Transcript Slide 1

Breast cancer case study
Enter resource
level 8 - undergraduate students
Introduction to this resource
This case study follows the progress of a patient and her family in
the genetic clinic.
Different clinical areas gather family history information using
different methods. Before progressing with this case study you may
want to refresh your knowledge of family history taking. Otherwise
click the ‘Next’ button below.
Next
Family History –Symbols and
relationship lines
• You first need to know the symbols and
relationship lines. Here you can find these
and it would be useful to print out this
document whilst you constructing the family
tree.
Next
Constructing family tree
• This animation is a step by step presentation
of the details in creating a meaningful family
tree.
• PowerPoint presentation of this animation is
also available at ScotGEN website
Back to
module
The red boxes are "action boxes", and they provide suggested activities,
such a discussions, reflection points and more practical activities.
The light blue boxes are "content boxes", read them carefully because
all the key information can be found here.
The green boxes are "answer boxes", and they provide the answer to
the previous activity.
The orange boxes are “practice boxes", they highlight areas where
clinical practice varies in different settings.
Click for suggested
learning outcomes
Learning outcomes
 Describe the role of genes in the development of breast cancer
 Develop insight into the underlying basis of familial predisposition
to breast cancer
 Examine the role of the genetic services in providing risk
assessment, diagnosis, management options & genetic testing in the
Scottish context
Next
Breast cancer affects around 1 in 10 British women
at some time in their lives.
Most cases of breast cancer arise by chance.
However, a few women are more likely to develop
breast cancer because of their genetic make up.
In this case study you will learn about how breast
cancer can run in families, and what can be done
to help women who have a family history of breast
cancer.
Start
Index
Index
• Breast Cancer case study – Part I
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Referral to the Genetics Clinic
Causes of Breast Cancer
Risk of Breast Cancer
Mammography
Note for educators
Breast Cancer case study – Part II
Genetic testing – Part I
Genetic testing – Part II
Start
Breast Cancer case study – Part I
Mollie Briggs has surgery for breast cancer when she is 42. She tells the staff
nurse looking after her that her mother also had breast cancer in her 40s. She
is worried about the risks to her two teenage daughters and her sister Wendy
Adams.
Next
Action box
(Prior knowledge of drawing a family tree is required for this activity)
Different genetic clinics use different methods to gather family history
information. The process of drawing a family tree is the same however the
information is gathered. See section 2 for more information.
 Open the completed family history form from Wendy Adam
 Now draw the family tree (pedigree) from the form. It is important you do
this to complete the case study
You may need a reminder of pedigree symbols and relationship lines
This activity should take about half an hour.
Click for answer
Answer box
Below you will find a computer drawn family tree from Wendy’s completed
family history form.
 Open the correct drawing document to see what your family tree
should look like.
 Compare the correct drawing document with the family tree you have
drawn yourself and correct any errors you have made. Keep this family tree
for use in later activities.
Although your family tree will be hand drawn, and you may have a different
key to represent the different types of cancers, the structure of the family
tree should look the same.
Next
Referral to the Genetics Clinic
The staff nurse advises Mollie to tell her sister to ask for a referral to
the local genetics clinic.
Mollie and her sister attend the genetic clinic together. A genetic
counsellor draws the family tree like you have done. With written
consent, s/he confirms that their mum had breast cancer using the
Scottish cancer registry.
It is good practice in a genetic department to confirm the primary
diagnosis of cancer from clinical records for relevant affected relatives.
Click for next activity
Practice point
Read the following information about confirmation of cancer.
Why should we confirm cancers?
• Some people share the wrong
information with their family.
• Confirm the aetiology of specific
cancers.
• Confirm age at diagnosis.
Note:
If a person with cancer is alive
and their cancer is required to be
confirmed, a signed consent
form must be sent to cancer
registry with the request.
Click here to see one sample
form. (each service will have their own
Sources used to confirm a
cancer diagnosis.
Hospital notes or electronic
file, GP notes, cancer registry,
births, marriages & deaths and
occasionally from patient held
notes or letters.
Different genetic services use
these different options to
different degrees depending
upon availability.
consent forms)
You could discuss as a
group, any difficulties you
may experience with getting
information to confirm
cancers.
Next
The genetic counsellor explains the causes of breast cancer.
Action box
Mutations in one or more genes in a cell can cause cancer. A person can inherit a
mutation (gene change) from his/her parents or acquire it during his/her lifetime. A
somatic (acquired) mutation can be caused by environmental factors, such a cigarette
smoke, radiation, alcohol.
Click for animation
The genetic counsellor explains the causes of breast cancer.
Action box
Mutations in one or more genes in a cell can cause cancer. A person can inherit a
mutation (gene change) from his/her parents or acquire it during his/her lifetime. A
somatic (acquired) mutation can be caused by environmental factors, such a cigarette
smoke, radiation, alcohol.
Sporadic
breast
cancer
No mutation inherited at birth
Radiation
Other unknown
factors
Dietary and
hormonal factors
Familial
breast
cancer
Mutation inherited at birth
Click for next activity
Breast
cancer
Practice point
Genetic counsellors use evidence based guidelines to estimate risk and
recommend management for patients with familiar breast cancer.
There are local variations in the guidelines.
In Scotland, agreed guidelines were the subject of a recent health department
letter (HDL). They can be viewed here.
In England and Wales the NICE guidelines are used.
Click for next activity
Risk of breast cancer
The counsellor explains that in Mollie’s case the cancer is unlikely to be
caused by mutations in the high risk genes BRCA1 or BRCA2, but that
Wendy does have a moderate risk of developing breast cancer. Her risk is
more than twice that of the general population.
Practice point
Look at the following links for information about:
 Screening
 Genetic counselling: from Macmillan website and Nursingtimes website
 Heredity: from Macmillan website and Nursingtimes website
Next
Mammography
Mammography is the key screening strategy in the moderate risk group.
The evidence can be found within the NICE guidelines.
Action box
Click here for more information about mammography.
Done
Action box
With the family history you have constructed, use your local breast cancer
genetics guidelines to determine what surveillance and screening Mollie’
daughters will be offered and from what age.
Click for answer
Answer box
According to both the Scottish and NICE guidelines, Wendy should be offered
annual mammography from her present age until 50.
Next
Note for educators
First part of the learning object finishes here.
The following part can be used to follow part one for a more in depth exercise.
Next
Breast Cancer case study – part 2
Four years later Wendy’s aunt Catherine Smart is diagnosed with ovarian
cancer and she learns that her mother’s paternal aunt also had breast
cancer.
Done
Action box
 Add this new information to your pedigree.
 Use your local guidelines to reassess Wendy’s risk.
Click here for answer
Answer box
 Open the correct drawing document to see what your family tree
should look like now.
 The new family history information changes Wendy’s risk to high based on
Scottish and NICE guidelines.
Next
Genetic testing – Part I
The genetic counsellor tells Wendy that genetic testing would now be
available for her family. The counsellor explains that with Mollie’s informed
consent her sample can be tested and that the result could have
implications for other relatives.
Next
Practice point
Genetic testing always requires a DNA sample from an affected relative.
The testing and interpretation of results is complex and can take several
months.
Go to the Macmillan website for more information about genetic testing.
Next
Mollie consents to give a sample for testing of the BRCA1 and 2 genes.
The test shows she has a mutation (also may be described as a gene
change) in the BRCA2 gene.
Click here to see
Mollie’s results
Next
Action box
 What is Wendy’s risk of breast cancer now?
 Is she at risk of any other type of cancer?
Click for answer
Answer box
Mum
Dad
Working copy of
BRCA gene
Faulty copy of
BRCA gene
Children
 Wendy has a 50% or 1:2 chance of inheriting the faulty gene.
 BRCA1 risk of Breast cancer ~80%; Ovarian cancer ~65%
 BRCA2 risk of Breast cancer ~88% and Ovarian ~37%
Ref: Evans DG et al. (2008). Penetrance estimates for BRCA1 and BRCA2 based on genetic testing
in a Clinical cancer Genetics Service setting: risk of breast/ovarian cancer quoted should reflect the
cancer burden in the family. BMC Cancer 8:155 [Electronic version]
Next
Answer box
Mum
Dad
Working copy of
BRCA gene
Faulty copy of
BRCA gene
Children
 Women who inherit a faulty BRCA1 or BRCA2 gene will have a very high
chance of developing breast and ovarian cancer.
 Men who inherit a faulty gene have an increased risk of developing prostate
cancer and can pass the gene on to their children.
 Men with BRCA2 gene changes have an increased risk of developing breast
cancer themselves.
Next
Genetic testing – Part II
Wendy is offered a blood test to see if she has inherited the gene change.
She is sent away to think about it and comes back to have the test a
month later. She decides to take the test.
Click for next activity
Action box
Click below to view Wendy’s result.
Click here to see
Wendy’s results
Next
Wendy is very pleased that she and her children are now at population risk
of breast and ovarian cancer. Neither she nor they need to consider
prophylactic surgery or have additional screening outwith the National
Breast Screening Programme (NBSP).
Click for next activity
Action box options for educator- discussion
What is the risk to her
children now?
What if Wendy’s test
had shown a mutation?
Practice point
Read about DNA analysis of the BRCA1 and BRCA2 genes.
Click for answers
Answer box
What if test result was
positive?
Wendy would be at a very
high risk of breast and
ovarian cancer
•1:2 (50%) risk of passing
the faulty gene to her
children.
• Wendy would have
additional options of MRI or
prophylactic mastectomy.
• Prophylactic bilateral
salpingo-oopherectomy.
What is the risk to her children
now?
• Their risk is similar to that of the
general population.
Next
Congratulations!
You completed this case study.
Further reading