Colorectal Cancer

Question 1

What are the risk factors of bowel cancer?

Answer 1

-Most are sporadic with no clear influence
-Some are caused by familial risk
-Some caused by genetic conditions
-Underlying IBD

Question 2

List some of the risk factors for sporadic cases of colorectal cancer.

Answer 2

Age
Male
Previous adenocarcinoma
Environmental: diet, obesity, diabetes, smoking, lack of exercise

Question 3

What do the majority of colorectal cancers arise from?

Answer 3

Pre-existing polyps

Question 4

What are some indications of a high risk polpy?

Answer 4

Size
Number of polyps
Degree of dysplasia (abnormal development).
Villous architecture

Question 5

Describe how adenocarcinomas can develop from epithelium.

Answer 5

Activation of oncogenes
Loss of tumour suppressor genes
Defective DNA pathway repair genes

Question 6

What is the presentation of colorectal cancer?

Answer 6

Rectal bleeding- especially mixed in stool
Iron deficiency anaemia
Palpable mass
Weight loss
Altered bowel opening to loose stools >4week

Question 7

Where would a palpable mass usually be found in those with colorectal cancer?

Answer 7

Rectal or right abominable mass

Question 8

What is the investigation of choice for colorectal cancer?

Answer 8

Colonoscopy as allows imaging and biopsies to be taken simultaneously

Question 9

What are patients often given before colonscopy?

Answer 9

Sedation and analgesia as uncomfortable procedure

Question 10

Which radiological imaging can be used for the investigation of colorectal cancer?

Answer 10

Barium enema
CT colonography- imaging of choice

Question 11

What are some of the disadvantages of radiological imagining in terms of colorectal cancer?

Answer 11

Ionising radiation
Bowel preparation
No histology

Question 12

What are the disadvantages of colonoscopy?

Answer 12

Sedation required
Risk of perforation
Bowel preparation

Question 13

Which imaging technique would be used to help determine staging of cancer in the chest/abdomen/pelvis?

Answer 13

CT

Question 14

Which imaging technique would be used to help determine staging of cancer in the rectum?

Answer 14

MRI

Question 15

What is the main treatment for colorectal cancer?

Answer 15

Surgery

Question 16

What is the management if the cancer has metastases to the liver?

Answer 16

Partial hepatectomy

Question 17

Discuss the chemo/radiotherapy for patients with rectal cancers.

Answer 17

Radiotherapy combined with chemo before patient undergoes surgery

Question 18

In terms of palliative care, what might be given?

Answer 18

Chemotherapy
Colonic stenting

Question 19

Why might colonic stenting be given as a palliative measure?

Answer 19

Relieves chronic obstruction

Question 20

How is colorectal cancer getting controlled on a population level?

Answer 20

Screening of high risk groups and average high risk population

Question 21

What is the first part of screening for colorectal cancer?

Answer 21

Faecal tests- either FIT or FOBT

Question 22

What might happen is someone has signs of colorectal cancer in their screening faecal test?

Answer 22

Will undergo colonoscopy

Question 23

Which age group get screened for bowel cancer in Scotland?

Answer 23

50-74

Question 24

Which heritable conditions put individuals at higher risk of developing colorectal cancer?

Answer 24

FAP (familial adenomatous polyposis)
MAP (MUTYH-associated polyposis)
HNPCC (hereditary nonpolyposis colorectal cancer)

Question 25

Which other groups are considered to have a higher risk and are screened for colorectal cancer?

Answer 25

Individuals with IBD Familiar risk Previous adenocarcinomas/ colorectal cancer

Question 26

Is FAP autosomal dominant or recessive?

Answer 26

Autosomal dominant

Question 27

What happens in FAP?

Answer 27

Multiple adenomas develop throughout colon usually in childhood, high risk of malignant changes in 20s

Question 28

How often do those with FAP get screened for colorectal cancer?

Answer 28

Every year from the age of approx. 10-12 via colonoscopy

Question 29

There are some extracolonic manifestations of FAP. List some.

Answer 29

Benign hyperplastic polyps in stomach. Duodenal adenocarcinomas.

Question 30

Which tumours may those with FPA also develop?

Answer 30

Desmoid tumours Non-cancerous growths in connective tissue

Question 31

Is MAP autosomal dominant or recessive?

Answer 31

Autosomal recessive

Question 32

How is MAP similar to FAP?

Answer 32

Polyps develop but tend to be in early adulthood rather than childhood.

Question 33

How often do those with MAP get screened for colorectal cancer?

Answer 33

Every year from the ages of 18-20. Upper GI surveillance may occur from 35yrs.

Question 34

Why may upper GI surveillance occur in those with MAP from 35yrs?

Answer 34

Higher risk of duodenal carcinomas

Question 35

Is HNPCC autosomal dominant or recessive?

Answer 35

Autosomal dominant

Question 36

What causes HNPCC?

Answer 36

Mutation in DNA mismatch repair genes

Question 37

Those with HNPCC also display a condition called microsatellite instability. What does this mean?

Answer 37

Frequent mutations in short repeated DNA sequences.

Question 38

How often do those with HNPCC get screened for colorectal cancer?

Answer 38

Screening from 25yrs, every 2 years

Question 39

At which other sites could you get cancer relating to HPNCC?

Answer 39

Stomach Pancreas Endometrium Genitoruinary

Question 40

How often are those with a family history of colorectal cancer offered screening?

Answer 40

High risk- colonoscopy every 5yrs from age of 50 Low risk- one colonoscopy at 55yrs

Question 41

How often are those with a IBD offered screening?

Answer 41

10 years after diagnosis, then depends on duration and extend of inflammation.

Question 42

How often are those with a history of colorectal cancer offered screening?

Answer 42

Colonoscopy one year after surgery and then every three years

Question 43

How often are those with previous adenocarcinomas offered screening?

Answer 43

Depends on number of polyps, size and degree of dysplasia

Question 44

Undetectable levels of what could be a good rule out test for significant bowel disease?

Answer 44

Undetectable levels of faecal haemoglobin