you can learn about targeted treatment options that may be available for you.
- Informing your family – If you learn you have an increased risk for a type of cancer, it is important to let your family members know they may be at risk so they can decide whether they would like to get tested.
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