Each year, more than 200,000 women in the U.S. learn they have breast cancer.
While most happen by chance, 5 to 10 percent of breast cancer cases are
linked to an inherited gene mutation.
How Can Breast Cancer be Inherited?
Hereditary breast cancer is caused by abnormal genes passed from parent
to child — from either the mother’s or father’s side.
Genes are made up of DNA, which contain instructions for regulating cell
growth. Damage or changes in the DNA can produce the wrong set of instructions,
altering normal cell production.
DNA can become damaged or changed as a result of natural aging processes,
environmental and lifestyle factors or an inherited genetic mutation.
Some DNA changes are harmless, but others can give rise to cancer by allowing
cells to grow and divide in an uncontrolled way, forming a tumor.
BRCA1 and BRCA2 Genes
The most common cause of hereditary breast cancer is an inherited genetic
mutation in the BRCA1 or BRCA2 gene (BReast CAncer genes 1 and 2).
Despite what their names suggest, these genes don’t cause cancer.
Instead, they normally play a role in protecting you from cancer by repairing
damaged DNA and keeping breast and other cells from growing uncontrollably.
Because of this, the BRCA genes are actually known as tumor-suppressing
genes. In some people, these tumor-suppressing genes don’t function
properly because they contain hereditary mutations passed down from parent
to child. This can, in turn, lead to the development of cancer.
How Much Does Having a BRCA1 or BRCA2 Gene Mutation Increase Your Risk?
Women with a BRCA1 or BRCA2 mutation face a dramatically increased lifetime
risk of breast cancer: 72 percent of women who inherit a BRCA1 mutation
and about 69 percent of women who inherit a BRCA2 mutation are likely
to develop breast cancer by the age of 80, compared with about 12 percent
for women with no inherited genetic risk.
Men with BRCA2 mutations, and to a lesser extent BRCA1 mutations, are also
at increased risk of breast cancer and prostate cancer.
Men and women with mutations in BRCA1/BRCA2 may be considered at an increased
risk for melanoma and pancreatic cancer as well.
While the risk of breast cancer is higher for those who have a BRCA1 or
BRCA2 mutation, increased screening and preventative surgical options
have been shown to dramatically reduce the risk of cancer or identify
cancer early, when it is most easily treated and cured.
Getting Tested for a Genetic Mutation
Learning about your hereditary risk can go a long way in helping you take
the right steps to prevent breast cancer.
A genetic counselor can help you assess your cancer risks and answer any
questions you may have. Your counselor can also help determine whether
you and your family are likely to have a mutation that make it worth getting tested.
Genetic testing involves a blood or saliva test performed by a specialized
laboratory. Testing is usually recommended when you have any of the following:
- A known BRCA1, BRACA2 or other inherited mutation in your family.
- A strong family health history of breast and ovarian cancer, early onset
cancers or multiple cancers in a single person.
- A moderate family health history of breast cancer and are of Ashkenazi
Jewish or Eastern European descent.
- A personal history of female breast cancer that meets certain criteria
such as age at diagnosis, type of cancer and family health history.
- A personal history of ovarian, fallopian tube or primary peritoneal cancer,
male breast cancer, pancreatic cancer or prostate cancer.
To make an appointment with genetic counselor, call Rocky Mountain Cancer
Centers at 303-930-7872.