5.4 Familial Cancer Flashcards Preview

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Flashcards in 5.4 Familial Cancer Deck (31):
1

What are the types of mutations that can arise to cause cancer?

Acquired - somatic
Inherited - Germline

2

What are the genes usually involved in cancer?

Mutated or activated oncogenes
Loss or mutated tumour suppressor genes
DNA repair genes

3

How do oncogenes cause cancer?

1 mutation which causes accelerated cell division

4

What is the oncogene over expressed in colon cancer?

RAS and C-MYC

5

What is the oncogene over expressed in hereditary papillary renal cancer?

MET

6

What is the oncogene over expressed in familial melanoma cancer?

CDK4

7

What is the oncogene over expressed in CML cancer?

BCL/ABL

8

What is the two hit hypothesis?

1 mutation causes the carrier to be susceptible and the 2nd mutation or loss causes cancer

9

What type of gene is associated with familial cancer syndrome?

Tumour suppressor genes

10

What are the clinical features suggestive of familial/inherited susceptibility?

Occurs at young age
Multiple tumours in single organ or bilateral paired
More than 1 primary
Family history or same type or related type
High rate in family

11

What is the gene associated with retinoblastoma?

RB1 gene on chromosome 13

12

What are the features of retinoblastoma?

Unilateral until 26 months, bilateral 8 months
Familial likely to be bilateral younger

13

What type of genes are BRCA 1 and 2 and what is their inheritance)

Tumour suppressor genes (autosomal dominant)

14

Where are BRCA 1 and 2 located?

1: chromosome 17
2: chromosome 13

15

How do tumours in BRCA 1 and 2 carriers occur?

Need to have inactivation of both alleles, one inactivated as a result of inherited germline mutation and the second is acquired (somatic inactivation)

16

What are the pathologic features of BRCA 1 and 2 breast cancer?

1: triple negative, high grade occurring in young women

2: ER+ and may occur late

17

What are the management options for BRCA carriers?

Cancer screening
Prophylactic mastectomy
Prophylactic salpingo-oophrectomy

18

Which gene is associated with increase risk of Male breast cancer?

BRCA2

19

What is category 1 gene mutations and give examples

Highly penetrant genes with will recognised syndromes
BRCA 1/2, p53, CDH1, STK11, MMR

20

What needs to be considered with genetic screening?

Need to give counselling and it is hard to know what to do with category 2/3 results

21

What is TP53 mutation associated with?

Li-Fraumeni

22

What is PTEN mutation associated with?

Cowden/PTEN hamartoma

23

What is STK11 mutation associated with?

Peutz-Jeghers

24

What is MMR gene mutations associated with?

Lynch (HNPCC)

25

What is the difference between tumour suppressor genes and DNA repair genes?

TSG are directly involved in growth inhibition or differentiation while DNA repair genes are indirectly involved

26

What usually occurs as a result of inactivation of DNA repair genes?

Increased rates of mutation in other cellular genes including proto-oncogenes and tumour suppressor genes

27

What are the examples of DNA repair genes?

Neucleotide excision repair, mismatch repair and somatic mutational disorders

28

How does Neuleotide excision repair work and what disorder results from muatation?

repairs helix-istorting chemical adducts especially UV light

Xeroderma Pigmentosa

29

What results from germline mutations in MMR genes and what are the genes?

HNPCC (Lynch syndrome) - typically right sided/proximal colon cancer
MSH2, MLH1, MSH6 (PMS1, PMS2)

30

What other cancers are associated with the MMR germline mutations?

Colorectal, Endometrial, Gastric, Ovarian, Biliary tract, Urinary tract, Small bowel, Brain/CNS

31

What are the two (3) most common genes that are lost in HNPCC?

MSH2 and MSH6 the most common
MHL1 can also occur in sporadic CRC