Breast and Ovarian Cancer
While much has been written about families with an inherited predisposition to breast/ovarian cancer, only 5-10% of women with breast or ovarian cancer have an inherited predisposition from a gene mutation. Most breast and ovarian cancer is due to random, or sporadic, errors (mutations) in genes. These errors happen over a lifetime.
What is the chance of developing breast or ovarian cancer?
If you are female and live to age 80, your chance of developing breast cancer at some point in your life is one in nine or 11%, and one in 70 or 1.4% for developing ovarian cancer. Breast cancer in men is rare, about one in 1000.
What is known about the genes that predispose to breast/ovarian cancer?
In 1994 and 1995, two genes were identified which are known as BRCA1 and BRCA2. Both of these genes, when working properly, protect against the development of cancer in the breast and the ovaries of women. When there is a mutation or error in one of these genes, they may no longer offer protection against these specific cancers. It is possible that other predisposing breast/ovarian cancer genes will be identified in the future.
How do you identify someone who might have higher chance of carrying a BRCA1 or BRCA2 gene mutation?
We identify those at a higher genetic risk primarily through a review of the family cancer history. We evaluate the family taking into account the ages of family members when they were diagnosed with cancer, the particular types of cancer, and the relationship between family members who have cancer.
The hallmarks of families who appear to be at higher risk for carrying a predisposing mutation in BRCA1 or BRCA2 include the following:
1) Multiple family members with breast and/or ovarian cancer, usually in more than one generation
2) Unusually early ages of onset of the cancers
3) Individuals with multiple cancers, for example a woman with both breast and ovarian cancer
4) The presence of both breast and ovarian cancer in the family but in different family members
5) Male family members with breast cancer
We consider both the mother's and the father's sides of the family separately, as these genes are carried by men as well as women. For some individuals or families, DNA testing is available to identify mutations.
How can I learn more about my personal risk for carrying a predisposing BRCA1 or BRCA2 gene mutation?
Evaluation and counseling about your personal and family history of breast/ovarian cancer is available through your local Kaiser Permanente Genetics Department. You may be referred by your healthcare provider, or you may call the Genetics department yourself.
What should I expect if I call the Genetics department to ask about my breast/ovarian cancer risk?
Most people will begin the information and counseling process by attending a class, which provides general information about the relationship between genes and breast/ovarian cancer and about the genetic evaluation and testing process. The class offers information to help you decide if testing would be available and useful to you and your family. Testing is not appropriate for all families.
Individual counseling may be scheduled to obtain an evaluation of your risk for carrying a predisposing gene mutation for breast/ovarian cancer. DNA testing to detect these mutations is available for selected families only. For those who do have testing, at least two appointments, in addition to the information class, will be scheduled. The evaluation/counseling/testing process may take weeks or months to complete.
How can I prepare before contacting the Genetics Department?
Before contacting your local Kaiser Permanente Genetics Department, it is helpful if you have gathered all the medical information that you can about your family members. It is especially important to know the type of cancer and the age of diagnosis for affected relatives. We are interested in all cancers in the family so that we may have the most information possible. We will take a complete family history including family members without cancer. Medical records/death certificates may be requested to help determine your risk before genetic testing is offered.
Genetic information often has an impact on many family members, and may be emotionally complicated by the nature of the relationships within a family. These issues will be considered and discussed during the process of genetic counseling.
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