13. Cancer of the Gut

Question 1

Where can you get cancer in the digestive system?

Answer 1

Pretty much everywhere

Question 2

Define cancer

Answer 2

A disease caused by an uncontrolled division of abnormal cells in a part of the body

Question 3

Define primary cancer

Answer 3

Arising directly from the cells in an organ

Question 4

Define secondary cancer

Answer 4

Spread from another organ, directly or by other means (blood or lymph)

Question 5

Where can secondary tumours commonly form?

Answer 5

Liver, lung and brain

Question 6

Where are squamous epithelial cells found?

Answer 6

Upper 2/3 of oesophagus, rectum

Question 7

Where is glandular epithelium found?

Answer 7

Throughout the gut

Question 8

What cancers do squamous cells form?

Answer 8

Squamous cell carcinomas

Question 9

What cancers do glandular epithelium form?

Answer 9

Adenocarcinomas - most cancers of the GI tracts

Question 10

List two neuroendocrine cells?

Answer 10

Enterochromaffin cells

Interstitial cells of Cajal

Question 11

What cancers do enterochromaffin cells form?

Answer 11

Carcinoid tumours

Question 12

What cancers do interstitial cells of Cajal form?

Answer 12

Gastrointestinal stromal tumours

Question 13

What cancers does smooth muscle form?

Answer 13

Leiomyoma/Leiomyosarcomas

Question 14

What cancers does adipose tissue form?

Answer 14

Lipomas

Question 15

What is dysphagia?

Answer 15

Difficulty swallowing

Question 16

How is oesophagus divided into?

Answer 16

Thirds: Cervical oesophagus, middle and lower oesophagus

Question 17

As you go down the oesophagus how does the structure of the muscle change?

Answer 17

Increased smooth muscle less skeletal muscle

Question 18

What are the two types of oesophageal cancer that can arise?

Answer 18

Adenocarcinoma

Squamous cell carcinoma

Question 19

Where does adenocarcinomas arise?

Answer 19

Lower 1/3 of oesophagus

Question 20

What is associated with adenocarcinoma?

Answer 20

Acid reflux

Question 21

Where does squamous cell carcinomas arise?

Answer 21

Upper 2/3 of the oesophagus

Question 22

What is associated with squamous cell carcinoma?

Answer 22

Acetaldehyde pathway - alcohol stresses squamous cells

Question 23

Describe the progression from acid reflux to cancer

Answer 23

Oesophagitis (inflammation) -> Barrett’s (metaplasia) -> Dysplasia -> Carcinoma (neoplasia)

Question 24

What does chronic exposure to acid in the oesophagus cause?

Answer 24

Injury, ongoing inflammation, cytokine drive eventually leading to cancer

Question 25

What are the risk factors for bowel cancer?

Answer 25

``` Family history Specific inherited conditions Uncontrolled Ulcerative Colitis Age Previous polyps ```

Question 26

What mutation in the normal epithelium of the bowel results in a hyperproliferative epithelium

Answer 26

APC mutation

Question 27

What does a hyperproliferative epithelium develop to?

Answer 27

small adenoma

Question 28

What mutation converts small adenoma to large adeoma?

Answer 28

K-ras mutation

Question 29

What mutation converts the large adenoma to colon carcinoma?

Answer 29

p53 mutation and loss of 18q

Question 30

How is the pathology of cancer controlled?

Answer 30

Not a single gene but a sequence of genetic errors

Question 31

What are the sequence of errors that leads to cancer?

Answer 31

APC, K-ras, p53 and 18q

Question 32

What are the symptoms of bowel cancer?

Answer 32

Asymptomatic (caecum) (incidental symptoms) Change in bowel habit (Diarrhoea + constipation0 Blood in stool Acute intestinal obstruction

Question 33

What are the symptoms of pancreatic cancer?

Answer 33

No specific symptoms | 'Silent killer'

Question 34

What is Virchow's triad for pancreatic cancer?

Answer 34

70% - pain 10% - anorexia 10% - weight loss

Question 35

Define ascites?

Answer 35

Fluid in the abdominal cavity

Question 36

What are the late symptoms of pancreatic cancer?

Answer 36

Weight loss Jaundice Ascites Obstructed gall baldder