L15: Colon Cancer

Question 1

What markers do we use in the immunochemistry test of colon cancer

Answer 1

CK20
CDX2
CK7

Question 2

If the markers of CK20 and CDX2 are positive what does this indicate

Answer 2

Tumour is bowel origin

Question 3

What does CK7 negative test indicate

Answer 3

The tumour is not from another site

Question 4

Before offering chemotherapy in colon cancer what test is required

Answer 4

Molecular biology test

Question 5

What does molecular biology test allow us to identify

Answer 5

Microsatellite stable colon cancer

Microsatellite in stable colon cancer

Question 6

What are microsatellite instable tumours due to

Answer 6

Inactivation of the mismatch repair genes

Question 7

What are micro satellite stable colon cancers due to

Answer 7

Mutations in TSG
Oncogenes
Chromosomal instability

Question 8

In the molecular biology test what 3 things do we look for

Answer 8

Mismatch repair proteins
RAS
BRAF

Question 9

If there is a loss of MMR gene what is the prognosis like

Answer 9

Good

Question 10

What immunohistochemistry do we use for

Answer 10

MLH1
MSH2
MSH6
PMS2

Question 11

What are the 2 types of microinstability tumours

Answer 11

Sporadic

Familial

Question 12

What are familial microsatellite instability high tumours caused by

Answer 12

Lynch syndrome

Question 13

What is lynch syndrome

Answer 13

An autosomal dominant condition which causes germ line mutation of the MMR gene

Question 14

What does loss of MSH2 and MSH6 indicate

Answer 14

Lynch syndrome

Question 15

What does loss of MLH1, no BRAF mutation and no MLH1 promoter methylation indicate

Answer 15

Lynch syndrome

Question 16

What does loss of MLH1 and BRAF mutation, MLH1 promoter methylation indicate

Answer 16

Sporadic microsatellite instability tumour

Question 17

Why do we look for RAS and BRAF mutations in colon cancer

Answer 17

To determine if we can treat it with a EGFR treatment

Question 18

If there is a RAF mutation what does this indicate

Answer 18

It does not respond to anti EGFR treatment

Question 19

If there is a BRAF mutation what does this indicate

Answer 19

Poor prognosis but not a negative predictive marker for anti EGFR therapy

Question 20

What inflammatory bowel disease is likely to cause cancer

Answer 20

Ulcerative colitis if not followed up

Question 21

What cells does colon cancer originate from

Answer 21

Glandular cells

Question 22

What are colon cancers called

Answer 22

Colorectal adenocarcinoma

Question 23

Where does microstatellite instability colorectal cancers present at

Answer 23

Right colon

Question 24

What does chromosomal instability i.e microsatellite stable tumours present at

Answer 24

Left Colon