Genetics and Family History
Will Your Children Inherit Breast Cancer from You?
As a breast cancer survivor, you might worry about passing the disease on to your children. Will your children develop breast cancer because you’ve had it?
The answer to this question is not a clear yes or no. Having a relative with breast cancer does increase people’s (both men’s and women’s) chances of getting it. This means that your children are at a greater risk for developing breast cancer than people without a family history of the disease. However, there are many factors aside from inheritance that are equally, if not more, important in bringing about the onset of breast cancer.
Most women with breast cancer do not have a close female relative with the disease.
You may wonder exactly how breast cancer can be passed from you to your children. Genetic inheritance of diseases, or anything else, is extremely complex. In general, genetic traits, like eye color or susceptibility to certain diseases, are passed from parents to children through their DNA. DNA is a long chain of molecules containing the codes for a person’s inherited traits. Children get one set of DNA from their mother and one from their father. In the specific case of breast cancer inheritance, this means that if a person’s mother or father has breast cancer in the family, s/he is at a higher risk of getting it.
Researchers have discovered that specific genes, which are parts of the DNA chains, are linked to higher risk for breast cancer if they are altered, or damaged, in certain ways. BRCA-1 and BRCA-2 (BRCA stands for BReast CAncer) are two of these genes. Children who inherit the altered, or high-risk, variants of these genes from their parents have a higher chance of developing breast cancer than people without them. Researchers are working on finding other genes that, when altered, may be related to breast cancer.
Here are some facts about inheriting the high-risk variants of the BRCA-1 or BRCA-2 genes:
- The high-risk variants are found in less than 0.5% of the general population and account for only about 5-10% of all breast cancer cases, and possibly fewer.
- A person with a family history of breast cancer has a higher chance of having a high-risk variant, but does not necessarily have one.
- A woman with one of the high-risk variants has an 80% chance of developing breast cancer before age 70.
- The high-risk variants are more common among Ashkenazi Jews than other populations. They are found in 2.5% of all members of this group and account for over 25% of breast cancer cases diagnosed before age 40 in the group.
Given this information, some women with a family history of breast cancer may decide to undergo genetic testing to discover whether they carry the high-risk variants of cancer-causing genes. With early discovery, a woman may be able to make lifestyle changes or undergo treatments to reduce her risk of developing breast cancer in the future.
However, the decision on whether or not to get tested for breast cancer genes is not an easy one. Getting tested, regardless of the results, may have serious consequences for a person’s ability to qualify for health and life insurance, employment and disability benefits. It can also have a negative impact on a person’s relationships and life outlook.
Visit the websites listed here for more information on the genetic basis of breast cancer and genetic testing for the disease.
This is the general site of the National Cancer Institute with links to many informative articles on genetics and breast cancer and on other aspects of the disease.
Information from the National Breast Cancer Coalition on the considerations and risks involved in genetic testing.
The site of a nonprofit organization called FORCE--Facing Our Risk of Cancer Empowered--for women who know they are at a higher risk for breast cancer or who are wondering whether they face such a risk.
The site of the National Society of Genetic Counselors provides some information on what to expect at your first meeting with a genetic counselor as well as a resource page for finding a counselor in your area who is a member of the society.