Genetic Testing And Counseling

Hope is a thing with feathers that perches on the soul, and sings the tune without the words, and never stops at all.

— Emily Dickinson

More and more, cancer genes—especially breast cancer genes—and genetic tests are in the news. It can be difficult to make sense of the dizzying array of scientific discoveries and what they mean to you. Do you think you have a family history of breast cancer? Should you consider a genetic test for breast cancer? What happens when you have a genetic test? Will it tell you if you’re going to get breast cancer?

In this section, we provide answers to some of the most common questions about genes, breast cancer, and genetic testing. We’ll begin with the basics.

What is a gene?
Genes are pieces of DNA that are passed down from parent to offspring. DNA is the chemical material inside our cells that makes instructions to run the body. Each gene contains instructions to make a certain product for the cell. There are approximately 35,000 genes in each cell of the human body.

Genes influence how our bodies function and grow. They determine other characteristics about us such as the color of our hair and eyes. Human genes come in pairs. One set of genes is passed down (or inherited) from the mother, and the other set is passed down from the father.

How do genes relate to breast cancer?
Most cancer occurs by chance and is not due to an inherited or single environmental cause. If a gene contains a mistake (or mutation), it may not work properly. In fact, we all have several mutations, many of which cause no harm. However, certain mutations can increase the risk for illnesses such as cancer.

All mutations are either passed down from parent to child (inherited mutations), or happen during a person’s lifetime (sporadic mutations). The great majority of breast cancers are due to sporadic mutations.

Sporadic gene mutations are caused by the body’s response to stresses in the environment, such as chemicals, radiation and hormones. Usually, the body can fix these errors before they cause problems. However, over a long period of time, they may add up and result in diseases such as breast cancer. This is why people tend to develop cancer later in life.

What are breast cancer genes?
Scientists have found a number of genes that affect breast cancer risk. When mutated, these genes can cause a greater risk for breast (and ovarian) cancer to be passed down from generation to generation. Most cases of inherited breast cancer are related to two genes: BRCA1 and BRCA2.

The role of the BRCA genes in the body is to keep cells growing at a controlled normal rate, and not too quickly. A mistake (or mutation) in a BRCA gene can allow cells to grow and divide unchecked, resulting in cancer.
Scientists believe that about 5 - 10 percent of breast cancers are caused by inherited BRCA1 or BRCA2 mutations. This means that the vast majority of breast cancers (90-95 percent) occur by chance.

What are the risks for a woman who carries a BRCA mutation?
A woman with a BRCA1 or BRCA2 mutation is much more likely to develop breast and ovarian cancer than a woman without a mutation. Scientists estimate that the risk to develop breast cancer over her lifetime (by age 70) is 14 to 87 percent (compared to the general population risk of about 13 percent). The risk to develop ovarian cancer ranges from 10 to 68 percent over a woman’s lifetime (compared to 1.7 percent). Not every woman who has a mutation in a BRCA1 or BRCA2 gene will get breast or ovarian cancer. It is difficult to say what the exact risk of breast cancer is, but it depends on gene factors and age.

What is a genetic test for breast cancer risk?
When a person has a genetic test for breast or ovarian cancer, a small sample of blood is drawn. Two genes (BRCA1 and BRCA2) are examined to see if they contain mutations that could increase a woman’s risk for breast cancer.

What do the results of a genetic test for breast cancer risk mean?
Genetic testing for any disease risk is a more complex issue than it may at first seem. Testing for breast cancer risk is more than simply a “yes” or “no” answer, and it is far from an exact science. Due to the complexities of genetic testing, it is important for your test result to be interpreted by a professional experienced in genetic testing, such as a genetic counselor.

  • A positive result means that a woman has a BRCA mutation that is known to increase the risk of developing breast or ovarian cancer. However, a positive result does not mean that a woman will definitely develop breast or ovarian cancer.
  • A negative result usually means that a woman does not have a known BRCA mutation. There is a small chance that a negative test result means the test did not find a mutation when, in fact, a woman actually does have one.
  • In a small percentage of cases (about 10 percent) the genetic test for breast cancer risk returns an uninformative, ambiguous or vague result.

Other points to consider about genetic testing for breast cancer risk include:

  • A family history tree or “pedigree” should be drawn by a genetic counselor, geneticist or healthcare provider to help determine if the breast cancer is inherited.
  • A family member who has had breast cancer should be tested initially to identify more accurately the gene mutation. Then, other family members can be tested for the known mutation more reliably and at a lower cost.
  • The father’s family history is important in assessing breast cancer risk because altered BRCA genes can be passed down on the father’s side as well.
  • Genetic information applies not only to the person having the test, but also to family members and the person’s children.

For these reasons and others, it is important for people considering genetic testing to talk to a genetic counselor. Genetic counselors for cancer risk in North Carolina usually work in genetics clinics in large hospitals or comprehensive cancer centers. Genetic counselors are trained to recognize patterns of inherited disease in families and to counsel patients about the specifics and pros and cons of genetic testing. (See our list of Cancer Genetic Risk Clinics in North Carolina at the end of this section).

A negative genetic test result does not mean that a woman will never get breast cancer. She still has the same risk of getting breast cancer as women in the general population, which is about a 13 percent chance over a woman’s lifetime.

When should someone consider genetic counseling or testing?
This is an individual decision. However, if a woman has a significant family history of breast cancer (see Who is More Likely to Have a BRCA1 or BRCA2 Mutation? on page 84), she may benefit from genetic counseling and, in some cases, genetic testing.

If a woman has a BRCA gene mutation, what can she do?
If you are at increased risk for breast or ovarian cancer, you can make choices that may help reduce your risk of getting cancer, or help find cancer early. Of course, you can take these steps with or without getting tested for a BRCA1 or BRCA2 alteration.

  • Increase screening. You may choose to be monitored more closely for any sign of cancer. This may include more frequent mammograms, breast exams by your doctor, breast self-exams, and an ultrasound exam of the ovaries. Breast MRIs have also been shown to be effective in detecting breast cancer in high-risk women.
  • Consider preventive drug therapy. You may choose to take one of a few drugs that are known to reduce the risk of developing breast cancer. As with all drugs, these have side effects that must be balanced with the benefit of taking such a drug. Talk to your healthcare provider or oncologist for more information.
  • Join a research study. Because it is not yet possible to prevent cancer, you may choose to join a research study aimed at developing better screening measures or to identify new ways to reduce cancer risk.
  • Make healthy lifestyle choices. Some research studies have shown that physical activity and other lifestyle factors such as avoiding obesity can reduce breast cancer risk in BRCA mutation carriers.
  • Consider prophylactic (preventive) surgery, during which your healthy breasts and/or ovaries are removed. These surgeries are the most effective way to reduce your risk of breast or ovarian cancer, but they are a more drastic option.

Who Is More Likely To Have A Brca1 Or Brca2 Mutation?
Most women do not have a mutation in the BRCA1 or BRCA2 gene. If a woman has one or more of the below factors, there is an increased possibility that she may carry an inherited BRCA mutation.

  • Two or more close blood relatives who had breast cancer, ovarian cancer, or both, at any age.
  • One or more close blood relatives who had breast cancer before age 50 or ovarian cancer at any age.
  • One or more close blood relatives with two or more tumors of the breast or breast cancer in both breasts (bilateral).
  • A male blood relatives who has had breast cancer.
  • Ashkenazi (Eastern European) Jewish ancestry and any family members with breast or ovarian cancer.

Note that an affected family member can be on the mother’s or father’s side (breast and/or ovarian cancer can be passed down through the father or the mother).

“Close blood relatives” include sisters, daughters, mothers, aunts and grandmothers.

Adapted from Fact Sheet on Genetic Testing for Breast and Ovarian Cancer Susceptibility from the Centers for Disease Control, http://www.cdc.gov/genomics/info/factshts/breastcancer.htm

What are possible benefits of genetic testing for breast cancer risk?

  • A genetic test may help you make more informed medical decisions and lifestyle choices.
  • Knowing the results of a genetic test may help you better cope with your cancer risk, and help you decide whether or not to have preventive drug therapy or surgery.
  • The genetic test may give your family members useful information, and it is important to share the results. You may want to know the results for your children’s sake.
  • A genetic test may reduce feelings of uncertainty.
  • A genetic test may give your physician more information to decide on treatment recommendations for you.
  • A positive result may increase your likelihood of keeping up with recommended screening (mammograms, breast exams, etc.) on a regular basis.
  • A negative result may relieve some anxiety for you and your children by knowing that you most likely do not have an altered BRCA gene.
  • A negative result may help you avoid extra screening for breast cancer.

What are potential disadvantages of genetic testing?

  • The result of genetic testing does not eliminate uncertainty. A positive test does not predict that a person will get breast cancer­— only that a person is not at increased risk. Also, a negative test does not mean that a person will never develop breast cancer.
  • Genetic tests can be expensive, and they may or may not be covered by a person’s insurance.
  • There is no proven way to reduce cancer risk completely in persons who test positive.
  • There is no guarantee that test results will remain private.
  • If you test positive for a genetic condition, it is unlikely, but possible, that you may face discrimination from employers or insurers about obtaining or keeping health or life insurance, or employment.Federal laws against insurance and job discrimination currently are inconsistent. However, in North Carolina the law forbids genetic discrimination. Health insurance companies are not allowed to ask about genetic testing on the application form. (Life insurance is different. It is considered optional, and life insurance companies can consider a positive genetic test result as a reason for higher premiums.)
  • Genetic testing can have a psychological impact. If you test positive, you could experience negative feelings such as fatalism, anxiety, decreased self-image, depression, shame, or blame. If you test negative, you may feel guilt that you have been “spared” if other family members test positive.

Why is genetic counseling important?
As you can see from the above description of genetic testing for breast cancer risk, this type of test is not just a simple blood test. It is a complex issue. That is why it is a good idea to see a genetic counselor before considering genetic testing.

Genetic counselors have been trained in genetics and genetic testing and can advise their patients about whether they should consider a genetic test. They can explain the basics of the test, as well as how the test is interpreted, and its limitations and drawbacks. They can take a family history (or pedigree) to see whether a person would be a good candidate for genetic testing.

Genetic counselors usually work at large hospitals that have genetics centers. They may charge for a consultation, and they can help to verify insurance coverage before undergoing counseling or testing. Coverage will vary from policy to policy. See our listing of Cancer Genetic Risk Clinics at the end of this section to find these hospitals and phone numbers to call in North Carolina.

What is the difference between a geneticist and a genetic counselor?
A geneticist is usually an MD who specializes in genetics. Genetic Counselors generally are not MDs, but have a two-year Masters degee in a genetic counseling program.

Be prepared with information.
One piece of information that may help to determine whether you could have a hereditary risk for breast cancer is your family’s history of cancer. A pedigree shows your family’s history of cancer. For your healthcare provider or genetic counselor to draw a pedigree, you will need to know the kinds of cancers that your relatives had, the ages at which they had cancer, and whether any female relatives were diagnosed with breast cancer before or after menopause (usually around age 50).

Take your time and gather as much information as you need. You are the best judge of deciding what is right for you.

Portions of this section were adapted from National Cancer Institute educational publications about genetics and breast cancer (800.4.CANCER or http://www.cancer.gov).

RESOURCES

Organizations

American Cancer Society (ACS)
800.ACS.2345 or 866.228.4327 (TTY)
http://www.cancer.org
Provides information and services for all forms of cancer, diagnosis, treatment, and many other topics. Free booklets are available on a wide variety of topics relating to breast cancer, including risk factors and genetics.

Council for Responsible Genetics
617.868.0870
http://www.gene-watch.org
This non-profit, bio-ethics organization considers the social, ethical, and environmental implications of the new genetic technologies. Offers educational publications, a newsletter (GeneWatch) and information about genetic discrimination.

FORCE: Facing Our Risk of Cancer Empowered
954.255.8732
http://www.facingourrisk.org
A non-profit organization for women (and their families) at high risk of getting breast or ovarian cancer due to family history or other factors. Web site has information about evaluating risk, support, insurance and privacy issues.

Genetic Alliance
202.966.5557 or 800.336.GENE (800.336.4363)
http://www.geneticalliance.org
This international coalition of individuals, professionals and genetic support organizations works to help people affected by genetic conditions. Provides resources, information on support groups, educational publications, a listserv and more.

Hadassah: The Women’s Zionist Organization of America
212.303.8094
http://www.hadassah.org
Hadassah, a Jewish women’s health, education and advocacy organization, publishes free brochures on genetics and breast cancer risk, especially for women of Ashkenazi Jewish descent.

Myriad Genetics, Inc.
801.584.3600
http://www.myriad.com
Myriad Genetics holds the patent on BRCA1/BRCA2 testing. Hospitals and clinics send patient samples to evaluate for a fee. Offers educational materials about genetic testing, including a video and newsletter.

National Adoption Information Clearinghouse
703.352.3488 or 888.251.0075
http://www.calib.com/naic
NAIC has information about state adoption laws and how to access adoption records, as well as other resources such as support groups for adoptees looking for birth information.

National Cancer Institute’s Cancer Information Service
800.4.CANCER (800.422.6237)
http://www.cancer.gov
One of the best resources available for cancer patients, this government organization provides a toll-free hotline in English and Spanish for questions about any type of cancer (800.4.CANCER). Offers several free booklets about genetics, gene testing, and breast cancer.

National Society of Genetic Counselors
610.872.7608
http://www.nsgc.org
NSGC has educational publications and information for genetic counselors and patients and an online resource locator (at http://www.nsgc.org/resourcelink.asp) that lists genetic counselors and their services in your area.

Sharsheret
866.474.2774
http://www.sharsheret.org
An organization devoted to Jewish women with breast cancer. Has educational publications about genetics and breast cancer and links women at high risk with similar volunteers who offer to share their experiences.

Books and More

Breakthrough: The Race to Find the Breast Cancer Gene, by Kevin Davies and Michael White (1996). Describes the history of the BRCA1 gene discovery and includes information about breast cancer genetics.

Web Sites

Cancer Genetic Services Directory
http://www.cancer.gov/search/geneticsservices
This site from the National Cancer Institute offers a directory of cancer genetic professionals; search by type of cancer or genetic syndrome and state.

Gene Tests/Gene Clinics
http://www.geneclinics.org
Contains listings of all the gene tests currently available. Has an “Educational Materials” section that describes genetic testing and services.

Genetic Testing: A Public Health Perspective
http://www.cdc.gov/genomics/info/perspectives/testing.htm
This site, from the Centers for Disease Control, compiles many links to information about genetic testing. Helpful for patients, healthcare providers, and public health personnel.

Genetics Education Center at University of Kansas Medical Center
http://www.kumc.edu/gec/support/cancer.html#breast
This site has online links for genetics and breast cancer.

Glossaries of Genetic Terms
http://www.kumc.edu/gec/glossary.html
This site, from the Genetics Education Center at University of Kansas Medical Center, provides links to several glossaries that provide definitions for genetic terms.

Learning About Breast Cancer (National Human Genome Research Institute)
http://www.genome.gov
Click on “Health,” then “Specific Genetic Disorders” to the left, and then “Breast Cancer” to view information about hereditary breast cancer and genetic testing.

The Genetics of Cancer
http://www.cancergenetics.org
Designed to help with understanding the genetic basis of cancer, genes, and how they relate to cancer and genetic testing.

Your Genes, Your Choices: Exploring the Issues Raised by Genetic Research
http://www.oml.gov/hgmis/publicat/genechoice/index.html
An excellent primer written at a basic level.