Familial ovarian cancer
The two genes involved in familial breast cancer (BRCA1 and 2)
are also involved in familial ovarian cancer and many families are
looking for information on the possibility of genetic testing for
ovarian cancer.
Can anyone have a genetic test to tell if they will
develop ovarian cancer?
Most cancer genetic cancer centres offer testing to families
with at least three people affected with ovarian or breast
cancer.
The two genes involved in ovarian and breast cancer, called
BRCA1 and BRCA2, are long genes and a fault in one of these genes
can occur anywhere along the line-up of the gene. Different
families have different faults. In order to detect a faulty gene we
therefore have to take a blood sample from someone with ovarian or
breast cancer in the family and work our way along the gene until
we have identified the fault responsible in that particular family.
Once we have found the fault in someone with ovarian or breast
cancer in the family we are then able to offer genetic testing to
other people in that family to tell if they have inherited the
faulty gene.
Genetic testing is a two stage process. The first stage is to
identify the faulty gene in the family, and the second stage is
then to test other members of that family, if they wish to
determine if they have the faulty gene. Because detecting a faulty
gene is a difficult and time consuming process most centres offer
to search for a faulty gene in families where it is probable that a
faulty gene is present, ie families with three or more people with
ovarian or breast cancer, with one person in the family, with
ovarian or breast cancer willing to give a blood sample to allow us
to start the faulty gene search.
If a faulty gene is found in my family, do I have to
have a genetic test?
Once a faulty gene has been identified in your family you will
be offered a genetic test, but you do not have to take up the
offer. It is entirely up to you, and you will have to decide if you
want a test. There will be no pressure on you at all.
If a faulty gene is found and then my test shows I have
that faulty gene, what are the options available to
me?
If you have the faulty gene then you have two possible options
available at the moment:
- Screening as part of the national trial, UK Familial Ovarian
Cancer Screening Study (UKFOCSS) - having regular screening tests
(annual ultrasound and 4 monthly CA125 measurements) to try and
detect ovarian cancer early.
- Surgery - usually keyhole to remove the ovaries and tubes to
try and prevent ovarian cancer developing.
If you have a faulty BRCA1 or BRCA2 gene you are also at
increased risk of breast cancer, and again the options are
similar:
- Screening - regularly mammography to try and pick up early
breast cancer, or
- Surgery - bilateral mastectomy to remove the breast tissue thus
trying to prevent the development of breast cancer.
It is very likely that a third option of taking different drugs
in research studies to try and prevent the development of these
cancers will become available soon. One study, the International
Breast Cancer Intervention Study (IBIS) offers a trial of Tamoxifen
or a dummy tablet to those with a family history of breast cancer.
There are no drug studies available for women with a family history
of ovarian cancer, or for women who have had a genetic test which
proves they carry the faulty BRCA1 or BRCA2 genes.
If a faulty gene is found, and my genetic test shows
that I do not have that faulty gene, what happens
then?
If you do not have the faulty gene which runs in your family,
then your chance of developing ovarian or breast cancer is no
higher than anyone else your age in the population, and therefore
extra screening will be stopped. You will still be encouraged to
join the National Breast Screening Programme when you are 50.
If my mother and my aunt both developed ovarian cancer,
will I never be offered gene testing?
As techniques for identifying faulty genes improve, it is
very likely that many more people will be offered testing.
My mother has ovarian cancer, and no-one else in the
family has ovarian or breast cancer. Should I be
screened?
If your mother is the only person in the close family with
ovarian or breast cancer, then your risk of developing ovarian
cancer is only slightly increased. There is currently no screening
available on the NHS.
Who can get screening because of their family
history?
The UKFOCSS Study offers screening with annual ultrasound and 4
monthly CA125 measurement to women between the ages of 25 and 65,
who come from an "at risk" family. An "at risk" family is defined
as:
- Two first degree relatives with ovarian cancer.
- One first degree relative with ovarian cancer and one first
degree relative with breast cancer, diagnosed under the age of
50.
- One first degree relative with ovarian cancer and two first or
second degree relatives with breast cancer, diagnosed under the age
of 60.
- The presence of a faulty ovarian cancer causing gene in the
family.
- Three first or second degree relatives with bowel cancer and
one case of ovarian cancer in the family.
A first degree female relative is mother, daughter or
sister.
A second degree female relative is grandmother, granddaughter,
aunt or niece.
You will be offered screening in this study if you come from an
"at risk" family and you have a first degree relative who has
breast or ovarian cancer. If you think you are eligible for this
study ask your general practitioner to refer you to your nearest
participating centre.
I have ovarian cancer. What's the risk for my
daughter?
Many women with only one close relative who has developed
ovarian cancer are understandably anxious about their own risk. The
risk to women in this group is slightly, but not greatly,
increased. The risk increases if more family members have developed
ovarian or breast cancer.
The current view is that the value of ovarian cancer screening for
your daughter is uncertain. When the current trials report in 2015,
it should be possible to have more information and it is likely
there will be a national ovarian cancer screening programme for all
women over 50, if the results show that screening can save
lives.
Macmillan's OPERA tool
OPERA (Online Personal Education and Risk Assessment) asks you
some specific questions about your personal and family history of
breast and ovarian cancer; it then summarises your answers, and
gives you your 'personal assessment', which includes personalised
information and support about inherited cancer risk.
Click here to access
the online tool