genetic oncology

Question 1

what percentage of breast cancer is familial?

Answer 1

10%

Question 2

what are the common genetic mutations that can cause breast cancer?

Answer 2

BRCA1 mutation- chromosome 17
BRCA2 mutation- chromosome 13
both are tumour suppressor genes

Question 3

what cancers can be caused by BRCA1 mutation?

Answer 3

80% breast cancer
40% ovarian cancer
possible young-onset colorectal cancer

Question 4

what cancers can be caused by BRCA2 mutation?

Answer 4

80% breast cancer in m + f
ovarian cancer (less than BRCA1)
prostate cancer

Question 5

what is li-fraumeni syndrome?

Answer 5

autosomal dominant
consists of germline mutation to p53 tumour suppressor gene

Question 6

Li-Fraumeni Syndrome has a high-incidence of malignancies such as?

Answer 6

sarcomas
leukaemias

Question 7

when is Li-Fraumeni syndrome diagnosed?

Answer 7

when individual develops sarcoma <45yo
first degree relative diagnosed with any cancer <45yo + another family member develops malignancy <45 or sarcoma at atny age

Question 8

what is Lynch Syndrome or HNPCC?

Answer 8

hereditary non-polyposis colorectal cancer (often right sided colorectal ca)
autosomal dominant
80% can get develop colon +/- endometrial cancer at young age

lynch 1- colorectal ca
lynch 2- CRC + other eg ovarian, endometrial, pancreas, small bowel, renal pelvis

Question 9

what criteria is used to identify high risk individuals with lynch syndrome?

Answer 9

amsterdam criteria

3 or more family members w colorectal cancer
1 of which has to be first degree relative of other two
2 successive affected generations
1 or more colon cancers diagnosed <50yo
FAP excluded- familial adenomatous polyposis

Question 10

what is gardners syndrome?

Answer 10

autosomal dominant familial colorectal polyposis
variant of FAP
mutation of APC gene located on chromosome 5 (tumour suppressor gene)
multiple coloni cpolyps

Question 11

what are extra colonic disease in gardners syndrome?

Answer 11

skull osteoma
thyroid cancer
epidermoid cysts

can see desmoid tumours in 15%

Question 12

what is peutz-jehgers?

Answer 12

multiple GI hamartomatous polyps
autosomal dominant
10-20% lifetime risk of colorectal ca
risk of other ca- pancreas, lung, breast, ovaries, uterus, testes

Question 13

how can peutz-jehgers present?

Answer 13

mucocutaneous hyperpigmentation in lips/palms

Question 14

what are common cancers?

Answer 14

breast
prostate
lung
colorectal
skin cancer

Question 15

which cancers have highest mortality?

Answer 15

lung
colorectal
breast
prostate
pancreas