A critical part of managing your health is understanding your risks for certain inherited medical conditions. Certain types of cancer, such as breast and colon cancer, appear more frequently in some families, while other diseases, such as coronary artery disease, type 2 diabetes, depression and blood clotting disorders, may be common in others. Collecting an accurate family history will help you and your health care provider identify conditions that may require increased surveillance and preventive measures.
Genetic mutations and cancer risk
When the cells in your body grow and divide normally, they follow genetic instructions on how fast to grow and when to stop. But this natural process of cell growth can break down, causing cells to grow out of control. When this happens, repair genes called BRCA1 and BRCA2, each located on different chromosomes, stop uncontrolled cell division in breast and ovarian cells before cancer can take hold. Each person has two copies of both the BRCA1 and BRCA2 genes — one from the mother and one from the father. As long as one copy of each gene functions normally, cancer won’t form in the breasts or ovaries. But if both copies are damaged by exposure to known carcinogens, including those from cigarette smoke and other chemicals, cancer can grow.
Some people, however, are not born with normal BRCA genes. Instead, they inherit a mutation in one of their BRCA1 or BRCA2 genes, resulting in a lack of back-up protection should any damage occur to the remaining normal gene. People born with a BRCA gene mutation carry a much higher risk of developing breast and ovarian cancer. This is called Hereditary Breast and Ovarian Cancer Syndrome (HBOC).
There are genetic tests available to check for some of the known gene mutations associated with cancer.
Family history and cancer risk
What’s your risk for developing cancer? It depends on your family history.
One in eight women (12 percent) will develop breast cancer, but:
- The risk for women who have a family history of breast cancer, but no known genetic mutation is approximately 20 to 30 percent.
- The risk for women with a genetic mutation inherited from either parent (HBOC) is approximately 60 to 87 percent.
One in 100 women (1 percent) will develop ovarian cancer, but:
- The risk for women who have a family history of ovarian cancer, but no known genetic mutation is approximately 4 to 7 percent.
- The risk for women with a genetic mutation from either parent (HBOC) is approximately 20 to 54 percent.
One in 20 women (4.9 percent) will develop colon or rectal cancer, but:
- The risk for women who have a family history of colorectal cancer, but no known genetic mutation is approximately 12 to 24 percent.
- The risk for women with a genetic mutation from either parent (Lynch Syndrome) is up to 82 percent.
One in 38 women (2.6 percent) will develop uterine or endometrial cancer, but:
- The risk for women who have a family history of endometrial cancer is up to 7 percent.
- The risk for women with a genetic mutation from either parent (Lynch Syndrome) is up to 71 percent.
Warning signs that your family may carry a gene for hereditary breast or ovarian cancer
- You have one relative with bilateral breast cancer (both breasts), breast and ovarian cancer, or male breast cancer.
- You have two relatives with breast cancer (one before age 50), ovarian cancer (at any age), or one with breast cancer and one with ovarian cancer.
- You have three relatives with breast cancer (any age).
- You have any relative with a BRCA mutation.
- You have Ashkenazi Jewish ancestry (Central or Eastern European) and one relative with breast or ovarian cancer.
To find out more about your cancer risk, take our free cancer risk assessment screening test at your next visit!
If there is a reasonable likelihood that you could carry a gene for one of the hereditary cancers based on your family history, you should consider testing for that gene. Testing may give you peace of mind, and the results could affect your lifestyle choices. Medical options exist for prevention, early detection and treatment. Federal law prevents discrimination based on genetic cancer screening results.