Colorectal carcinoma (brief)

Question 1

How common is it?

Answer 1

2nd commonest tumour

commonest GI malignancy

1 in 18 people.

Question 2

Who does it affect?

Answer 2

M: F 3:1

Peak age of incidence 45-64 but is ↑ in younger ages.

Question 3

What risk factors are there?

Answer 3

Polyposis syndromes (including FAP, HNPCC, juvenile polyposis)

Strong FH

Previous history of polyps or CRCa

Chronic UC or Crohn’s disease

Diet poor in fruit and veg

Question 4

How does it present?

Answer 4

Rectal location

• Pr bleeding: deep red on the surface of stools
• Change in bowel habit: difficulty with defecation, sensation of incomplete evacuation, and painful defecation (tenesmus)

Descending-sigmoid location

• PR bleeding, typically dark red, mixed with stool, sometimes clotted
• Change in bowel habit, typically increased frequency, variable consistency, mucus PR, bloating and flatulence

Right sided location
- Iron deficiency anaemia

Emergency presentations (40% picked up this way):

• Large bowel obstruction (colicky pain, bloating, bowels not open)
• Perforation with peritonitis
• Acute OR bleeding

Question 5

Investigations?

Answer 5

Pr Examination or rigid sigmoidoscopy for rectal.

Flexible sigmoidoscopy should identify up to 75% of tumours. Colonoscopy is more reliable.

Tumour marker CEA not useful as diagnostic but is for monitoring.

Abdominal CT

Question 6

Treatment?

Answer 6

Surgical resection is the only curative treatment. Can be suitable if there are mets so long as you can also resect the liver and lung. Preoperative chemo is also used. Chemo is also useful in palliative treatment.