Colorectal Cancer

Question 1

Outline the Dukes staging system

Answer 1

I - within the muscularis mucosa
II - extension through the muscularis mucosa into the serosa
III - involvement of regional lymph nodes
IV - distant metastases

Question 2

Describe the epidemiology of colorectal cancer

Answer 2

Age > 75
Men > women
2nd most common cause of cancer deaths
Geography - western diet (low fibre, high fat, processed meat)

Question 3

How can the risk factors for colorectal cancer be categorised?

Answer 3

Lifestyle

Genetic

Question 4

What are the lifestyle risk factors for colorectal cancer?

Answer 4

Low fibre, low fat diet
Red/processed meat
Obesity
Smoking
Alcohol
Low exercise

Question 5

What are the genetic risk factors?

Answer 5

Familial adenomatous polyposis - autosomal dominant mutation in APC gene.
HNPCC - autosomal dominant mutation in MMR gene
Family history
IBD (Chrohn’s)

Question 6

Why is the risk of cancerous transformation of a polyp greater in FAP?

Answer 6

The risk of transformation in any given polyp is similar to that in normal polyps but the overall risk is very high due to the vastly increased number present.

Question 7

What is important to remember about the symptoms of colorectal cancer?

Answer 7

They can vary slightly depending on the location of the cancer.

Question 8

What are the left sided symptoms of colorectal cancer (descending-sigmoid)?

Answer 8

Overflow diarrhoea
PR bleeding tenesmus
Constipation
Abdominal pain 
Decreased stool calibre 
Symptoms of obstruction

Question 9

What are the right-sided symptoms of colorectal cancer?

Answer 9

Bloating
Weight loss
Weakness
Iron deficiency anaemia 
Vomiting

Question 10

What are the symptoms of rectal cancer?

Answer 10

Obstruction
Tenesmus
Bleeding

Question 11

Where is colorectal cancer most common?

Answer 11

Rectum (45%)
Left-sided (30%)
Right-sided (20%)

Question 12

What are the criteria for a referral for suspected colorectal cancer on the 2ww pathway?

Answer 12

40+ with unexplained weight loss and abdominal pain
50+ with unexplained rectal bleeding
60+ with iron deficiency anaemia or changes in Bowel habit
Test shows occult blood in faeces

Question 13

Describe the colorectal cancer screening program

Answer 13

Bowel cancer testing kit (FOB) sent every 2 years to men and women between the ages of 60 and 74 years. 3 separate stool samples are required for analysis.

Question 14

What is the tumour marker for colorectal cancer?

Answer 14

CEA

Question 15

What antibiotic prophylaxis is required for colorectal surgery?

Answer 15

Metronidazole and Gentamicin