Download Understanding Genetic Cancer Risk: BRCA1 and 2

Page 1 of 4
Understanding Genetic Cancer Risk: BRCA1 and 2
Genetic cancer risk
BRCA1 and BRCA2 genes
About 5 to 10 out of 100 cancers are due to an
inherited gene.
A family with these genes often has:
• The same type of cancer in more than one
person.
• Cancers found at a young age (before age 50).
• People with more than one cancer.
• Cancer in two or more generations.
The tables show the chance of
getting cancer over a lifetime. It
compares a group with normal
BRCA genes and a group with
a BRCA mutation. Having a
mutation does not mean you will
develop cancer. But your risk is
much greater.
For example, out of 100 women
with a BRCA mutation, 40 to 80
will get breast cancer.
We each inherit two copies of every gene in our
bodies: one from our mother and one from our
father. Each gene has a specific job to do. When a
gene has a mistake or “mutation,” it does not work
like it should. Everyone has two copies of BRCA1
and two copies of BRCA2. A single mistake in one
of the copies increases the risk for cancer of the
breast and ovaries. The risk for pancreatic cancer
and melanoma may also increase slightly in some
families.
A person’s ethnic background also plays a role. For
example, people of Ashkenazi Jewish origins have a
higher chance of having a BRCA gene mutation.
Women
In general
with BRCA mutation
Breast cancer
12 out of 100
40-80 out of 100
Ovarian cancer
1-2 out of 100
10-40 out of 100
Men
In general
with BRCA mutation
Breast cancer
less than 1 in 100
7 out of 100
Prostate cancer
16 out of 100
20 out of 100
If you are deaf or hard of hearing, please let us know. We provide many free services including
sign language interpreters, oral interpreters, TTYs, telephone amplifiers, note takers and written materials.
Page 2 of 4
Inheritance
Advantages to testing
When a parent has a BRCA mutation, each child
has a 1 in 2 chance they will inherit the mutation.
Therefore, each child has a 1 in 2 chance of being at
increased risk for having cancer.
The results may
• clarify your cancer risk.
• help you make medical decisions.
• explain the cancers in your family.
• give useful information to your family (if you
share your results).
Disadvantages to testing
Dad = affected
1 gene mutation
Mom = not affected
normal genes
The results may
• cause you to feel sad, angry or upset on learning
about a cancer risk.
Affected
1 gene mutation
Not affected
normal genes
Not affected
normal genes
Affected
1 gene mutation
Genetic testing
Genetic testing involves a simple blood test. The
test looks in the BRCA1 and BRCA2 genes for any
changes that are linked to cancer risk. If possible, the
person who has had cancer should be tested before
other family members. This helps us see whether or
not a gene is linked with the cancer in the family.
Results
There are three possible results of testing:
• We may find a harmful mutation (positive).
• We may find no mutation (negative).
• We may find a change in one of the genes, but
it is unclear how this affects family cancer risk
(change of unknown importance).
• leave you confused about the meaning of a test
result.
• lead to concerns about discrimination (see
below).
Genetic Information Nondiscrimination Act
(GINA)
GINA is a federal law that protects people from
discrimination based on a genetic test result. The
law protects your rights to health insurance and
employment. To learn more, visit the National
Human Genome Research Institute at: www.
genome.gov/10002077.
Page 3 of 4
Reducing inherited cancer risk
Screenings for women with a BRCA mutation:
Breast
• Age 18: Begin breast self-exams monthly.
• Age 25: Begin breast exams in clinic every 6 to 12
months.
• Age 25 (or younger): Begin yearly breast MRI.
• Age 30: Begin yearly mammogram in addition
to breast MRI. Alternate these exams every 6
months.
• Consider preventive chemotherapy or
preventative mastectomy.
Questions to ask yourself
• If I have a gene mutation, how will the test result
affect me and my family? If I don’t have a gene
mutation?
• Should I share my test results? How will my
family react to this news, which may also affect
them?
• Are my children ready to learn new information
that may one day affect their own health?
Resources
FORCE: Facing Our Risk of Cancer Empowered
www.facingourrisk.org
Bright Pink: www.bebrightpink.org
Ovarian
American Cancer Society (ACS): www.cancer.org
• At age 30 (or younger): Consider ultrasound and
CA-125 blood test every 6 months.
National Cancer Institute (NCI): www.cancer.gov
• By ages 35-40 (or after child bearing): Consider
removing the ovaries and fallopian tubes.
Screenings for men with a BRCA mutation:
• Age 35: Self-breast exams training and education
• Age 35: Start breast exams in clinic, every 12
months.
• Age 40: BRCA2 carriers begin prostate cancer
screening
• Age 40: BRCA1 carriers consider prostate cancer
screening
Both men and women should talk to their doctor
or genetic counselor about screening for pancreatic
cancer and melanoma.
Please call us if you have any questions
or concerns.
Cancer Risk Management Program
612-626-9898
Appointment Scheduling
1-855-4-UMP-CANCER (1-855-486-7226)
Page 4 of 4
www.fairview.org
For informational purposes only. Not to replace the advice of your health care provider.
Copyright © 2014 Fairview Health Services. All rights reserved. SMARTworks 521837– REV 04/15.