Geriatrics- Genetic Predisposition to Cancer

Question 1

What % of breast cancers have a family/hereditary link?

Answer 1

Approx. 25%

Question 2

What % of ovarian have a hereditary link?

Answer 2

5-10%

Question 3

What % of colorectal cancer have a family/hereditary link?

Answer 3

10-30%

Question 4

What is the other name for HNPCC which is a bowel cancer syndrome?

Answer 4

Lynch syndrome

Question 5

Give an example of a cancer caused by a somatic mutation (non-germline).

Answer 5

Breast cancer

->usually happens in one cell, if treated, it’s done. However, sometimes people can have other geneic predispositions to cancer

Question 6

What type of mutation can cause cancer family syndromes?

Answer 6

Germline mutations.

->these are inheritable

Question 7

Which two ways in the cell cycle can cause dramatic increase in cell division and therefore cause cancer?

Answer 7

Switch on oncogenes
Switch off tumour suppressor genes

Question 8

What is retinoblastoma?

Answer 8

A tumour of the retina, caused by lack of tumour suppressor genes

->can be spotted when taking photos with a flash, pupil of eye appears white

Question 9

What is the main mechanism of action for familial cancer, like Lynch syndrome?

Answer 9

DNA Mismatch Repair

->usually sorted by DNA repair, however, not always noticed

Question 10

Which cancers are those with Lynch syndrome at increased risks of?

Answer 10

Colorectal
Endometrial
Urinary tract
Gastric
Ovarian

Question 11

What are some of the clinical features of HNPCC/Lynch syndrome regarding colorectal cancer?

Answer 11

Earlier age at CRC diagnosis
CRC tends to affect right side of colon- this is bad as harder to diagnose. This is because if there is a colon cancer in the left side, there will be bleeding symptoms and constipation.

Question 12

RECAP- which genes cause a risk of breast cancer?

Answer 12

BRCA1/2

Question 13

What is important to note about breast cancer relating to BRCA1/2?

Answer 13

Patient more at risk of a secondary breast cancer

Question 14

There is also an increased chance of ovarian cancer with BRCA1/2. Which gene especially have an increased risk?

Answer 14

BRCA1

Question 15

In men with BRCA1/2, what impact might this have on them?

Answer 15

Increased risk of prostate cancer

Question 16

In men with BRCA1/2, what impact might this have on their female offspring?

Answer 16

Increased risk of breast cancer

Question 17

Which BRCA gene is more likely to cause prostate cancer in men or increase the risks of them passing it onto daughters?

Answer 17

BRCA2

Question 18

When may you suspect hereditary cancer syndromes?

Answer 18

Cancer in 2 or more close relatives
Early age at diagnosis
Multiple primary tumours
Bilateral or multiple rare tumours
Characteristic patterns of tumours e.g. breast and ovary

Question 19

What are the most important things to reduce risks of cancers, especially if there is a genetic risk?

Answer 19

Stop smoking
Exercise
Good diet

->much more effective than medicines

Question 20

Which operation can be done if there is a high risk family history of breast cancer?

Answer 20

Prophylactic mastectomy

->significantly reduces breast cancer risk in women who have the BRAC gene.

Question 21

Which operation can be done if there is a high risk family history of ovarian cancer in those with BRCA or Lynch syndrome?

Answer 21

Prophylactic oophorectomy and salpingotomy

Question 22

What is done in those with colorectal cancer gene carriers/Lynch syndrome?

Answer 22

Colonoscopy
Prophylactic aspirin given

Question 23

In bowel tumours, what can be tested for in the tumour?

Answer 23

Can test the tumour for Lynch syndrome

Question 24

First degree relatives?

Answer 24

One step away in family tree e.g. siblings, parents

Question 25

Second degree relatives?

Answer 25

Two steps away in family tree e.g. grandparents, uncles, aunts

Question 26

Third degree relatives?

Answer 26

Three steps away in family tree e.g. first cousins

Question 27

In Li-Fraumeni syndrome, there is a high risks of rarer cancers in a family. Give some examples where you would be suspicous.

Answer 27

Family history of many severe cancers.

e.g.
bilateral breast cancer
2 different types of cancer
brain tumours
soft tissue sarcoma, especially in children
leukaemia
early onset breast cancer

->more to just be aware of having high clinical suspicion of these rarer cancers clustering in families