
Breast
and Ovarian Cancer Risk Assessment
Overview
of Breast and Ovarian Cancer
Breast
cancer is a common disease affecting more than 180,000 women and
1,600 men each year. A womans lifetime risk for developing
breast cancer is about 1 in 8 or 12%. The lifetime risk for ovarian
cancer is 1 in 70 or 1.4%. Because breast cancer is common, many
women will have one, two or even more relatives with breast cancer
just by chance. It is also possible for the cancer to be caused
by an inherited genetic alteration in one of the genes for breast
and ovarian cancer. These genes are known as BRCA1 and BRCA2
(for the first and second breast cancer genes to be identified).
Individuals that have a genetic alteration in one of these genes
will have a significant increase in their risk for breast and ovarian
cancers. Only 5-10% of all breast and ovarian cancer is thought
to be inherited.
The
Genetics of Breast/Ovarian Cancer
We
receive our genetic information from both of our parents. The genetic
information tells our body how to grow and function. The individual
pieces of genetic information are called genes. Each person has
two copies of about 100,000 genes. Sometimes a change occurs in
a gene which stops the gene from working properly. Such a change
is called a "mutation" or "alteration". We know
that some genes function to protect our body from developing cancer.
If a person has a mutation in a cancer-protection gene, that gene
does not work properly and the person has a higher chance of developing
cancer. This is genetic susceptibility to cancer. If an individual
has a genetic alteration that results in an increased susceptibility
to cancer, they will have a 50% chance to pass this genetic alteration
on to their children. This alteration can be passed down from the
maternal or the paternal side of the family. Women with an alteration
in BRCA1 have an increased susceptibility to develop breast
and/or ovarian cancer and men have an increased susceptibility for
developing prostate cancer. Women with an alteration in BRCA2
have an increased susceptibility to develop breast and/or ovarian
cancer and men have an increased susceptibility for developing breast
and/or prostate cancer.
Ashkenazi
Jewish Ancestry
Alterations
in BRCA1 and BRCA2 have been found in all races and
ethnic groups but, in some populations, specifically the eastern
European (Ashkenazi) Jewish population, mutations in these genes
are more common. Individuals of Ashkenazi Jewish ancestry with one
or more relatives with early onset breast or ovarian cancer at any
age may be appropriate for genetic testing. It has been estimated
that approximately 1 in 40 (2.4%) individuals who are of Eastern
European Jewish descent carry one of these three alterations. Individuals
that test negative for these three common genetic alterations should
proceed to have full gene sequencing. Researchers are now beginning
to identify other common genetic alterations in the BRCA1 and BRCA2
genes found in other ethnic populations such as Iceland, The Netherlands,
Belgium, Finland, Sweden, South Africa, and France.
The
Characteristics of Hereditary Breast/Ovarian Cancer
Personal or family history of the following:
- Pre-menopausal
breast cancer with or without ovarian cancer
- Breast
cancer in both breasts (bilateral)
- Ovarian
cancer at any age
- Breast
and ovarian cancer within the same individual
- Breast
cancer in a male
- Genetic
alteration identified in BRCA1 or BRCA2
Cancer
Risk Assessment
Cancer
risk assessment provides information about cancer risk, cancer screening,
and genetic testing that is based on family and medical history
evaluation. Genetic counselors, medical geneticists, and medical
oncologists help individuals and their families understand how certain
cancers may cluster in families and what preventative measures are
available to lessen the risk to individuals. The cancer risk team
will help individuals and families explore the risks, benefits,
and limitations of current genetic testing methods and will help
determine whether a family would be appropriate to consider the
option of genetic testing. Genetic testing, and the results that
it provides, may alter your personal surveillance strategy and modify
the risk for other family members to develop these types of cancer.
Once
your cancer risk appointment is completed, you will receive a personally
tailored letter detailing appropriate cancer surveillance and prevention
strategies. Genetic counseling and cancer risk assessment can be
of benefit to anyone with concerns regarding their risk for developing
cancer even without a desire to pursue genetic testing.
What
happens during an appointment for cancer risk assessment
The
risk assessment team will provide an estimation of a persons
risks for specific cancers based upon age, family history, and other
risk factors. It is important to provide the cancer risk team with
accurate family history information including the types of cancers
in your family and the ages at which they occurred. It is often
helpful to obtain medical records and death certificates whenever
possibly in order to verify each cancer diagnosis. The cancer risk
team will discuss the possible role of genetics in a persons
family, the emotional issues regarding the risks of cancer, cancer
screening and cancer risk reduction recommendations tailored to
the individuals level of risk, and the availability of genetic
testing for certain cancers including the risks, benefits, and limitations
of genetic testing. At some centers, it may also be possible to
have a physical examination by a clinical oncologist or gynecological
oncologist during your visit. While anyone can benefit from cancer
risk assessment, it may be especially helpful for individuals that
have a parent or sibling with cancer, breast and other cancers within
a family with early ages of occurrence, multiple first or second-degree
relatives with breast or ovarian cancer, if a genetic alteration
in a BRCA gene has been identified in the family, if there
is male breast cancer in the family, or if someone is just anxious
about breast cancer in general.
Genetic
Testing
Genetic
testing to determine if an individual or family has a breast cancer
gene alteration is offered to appropriate families following cancer
risk assessment. Currently, genetic testing is available for BRCA1
and BRCA2 mutations on a clinical basis. Mutation testing
is most informative when performed on a family member that has had
cancer. If a mutation is identified in that individual, this will
assist with their cancer management. Once a mutation is identified
in a family, anyone can be tested for that specific mutation. Traditionally
the consideration of genetic testing takes place in a multi-step
format. Many centers require that the individual considering testing
have a complete educational session with a genetic counselor. At
this appointment the risks, benefits, and limitations of genetic
testing are reviewed extensively. It is important for individuals
being tested to understand the value of the information that testing
provides, how it will affect future surveillance for them and other
family members, and the impact that this information may have on
themselves and their children. After taking some time to think about
the option of genetic testing, this individual can schedule a 2nd
appointment and return to the clinic to ask additional questions
and have blood drawn. The results of testing typically take between
4 to 6 weeks at which time a third appointment is scheduled to review
these results.
If
an alteration in the BRCA1 and BRCA2 genes is not
identified, it is possible that a different cancer susceptibility
gene is responsible for the cancer in the family and does not necessarily
mean that the breast cancer is not inherited in your family. Options
for cancer prevention and surveillance would be based on the genetic
risk assessment.
Management
options for mutation carriers or patients at moderate-to-high risk
for breast and/or ovarian cancer:
Cancer
surveillance recommendations and strategies will be made based upon
the outcome of a patients cancer risk assessment appointment.
For women who are BRCA1 or BRCA2 mutation carriers,
the current management options are increased screening and prophylactic
(preventative) surgery. Breast screening options include: monthly
self-breast exams, breast exams annually or biannually by a specialist,
annual or biannual mammography. Ovarian screening options include:
annual pelvic exams, transvaginal ultrasound and CA-125 blood test.
Preventative surgery options should be discussed with specialists.
Additionally, a chemoprevention agent called Tamoxifen has been
approved for use in women at increased risk for breast cancer. The
risks and benefits of taking Tamoxifen should also be discussed
with a specialist. There may also be clinical trials that patients
may be eligible for participation in that may reduce their risk
for breast or ovarian cancer.
Other
issues:
Many
people are concerned that genetic testing may be used by employers
or insurance companies to discriminate against those at increased
risk for cancer. Legislation exists to protect individuals in large
group health insurance plans, but this has not been sufficiently
tested in court. Furthermore, life and disability insurance policies
are not protected. Many individuals choose not to inform their insurance
companies about the testing in order to avoid this issue and choose
to pay for testing out of pocket. This is an important issue that
can be discussed with the cancer risk assessment team.
There
is no reason to be concerned about insurance discrimination following
a genetic counseling/cancer risk assessment appointment. Individuals
seek genetic counseling for a multitude of reasons and it has not
been known to adversely affect insurability. Many insurance companies
will pay for the cost of counseling and genetic testing. Lately,
President Clinton signed an executive order prohibiting genetic
discrimination for Federal employees.
Confidentiality
is, of course, of paramount importance in cancer risk assessment.
Most risk evaluation programs have careful safeguards to help ensure
that family and medical history information as well as genetic testing
results are not released to anyone without written consent from
the individual concerned.
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