Colorectal Cancer

Question 1

Which % of colorectal cancer is sporadic?

Answer 1

85%

Question 2

What’s the difference between FAP and HNPPC?

Answer 2

FAP=germline mutation of a tumour suppressor gene

HNPPC=mismatch of DNA repair genes

Question 3

What is FAP associated with?

Answer 3

> 100 adenomas in colon

High malignancy risk

Question 4

How often do those with FAP need a colonscopy?

Answer 4

Annually from 10 onwards

Question 5

Where do the majority of cancers arise from?

Answer 5

Pre-existing polyps

Question 6

What are pedunculated adenomas?

Answer 6

Upright

Question 7

What’re sessile adenomas?

Answer 7

Flat

Question 8

What transcription factors are associated with activation of oncogenes?

Answer 8

C-myc

K-rays

Question 9

What transcription factors are associated with the loss of tumour suppressor genes?

Answer 9

APC
P53
DCC

Question 10

What’s microsatelite instability?

Answer 10

Defective DNA repair pathway genes

Question 11

Radiography is only used for which type of cancer?

Answer 11

Rectal only

Question 12

S+S of colorectal cancer

Answer 12

Rectal bleeding
Altered bowel openings to loose stools for more than 4 weeks
Iron deficiency anemia in men of any age and non-menustrating women
Palpable rectal or lower abdominal mass
Systemic symptoms of malignancy eg weight loss

Question 13

Why do we use colonoscopies?

Answer 13

Allows tissue biopsies to be taken

Can remove polyps

Question 14

What’s taken before a colonoscopy?

Answer 14

Laxatives

Question 15

What 3 Ix are used for diagnosing colorectal cancer?

Answer 15

Colonoscopy
Barium enema
CT colonography

Question 16

What Ix are used in the staging of colorectal cancer?

Answer 16

CT chest/abdo/pelvis 
MRI
PET
Duke’s staging 
-the closer to duke’s D, the worse

Question 17

FIT vs FOBT screening

Answer 17

FIT (faecal immunological test)

• newer, more reliable
• can be used to disregard cancer at different GP practices
• if +ve=colonoscopy
• can alter the cut off for different groups
• more user friendly

FOBT=faecal occult blood test

• old test
• not as reliable

Question 18

3 other methods of screening apart from FIT/FOBT

Answer 18

Flexible sigmoidoscopy
Colonoscopy
CT colongraphy

Question 19

What’re the continence factors?

Answer 19

Anatomical

• puborectalis sling
• sphincter complex
• Anal cushions

Rectal compliance
Stool consistency
Central control
Anorectal sensation

Question 20

What’s screening?

Answer 20

Presumptive identifications of an unrecognised disease in an apparently healthy, asymptomatic population by using tests which can be easily and quickly distributed

Question 21

Presentation of colorectal cancer

Answer 21

Colicky abdominal pain
Rectal bleeding 
Change in bowel habits 
Weight loss
Tenesmus 
Fatigue 
Vomiting

Question 22

What is involved in pre-op management in colorectal cancer?

Answer 22

Colon and rectum treated as 2 separate entities 
MDT discussion 
Anaesthetic assessment 
stoma nurse appointment 
MRI 
Neoadjuvant chemo 
May need pre op stoma formation

Question 23

What’re the principles of bowel astomosis?

Answer 23

Tension free
Well perfused
Well oxygenated 
Clean surgical site
Acceptable systemic state

Question 24

Which stoma has a spout?

Answer 24

Illeostomy

Question 25

Which stoma produces solid stools?

Answer 25

Colostomy

Question 26

Where are the stomas for an ileostomy and a colostomy found?

Answer 26

Ileostomy=RIF

Colostomy=LIF

Question 27

Complications of stoma?

Answer 27

Bleeding 
Infection
Anastomotic leak
Stoma problems 
-herniation 
-prolapse 
-herniation
-high output 
Damage to surrounding nerves
-bowel/urinary/sexual dysfunction 
Impaired fecundicity in younger women

Question 28

Benign causations of large bowel obstruction

Answer 28

Strictures
-diverticular
-ischemic
Volvulus
-loop of insetting twists round its self and the mesentery
Faecal impaction
Intussusception
-intestine folds into the part directly superior to it
Pseudo-obstruction
-severe impairment of the bolus to be moved through the intestine