Genetics and Breast Ca

Question 1

What % of breast cancers are hereditary?

Answer 1

5-10%

Question 2

Of the familial breast cancers, what does the BRCA mutation contribute?

Answer 2

20-25%

Question 3

What factors in the environment increase our risk of breast cancer?

Answer 3

Smoking
Not breastfeeding
Increasing age
Obesity 
Late menopause
Lack of physical activity 
OCP 
Excessive alcohol
HRT
Increased breast tissue density

Question 4

What are the most prevalent genetic mutations implicated in breast cancer?

Answer 4

BRCA1 and 2
Tp53 (Li Fraumeni)
pTEN (cowden’s syndrome)
STK11 (Peutz-Jeghers syndrome)

Question 5

What is a family that has a high risk history?

Answer 5

Strong family history
BRCA mutations
Lifetime risk >30%
4 or more relatives with breast cancer under 60 or any ovarian cancer
20% likelihood of BRCA 1 or 2 or p53 mutation

Question 6

What is a family that has a moderate risk history?

Answer 6

Weaker family history 
Lifetime risk 17-30% 
One first degree relative with breast cancer under 40 or a male at any age 
2 breast cancer under 60 
3 at any age

Question 7

What are families with low risk histories?

Answer 7

Little to no family history
Lifetime risk <17%
Population risk

Question 8

What is a first degree relative?

Answer 8

Mother
Sister
Daughter

Question 9

What is a second degree relative?

Answer 9

Grandmother
Granddaughter
Aunt
Niece

Question 10

What surveillance should be offered to women with a moderate risk of breast ca?

Answer 10

Surveillance offered from age 40 via mammography

Annual until age 50 then into normal programme

Question 11

Describe a very high risk family history

Answer 11

Female carrier of BRCA1 or 2 or p53

50% risk of carrying mutation

Question 12

What surveillance should be offered to women with a high risk of breast ca?

Answer 12

Surveillance starts at 35
MGM 2 yearly below age 40, annual 40-50 and 18 monthly 50-70
Offer genetic testing

Question 13

What surveillance should be offered to women with a very high risk of breast ca?

Answer 13

Surveillance from age 25 
Annual breast exam from age 25
Mammography 2 yearly from 30-39, annually from 40-50 and 18 monthly from 50-70 
Breast MRI offered from ages 30-49
Prophylactic mastectomy +/- oophorectomy

Question 14

Describe the national breast screening programme

Answer 14

Starts at 50-70
3 yearly mammograms
Can continue at own request

Question 15

What are factors in the history that suggest a familial cancer?

Answer 15

Unusually early onset
Multiple primaries
Clustering of same type of cancer
Cancers in multiple generations in a family
Tumour histology/ pathology
Different types of cancer or unusual cancer seen in rare cancer syndromes
Founder mutations

Question 16

Out of BRCA 1 and BRCA 2; which confers the highest risk in men?

Answer 16

BRCA 2

Question 17

Out of BRCA 1 and BRCA 2, which confers the highest risk in women?

Answer 17

BRCA 1 - particularly ovarian cancer

Question 18

Who should be tested for the BRCA mutation?

Answer 18

Epithelial ovarian cancer
Breast cancer <45 years
Bilateral breast cancer both <60 years
Triple neg breast cancer
Male breast cancer
Breast cancer + parent, child or sibling with any of the above criteria

Question 19

Describe a diagnostic genetic test?

Answer 19

First test in family

Find cause, tailor treatment, assess future cancer risk

Question 20

Describe a predictive genetic test

Answer 20

Asymptomatic relatives

Assess risk, discuss options for prevention (screening/ surgical)

Question 21

Is there increased screening for ovarian cancer in BRCA mutations?

Answer 21

No

Bilateral salpingo-oophorectomy around age 40

Question 22

Is there increased breast screening in women with BRCA mutation?

Answer 22

Annual mammograms from 30-70
Annual breast MRI from 30-50
Double mastectomy +/- reconstruction