Hope is a thing with feathers
that perches on the soul, and sings the tune
without the words, and never stops at all.
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.
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.
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.
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.
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
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.
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.
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.
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
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
- 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
- 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.
not only to the person
having the test, but
also to family members
and the person’s
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
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.
woman has a BRCA gene mutation, what can
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.
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
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.
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.
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.
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.
Is More Likely To Have A Brca1 Or Brca2
women do not have a mutation in the
BRCA1 or BRCA2 gene. If a
woman has one or more of the below
there is an increased possibility that
she may carry an inherited
or more close blood relatives who
had breast cancer,
ovarian cancer, or both, at any age.
or more close blood relatives who
had breast cancer
before age 50 or ovarian cancer at any age.
or more close blood relatives with
two or more tumors
of the breast or breast cancer in both breasts
male blood relatives who has had
(Eastern European) Jewish ancestry
and any family
members with breast or ovarian cancer.
that an affected family
member can be on the
side (breast and/or
ovarian cancer can
be passed down through
the father or the
blood relatives” include
mothers, aunts and
from Fact Sheet on
Genetic Testing for
Breast and Ovarian
from the Centers for
Disease Control, 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.
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
- 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.
are potential disadvantages of genetic testing?
result of genetic testing does not eliminate
uncertainty. A positive test does not
predict that a person will get breast
that a person is not at increased risk.
Also, a negative test does not mean that
a person will never develop breast
tests can be expensive, and they may
or may not be covered by a person’s
- 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.)
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.
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 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
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.
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).
your time and gather as much information
as you need. You are the best judge
of deciding what is right for you.
of this section were adapted from National
Cancer Institute educational publications
about genetics and breast cancer (800.4.CANCER
American Cancer Society (ACS)
800.ACS.2345 or 866.228.4327 (TTY)
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
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
FORCE: Facing Our Risk of Cancer Empowered
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
202.966.5557 or 800.336.GENE (800.336.4363)
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.
Zionist Organization of America
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
Myriad Genetics, Inc.
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
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.
Cancer Information Service
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
NSGC has educational publications and information
for genetic counselors and patients and an
online resource locator (at www.nsgc.org/resourcelink.asp)
that lists genetic counselors and their services
in your area.
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.
Cancer Genetic Services Directory
This site from the National Cancer Institute
offers a directory of cancer genetic professionals;
search by type of cancer or genetic syndrome
Gene Tests/Gene Clinics
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
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
This site has online links for genetics and
Glossaries of Genetic Terms
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)
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
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
An excellent primer written at a basic level.