Colorectal Carcinoma

Question 1

RF for colon cancer

Answer 1

Strong FHx link 
Male 
Age 
Smoking 
IBD 
Genetic predispositions
Diet - low fibre - ^red/processed meat 
Alcohol 
Previous colon cancers/polyps

Question 2

what are the two main genetic predispositions for colon cancer

Answer 2

FAP (<1%) - Rare autosomal dominant condition - patient develops hundreds of polyps

HNPCC (5%) - Autosomal dominant - affecting proximal colon - highly aggressive

Question 3

what % of colon cancers occur in:

rectum
left-sided
right-sided

Answer 3

rectum 30%
left-sided 50%
right-sided 20%

Question 4

in right-sided, left-sided and rectum colon cancers - what does the lesion look like?

Answer 4

right sided and rectum = mass (cauliflower)

left sided = stricture (apple core lesion)

Question 5

what symptoms do you get with right sided colon cancer?

symptomatic or asymptomatic?
weight loss?
type of anaemia?

frequency?
type of pain?
blood in stool?

Answer 5

Asymptomatic
Weight loss
Iron deficiency anaemia

increase frequency as bowel is filling quicker
ache - subtle pain so poor prognosis as found at later stage
no BUT found in faecal occult blood

Question 6

what symptoms do you get with left sided colon cancer?

blood in stool?
frequency?
type of pain?

Answer 6

blood mixed in with stool - closer to rectum the brighter the blood.

frequency is reduced due to stricture

colicky severe pain (trying to get through apple core)

Question 7

what symptoms do you get with rectum colon cancer?

tenesmus?
blood in stool?
frequency?

Answer 7

tenesmus yes - feeling of mass
fresh red blood not mixed in with stool
increased frequency due to feeling of mass

Question 8

what tests would you do for colon cancer?

Answer 8

PR exam
Bloods: FBC (microcytic anaemia),
AXR/CT

Question 9

whats the tumour marker for colon cancer?

Answer 9

CEA

Question 10

what procedure would you after AXR or CT?

Answer 10

colonscopy or sigmoidoscopy depending on site of cancer

Question 11

polyps carry as risk of malignant transformation?

Answer 11

yes

Question 12

screening for ALL men AND women between 60-75 if they test +ve for what?

Answer 12

Faecal occult blood home testing kit performed every 2 years

Question 13

2 types of staging for Colon cancer ?

Answer 13

1. TNM (tumour, node, metastases)

2. Duke’s classification (A-D)

Question 14

right hemicolectomy?

transverse hemicolectomy?

left hemicolectomy?

anterior resection?

low anterior resection?

Answer 14

caecal +ascending colon

transverse colon

descending colon

upper rectum

lower rectum

Question 15

explain Duke’s classification

A
B
C
D

Answer 15

A - within muscularis
B - through serosa
C - lymph nodes
D - metastases