Breast cancer gene?
Originally Published: December 1, 1994 - Last Updated / Reviewed On: October 18, 2012
I am an undergrad here. My maternal grandmother had (and survived) breast cancer before the age of forty. In her thirties, my mother had breast cancer (it was advanced, but she recovered), only to (a few years later) be diagnosed with ovarian cancer, which was unfortunately terminal. I know that given these two facts, it is likely that I may be at a higher risk, and my doctors at home watch me carefully. Given the discovery of BRCA-1 (the breast/ovarian cancer gene), I am wondering what to do — should I be tested? Will it matter? I have made an appointment with a women's health care provider to get some advice, but I still wanted to ask you.
Also, I was wondering if you know if it is possible (or advantageous) to see if I could get my mother's medical records — is this legal? I am not sure what, if anything, I should be doing now (besides exercising, eating right, etc., the obvious)...
Nature or nurture?
Dear Nature or nurture?,
It may be reassuring to know that a family history of cancer does not mean that cancer is inevitable. Although family history and age are indicators of increased risk, family history alone is by no means the only determinant of cancer.
Both men and women have BRCA1 and BRCA2 genes (short for BReast CAncer Susceptibility Gene 1 and 2), but it is the mutation of these genes that is associated with an increased risk of breast and ovarian cancers. These genes belong to a class of genes known as tumor suppressors. The chance of inheriting a mutation is 50% if a patient’s mother or father has a BRCA1 or BRCA2 mutation. Conversely, if a patient has a confirmed BRCA1 or BRCA2 mutation, it means that one of their parents has the mutation (except for in very rare cases). Men and women with altered versions of BRCA1 or BRCA2 are at a higher risk of developing breast cancer compared to men and women who have normal BRCA genes, and may be at increased risk of other cancers.
According to estimates of lifetime risk, a woman who has inherited a harmful mutation in BRCA1 or BRCA2 is about five times more likely to develop breast cancer than a woman who does not have such a mutation. Among white women in the United States, it is estimated that inherited BRCA1 and BRCA2 mutations account for 5 to 10 percent of breast cancers. In women, mutations of BRCA1 are linked to uterine, colon, and cervical cancer, and mutations of BRCA2 are linked to gall bladder, bile duct, melanoma, and stomach cancer. In both men and women, mutations of BRCA1 and BRCA2 are linked to pancreatic cancer, and in men, mutations of BRCA1 and BRCA2 are linked to testicular and early-onset prostate cancer (with BRCA2 having a stronger association). Breast cancer continues to be rare for men, however, even if they have an altered BRCA1 or BRCA2 gene. Individuals who have a personal or family history of breast cancer, particularly if breast cancer has been present in two or more close relatives, multiple generations, or if the breast cancer developed at early ages, may want to consider genetic testing to learn more about her/his personal cancer risks.
It sounds like you've made the choice to learn more about the testing process, and your health care provider or genetic counselor should be able answer your questions and discuss your concerns. There’s a website called The Penn II Risk Model where you can determine your personal and familial risk of having the BRCA1 or BRCA2 gene (not an assessment of breast cancer risk), used to see if a patient is a good candidate for genetic testing. You also may want to think about how the results of genetic testing will impact your life. What support systems do you have in place to help you understand the results and cope with the feelings that may accompany a positive or negative result? Not all of BRCA gene mutations carry the same amount of risk, so a genetic counselor will be particularly helpful in assessing your medical health, lifestyle, and family history. A genetic counselor can also work with you to create a strategy for managing your personal cancer risks. Other things to consider in the testing process include potential discrimination and cost. Although genetic discrimination by insurance agencies or employers is prohibited (following the recent passage of the Genetic Information Nondiscrimination Act), life insurance, disability insurance, and long-term care insurance are not covered. A positive BRCA1 or BRCA2 test result in a patient’s medical records could affect their coverage/insurance costs. Additionally, the cost of the BRCA test itself can vary greatly depending on your insurance coverage — from hundreds to thousands of dollars — so you may want to find out about your insurance company’s policies regarding genetic tests. If you decide that genetic testing is an option you'd like to take, only a blood sample is required, but results may take several weeks or even months.
While the results of the test may be informative, the test also has limitations. Most notably, a negative result is not a guarantee that cancer will not eventually develop, and finding an altered BRCA1 or BRCA2 gene will not indicate if or when breast cancer will develop. In the case of a positive result, knowledge of a BRCA mutation would signify the need for more careful monitoring by your health care provider. Risk management options include:
- Surveillance, including frequent clinical breast exams and mammograms.
- Hormone therapyhas shown promise. Drugs such as tamoxifen and raloxifene, taken over the course of 5 years, have been effective in reducing breast cancer among high risk women, although it is unclear whether this is true for women with BRCA mutations.
- Lifestyle changes, such as changes in diet and exercise.
- Some women choose to have preventative surgery to remove healthy breast tissue, known as a prophylactic mastectomy. A prophylactic mastectomy can reduce a patient’s chance of developing breast cancer by up to 90% and is only recommended for patients perceived as having a high breast cancer risk. There are side effects such as loss of sensation in the breast and many women choose to have reconstructive surgery after having the procedure.
If you discover you are at high risk for developing breast cancer, having an honest conversation with your genetic counselor or health care provider about what preventive actions are right for you may give you some peace of mind. Accessing your mother's medical records may not be necessary at this point. If at any time you are referred to a cancer specialist, however, it might be helpful to have her/him look at those records, if they are still available. To have them released, you will most likely need to write a letter or fill out a request form to your mother's primary care provider. Depending on the medical facility and the laws governing them, you may or may not have access to these files.
For more information, you can also visit the Cancer Genetics at the National Cancer Institute's (NCI) website or call the NCI's Cancer Information Service (CIS) at 1-800-4-CANCER (422-6237) for more information. The National Cancer Institute can also help you to stay informed of available options.
It's admirable that you are exploring options with consideration of your present and future personal health. Best of luck reaching a conclusion that supports your health and happiness.