Colorectal Carcinoma

Question 1

Common type of patient who gets colorectal cancer?

Answer 1

60+ western male

Question 2

What are the benign precursors to colorectal cancer?

Answer 2

Colonic adenomas

Question 3

What is the main characteristic of a colonic adenoma?

Answer 3

Dysplastic epithelium

Question 4

Large bowel polyps can bleed leading to…

Answer 4

Iron deficiency anaemia

Question 5

What are the three types of colonic adenoma?

Answer 5

Tubular
Villous
Tubulovillous

Question 6

What does APC stand for?

Answer 6

Adenomatous polyposis coli

Question 7

What is APC’s role in cancer?

Answer 7

breaks down beta-catenin, so mutation of APC gene = increased beta-catenin = promotes cell proliferation

Question 8

Name two other genes involved in colorectal cancer

Answer 8

KRAS

p53

Question 9

What two dietary factors contribute to an increased risk of colorectal cancer?

Answer 9

low fibre

high refined sugars

Question 10

What disease increases your risk of colorectal cancer?

Answer 10

IBD

Question 11

What are your chances of dveloping colorectal cancer if you have a 1st degree relative with it?

Answer 11

1/10

compared to 1/50 with no relative

Question 12

What commonly used drug is thought to be protective from colorectal cancer?

Answer 12

Aspirin 300mg/day

Question 13

What are 95% of colorectal cancers?

Answer 13

Adenocarcinomas

Others: lymphoma, GIST, carcinoid

Question 14

Where do the majority of colorectal cancers occur?

Answer 14

Rectum 35%
Sigmoid 25%
Caecum and ascending colon 20%
Transverse 10%
Descending 5%

Question 15

What are the 5 main presentations of LEFT colorectal cancer

Answer 15

Altered bowel habit
PR Mass (60%)
Obstruction (25%)
Bleeding/mucous PR
Tenesmus

Question 16

What are the 3 main presentations of RIGHT colorectal cancer

Answer 16

Anaemia
Wt Loss
Abdo Pain

Question 17

What three blood tests would you want to perform in ?colorectal cancer

Answer 17

FBC: Hb
LFT’s: AFP(mets)
Tumour marker: CEA

Question 18

What types of imaging/scopes would be used in ?colorectal cancer

Answer 18

CXR: lung mets
US liver: mets
CT and MRI: staging
Endoanal US: for staging rectal tumours
Ba/gastrograffin enema: apple-core lesion
Flexi sig(65% of tumours accessible)/colonoscopy

Question 19

What is the name of the staging criteria used for colorectal cancer

Answer 19

Dukes

Question 20

What is a Dukes A, and what is its % 5yr survival rate?

Answer 20

Confined to bowel wall - 90% 5yr survival

Question 21

What is a Dukes B, and what is its % 5yr survival rate?

Answer 21

Through bowel wall but no lymph nodes - 60% 5yr survival

Question 22

What is a Dukes C, and what is its % 5yr survival rate?

Answer 22

Regional lymph nodes - 30% 5yr survival

Question 23

What is a Dukes D, and what is its % 5yr survival rate?

Answer 23

Distant mets - <10% 5yr survival

Question 24

What sort of management do colorectal cancer patients need

Answer 24

MDT

Question 25

What percentage of colorectal cancer patients are amenable to radical surgery

Answer 25

60%

Question 26

What test is used to screen for CRC?

Answer 26

Faecal occult blood testing

+ve test -> colonoscopy

Question 27

What age group qualifies for screening and how often are they tested

Answer 27

60-75

every 2 years

Question 28

What other screening tests are used for CRC, how often are they used and what age group qualifies?

Answer 28

Flexi sig

Once only

55-60