Many people wonder whether a family history of cancer may increase their own risk of developing cancer. While most cancers occur by chance, some are related to inherited genetic changes that can be passed down through families. Understanding your personal and family history can help identify individuals who may benefit from genetic counseling, genetic testing, or additional cancer screening.
Here you'll find information about who may benefit from genetic testing, what genetic test results can mean, common hereditary cancer syndromes such as BRCA and Lynch syndrome, and options for reducing cancer risk or detecting cancer earlier.
Most cancers develop because of genetic changes that occur over a person's lifetime and are not inherited. However, a smaller proportion of cancers are related to genetic changes that are passed down through families.
These inherited genetic changes are sometimes called pathogenic variants or mutations. Having one does not mean that you will definitely develop cancer. Instead, it may increase your risk of developing certain types of cancer compared with the general population.
Certain patterns in a personal or family history can make an inherited cancer syndrome more likely. Recognizing these patterns can help us identify people who may benefit from genetic testing, additional cancer screening, or strategies to reduce cancer risk.
Not everyone with a family history of cancer needs genetic testing. However, certain patterns in your personal or family history can suggest that cancer may be more likely to have an inherited cause.
Genetic counseling or testing may be worth considering if you or a close family member has:
Cancer diagnosed at an unusually young age
Several family members with the same or related types of cancer
More than one separate cancer diagnosed in the same person
Ovarian cancer, pancreatic cancer, or male breast cancer
Certain patterns of breast, colorectal, uterine/endometrial, or prostate cancer
Cancer affecting both paired organs, such as breast cancer in both breasts
A known hereditary cancer gene variant in the family
Your family history matters on both your mother's and your father's sides of the family. When reviewing your history, it is especially helpful to know which relatives had cancer, what type of cancer they had, and approximately how old they were when they were diagnosed.
These are examples rather than a complete list. Recommendations for genetic testing depend on the specific cancers in your family and other details of your personal history. If you're unsure whether your history is significant, we can help determine whether a genetic counseling evaluation would be helpful.
Genetic testing usually looks for inherited changes in a sample of blood or saliva. Testing for hereditary cancer risk increasingly uses multigene panels, which evaluate several genes associated with cancer risk at the same time rather than testing only BRCA1 and BRCA2.
When possible, testing may be most informative when it begins with a family member who has actually had the cancer of concern. However, testing may still be appropriate even when an affected relative is unavailable.
A genetic counselor can review your personal and family history, help determine which testing is appropriate, discuss insurance coverage and potential costs, and help you understand what the results may mean for you and your family.
Genetic testing results can sometimes be confusing. Your result will generally fall into one of three categories: positive, negative, or a variant of uncertain significance (VUS). What the result means depends on your personal and family history and, in some cases, whether another family member has already had genetic testing.
A positive result means that testing identified a genetic change known to increase the risk of one or more types of cancer. It does not mean that you currently have cancer or that you will definitely develop cancer.
Recommendations depend on the specific gene involved and may include earlier or more frequent cancer screening, additional types of screening, medications, or risk-reducing surgery. Because inherited genetic variants can run in families, your relatives may also have the option of being tested for the same variant.
A negative result means that testing did not identify a harmful genetic variant in the genes that were tested. However, a negative genetic test does not always mean that your cancer risk is average.
If a specific genetic variant is already known in your family and you test negative for that variant, this is generally very reassuring. If no genetic cause has previously been identified in your family, a negative result may be less definitive. Your personal and family history may still indicate an increased cancer risk or a need for additional screening.
Sometimes testing identifies a genetic change, but there is not yet enough information to know whether that change increases cancer risk. This is called a variant of uncertain significance, or VUS.
A VUS is not considered a positive genetic test. In most situations, it should not change your cancer screening or lead to risk-reducing surgery by itself. As researchers learn more about genetic variants, a VUS may eventually be reclassified as either benign or disease-causing.
Genetic test results should always be interpreted in the context of your personal history and family history. If your results identify a pathogenic variant, are difficult to interpret, or don't seem to explain a strong family history of cancer, genetic counseling can help determine what the results mean for you and whether your screening recommendations should change.
BRCA1 and BRCA2 are genes that normally help protect cells from developing cancer. Some people inherit a harmful change (pathogenic variant) in one of these genes, which can significantly increase the risk of developing certain cancers.
BRCA1 and BRCA2 are best known for their association with breast and ovarian cancer, but they can also increase the risk of other cancers, including pancreatic and prostate cancer. These genetic changes can be inherited from either your mother's or your father's side of the family, and both women and men can carry and pass them on.
If a BRCA1 or BRCA2 pathogenic variant is identified, there are several ways we can help manage that increased risk. Depending on the gene, your age, and your individual circumstances, this may include earlier or additional cancer screening, medications, or risk-reducing surgery. Testing may also provide important information for other members of your family.
Learning that you have an increased hereditary cancer risk can feel overwhelming, but it also gives us an opportunity to be more proactive about cancer prevention and early detection.
Recommendations depend on the specific gene involved, your age, personal and family history, and your individual goals. Depending on the type of cancer risk, options may include earlier or more frequent cancer screening, additional types of screening, medications that can lower cancer risk, lifestyle changes, or risk-reducing surgery.
For some hereditary cancer syndromes, surgery can significantly reduce the risk of developing certain cancers. This may include risk-reducing mastectomy for some patients at very high risk of breast cancer or removal of the fallopian tubes and ovaries (risk-reducing salpingo-oophorectomy) for patients at increased hereditary risk of ovarian cancer. The recommended timing varies depending on the specific gene and is also influenced by plans for future pregnancy, age, and other health considerations.
These decisions are highly individualized. Having a pathogenic variant does not automatically mean that you need preventive surgery. Genetic counselors and specialists can help you understand your individual cancer risks and compare the benefits, limitations, and timing of the available options.
Lynch syndrome is an inherited condition that increases the risk of several types of cancer. It is most commonly associated with colorectal cancer, but it is also an important hereditary cancer syndrome in gynecology because it can significantly increase the risk of endometrial (uterine) and ovarian cancer. Other cancers, including stomach, urinary tract, pancreatic, and certain other cancers, may also occur more frequently in people with Lynch syndrome.
Lynch syndrome is caused by a pathogenic variant in one of several genes involved in repairing DNA. The specific gene involved can affect which cancers are most likely and how high those risks are.
If you have Lynch syndrome, recommendations may include earlier or more frequent cancer screening and, in some situations, risk-reducing surgery. For women who have completed childbearing, hysterectomy and removal of the fallopian tubes and ovaries may be considered to reduce the risk of gynecologic cancers. The recommended approach and timing depend on the specific gene, your age, family history, and your individual goals.