GI bleeding

Question 1

how can you tell apart lower GI bleeding from upper GI bleeding?

Answer 1

In lower there is unaltered fresh blood in the faeces

Question 2

how does an upper GI bleed change to stools?

Answer 2

• melaena as the blood has been digested

Question 3

what is the most common tumour of the anus?

Answer 3

• squamous cell carcinoma

Question 4

where does UC not spread any higher than?

Answer 4

the ileocaecal valve

Question 5

what are signs of UC?

Answer 5

• chronic diarrhoea
• rectal bleeding
• abdominal pain
• exacerbation and remission

Question 6

what are modes of presentation for colorectal cancer?

Answer 6

- iron deficient anaemia
(especially right sided)
- melaena
- frank bleeding
- tenesmus

Question 7

what is the single most important risk factor for colorectal cancer?

Answer 7

age at 50

Question 8

what is the cause of familial adenomatous polyposis?

Answer 8

• germline mutation of APC gene on long arm of chromosome 5

Question 9

what can be used as a tumour marker for colorectal cancer?

Answer 9

• CEA

Question 10

in what colorectal cancers is a right hemicolectomy necessary for?

Answer 10

tumours of the caecum
ascending colon
transverse colon

Question 11

what are side effects of a right hemicolectomy?

Answer 11

transient diarrhoea

Question 12

what colorectal cancers are treated with a left hemicolectomy?

Answer 12

tumours in the distal transverse colon or descending colon

Question 13

for what tumours is an anterior resection for?

Answer 13

• low sigmoid or high rectal tumours

Question 14

for what tumours is an abdominal perineal resection for?

Answer 14

low in the rectum, less than 8cm from the anal canal

Question 15

what is used in adjuvant therapy of colorectal cancer for colorectal cancer with mets?

Answer 15

5 fluorourcil and levamisole

leucovorin or folinic acid

Question 16

what is the follow up for colorectal cancer?

Answer 16

• FOB every 6 months for 4 years then annually
• colonoscopy annually for the first two years then every 3 years
• CEA levels

Question 17

what do a majority of colorectal carcinomas arise from?

Answer 17

benign adenomatous polyps

Question 18

where is the APC (adenomatous polyposis coli) gene found?

Answer 18

Chromosome 5

Question 19

what type of gene is the APC gene?

Answer 19

A tumour suppressor gene

Question 20

what happens due to a deletion of both copies of the APC gene?

Answer 20

• persistant proliferation of the colonic crypt leading to an adenoma formation

Question 21

other than the APC genes what other genes are linked with adenoma formation?

Answer 21

• beta catenin

- MCC

Question 22

activation of what gene is linked with the malignant change from adenoma to adenocarcinoma?

Answer 22

• activation of c-Ki-ras oncogene